GUM Flashcards

Question

Type 4 hypersensitivity reaction

Answer 1

ACID Type 1: IgE - medicated; quick onset after exposure (meds, latex) ALLERGIC Type 2: Ig-G mediated cytotoxic: Cells destroyed by bound ab, either by activation of compliment or by cytotoxic T cell (phagocytosis). (Rh Incompatibility in Pregnancy - hemolytic, Antiphospholipid Syndrome) CYTOTOXIC Type 3: Immune complex - mediated: Ag-Ab complexes are deposited in tissues, causing activation of complement which attracts neutrophils to the site (Postpartum Endometritis, SLE, PID, non-septic Post-Gonococcal Arthritis, HIV assoc GN, drug induced serum sickness like reactions, vasculitis, SJS partially) IMMUNE COMPLEX DEPOSITION Type 4: Delayed or cell-mediated T cell mediated. Th1 cells secrete cytokines which activate macrophafes and cytotocic t calls (Latex, nickel, contact detmatitis, tertiary syphilis, TB, endometriosis?, SDI rejection, Reactive arthritis, abacavir hypersensitivity syndrome, SJS partially) DELAYED

Answer 2

Function: Presents exogenous antigens (e.g., from extracellular bacteria or other pathogens) to CD4+ helper T cells. This activates the immune system to produce antibodies or recruit other immune cells. Structure: Composed of an α-chain and a β-chain, both anchored in the membrane. Expression: Restricted to antigen-presenting cells (APCs) like dendritic cells, macrophages, and B cells. Antigen Source: Extracellular proteins are taken up via phagocytosis or endocytosis, processed in endosomes, and loaded onto MHC class II. Examples: Immune response to bacterial or parasitic infections. HLA Genes: HLA-DP, HLA-DQ, HLA-DR. Function: Critical for: Activation of Th cells. Cytokine release and coordination of the immune response.

Answer 3

Function: Presents endogenous antigens (e.g., viral or tumor-derived proteins) to CD8+ cytotoxic T cells. This helps identify and eliminate infected or abnormal cells. Structure: Composed of a heavy chain (α-chain) and β2-microglobulin. Expression: Found on almost all nucleated cells. Antigen Source: Intracellular proteins processed by the proteasome and transported to the endoplasmic reticulum by TAP (Transporter Associated with Antigen Processing). Examples: Viral infection detection, tumor surveillance. HLA Genes: HLA-A, HLA-B, HLA-C (human equivalents of MHC class I). In HIV, initially MCH1 but then it is downregulated as HIV adapts.

Answer 4

MHC molecules are central to immune surveillance and activation. Variants in MHC genes (e.g., HLA subtypes) influence susceptibility to infections, autoimmune diseases, and hypersensitivity reactions. Key Differences Between MHC I and MHC II MHC Class I MHC Class II Ag Intracell (endog) Ag Ext(exog) Present toCD8+ CD4+ Helper All nucleated cells APCs Genes:HLA-A,B,C HLA-DP,DQ,DR Detect infected cell Coord respons

Answer 5

HLA genes (Human Leukocyte Antigen genes) are a group of genes located in the major histocompatibility complex (MHC) region on chromosome 6 in humans. These genes encode proteins that play a critical role in the immune system by helping the body distinguish between self and non-self (e.g., pathogens, foreign tissues). HLA genes define an individual’s immune profile. Their extreme variability ensures population-level diversity, improving defense against a wide range of pathogens. However, this variability also contributes to challenges in organ transplantation, autoimmunity, and drug hypersensitivity.

Answer 6

A gumma is a soft, tumor-like growth of inflamed tissue that occurs in the late (tertiary) stage of syphilis/ Characteristics: Gummas are granulomatous lesions, meaning they consist of clusters of immune cells attempting to wall off the infection. They can appear in various tissues and organs, including the skin, bones, liver, and other internal organs. Presentation: They may present as painless, rubbery masses or ulcers. Over time, they can cause tissue destruction and scarring. Pathophysiology: Gummas result from a chronic inflammatory response to the bacteria and are a sign of prolonged, untreated syphilis. No spirochetes in gumma, but can get coagulative necrosis in the middle of the gumma.

Answer 7

Spirochetes die and break open releasing a lot of antigens - immune system goes into overdrive - fevers, sweating, joint pains (last for hours days, conservative management)

Answer 8

The p24 antigen is a protein found in the HIV virus that is used to diagnose early HIV infection. It is present in high levels in the blood of people who are newly infected with HIV. How it's used The p24 antigen is detected in blood tests to diagnose HIV infection. These tests are often used in combination with tests that detect HIV antibodies, which are produced by the body in response to the virus. When it's used The p24 antigen is used to diagnose HIV infection early, when antibody levels are still low. This is important because early detection allows for prompt treatment and can significantly improve quality of life. Limitations The p24 antigen is not reliable for diagnosing HIV infection after the earliest stages. This is because antibodies to p24 are produced during seroconversion, making the p24 antigen undetectable.

Answer 9

Combination assay: HIV ab, p24 antigen If NEG: HIV NAAT HIV NAAT pos - dx HIV; neg - neg HIV If POS: HIV1/HIV2 antibody differentiation assay - dx HIV Then if dx: Viral load T cell subtype Viral resistant testing FBC, UE, LFT, Glucose Fasting lipid studies Latent TB Hep b/c serology STIs Toxoplasmosis serology Cervical smear

Answer 10

Combination test: detects HIV IgM and IgG antibodies as for third generation tests + p24 antigen using monoclonal antibodies Window period = 45 days BHIVA recommend as first line using a venous sample Studies have shown the median time to detection was 17.8 days, with 99% detected by 44.3 days

Answer 11

Serovar A, B, C: Trachoma (keratoconjunctivitis) * Low income countries, highest in Africa * Infection of the eye could cause blindness * Spread through hand to eye contact or by insect vector Serovar D, E, F: Common cause of genital disease (DEF DEFINITELY, BUT DICK D-K ALL GENITAL ) Serovar G, H, I, J, K: Less common cause of genital disease * in infected newborns cause keratoconjunctivitis or pneumonia Serovar L2: Common cause of Lymphogranuloma venereum Serovar L1, L3: Less common cause of Lymphogranuloma venereum * Tropical and subtropical regions * STD: painless papule or shallow ulcer at the site of inoculation, untreated could progress into perirectal abscesses or lymphedema of the genitals

Answer 12

Amsel criteria BV Clue cells Discharge - white/grey/yellow Essence - amines Four.5 pH below Gardnerella and prevotella H is like M: metronidazole (/ clindamycin)

Answer 13

Aciclovir 400mg twice daily (TDS in preg) or Aciclovir 200mg four times daily or Famciclovir 250mg twice daily or Valaciclovir 500mg once daily

Answer 14

Chlamydia trachomatis (most common) Mycoplasma genitalium Ureaplasmas Trichomonas vaginalis Adenoviruses Herpes simplex virus

Answer 15

Properties: Beta-lactams Contain a beta-lactam ring Bind to the active sites of penicillin binding proteins (transpeptidases) during synthesis of peptidoglycan Example: Penicillins Cephalosporins Carbapenems

Answer 16

Oral lesions: PCR should be used instead (commensal treponemes are found in the oral cavity so increasing the false positive rate) Dry lesions seen in secondary syphilis (condyloma lata or mucous patches)

Answer 17

Start within 24 hours, no later than 72 hours First line: Tenofovir disoproxil 245mg/emtricitabine 200mg + Raltegravir 1200mg OD for 28 days. PEP is available from GUM clinics and A&E Factors that increase risk of HIV transmission when index case is not on ART: *High viral load in index case *Mucosal barrier breaches: ulceration, tissue trauma *Menstruation or other bleeding *Pregnancy/post-partum *STI in the index case *Genital ulceration in the recipient An undetectable viral load is <200 copies/ml >200 copies/ml is considered detectable and transmissible

Answer 18

Azithromycin 1g orally as a single dose, followed by 500mg once daily for two days Erythromycin 500mg four times daily for seven days Erythromycin 500mg twice daily for 14 days Amoxicillin 500mg three time a day for seven days

Answer 19

Nucleus: E: Have a nucleus P: No nucleus (DNA in nucleoid) Organelles: E: Membrane-bound organelles (e.g., mitochondria, ER) P: No membrane-bound organelles Size: E: Larger (10-100 µm) P: Smaller (0.2-2 µm) DNA: E: Linear chromosomes in nucleus P: Circular DNA in nucleoid Cell Division: E: Mitosis & meiosis P: Binary fission Ribosomes: E: 80S ribosomes P: 70S ribosomes Cell Wall: E: Present in plants/fungi, absent in animals P: Present (made of peptidoglycan) Energy Production: E: Mitochondria (aerobic respiration) P: Plasma membrane (varied respiration) Reproduction: E: Sexual & asexual reproduction P: Asexual reproduction (binary fission) Examples: E: Plants, animals, fungi P: Bacteria, archaea

Answer 20

Cell wall Gram pos +/- capsule (more virulent) Thick layer peptidoglycan (polymer of sugar and aa) - RETAINS DYE - Plasma membrane (phospholipid bilayer) Gram neg +/- capsule (more virulent) Surface/ outer membrane membrane (LPS and protein) Thin layer peptidoglycan (superfical) Plasma membrane

Answer 21

1. Application of crystal violet (enters and stains all bacteria) 2. Application of iodine (forms a complex with cv that partially traps it in the peptidoglycan layer) 3. Alcohol wash (thin layer peptidoglycan in gram NEG, all washed out) (Gram POS stay purple) 4. Application safranin (stains NEG cells pink)

Answer 22

Gram positive cocci (Stap, Strep, Enterococcus) Gram neg cocci (Neisseria) Gram pos rods/ bacilli (Clostridium, Actinomyces) Gram negative rods / bacilli (Enterobacteriaceae, Bacteroides)

Answer 23

Clusters - Staphylococcus S. Aureus and Coagulase neg staph (e.g., Staphylococcus epidermidis) ***Clinical relevance *** Toxic Shock Syndrome (TSS): S. aureus produces toxins associated with TSS, especially linked to prolonged tampon use or menstrual cups. Skin and ST infections Short chains and pairs (diplococci) - Streptococcus, Enterococcus, and Peptostreptococcus (can sometimes appear as short chains or pairs depending on the strain and preparation method). ***Clinical relevance *** *Streptococcus agalactiae (Group B strep, GBS can cause neonatal sepsis, meningitis, or pneumonia if transmitted during delivery). *Streptococcus pyogenes (Group A - endometritis or wound infections). *Enterococcus spp. (Enterococcus faecalis, Enterococcus faecium) - complicated UTIs

Answer 24

Neisseria Moraxella ***Clinical relevance *** Gonorrhea

Answer 25

Clostridium (aerobic) Clostridium perfringens (gas gangrene), Clostridium difficile, Clostridium tetani ***Clinical relevance *** Postpartum or post-abortion infections, particularly in unsafe conditions. Necrotizing infections in the pelvic area. Actinomyces (facultative anaerobe, branching morphology) Actinomyces israelii. ***Clinical relevance *** Pelvic actinomycosis,

Answer 26

Enterobacteriaceae family Escherichia coli, Klebsiella, Proteus, etc ***Clinical relevance *** UTIs: E. coli Pelvic Infections: Secondary infections during PID, postpartum infections, or after gynecological surgery. Bacteroides spp. (Anaerobic gram-negative rods) ***Clinical relevance *** Commonly involved in polymicrobial infections in the pelvic region, such as pelvic inflammatory disease (PID), abscesses, and postpartum endometritis.

Answer 27

Bacteroides spp. (Gram-negative rods) Part of normal gut and vaginal flora but become pathogenic when they invade sterile sites. ***Clinical relevance *** Polymicrobial infections like PID, post-surgical infections, postpartum endometritis, and tubo-ovarian abscesses. Peptostreptococcus spp. (Gram-positive cocci) Normal flora of the mouth, gut, and vagina. ***Clinical relevance *** Often found in mixed anaerobic infections, including pelvic abscesses, PID, and post-abortion infections. Clostridium spp. (Gram-positive rods) (A) Clostridium perfringens: Gas gangrene, often post-abortion or after gynecological surgery. (B) Clostridium difficile: Antibiotic-associated diarrhea, which can complicate care in SRH settings. Fusobacterium spp. (Gram-negative rods) Involved in polymicrobial pelvic infections, such as tubo-ovarian abscesses or necrotizing infections.

Answer 28

Microorganisms that are difficult to grow in the laboratory because they have complex or restricted nutritional and/or environmental requirements. DIFFICULT TO CULTURE. 1. Non growing or intracellular (chlamydia, mycoplasma) 2. Slow growing 3. Dormant = non growing, resistant 4. Dead bacteria (take sample before giving abx!) Lactobacillus Gardnerella vaginalis Chlamydia trachomatis Neisseria gonorrhoeae Treponema pallidum Ureaplasma spp. and Mycoplasma spp. Campylobacter sp.

Answer 29

Gram-negative rods: All members of this family are rod-shaped and stain pink with the Gram stain. Facultative anaerobes: They can survive in both aerobic and anaerobic conditions. Ferment glucose: They can metabolize glucose to produce acid. Oxidase-negative: They lack the enzyme cytochrome oxidase. Catalase-positive: Most members produce the enzyme catalase. Nitrate reducers: Many reduce nitrate to nitrite.

Answer 30

Protein synthesis In cytoplasm or plasma memb

Answer 31

Small, contain dsDNA Independent Round or circular Few genes often confer selective advantage to the bacteria e.g. resistance

Answer 32

PILI - hair like, allow to attache to other cells FIMBRIAE - small pili FLAGELLA - tail like, movement ENDOFLAGELLA

Answer 33

Small facultative anaerobes pleomorphic without cell wall (peptidoglycan) with small genome. Parasites of human and animals * Sensitive to environmental factors – limited survival STD: Mycoplasma hominis, M. genitalium, Ureaplasma, urealyticum - usually commensal/ opportunistic. (Respiratory patogen: Mycoplasma pneumoniae) Could cause infection: * Non-Gonococcal Urethritis (NGU) - M. genitalium or Ureaplasma urealyticum * Pelvic inflammatory disease (PID) - M. hominis or M. genitalium Diagnosis PCR (quantitative – could differentiate colonisation and infection) Culture detection based on urease and other enzyms activity Therapy tetracyclines, macrolides, fluoroquinolones

Answer 34

Doxycycline 100mg bd for seven days followed by azithromycin 1g orally as a single dose then 500mg orally once daily for 2 days where organism is known to be macrolide-sensitive or where resistance status is unknown (1D) Moxifloxacin 400mg orally once daily for 7 days if organism known to be macrolide-resistant or where treatment with azithromycin has failed (1B) complicated (pid, e-o) Moxifloxacin 400mg orally once daily for 14 days (1D)

Answer 35

* Spore forming gram-positive anaerobic bacterium * Difficult to culture - difficille * Disease cause only toxin producing strains * Colonizer of gatrointestinal tract human (5%) andanimals, common in water and soil * Post antibiotic diarhoea (clindamycin, fluoroquinolones, 2nd and higher gen. of cephalosporines), toxic megacolon, pseudomembranous colitis * Nosocomial infection Treatment * Metronidazol, vancomycin, fidaxomicin * Fecal transplantation Prevention * Hand washing * !Alcohol desinfection does not work – alcohol promotes spore germination!

Answer 36

Recommend in Dx of NGU S+S of PID Current sexual partners of persons infected with M. gen Consider in S+S muco-purulent cervicitis, particularly PCB Dx of epididymitis Dx of sexually-acquired proctitis

Answer 37

Uncomplicated (urethritis, cervicitis) (A) where organism is known to be macrolide-sensitive or where resistance status is unknown: Doxy 100mg bd for 7 days followed by azithromycin 1g orally as a single dose then 500mg orally once daily for 2 days (B) where organism known to be macrolide-resistant or treatment with azithromycin has failed: Moxifloxacin 400mg orally once daily for 7 days Complicated (PID, epididymo-orchitis) Moxifloxacin 400mg orally once daily for 14 days (1D) Preg/BF Uncomplicated 3 day course of azithromycin In women with likely macrolide resistance, or with upper genital tract infection in pregnancy, options are limited. (Moxi not safe in preg, doxy considered safe in 1st trimester but BNF advises against)

Answer 38

Obligate intracellular pathogens * Unable to syntetize ATP * Peptidoglycan is missing * EB – infection * RB – reproduction Could grow on cell culture * But low sensitivity Serotype determines type of infection Treatment: macrolides, tetracyclines, fluoroquinolones

Answer 39

RNA viruses Single-stranded Positive sense Enveloped Contain ‘gag’, ‘pol’ and ‘env’ genes Cause long-duration illnesses with long incubation times

Answer 40

Oestrogen containing contraceptives increases recurrence risk.

Answer 41

In patients with diabetes, Candida galbrata is more common

Answer 42

Single stranded circular DNA Self-replicating Genome of only 580 kilobases Does not contain a cell wall or membrane bound organelles

Answer 43

Empirical treatment includes ceftriaxone 500 mg intramuscularly as a single dose plus doxycycline 100 mg orally twice daily for 10-14 days. For likely ct/gc and enteric, consider 1g ceftriaxone intramuscularly + ofloxacin 200 mg twice daily For enteric organisms, recommended treatment is ofloxacin 200 mg orally twice daily or levofloxacin 500 mg orally once daily for 10 days. Where Mycoplasma genitalium has been tested and identified, treatment should be guided to include an appropriate antibiotic (e.g. moxifloxacin). Check them in 14 days

Answer 44

older patient, not sexually active, recent instrumentation (such as prostatic biopsy, vasectomy or catheterisation), men who practice insertive anal intercourse, men with known abnormalities of the urinary tract or positive urine dipstick for leucocytes and nitrites

Answer 45

DNA NAAT tests usually take 14 days to reliably exclude ongoing infection. RNA NAAT tests take 7 days.

Answer 46

Molluscum contagiosum is a viral skin infection caused by a poxvirus, leading to small, painless, dome-shaped papules with a central dimple.

Answer 47

Lesions generally resolve within 6–12 months but may persist longer in some cases.

Answer 48

Treatment is considered for cosmetic reasons, persistent cases, or if lesions are causing significant discomfort or psychosocial distress. Options include cryotherapy, curettage, topical treatments like podophyllotoxin or imiquimod, and laser therapy.

Answer 49

Ritonavir Atazanavir Fosamprenavir Tipranavir

Answer 50

RNA Single stranded Positive sense Enveloped Contain gag, pol and env genes Cause long duration illnesses with long incubation times

Answer 51

alpha heamolysis - partial / greening hemolysis assoc with reduced red cell hb beta hemolysis complete lysis with yellow/ pale blood agar appearance gamma - absent haemolysis with no change in appearance

Answer 52

Painless papule/pustule/shallow erosion/ulcer in coronal sulcus, fourchette, posterior vulva, posterior vaginal wall, cervix. Can be extra-genital – peri-anal, lip, oral cavity, extra-genital LNs 3 – 30 days after acquisition Common manifestations: MSM most likely to present with LGV proctitis – PR bleeding, D/C +/- mucous, tenesmus, constipation. Fever and malaise. Heterosexual individuals most likely to present with unilateral (2/3rds) tender inguinal +/- femoral lymphadenopathy. Bubo formation 🡪 ulcerate 🡪 discharge pus 🡪 chronic fistulae. Groove sign: inguinal LNs and femoral LNs enlarge above and below the inguinal ligament, ligament creates groove between the enlarged LN chains. Pathopneumonic for LGV but only arises in 15 – 20% cases Examples: MSM with haemorrhagic proctitis Heterosexual cis-male with unilateral tender inguinal and femoral lymphadenopathy Heterosexual cis-female with large fluctuant “bubo” lymph nodes discharging pus in right inguinal region MSM with rectal pain and discharge, fever and tenesmus

Answer 53

PMNLs >10 on microscopy Swab from ulcer base exudate Urethral swab/first-pass urine in urethritis NAATs/swabs from rectal/pharyngeal sites

Answer 54

Proctocolitis Rectal cancer Fistulae and stricture formation Chronic granulomatous disfiguring fibrosis/scarring Tertiary infective changes occur more commonly in women reflecting involvement of retroperitoneal lymphatics. Note male anatomy = most drainage is to superficial inguinal lymph nodes.

Answer 55

Doxy 100bd for 21 days Allergy: tetracycline allergy use macrolides and TOC Pregnancy/breastfeeding: avoid tetracyclines, use macrolides and TOC Fluctuant buboes: aspirated through healthy adjacent skin, surgical incision contraindicated

Answer 56

Gram –ve (rods) bacterium H. ducreyi 3 – 7 day incubation period after sexual intercourse Tender erythematous papules (prepuce, frenulum, vulva, cervix, perianal) 🡪 pustules 🡪 rupture to superficial painful ulcers (ragged edges, granulomatous base, purulent exudate) 50% inguinal lymphadenitis – unilateral and painful – may progress to buboes Dx = painful genital ulcers, regional lymphadenopathy, STS & HSV –ve Microscopy (gram –ve rods), NAATs, culture Rx – ceftriaxone 250mg IM stat, azithromycin 1g PO stat 2nd line = cipro and erythromycin PN = those who had sex with patient since 10 days prior to symptom onset All should be followed-up

Answer 57

If symptomatic – look back 4 weeks for PN. If asymptomatic – look back 12 weeks for PN. TOC should be performed 2 weeks after completing treatment. Routine TOC not necessary.

Answer 58

1. Chancroid (painful) Haemophilus ducreyi Multiple and deep ulcers Base have gray/yellow exudate Organisms clamp in long parallel school of fish 2. Genital herpes (painful) HSV1/2 Multiple small grouped ulcer Shallow with erythematous base Multinucleated giant cells and intranuclear inclusions 3. Granuloma inguinale/ Donovanosis (painless) Klebsiella granulomatis Extensive and progressive ulcers without lymphadenopathy Base will have granulation tissue Deep staining showing gram negative intracytoplasmic cysts (Donovan bodies) 4. Syphilis (painless) Treponema pallidum Single indurated well circumscribed ulcer (chancre) Clean base Thin, delicate, corkscrew-shaped organism on df microscopy 5. LGV (painless) Chlamydia Trachomatus L1-3 Small and shallow ulcers Large painful injuinal LN (groove sign)

Answer 59

Wasting of posterior spinal cord Loss of vibration sense and proprioception VPLS Vibration sense Prioprioception Lightnening pains Sensory ataxia If wasting of anterior spinal cord then get general paresis - loss of sensation, weakness, paralysis

Answer 60

lose light reflex keeps accom reflex

Answer 61

slurred speech altered behaviour memory loss difficulty coordinating mm movements paralysis

Answer 62

15-30 years after infection ASCENDING AORTA is predominant site of damage causing aortitis and anyreusm Endarteritis (inflammation of vasa vasorum)

Answer 63

HPV is thought to induce cancer via onco-proteins. The primary onco-proteins are E6 and E7 which inactivate two tumor suppressor proteins, p53 (inactivated by E6) and pRb (inactivated by E7)

Answer 64

Gardasilµ is a recombinant vaccine of virus-like particles (VLPs). These resemble HPV virions but lack viral DNA. They therefore provoke an antibody response but cannot induce infection or cancer.

Answer 65

(B hem strep) Most Staphylococcus aureus or Group A Strep (Streptococcus pyogenes) Can also be: Group G streptococcus Streptococcis dysgalactiae **toxic shock = sunburn like rash**

Answer 66

Genus is lentivirus which is a member of the retroviridae family

Answer 67

Rubella genus is Rubivirsu which is a member of the Togaviridae family

Answer 68

Hepatitis C genus is Hepacivirus which is a member of the Flaviviridae family

Answer 69

Cocci Staphylococcus (Facultative anaerobes) Streptococcus (Facultative anaerobes) Bacilli OR 'Rods' Bacillus (spore forming Facultative anaerobe) Clostridium (spore forming Obligate anaerobe) Actinomyces (spore forming Facultative anaerobe)

Answer 70

Cocci Nisseria gonorrhoeae (Obligate aerobes) Neisseria meningitidis (Obligate aerobes) Moraxella catarrhalis (Obligate aerobes) Bacilli OR 'Rods' Bacteroides (Obligate anaerobes) Escherichia coli (Facultative anaerobe) Proteus mirabilis (Facultative anaerobe) Enterobacter cloacae (Facultative anaerobe) Helicobacter/Compylobacter (spiral rod) (Facultative anaerobes) Salmonella (Facultative anaerobe)

Answer 71

Chlamydia Obligate aerobes

Answer 72

Treponema pallidum

Answer 73

Toxoplasma gondii is an intracellular protozoan parasite Primary host and source of infection is domestic cats T. gondii oocysts excreted in cat faeces, mature in environment and then ingested by secondary hosts which include humans Fetal consequences more severe if infection takes place within 10 weeks of conception Maternal-fetal transmission risk increases as the pregnancy proceeds but the consequences become less severe May cause miscarriage or fetal abnormalities such as microcephaly, hydrocephalus, cerebral calcifications, cerebral palsy, epilepsy choroidoretinitis and thrombocytopenia. Diagnosis can be via PCR or Immunoglobulins (IgM,IgG and IgA). MRI/CT may show ring enhancing lesions in CNS tissues. Treatment not usually required in the immunocompetent. In pregnancy treatment is indicated if recent infection suspected Treatment varies depending on local protocols (Spiromycin or combination of pyrimethamine, sulfadiazine, and folinic acid)

Answer 74

InTEGRAse inhibitors - RalTEGRAvir Inhibits HIV genome integration into host cell chromosome by inhibiting HIV integrase.

Answer 75

Drugs that end in "-vudine" are Nucleoside Reverse Transcriptase Inhibitors!

Answer 76

Drugs that end in "-navir" are Protease Inhibitors! ALL protease inhibitors are enzyme inducers and reduce contraception efficacy (do not effect: Depo injection, intrauterine contraception, barrier contraception)

Answer 77

Campylobacter – MSM diarrhoea Chlamydia psittaci (NB avian chlamydia spread through exposure to birds; NOT sexually transmitted) Cryptosporidium - MSM diarrhoea and chronic diarrhoeal illness in HIV + people (especially if low CD4) Giardia - MSM diarrhoea Hepatitis (A, B, C, D + E) Monkeypox Salmonella - MSM diarrhoea Shigella - MSM diarrhoea

Answer 78

Obligate intracellular gram negative - no uptake of purple WITHOUT cell wall murein - no uptake of pink (so not typically seen on micro but do see puss cells)

Answer 79

48-72 hours Elementary bodies (infectious form) Reticular bodies (metabolically active/ dividing form – divides via binary fission as no nucleus)

Answer 80

Serovars A-C: chlamydial conjunctivitis Serovars D-K of trachoma biovar: genital chlamydial infection Serovars L1-3: infect lymph nodes causing LGV (L2 most commonly)

Answer 81

10% transmission rate, with 75% concordance within partners Correct use of condoms reduces risk by ~40%

Answer 82

Spontaneous bacterial clearance estimated in 20-28% in 3 months, 50% at 12 months

Answer 83

Majority of women (up to 80%) have asymptomatic vaginal infection If symptoms: increased discharge, PCB/IMB, lower abdominal pain, deep dyspareunia, dysuria Complications: PID (up to 30% of cases if left untreated), endometritis/ salpingitis, SARA (rare) --> Increased future risk of tubal infertility and ectopic pregnancy following PID, also risk of PID associated perihepatitis (Fitz-Hugh Curtis Syndrome FHCS)

Answer 84

~50% of men have symptoms, the rest are typically asymptomatic Male urethral symptoms can be very mild -> lack of reporting Dysuria, urethral discharge CT makes up ~35-50% of all non-gonococcal urethritis (NGU) Complications: SARA, epididymitis/ epididymo-orchitis

Answer 85

asymptomatic in >60% of cases If symptoms: discomfort, discharge Rectal CT has up to 10% prevalence in MSM attending sexual health clinics à need LGV subtyping Can occur in women with no history of anal sex, and can be harder to clear rectally

Answer 86

#1 7/7 100mg doxycycline BD (teratogenic) Pregnancy or tetracycline allergy #2 first choice azithromycin 1g STAT followed by 500mg OD for 2/7 OR erythromycin 500mg BD 10-14 days OR ofloxacin 200mg BD 10-14 days (also not recommended for use in pregnancy) Partner notification for 6 months prior to diagnosis, except for symptomatic men (only 4 weeks needed) No routine TOC needed if #1 treatment completed TOC for all treated in pregnancy/ with #2 treatment options TOC should be performed at least 5 weeks following completion of treatment

Answer 87

Tetracycline class antimicrobial 98-100% effective at treating genital chlamydia with low resistance rates 92% for rectal chlamydia/LGV No significant metabolism occurs - excreted largely unchanged in urine and feces Should not be taken with calcium, magnesium, iron (metal ions) -> unabsorbable deposits Side effects primarily GI and skin/photosensitivity Contraindicated in pregnancy and breastfeeding – effects on skeletal and dental development

Answer 88

AN screening for 16-25yo The most common symptomatic presentation in babies if conjunctivitis --- 30-50% of exposed infants -> “chlamydia ophthalmia neonatorum” --- Incubation period 5-14 days average (can be up to 2 months) following exposure (delivery/ PROM) --- Can be mild -> severe with any corneal scarring being very rare Nasopharyngeal infection occurs in majority of exposed infants (70-80%) and is often asymptomatic ~1/3 can develop an apyrexial pneumonia from 1-3 months of age -- Can have adverse long term outcomes including obstructive pulmonary disease -- Can also cause a chronic otitis media if left untreated Vaginal and rectal infection of babies exposed at delivery can occur in ~10-15% of babies -- Typically asymptomatic -- Pre-pubertal infection ++ indicator of sexual abuse, however perinatal infection can persist for up to 3 years

Answer 89

L1,2,3 serovars, L2 most common Traditionally endemic to Africa/India/Caribbean etc - outbreaks in UK since 2003 High risk in HIV + MSM and those involved in dense social networks (sex parties/ clubs) PRIMARY Early/ primary infective lesion is often, mild/ transient and unnoticed Painless papule/ pustule Shallow erosion / ulcer – coronal sulcus /peri-anal SECONDARY Secondary infective stage is significant lymphadenopathy – inguinal +/- femoral, often tender and unilateral TERTIARY Most commonly presentation is at tertiary stage of infection, with rectal symptoms of haemorrhagic proctitis Can get significant associated systemic symptoms ie fever / malaise If left untreated LGV can cause significant morbidity and can mimic Crohn’s disease Fistulae, strictures etc TREATMENT BASHH state asymptomatic rectal CT is unlikely to be LGV and standard 7/7 treatment should be given with no need for LGV sub-testing (unless HIV + MSM) *****If CT + result from symptomatic rectal sample or from any site in HIV + MSM --> LGV sub-testing ****** Rectal pus cells (PMNLs >10/20 per field on microscopy) are predictive of LGV proctitis Treated with a 3 week prolonged course of #1 doxycycline 100mg BD OR Tetracycline 2g OD OR Minocycline (300mg loading -> 200mg BD) If tetracycline allergy or unsuitability (ie pregnant or breastfeeding) second line treatment is necessitated #2 erythromycin 500mg QDS, again for 3 weeks (preferred) OR azithromycin 1g weekly for 3 weeks (less preferable) High rates of co-infection with HIV and HCV so ensure risk reduction discussion and full BBV screening LGV TOC not routinely recommended if full first line treatment is completed TOC should be done for pregnant/ breastfeeding patients or any other groups not treated with #1 abx If required TOC should be done 2 weeks following completion of treatment (BASHH) All patients should be clinically followed up until symptoms have resolved Partner notification is recommended for 4 weeks if symptomatic/ 3 months if asymptomatic Should be treated epidemiologically /presumptively (BASHH)

Answer 90

40% in females with GC 25% in males with GC

Answer 91

Single episode of UPSI M-->F spread in 60-80%, reduced by 40% with condom use Single episode of UPSI F-->M spread in 20%, reduced by 75% with condom use

Answer 92

GC is cultured at 35-37 degrees, 5-7% CO2 on selective and enriched culture media Culture sensitivity predicts successful treatment to >95% Intermediate sensitivity suggests 5-15% failure rate and higher doses of abx may be more effective Resistance mechanism is typically due to plasmids (independent circular DNA fragments separate to chromosomes) or chromosomal mutations

Answer 93

IM 1g STAT ceftriaxone #1 recommendation (also suitable for breastfeeding/ pregnancy) Ciprofloxacin 500mg PO STAT does can be used if sensitivity is known Ciprofloxacin = quinolone abx, not suitable in pregnancy or breastfeeding

Answer 94

High prevalence of GC ciprofloxacin resistance in the UK ~36% Other alternatives if regional resistance <5%: Cefixime 400mg PO STAT + azithromycin 2g PO STAT (recommended if IM injection refused by patient or contraindicated) Gentamycin 240mg IM STAT + azithromycin 2g PO STAT (appt treatment for true penicillin allergy with unknown resistances, as likely not suitable for cipro alone) Spectinomycin 2g IM STAT + azithromycin 2g PO STAT (not recommended for pharyngeal infection) ****Due to increasing antimicrobial resistance a routine TOC is recommended 2 weeks following treatment*****

Answer 95

Symptomatic men with urethritis – 2 weeks prior to onset of symptoms Asymptomatic or infection at any other site – 3 months prior to diagnosis

Answer 96

Beta lactam antimicrobial, third generation cephalosporin Metabolism by gut flora >> inactive metabolites When given parenterally it is not metabolised >> excreted unchanged in urine and bile Can form precipitates with calcium (do not use concurrently) >> risk of cardiorespiratory arrest ~10% cross-reactivity of cephalosporins for those with true penicillin allergies From limited data, appears to be safe in pregnancy and breastfeeding

Answer 97

Ciprofloxacin is a bactericidal antibiotic of the fluoroquinolone drug class. It inhibits DNA replication by inhibiting bacterial DNA topoisomerase and DNA-gyrase

Answer 98

Infection is associated with adverse pregnancy outcomes: 3-6x increased in pre-term delivery and low birth weight babies Increased PROM Infection of chorio-amnion can occur and lead to septic abortion Increased rate of intrapartum pyrexia and post-partum/ post-abortion endometritis

Answer 99

Mild infections can cause rhinitis and pharyngitis --> vaginitis and urethritis --> severe infections are usually relating to ophthalmia neonatorum and sepsis Gonococcal ophthalmia neonatorum is a notifiable disease in the UK Conjunctivitis with purulent discharge in an infant within 21 days of birth (though more typically develops within 2-5 days of birth) Occurs in ~1/3 of exposed infants Associated with significant oedema of eyelids If untreated >> extends to subconjunctival connective tissue >> corneal ulceration and blindness

Answer 100

Flagellated protozoan parasite in human genitourinary tract Multiplication by mitosis every 8-12 hours; grows in moist environments at 35-27 degrees Average incubation period of 4-28 days Detection rates in male contacts are very dependent on timing of sexual activity <48 hours since last sex – 70% detection <5 days since last sex – 40% detection 14 days since last sex – 33% detection 21 days since last sex – 12% detection only Woman 50% symptomatic - frothy yellow dc Men 25% symptomatic

Answer 101

Women should be tested when presenting with vulvitis/ vaginitis Swab from posterior fornix for wet mount microscopy (40-80% sensitivity, highly specific) Self taken VVS for NAAT (88-97% sensitivity) Men should be tested if contact of TV or presenting with persistent urethritis Urine NAAT Consider urethral specimen (only 30% sensitivity of microscopy for males, remains highly specific) Direct wet microscopy slides must be read within 10 minutes of preparation as motility of the protozoa quickly declines NAAT PCR superior to culture testing – culture sensitivity only 34-59%

Answer 102

UNCOMPLICATED: The only effective agents for TV treatment are the 5-nitroimidazoles with a good overall cure rate (>95%) #1 400-500mg metronidazole BD for 5-7 days OR 2g single dose STAT (lower cure rate) Given limited treatment options, if true allergy, consider metronidazole desensitisation 2g STAT tinidazole is an alternative, but cross-reactivity unknown and not considered safe in metronidazole allergy. Also not suitable for use in pregnancy. No alcohol during and for 48 hours post-completion due to disulfiram-like (Antabuse) reaction. Metronidazole should be avoided during breastfeeding – caution is advised against high dose use during pregnancy (400mg BD 7/7 acceptable >> 2g STAT). In cases of refractory infection consider: #1 Repeat 7/7 treatment course of metronidazole (~40% response rate) #2 If no response to repeat treatment, consider higher dose regime (~70% response rate) Metronidazole or tinidazole 2g OD 5-7 days OR metronidazole 800mg TDS 7/7 Following this if ongoing infection consider resistance testing

Answer 103

Partner notification and TV treatment (irrespective of result) for the last 4 weeks is recommended No TOC

Answer 104

Anaerobic cover; protozoa, anaerobic bacteria (and some streptococci) Works by gaining entry into anaerobic organisms >> cytotoxic reaction Very good oral bioavailability Side effects – nausea/ vomiting, dry mouth, metallic taste Limited evidence for safety in pregnancy but is widely used where benefits felt to outweigh risks Does pass in to breast milk but no evidence of harm, high dose regimes should be avoided

Answer 105

Candida albicans main organism responsible (85-90%), Candida glabrata (3-15%) replicate via production of ‘buds’ from a blastospore (yeast cell)

Answer 106

Hyphae (long tubes of multiple cell units) Pseudo-hyphae (single elongated cells) (Chlamydo)spores (refractory bodies with double layered cell-walls) “mycelium” = entire yeast aggregate (spores, hyphae and branches of) C. glabrata does not produce hyphae or pseudo-hyphae

Answer 107

Recurrent vulvovaginal candidiasis (RVVC) = 4 or more episodes annually At least partial resolution of symptoms between episodes + microscopy or culture on at least 2 occasions of symptoms Chronic, persistent candidiasis that is not treated >> vulval lichenification and oedema Most commonly in older and obese diabetic patients

Answer 108

Diagnosis gold standard is with laboratory culturing (95-100% accuracy) Allows for speciation and resistance testing Can be fluconazole resistant so this is especially important in recurrent cases Microscopy of gram stained sample has limited sensitivity (~65%) Spores and hyphae stain gram + (purple)

Answer 109

Standard treatment recommends #1 150mg fluconazole STAT Not suitable in pregnancy or breastfeeding Clotrimazole pessary instead 500mg ON one dose OR 200mg ON 3/7 OR 100mg ON 6/7 If presence of dermatitis should be given Canesten HC (antimycotic -hydrocortisone combination cream) Balanitis should be managed with fluconazole 50mg PO OD 7/7 (+/- Canesten HC if very irritated)

Answer 110

Recurrent cases can be trialled with longer term suppressive treatment Induce with 150mg/ 72 hours PO for 3 doses Maintain with 150mg fluconazole weekly for up to 6 months Trial withdrawal (recurrence on withdrawal in up to 40%)

Answer 111

Presence of H2O2 (hydrogen peroxide) producing lactobacillus protective factor Most commonly lactobacillus crispatus and jensenii species Prevalence of BV only 4% in presence of these organisms, compared to 32% for those without CHC use also appears to be protective

Answer 112

Gardnerella species (particularly Gardnerella vaginalis) >>>>> Gram variable coccobacillus Found in high concentrations in >95% of cases of BV Presence of high levels of Gardnerella >> proliferation of other anaerobic species >> mixed infection: Mobiluncus Bacteroides Prevotella Gardnerella has asymptomatic commensal carriage in ~58% of women without BV Gardnerella forms a biofilm, strongly adherent to vaginal epithelium Formation of a biofilm >> increased resistance to protective mechanisms of normal vaginal flora (release of H2O2 and lactic acid from lactobacillus) and reduced penetration from antibiotics Biofilm structure implicated >> high rates of BV relapse and recurrence

Answer 113

Asymptomatic in 50% Abnormal discharge most common symptom Increased volume Thinner Grey >> white > yellow Offensive “fishy” odour ((Smell can be enhanced when vaginal pH raised i.e. during menstruation/ after sex)) Generally non-inflammatory and not associated with vaginitis/ irritational symptoms

Answer 114

Gardnerella isolated from urethral samples in up to 80% of male partners of women with BV However their concurrent treatment does not appear to reduce recurrence/ relapse rates Male condom use appears to reduce BV recurrence rates by ~5 fold

Answer 115

3 of 4 criteria to be met (1) Characteristic discharge (2) pH >4.5 (alkaline); indicative of lack of lactobacilli producing H2O2/ lactic acid NB: TV also causes alkaline discharge pH >4.5 vs candida is associated with pH <4.5 (3) Vaginal clue cells on microscopy ((Not done anymore in practice, but 4th criteria previously was + whiff test)) -- > Addition 10% potassium hydroxide to vaginal fluid àreleases fishy smelling amines

Answer 116

BV on gram stain (1) Reduced or absent lactobacilli (Gram + rods) --> Replaced by small gram variable bacilli adhering to shed epithelial cells (“Clue cells”) (2) Absence of polymorphs (pus cells) Use of Hay-Ison Gram-stain method for scoring: Grade 0 – epithelial cells with no bacteria Grade 1/ normal – epithelial cells with lactobacilli dominant Grade 2/ intermediate – epithelial cells w some lactobacilli and mixed bacteria Grade 3/BV consistent – epithelial cells w mixed bacteria and few/ absent lacto Grade 4 – epithelial cells with gram + cocci only (typically streptococci)

Answer 117

Treatment is typically with metronidazole 400mg PO BD 7/7 Option of 2g STAT dose metronidazole but associated higher rates of recurrence Metronidazole 0.75% intravaginal gel OD (nightly) 5/7 ***Similar efficacy demonstrated with 7/7 PO and 5/7 intravaginal gel treatment regimes**** Non-metronidazole treatments not often used in practice but do show similar efficacy for treatment: Clindamycin 300mg PO BD 7/7 Clindamycin 2% vaginal cream OD (nightly) 7/7 Both oral and topical clindamycin associated with pseudomembranous colitis

Answer 118

Treatment of any BV present is advised in pregnancy, but screening for BV is not recommended Treatment prior to 20 weeks gestation reduces risks of BV associated pre-term birth No evidence of metronidazole causing birth defects but cautious use is advised High dose regimes of metronidazole not recommended in pregnancy/ breastfeeding Systemic metronidazole changes taste of breastmilk Clindamycin is known to pass into the breastmilk Systemic treatment NOT contraindicated, but intravaginal treatment should be considered

Answer 119

Persistent Trial alternative treatment (metronidazole -> clindamycin) Consider removing Cu-IUD if present Recurrent Consider stopping menstrual flow via contraception to maintain lower vaginal pH 10 days induction therapy with intravaginal metronidazole gel -> twice weekly use for 16 weeks: Cures 75% Alternative options/ adjuncts Lactic or acetic acid gel for maintenance therapy in those with recurrent cases -> Either continuous use or cyclically i.e. for 3 days post-menstruation Vaginal or oral probiotics containing lactobacillus can be considered; evidence of benefit lacking

Answer 120

HIV transmission rates are 2-5 x increased in the presence of concurrent BV Some evidence of reduced efficacy of traditional TDF tenofovir vaginal PrEP in the presence of BV H2O2 producing lactobacilli species (BV protective species) are associated with lower HIV RNA within female genital secretions Absence of H2O2 producing lactobacilli species is associated with higher HIV RNA within female genital secretions, even in absence of BV

Answer 121

Gram negative parasitic bacterium; SPIROCHETE Mobile using flagella

Answer 122

Dark ground microscopy of sample from chancre (79-86% sensitivity) Syphilis PCR swab to be sent from chancre

Answer 123

Usually turns positive from 4 weeks post-infection; full window period of 3 months Treponemal-specific antibody tests; done first when screening (1) TPHA/TPPA (Treponema pallidum HaemAgglutination test) (2) Treponemal EIA (IgG/ IgM) Remains positive for life including after treatment Cardiolipin tests (not treponeme specific) (1) VDRL (Venereal Disease Research Laboratory) (2) RPR (Rapid Plasma Reagin) Insensitive in late syphilis (levels drop off as infection persists) but useful in acute infections (acutely rise) Becomes negative / decrease logarithmically after treatment RPR is the test of cure (AIMING FOR A 4X DECREASE IN RPR = SUCCESSFUL TREATMENT) Negative -> 1/2 = best result 1/8 -> 1/16 = worse and so on Note – 4x increase in RPR from test of cure level --> reinfection with syphilis

Answer 124

Syphilitic chancre; classically painless single ulcer with indurated edge Associated regional lymphadenopathy Typically develops ~ 21 days post-infection (9-90 days incubation) Self resolves within <8 weeks, may go unnoticed, especially if vaginal, oral or rectal

Answer 125

Dissemination of infection Occurs at 6 weeks à 6 months post-infection Typically causes generalised lymphadenopathy and non-specific, non-itchy, macular rash Rash classically starts on trunk à spreads outwards, effecting palms and soles Eventually self-resolves if infection not identified and treated at this stage

Answer 126

Asymptomatic ongoing infection Early latent if <2 years since infection Can cause recurrence of secondary syphilis symptoms in ~25% in first 2 years Late latent if >2 years since infection

Answer 127

Occurs in ~ 1/3 of people with untreated infection Multisystemic complications of chronic infection, via type VI hypersensitivity reaction Can take decades to manifest Types (1) Gummatous – 2-15 years Musculoskeletal/mucosal ‘gumma’ (growths/lumps as immune cells -> granulomas with central regions of coagulative necrosis) (2) Cardiovascular – 10-30 years Aortitis -> aortic regurgitation (30%) and aortic aneurysm formation (3) Neurosyphilis (A) Meningovascular 2-7 years: Focal arteritis -> infarction. Most common neurosyphilis manifestation. Consider in young adults presenting with CVAs. (B) General paresis 10-20 years (C) Tabes dorsalis 15-25 years: Spinal dorsal column inflammation -> degeneration. Loss of proprioception and vibration sense. Argyll Robertson pupil in 80%: Pupillary constriction with accommodation but not to light.

Answer 128

(%) Receptive anal intercourse 1.11 Insertive anal intercourse 0.06 Receptive vaginal intercourse 0.1 Insertive vaginal intercourse 0.082 Receptive oral sex 0.02 Insertive oral sex 0.0 Blood transfusion (one unit) 90-100 Needlestick injury 0.3 Sharing injecting equipment 0.67 Mucous membrane exposure 0.63

Answer 129

Benzathine penicillin (majority) or procaine penicillin (neurosyphilis) Early syphilis – benzathine penicillin 2.4M units IM single dose Later infection – 2.4M units IM weekly, for 3 weeks Neurosyphilis: Procaine penicillin 1.8 – 2.4M units IM daily for 14 days Plus PO probenecid (500mg QDS) for 14 days For cardiovascular and neurosyphilis, prednisolone should be given for 3 days starting 24 hours prior to treatment initiation Minimum serological review is needed at + 3, 6 and 12 months from treatment AND until serofast result

Answer 130

Caused by Rubella virus: A togavirus Single-stranded RNA genome Transmission primarily via the respiratory route Incubation period 14 days Congenital rubella infection teratogenic with poor prognosis and significant complications (sensorineural deafness, cataracts and cardiac abnormalities most common) No specific treatment. Key is prevention through vaccination programme Vaccination is via live attenuated virus so cannot be given to pregnant women who are found to be non-immune. If IgG and IgM are negative the patient is susceptible to Rubella infection. If IgG +ve and IgM -ve the patient should be considered immune. If IgM +ve this suggests acute infection or false positive IgM (not uncommon) 'Blueberry muffin' rash

Answer 131

Beta-lactam, naturally occurring penicillin Narrow spectrum and poor oral absorption -> IM administration; acts as depot, absorbed slowly Reduced dose required in renal impairment Crosses the placenta but is safe to use in pregnancy and breastfeeding

Answer 132

There are 2 treatment options: Spiramycin ASAP if fetus not infected or status of the fetus not known. This reduces risk of transplacental infection. This is continued until term, or until fetal infection is documented. Pyrimethamine, sulfadiazine and folinic acid where fetal infection is known e.g. positive amniotic fluid PCR. Monitoring for haemotoxicity required. Pyrimethamine should be avoided in the 1st trimester as teratogenic

Answer 133

Feeling of impending doom, hallucinations or seizures can occur immediately following inadvertent administration of procaine benzylpenicillin IV (neurosyphilis treatment)(rather than IM as intended) Self-resolving and lasts <20 minutes

Answer 134

can occur within 24 hours of treatment for spirochete infections Release of lots of spirochete material at once as they die -> fever, chills, myalgia, hypotension Febrile illness with onset within 4 hours of treatment administration Resolves within 24 hours

Answer 135

If tested and treated in the 1st trimester -> repeat test (+/- treatment) later in pregnancy: RPR at +1 months and +3 months to ensure adequately dropping Congenital syphilis is transplacental spread ONLY (most common cause of preventable stillbirth) **Can occur at any gestation **More likely to occur in early syphilis / with RPR >1:8 (rare after >=4 years infection) **No increased risk depending on mode of delivery **No increased risk depending on breastfeeding Infants tested at delivery and at +3 months (wp), even if maternal antenatal treatment successful

Answer 136

dsDNA within an icosahedral “nucleocapsid” which is then enveloped in a lipid protein membrane (derived from host cell) Incubation period generally 3-14 days HSV-1 is the most common cause of genital herpes in the UK HSV-2 is the strain most likely to cause recurrent anogenital herpes

Answer 137

Typically sacral ganglia (S2-S5) for anogenital herpes

Answer 138

90% of patients with HSV-2 symptoms have at least one recurrence in the following year 60% of patients with HSV-1 symptoms have at least one recurrent in the following year - recurrence beyond 1 yr rare

Answer 139

Total average resolution time (without treatment) 17-20 days

Answer 140

More common in first 6 months from infection In women, use of hormonal contraception and concurrent BV appear to increase HSV-2 shedding In men, circumcision may confer a weak protective effect against HSV-2 infection

Answer 141

HSV is common, with a lifetime seroprevalence of up to 80% Only 5-20% of HSV-2 seropositive individuals recall history of symptoms

Answer 142

HSV-2 rate of transmission between discordant couples is 15-20% per year

Answer 143

PCR swab from active lesions: Highly specific, and most sensitive method of diagnosis Antibodies typically appear within 2-3 weeks of infection - > Type specific serology for HSV-1 and 2 possible IgM detection = unreliable It is not possible to state if the infection is pre-existing or recent, only that infection has occurred Limited value given high rates of asymptomatic seropositive cases in general population

Answer 144

If started within 5 days of onset, evidence demonstrates 50% reduction in duration of symptoms as well as 60% reduction in viral shedding.

Answer 145

Synthetic purine nucleoside analogue Enzyme thymidine kinase (within HSV) converts aciclovir -> aciclovir triphosphate which interferes with viral DNA and inhibits it’s replication Does not eradicate persistent/ latent infection (supresses but doesn’t cure) Aciclovir is not licensed for use in pregnancy, however it is widely used and is not known to be harmful in pregnancy or breastfeeding When used as suppressive treatment, the usual dose is 400mg BD -> 400mg TDS is recommend for suppression in pregnancy due to the greater volume across which the drug is distributed (BASHH/RCOG)

Answer 146

ssRNA Faeco-oral spread Incubation period 4 weeks Diagnosed using serology Usually self-limiting condition (higher risk if liver disease or immunosuppressed / elderly)

Answer 147

Vaccination offered for high risk groups and those at risk of more serious infection: Chronic liver disease HIV Occupational risks – sewage workers, homeless shelters, working with apes/monkeys Men who have sex with men Transgender Injecting drug users Close contacts of someone with Hepatitis A If travelling to a high risk country 2 doses ideally given 6-12 months apart If 2nd dose delayed by >3 years then ‘course’ should be restarted Booster after 25 years

Answer 148

ds DNA virus! Spread through exposure to infected body fluids, including blood, semen and vaginal fluids: Sexual exposure, Injecting drug users, Vertical transmission mother-child. The UK is a very low prevalence country In areas of high endemicity, majority of infections are acquired during childhood (high rates of chronic infection) In low endemicity countries, majority of infections are acquired in adulthood via sexual activity of needle sharing in IVDU (lower rates of chronic infection) Average incubation period 3 months 95% of adult Hepatitis B --> spontaneous clearance Only small number of chronic infections (opposite of Hepatitis C) Significant number of childhood cases --> chronic infection (opposite of Hepatitis C) >90% of those exposed neonatally, and ~ 1/3 of those infected in early childhood Diagnosed with serology HbsAg + = infected HbeAg + = most infectious Chronic Hepatitis B is defined as presence of HbsAg in the blood for 6 months or more

Answer 149

(1) INFANT VACCINES From 2017 onwards the UK childhood vaccination schedule introduced Hepatitis B coverage Given at 8, 12 and 16 weeks of age (2, 3 and 4 months) Given as hexavalent vaccine which also covers for diphtheria, tetanus, pertussis, polio and Hib Additional doses of monovalent Hepatitis B vaccine given at birth, 1 month and 1 year for neonates born to Hepatitis B + mothers (2) HIGH RISK GROUPS Vaccination additionally recommended in the UK for those adults at higher risk: >> Injecting drug users >>HIV + (4 dose regime > usual 3 dose regime and immunity check 4-8 weeks following completion) >>MSM >>CSW >>Close/ familial contacts of infected individual >>Prison inmates >>Those with chronic liver or renal disease >>Occupational risk – healthcare workers, laboratory staff, residential home staff etc >>Travelling to higher prevalence country Monovalent vaccine, given at 0, 1 and 6 months Additional 5 year booster if still high risk If HIV + additional dose is given at 2 months; 4 doses given at 0, 1, 2 and 6 months Additional 5 year booster if still high risk (3) AS PEP Hepatitis B vaccine is also highly effective at preventing infection if given shortly after possible exposure Ideally within 24 hours of exposure; considered up to 1 week post-exposure as PEP (skin exposures ie needlesticks, sharing injecting equipment) Note: post-sexual assault guidelines recommend offer of Hepatitis B vaccine up to 6 weeks (A) VERY Rapid scheme Very-rapid/ super-accelerated course the given at 0, 7 and 21 days (B) Rapid scheme Accelerated course is given at 0, 1 and 2 months Additional 5 year booster if still high risk given at usual interval Note: The vaccine is safe to use in pregnancy and breastfeeding

Answer 150

For most people an immunity check is not required. Check if (1) RAPID SCHEME Consider checking immunity at 1-4 months post completion of primary vaccine course for those having accelerated vaccine post-exposure (2) HIV POS Immunity should be checked at 4-8 weeks post completion of primary vaccine course for HIV + patients WHAT ARE YOU LOOKING FOR ON RESULTS Ideal immunity >100. Immunity >10 = response Immunity <10 = no response. --> If 10-100 should receive further 1 dose of the vaccine. No further monitoring required here if immunocompetent. If HIV + recheck at + 4-8 weeks. --> If <10 should repeat vaccine course and further immunity check following completion. If <10 again = non-responder. Would require HBIG if exposed to Hepatitis B.

Answer 151

treatment is with tenofovir There is no curative treatment for chronic Hepatitis B infection and treatment is usually lifelong Hence very important to check Hep B status prior to using HIV PrEP or PEP (both contain tenofovir)

Answer 152

Antibodies to HBc are only acquired through NATURAL infection, not immunisation (c = caught) IgM anti-HBc implies acute infection – usually present for around 6 months following infection

Answer 153

ssRNA Spread via blood Long incubation period of up to 6 months Acute infection is often asymptomatic -> silent chronic infection and long term sequalae -> presentation Inversely to Hep B, acute infection acquired in neonatal period/ childhood -> good spontaneous clearance rates Acute infection acquired in adulthood has a tendency to not fully clear and -> chronic infection in >75% Unlike Hepatitis B, Hepatitis A is a curable condition Antibodies to Hep C remain + after successful treatment However this does not confer immunity and reinfection is possible Diagnosed with serology #1Hep C Ab Check Hep C Ab presence -> if –ve then no current or previous exposure/infection #2 Hep C RNA If + Hep C Ab then check Hep C RNA -> if –ve then previous cleared/ treated infection If Hep C RNA +ve then current infection is present TREATMENT Treated with Direct Acting Anti-viral (DAA) medications Treatment depends on viral genotype, many regimes Currently complex multi-drug regimes with sofosbuvir being commonly included The aim of treatment is sustained virological response (SVR). Undetectable serum HCV RNA at + 6/12 after the end of therapy --> Patient “cured” if this is achieved. Usually 8-12 week treatment course Very well tolerated with few side effects Clearance rate of >90%

Answer 154

nucleotide polymerase inhibitor USed in hep C treatment

Answer 155

important causes of peri-natal mortality treated with ribavirin – nucleoside analogue

Answer 156

antibody and antigen test uses monoclonal antibodies to test for HIV IgM HIV IgG p24 antigen WP 45 days from exposure If PEP given then 73 days from exposure (minimum of 45 days post completion of 28 days PEP)

Answer 157

Antibody only WP 90 days from exposure

Answer 158

Have 3/12 viral load monitoring Have a viral load <200 on 2 occasions >3/12 apart Are under joint supervision by HIV specialist and occupational health (registered)

Answer 159

HIV diagnosis is considered LATE if CD4 count is <350

Answer 160

NOT recommended for women with HIV and a CD4 count <200 Advise viral load is supressed <200 for at least 6 months prior to conception

Answer 161

In utero – 5-10% without ART with majority occurring in the third trimester Intra-partum – 10-20% without ART (viral load as main risk factor) Breastfeeding – 5-15% without ART

Answer 162

HIV RNA (VL) in breastmilk correlates with plasma VL Generally sit ~ 100 fold LOWER than plasma levels Higher transmission rates at onset of breastfeeding due to higher cellular content of colostrum Also higher transmission rates with increasing duration of feeding (more opportunities)

Answer 163

both increase risk of preterm delivery Women with HIV are recommended to have screening and treatment for BV in pregnancy

Answer 164

Dolutegravir – some limited evidence of link with neural tube defects (discuss with women at conception/ when planning conception) but more research is needed

Answer 165

VL <50 = normal vaginal delivery/ no restriction on options VL 50 – 399 = consider planned LSCS Consider CS trajectory, time on treatment, obstetric factors and woman’s view Risk of transmission increases from ~0.26% with LSCS to 1.1% with SVD in these VL ranges VL >=400 = planned LSCS at 38-39/40 (prevent/reduce chance of spontaneous labour)

Answer 166

Neonatal PEP with zidovudine recommended for babies born to mothers without undetectable (<50) VL NRTI

Answer 167

PROMISE trial – breastfeeding risk 0.3% at 6 months, 0.6% at 9 months, 0.7% at 12 months Risk of transmission via breastfeeding increased with: VL >50 Lower CD4 counts Longer duration of feeding Breast or nipple inflammation/ infections Neonatal gut/mouth inflammation/ infections Mixed feeding with food at <4 months Breastfeeding CAN be supported for women who are undetectable (VL <50) on treatment who are amenable to attending for regular (monthly) bloods monitoring and support from HIV teams

Answer 168

Triple ART 2 nucleoside reverse transcrip inhibs (NRTIs) AND EITHER  (A) a non-nucleoside rev transcript inhib(NNRTI) (B) OR a protease inhibitor (PI) (C) OR an integrase inhibitor (II)

Answer 169

Zidovudine (AZT), Emtricitabine and Tenofovir (Truvada combo) and many more General NRTI side-effects = peripheral neuropathy

Answer 170

Nevirapine, Efavirenz Side-effects = P450 enzyme INDUCERS, rash

Answer 171

Indinavir, Nelfinavir, Ritonavir, Saquinavir Side-effects = diabetes, hyperlipidaemia, buffalo hump, central obesity, P450 enzyme INHIBITORS (especially Ritonavir) 'Navir tease a pro': HIV drugs that end with -navir are protease inhibitors

Answer 172

Raltegravir, Elvitegravir, Dolutegravir NB dolutegravir associated with neural tube defects (5mg folic acid) 'It's grave/great you integrate': HIV drugs that end with -gravir are integrase inhibitors

Answer 173

ARTs must not be stopped suddenly – resistance is an issue >95% compliance is optimal to avoid resistance Equates to not taking the drug LATE on >2 occasions/week OR not missing >1 dose/ 2 weeks If taking with compliance between 50-95% this is maximal risk for resistance

Answer 174

A majority of ART medications are metabolised by p450 enzymes Beware concurrent long-term steroids, warfarin, phenytoin and rifampicin etc Absorption of ART requires stomach acid so omeprazole/ other PPIs can decrease absorption

Answer 175

Allergic rash may occur within first 4 weeks -> do NOT suddenly stop taking: Risk of resistance and also of sensitisation -> future anaphylactic reaction Mild GI upset Jaundice Long term toxicity can develop – regularly monitor U+Es, LFTs, FBC, urinalysis If Q risk >10% agents which increase CV risk (mainly protease inhibitors) avoided --> Monitor lipids, HbA1c and Q risk score Tenofovir disoproxil fumarate (traditional tenofovir; cheaper) can contribute to osteoporosis Monitor FRAX score +/- DEXA as per scoring Also important consideration for PrEP users as contains TDF Tenofovir typically Traditional TDF Tenofovir -> TAF Tenofovir (tenofovir alfenamide) = safer for bones and ?Kidneys Branded name Descovy; often called “TAF PrEP” (++ more expensive)

Answer 176

Within 72 hours of potential exposure to HIV 2 x NRTIs PLUS 1 x II Fixed-dose combination tablet combining emtricitabine and tenofovir (2 x NRTIs) (Previously branded Truvada, now often generic) AND raltegravir (integrase inhibitor) Most effective and best evidence base if started within 24 hours from exposure Evidence suggests PEP may reduce the chances of HIV infection by approximately 80% Weak evidence based compared to PrEP 28 day course PEP is recommended when risk is > 1/1000 PEP is considered if risk if >1/10,000 PEP is NOT recommended if risk if < 1/10,000 Your HIV positive partner has undetectable virus levels on treatment Human bites Another person’s semen gets in your eye You had oral sex only When starting HIV PEP check LFTs and U+Es and Hepatitis B screening This is because Tenofovir is also active against Hep B

Answer 177

Tenofovir and emtricitabine (2 x NRTIs) Must have U+Es monitored at least annually Traditional “Truvada” PrEP = tenofovir disoproxil fumarate (TD or TDF PrEP) with emtricitabine !! Concurrent use of depot contraception should be avoided due to BMD concerns Newer “Descovy” PrEP = tenofovir alfenamide (TAF PrEP) with emtricitabine Descovy/TAF safer for those with osteoporosis risk or chronic kidney disease, + expensive Can be taken daily (must be taken daily by anyone having frontal sex and generally recommended for those on gender affirming hormone therapy) OR only taken event based (evidence for cisgender MSM groups only – only evidence of efficacy for anal sex) 2 tablets between 2 - 24 hours before sex, then 1 tablet a day for 48 hours following the last episode of sex Daily dosing has the strongest evidence base (UK PROUD trial) NHS funded in England since April 2020 NHS funded in Scotland since April 2017

Answer 178

Hepatitis B 20-30% Hepatitis C 0.5-2% HIV 0.3% Hepatitis B - HR PEP available via vaccination +/- immune globulin (HBIG) Known HBsAg + source --> for known responders to HBV vaccine a BOOSTER dose should be given (majority) --> If they are in the process of being vaccinated OR are a non-responder they need to have hepatitis B HBIG + vaccine Unknown source --> for known responders, green book advises a booster dose of HBV vaccine (majority) --> For known non-responders HBIG + vaccine should be given --> Those in the process of being vaccinated should have an accelerated course of HBV vaccine Hepatitis C No PEP Followed up with serial serology for 24 weeks (6 months) If seroconversion, then treat (interferon +/- ribavirin) HIV PEP Single tablet tenofovir/emtricitabine – 2 x nucleoside reverse transcriptase inhibitors NRTIs (Now often generic but previously branded Truvada) PLUS 2 tablets of raltegravir (integrase inhibitor – “it’s great, you integrate”) ASAP following exposure, but may be started up to 72 hours following exposure 28 day course Serological testing at + 45 days minimum following completion of PEP Minimum of 73 days after exposure (if 28 day course of PEP completed) If sexual exposure, recommendation is for final testing to be done at 12 weeks (with STS serology) --> Reduces risk of transmission by 80%

Answer 179

In the human host, infection is with sarcoptes scabiei var hominis. Parasite: 8 legged mite infestation with a lifespan of 4-6 weeks. Viable on inanimate objects for 2-3 days Female mites burrow into the skin and lay eggs which hatch in 3-4 days Total time from hatching --> gravid mature females is 14 days. Transmission via prolonged skin to skin contact >10-20 minutes Holding hands is the most common route of transmission

Answer 180

Symptoms of classical scabies: Often asymptomatic for first 4-6 weeks in first episode of infestation People are infectious BEFORE the rash and itching develop --> Intense itching and skin irritation occurs via type IV delayed hypersensitivity reaction to mites Itch typically worse at night --> Symmetrical polymorphic lesions of skin, most commonly on hands in interdigital webs --> Classical nodules and papules seen on penis and scrotum if this area is effected In reinfections symptoms occur much sooner due to previous sensitisation, within 24-48 hours

Answer 181

Norwegian or “crusted” scabies occurs immunocompromised groups - failure of sensitisation to mites - itch less intense - rash more extensive - crusted lesions with thick hyperkeratotic scales -- highly contagious as bigger mite burden

Answer 182

(1) Permethrin (a pyrethoid) 5% cream is first line, 2 applications one week apart Apply to whole body from chin and ears -> down Apply to cool skin (not following bath /shower) Wash off after 8-12 hours If hands washed with soap within this window, reapply permethrin to hand area Reapply +1 week Suitable in pregnancy and breastfeeding; wash cream from nipples before feeds (2) Malathion (an organophosphate) 0.5% aqueous lotion If permethrin not appropriate (allergy to chrysanthemums - flowers!) Must be left on for 24 hours (less practical than permethrin) (3) Ivermectin oral – only for treatment resistant cases in classical scabies Note: Symptoms of irritation often persist for several weeks following successful treatment Sedative antihistamines and calamine lotion for symptomatic relief in addition to permethrin -> itch beyond 1 month post completion of treatment may suggest failure -> retreat.

Answer 183

Permethrin application OD for 7 consecutive days -> twice weekly until cure PLUS oral ivermectin

Answer 184

Household contacts and sexual contacts should be concurrently treated to avoid reinfections Partner tracing for 4 weeks prior to symptoms is recommended

Answer 185

Pthiriasis or pediculosis = pubic lice Wingless insects, unable to fly/ jump, feed from human host via blood sucking (typically at hair follicle base) 3 species of lice effect humans: (1) Pthirus pubis (pubic or “crab” lice) (2) Pediculus humanus capitis and (3) corporis (head /body lice) Pubic lice, unlike body/head lice, are NOT known to be vectors of BBV or human disease 95% of sexual contacts of an active carrier -> develop infestation Symptoms: Itching/ irritation (hypersensitivity reaction) ~40% develop skin erythema If very hairy -> thighs, perineum, trunk, abdomen Occasionally can infest eyelashes / eyebrows ->blepharoconjunctivitis Treatment should be applied to all body hair (leave on as per scabies instructions and repeat +1 week): Permethrin 5% cream Malathion 0.5% aqueous solution Clothes and bed linen should be washed at >50 degrees Contact tracing of all partners in past 3 months recommended

Answer 186

non-enveloped double stranded DNA virus LR genital warts – HPV type 6, 11, 42 and 44 Highest risk strains 16 and 18 responsible for >70% of cases (Other high risk oncogenic strains include 31, 53 and 58)

Answer 187

Responsible for >90% of anal intra-epithelial neoplasia (AIN) AIN is a pre-invasive lesion -> anal cancer if left undiagnosed/ untreated Majority of subsequent invasive anal cancers that do occur are squamous cell carcinomas

Answer 188

Responsible for >40% of penile intra-epithelial neoplasia (PIN)

Answer 189

Responsible for >40% of vulval and vaginal cancers

Answer 190

(1) Usual type VIN More strongly associated with HPV, smoking and immunosuppression Not associated with inflammatory skin conditions More common in pre-menopausal population (~40s) Some cases may self-resolve Less likely to progress to squamous cell carcinoma than differentiated VIN If left untreated/unmonitored, time to squamous cell carcinoma --> 6-7 years (2) Differentiated VIN Associated with inflammatory skin conditions, lichen sclerosis AND lichen planus More common in post-menopausal population (>60s) More likely to progress to squamous cell carcinoma >> usual type VIN Average time to progression if left untreated --> 2-4 years

Answer 191

E6 -> P53 inhibition P53 usually acts as tumour suppressor E7 -> pRB (retinoblastoma protein) inhibition

Answer 192

Recombinant protein vaccine Should ideally be given before first sexual contact In UK children (all genders) receive at 12-13 years of age (during school Year 8) since 2008 (since 2019 all gender kids) Covers 9 important HPV strains; 6, 11, 16, 18, 31, 33, 45, 52 and 58 Other eligible groups: Men <45 years who have sex with other men Girls aged <25 years who missed school Transgender people Sex workers People living with HIV People <25 years only need 1 dose generally If aged 25 – 45 years may need 2 doses (given at 6 months – 2 years apart) If weakened immune system i.e. HIV + then 3 doses are recommended, ideally within 1 year

Answer 193

40% of warts resolve spont in 4 months (immunocompetent) Smoking cessation increases rates of spontaneous clearance Treatment comes with risk of scarring and pigmented skin changes If patient wishing for treatment, there is no single first line option; choices include: (A) Cryotherapy (usually weekly for 4 weeks) – more practical for smaller number/ volume warts (B) Imiquimod (Aldara) (C) Podophyllotoxin (Warticon)

Answer 194

Wart treatment Immune response stimulator (I with I) Application 3 x weekly (alternate nights) --> wash off 10-16 hours later, for up to 16 weeks Better for keratinized warts, but also suitable for soft/ non-keratinized lesions Generally takes longer to work than podophyllotoxin Generally accepted as safe in pregnancy (though not licensed)

Answer 195

Ward treatment Anti-mitotic agent which should cause local tissue necrosis 0.5% solution or 0.15% cream Application for BD 3 consecutive days, repeated at weekly intervals for one month Better for softer, non-keratinized warts Podophyllotoxin is contraindicated in pregnancy (teratogenic)

Answer 196

Benign skin eruption caused by molloscum contagiosum virus (MCV) - DNA virus 4 subtypes MCV 1-4 clinically indistinguishable (mcv 1 common, 2 in immunosup) Incubation period (contact à lesions) for most is between 2-12 weeks (some cases up to 6 months) Causes smooth, pearly umbilicated lesions 2-6mm in size Usually lesions spontaneously resolve within 3 months Options as per wart management in exceptional cases warranting treatment Molloscum can be an indicator condition for HIV, and is found in up to 20% of HIV + individuals Children <15 years (account for 90% of GP attendances for molloscum) . Autoinoculation can occur from itching/ picking --> 10-15% of children have genital lesions STI More common in 20-29 year demographic Lesions prone to koebnerization (new skin lesions of a pre-existing dermatosis on areas of cutaneous injury in otherwise healthy skin. I)

Answer 197

The hepatitis A monovalent vaccine is given in two doses, 6–12 months apart.

Answer 198

Injecting drug users MSM CSW Close/ familial contacts of infected individual Prison inmates Those with chronic liver or renal disease Occupational risk Travelling HIV+ve Monovalent vaccine, given at 0, 1 and 6 months --> Additional 5 year booster if still high risk --> HIV - 4 dose regime (0, 1, 2, and 6) and immunity check 4-8 weeks following completion(10-100 should receive further dose) Accel is 0, 1, 2 months Super accel is 0, 7 and 21 days (check immunity 1-4 months post primary vacc) Also used as PEP one week after (although offer post SA 6weeks after)

Answer 199

Twinrix Adult Twinrix® is given in three doses, at 0, 1, and 6 months. If Twinrix® is given as a rapid schedule (on days 0, 7, and 21), a booster dose is needed at 1 year.

Answer 200

now anyone under age of 25 who hasnt had. Or MSM < 45 2 doses 6-24 months apart

Answer 201

Uses the smallpox vaccine outside of it’s licence 2 doses given 28 days (1 month) apart --> protected from 7 days following second dose --> Optional booster dose at + 2years --> Could also be used as a form of PEP – recommended within 4 days of exposure (considered up to 14 days) (ended but ?restarted?) Thought to be up to 85% effective at preventing MPX (after full course – 2 doses) Was recommended for: MSM Group sex /sex on premises attenders Sex on premises staff Sexual health and relevant hospital department staff Full course wa

Answer 202

1 = none/ prepubertal 2 = breast buds only, onset of puberty 3 = enlargement of breast and areola continue with no separation in breast-areola contour 4 = nipple and areola project to form secondary mounds above the level of the surrounding breast 5 = adult; nipple only projected, areola is confluent with the breast

Answer 203

1 = none/ prepubertal 2 = very sparse hair growth, light/soft hair quality still 3 = hair becomes darker and thicker but remains sparse 4 = more like adult coverage but not full, spares the inner thighs 5 = full adult coverage including inner thighs

Answer 204

neurotransmitters including GABA and neuropeptide-Y