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Flashcards in Microbiology (finished) Deck (265):
1

What kind of cells are seen in a TB granuloma?

Langerhans' giant cells

2

What are the features of TB meningitis, how do you diagnose it, and what's the treatment?

  • Subacute presentation with weight loss, fever, night sweats, headache, neck stiffness, personality change, decreasing GCS and focal neurological deficit
  • Diagnosis:
    • CT - tuberculomata
    • LP: lymphocytic
  • Treatment: 12/12 anti TB treatment and steroids

3

What are the possible sites of extrapulmonary TB (other than meningitis and spinal) and who is at increased risk?

  • Lymphadenitis
  • Pericarditis
  • Abdominal (peritonitis, ileitis)
  • Genitourinary, renal, testicular
  • Skin
  • Liver
  • HIV coinfection increases risk

4

What are the features of spinal TB, how do you diagnose it and what is the treatment?

  • Fever, sweats, weight loss, back pain
  • Haematogenous spread causes initial discitis, followed by vertebral destruction and collapse +/- anteiror extension cauing ileopsoas abscess
  • Diagnosis: MRI/CT +/- biopsy/aspirate
  • Treatment: 12/12 anti TB drugs

5

How is TB vaccinated against and what are the considerations?

  • Attenuated strain of M bovis (Bacille Calmette Guerin)
  • Efficacy 0-80%; good for leprosy, TB meningitis and disseminated TB but bad for pulmonary TB
  • Given to babies born in or with parents/grandparents from areas with incidence >40/100,000, and previously unvaccinated new immigrants from high prevalence countries
  • Contraindicated in HIV patients

6

What's the difference in risk of latent TB becoming active with and without HIV coinfection?

HIV negative: 5-10% lifetime risk of activation.

HIV positive: 5-10% yearly risk of activation

7

How can TB be tested for?

  • Imaging: CT or CXR (upper lobe cavitation post primary)
  • Culture:
    • Sputum x3, BAL, urine, pus
    • Lowenstein-Jensen medium (gold standard)
    • Sputum: ZN/auramine staining: gram +ve rose, acid fast, aerobic, intracellular
  • Tuberculin skin tests: mantoux/heath using PPD
  • IGRA: e.g. Elispot, Quantiferon
  • NAAT: PCR-line probe assays, tests for sensitivities
  • Liquid culture mediums

8

What is the first line TB therapy and what are the side effects?

  • Rifampicin: drug interactions (raised transaminases, induces cytochrome p450), orange secretions, hepatotoxicity
    • Rifampicin - Red secretions
  • Isoniazid: peripheral neuropathy (give B6/pyridoxine), hepatotoxicity
    • iSOniazid - SO difficult to feel my toes and liver
  • Pyrazinamide: hyperuricaemia, hepatotoxicity
    • Pyrazinamide - there's PEE in my blood (and my liver's shit)
  • Ethambutol: optic neuritis, visual disturbances
    • EthamBUTol - BUT I can't see!
  • RIPE for 2/12 then RI for 4/12
  • Meningitis: increase RI stage fo 8-10/12
  • Latent TB: 6/12 isoniazid
  • Vitamin D supplements

9

What is the second line treatment for TB?

  • Injectables: capreomycin, kanamycin, amikacin
  • Quinolones (moxifloxacin)
  • Cycloserine, ethionamid/protionamide, PAS, linezolid, flofazamine

10

How do you treat resistant TB?

  • Mono: one drug only
  • MDRTB: R+I
  • XDRTB: R + I + injectables (kanamycin/amikacin) + quinolones
  • Latent TB: 6-9/12 isoniazid
  • Prophylaxis: isoniazid alone

11

What causes leprosy?

M leprae and M lepromatosis

12

What are the clinical features of leprosy?

  • Lifelony illness with 2-10 years incubation and poor transmission via nasal secretions
  • Most disability is cause dby nerve damage
  • Skin: depigmentation, macules, plaques, nodules, trophic ulcers
  • Neves: thickened nerves, sensory neuropathy
  • Eyes: keratitis, iridocyclitis
  • Bone: periostitis, aseptic necrosis

13

What is the clinical spectrum of leprosy?

  • Tuberculoid (TT): paucibacillary, Th1 mediated, depigmented lesions
  • BT: nerve damage
  • Borderline (BB): multiple plaques
  • BL
  • Lepromatous (LL): multibacillary, Th2 mediated, neuropathic ulcers

14

What are the features common to all non-TB mycobacteria?

  • Environmental
  • No person to person transmission
  • Associated with impaired immunity
  • Poor response to anti TB regimen

15

What are the possible features of M avium?

  • Intracellular complex
  • Children - pharyngitis/cervical adenitis
  • Pulmonar y- underlying lung disease (resembles TB)
  • Disseminated - cytotoxics, lymphoma, etc
  • AIDS - disseminated multibacillary infection, mycobacteraemia (consider in HIV patients with long standing diarrhoea)

16

What are the possible features of M marinarum?

  • Fish tank granuloma
  • Single or clusters of papules/plaques
  • Swimming pool/aquarium owners

17

What are the possible features of M ulcerans?

  • Buruli ulcer
  • Insect transmission: tropics/Aus
  • Early - painless nodule
  • Usually slowly progressive, leading to ulceration, scarring and contractures
  • Seldom fatal, hideous deformity

18

What are the clinical features of pneumonia?

  • Inflammation of lung alveoli
  • Patients are sick
  • Can be lobar or bronchopneumonia
  • Fever, cough, pleuritic chest pain, SOB
  • OFten localising signs and abnormal CXR

19

How is pneumonia generally managed?

  • CURB65 for severity and to guide treatment
  • Supportive (O2, fluids)
  • Antibiotics

20

What are the clinical features of bronchitis?

  • Inflammation of medium sized airways, mainly in smokers
  • Cough with sputum most days for 3 months, for 2 or more consecutive years
  • Cough, fever, oincreased sputum production, increased SOB
  • CXR normal

21

What are some causative organisms of bronchitis?

Viruses

S pneumoniae

H influenzae

M catarrhalis

22

How is bronchitis treated?

  • Bronchodilation
  • Physio
  • +/- antibiotics

23

What are the characteristics of S pneumoniae pneumonia?

  • Rusty coloured sputum
  • Usually lobar on CXR
  • Vaccinate at risk groups
  • Gram positive diplococci

24

What are the characteristics of H influenza pneumonia?

  • Smoking
  • COPD
  • Gram negative cocco bacilli

25

What are the characteristics of M catarrhalis pneumonia?

  • Smoking
  • Gram negative coccus

26

What are the characteristics of S aureus pneumonia?

  • Recent viral infection
  • EMQs: post influenza infection +/- cavitation on CXR
  • Gram positive cocci ; grape bunch clusters

27

What are the characteristics of K pneumonia pneumonia?

  • Alcoholism
  • Elderly
  • Haemoptysis
  • Gram negative rod
  • Enterobacter

28

What are the classical causes of pneumonia?

  • S pneumonia
  • H influenza
  • M catarrhalis
  • S aureus
  • K pneumonia

29

What are the atypical causes of pneumonia and what are some clues that point to them?

  • Legionella pneumophila - travel, air conditioning, water towers, hepatitis, low sodium
  • Mycoplasma pneumonia - common - systemic symptoms, joint pain, cold agglutinin test, arythema multiforme, risk of SJS and AIHA
  • Chlamydia pneumonia - hard to diagnose, TWAR agent
  • Chlamydia psittaci - birds
  • (Bordatella pertussis - whooping cough in the unvaccinated, usually travelling communtiy in EMQs)
  • (TB)

30

How do you diagnose and treat atypical causes of pneumonia?

  • No signs on chest exam or signs not keeping with CXR
  • May have extra pulmonary features e.g. hepatitis, low sodium
  • Don't respond well to penicillin as they don't have a cell wall
  • Use macrolides and tetracyclines

31

What organism causes respiratory tract infection in the following groups:

  • HIV
  • Neutropenia
  • BMT
  • Splenectomy
  • Cystic fibrosis

 

  • HIV - P jiroveci, TB, cryptococcus neoformans
  • Neutropenia - fungi - aspergillus spp
  • BMT - aspergillus and CMV
  • Splenectomy - encapsulated organisms - H influenza, S pneumonia, N meningitidis
  • Cystic fibrosis - pseudomonas aeruginosa, Burkholderia cepacia (v high mortality)

32

How do you diagnose the causative organism of pneumonia?

  • Urine antigen tests in severe CAP for S pneumoniae, legionella
  • Antibody tests - paired serum samples
    • At presentation and 10-14/7
    • Rise in Ab level over time
    • Most useful for difficult to culture ones (Chlamydia, legionella)
  • Immunofluorescence - antibody labelled with fluorescent dye - used in virology
  • PCP - also detected by silver stain in cytology lab: boat shpaed organisms
  • HAP - >48 hours into hospital stay without previous infection
  • BAL to differentiate URT and LRT microbes

33

How do you treat classical community acquired pneumonia?

  • Mild-moderate: amoxicillin or macrolide (5-7 days)
  • Moderate-severe: clarithromycin and coamoxiclav/cefuroxime (2-3 weeks)

 

34

How do you treat atypical community acquired pneumonia?

  • PRotein synth antibiotics - macrolide or tetracycline
  • Some hospitals use clarithromycin but this interacts with warfarin

35

How do you treat the various kinds of hospital acquired pneumonia?

  • 1st line - ciprofloxacin +/- vancomycin
  • 2nd line/ITU - piptazobactam and vancomycin
  • Aspiration: cefuroxime and metronidazone

36

How do you treat legionella pneumonia?

Macrolide and rifampicin

37

How do you treat staph aureus pneumonia?

Flucloxacillin

38

How do you treat pseudomonas spp pneumonia?

Piperacillin +/- tazobactam (tazocin) or ciprofloxacin +/- gentamicin

39

How do you treat MRSA pneumonia?

Vancomycin

40

Which STIs cause discharge?

  • Gonorrhoa
  • Chlamydia
  • Trichomonas
  • Candida
  • BV

41

Which STIs cause ulceration?

  • Syphilis
  • HSV
  • LGV
  • Chancroid
  • Donovanosis

42

Which STIs cause rashes, lumps or growths?

  • Genital warts - HPV
  • Molluscum contagiosum
  • Scabies
  • Pubic lice

43

What are the causes of genital ulcers and what distinguishes them?

  • Painful: herpes > chancroid
  • Panless: syphilis >lymphogranuloma venereum (LGV), granuloma inguinale

44

What kind of bacteria is Neisseria gonorrhoeae?

Obligate intracellular gram negative diplococcus

45

What does gonorrhoea cause in neonates?

Ophthalmia neonatorum (neonatal conjunctivitis) if left untreated in mother as passes to child in birth canal

46

What happens to patients with complement deficiencies who get gonorrhoea?

Can get disseminated gonococcal infection, causing septicaemia, rash +/- arthritis

47

How do you diagnose gonorrhoea?

  • Smears: urethral (95% sensitivity), rectal (20% sensitivity)
  • Culture from these is gold standard

48

How do you treat gonorrhoea?

  • Ceftriaxone IM - 250 mg single dose OR
  • Cefixime PO - 400mg single dose
  • If resistant, use spectinomycin IM - 2g single dose

49

What are the features of non gonococcal urethritis in men?

  • Most common STI in Europe
  • Mucoid/mucopurulent discharge

50

What is post gonococcal urethritis in men and how is it prevented?

  • Urethrtisi following gonorrhoea Rx
  • Prevented by concomitant Rx with a tetracycline

51

Who gets rectal proctitis?

MSM

52

What are the features of mucopurulent cervicitis?

Erythema and oedema, vaginal leakage; lots of causes but commonly GC

53

What is the most common cause of female infertilty in Europe?

PID (salpingitis) - ascending infection e.g. from gonorrhoea or chlamydia

54

What kind of bacteria is chlamydia?

Obligate intracellular pathogen which cannot be cultured on agar.  Gram negative.

55

Who gets chlamydia?

Younger people - 10% of UK under 25s are affected

56

How commonly is chlamydia asymptomatic?

50% of men, 80% of women

57

What is the growth cycle of chlamydia?

Exists in 2 forms:

  • Elementary bodies, stable, extracellular
  • Reticulate particles, intracellular, metabolically active

58

Which serovars of chlamydia cause which diseases?

  • A, B, C: trachoma (infection of the eyes which can cause blindness)
  • D-K: genital chlamydia  infection, opthalmia neonatorum

59

What are the possible complications of chlamydia infection?

  • PID
  • Increased risk of ectopic
  • Chronic pelvic pain
  • Reiter's syndrome
  • Ophthalmia neonatorum
  • Tubal factor infertility
  • Increased risk of endometriosis
  • Epididymitis
  • Adult conjunctivitis

60

How do you diagnose chlamydia?

  • NAATs: nucleic acid amplification tests
  • Gold standard
  • High sensitivity and specificity

61

How do you treat uncomplicated chlamydia infection and what are the considerations?

  • Azithromycin 1g (4 capsules) stat or doxycycline 100mg BD 7/7
    • Side effects: nausea and vomiting, photosensitivity
    • Contraindicated in pregnancy: disturbs bone growth, causes tooth discolouration
  • Erythromycin 500mg QDS 7/7 or 500mg BD 2/52 (side effects: GI problems)

62

What causes lymphogranuloma venereum and where is it common?

Lymphatic infection with chlamydia trachomatis serovars L1, L2, and L3.

Endemic in parts of the developing world and more recently MSM in the developed world.

63

What are the stages of LGV?

  1. Early LGV - primary stage 3-12/7
  2. Early LGV: secondary stage 2-25/52
  3. Late LGV

64

What are the features of early LGV in the primary stage?

  • Genital ulcer: painless, non indurated
  • Balanitis, proctitis, cervicitis

65

What are the features of early LGV in the secondary stage?

  • Inguinal buboes : painful, 2/3 unilateral, may rupture
  • Fever, malaise, rarely hepatitis, meningo-encephalitis, pneumonitis, proctocolitis, hyperplasia of lymphoid tissue

66

What are the features of late LGV?

  • Inguinal lymphadenopathy
  • Abscess formation
  • Genital elephantiasis
  • Genital ulcers
  • Frozen pelvis
  • Rectal strictures
  • Perirectal abscesses and fistulae
  • Lymphorroids

67

What are the features of the current LGV outbreak?

Rectal symptoms (pain, tenesmus, bleeding, mucous discharge); proctitis O/E

68

How do you diagnose LGV?

  • NAAT (currently unlicensed)
  • If positive sent to ref lab at central HPA
  • Confirmation of C trachomatis by real time PCR on 2 platforms
  • Genotypic identification of L1, L2 or L3 serovar

69

How do you treat LGV?

  • Tetracyclines: doxycycline 100mg BD for 21/7
  • Erythromycin 500mg QDS for 21/7 or erythromycin 1g weekly for 3/52

70

What is the causative organism of syphilis and what kind of organism is it?

Treponema pallidum - obligate gram negative spirochaete

71

Who gets syphilis?

Most cases are in HIV positive people - often coinfected with HCV or another STI, rising in the UK

72

How is syphilis diagnosed?

Treponemes can be seen in primary lesions by dark ground microscopy.  Can be detected with multiplex real time PCR.  Antibody detection is the diagnostic method of choice

73

What are the features of non-treponemal tests for syphilis?

  • Detect non specific antigens
  • CDRL slide test detects lipoidal antibody on both host and treponemal cells
  • Reagents contain cardiolipin, lecithin an cholesterol; can get biological false positives
  • RPR = modified VDRL test
    • Positive indicates treponemal infection
    • Useful in primary syphilis
    • Titre falls in response to treatment so can be used to monitor response

74

What are the treponemal tests for syphilis?

  • Detects antibodies against specific antigens from T pallidum
  • E.g.:
    • Enzyme immunoassay
    • Fluorescent treponemal antibody
    • T pallidum haemagglutination test
    • T pallidum particle agglutination test
  • More specific than non treponemal test
  • Remians positive for years despite effective Tx

75

What are is the course of disease of syphilis?

  1. Primary - 1-2 weeks after transmission
  2. Secondary - 1-6/12 after infection
  3. Latent
  4. Tertiary - years/decades later

76

What are the features of primary syphilis?

  • Macule -> papule -> indurated painless genital ulcer appearing 1-12 weeks following transmission
  • Often solitary
  • May persist for 4-6 weeks (chancre)
  • Clean base with serous exudate
  • Regional adenopathy

77

What are the features of secondary syphilis?

  • Systemic bacteraemia: low grade fever, malaise, symmetrical non pruritic maculopapular rash on back, trunk, arms, legs, palms, soles, face, 1-6/12 following infection
  • Mucosal lesions, uveitis, choroidoretinitis, alopecia, 'snail track' oral ulcers, condyloma cuminate (genital warts)
  • Neurological involvement: aseptic meningitis, cranial nerve palsies, optic neuritis, acute nerve deafness

78

What are the clinical features of latent syphilis infection?

No obvious signs but serological infection (asymptomatic infection)

79

What are the features of tertiary syphilis?

  • Gumma (Granuloma): rare, 2-40 years later, skin, bone, mucosa, spirochaetes, scanty-DTH rection
  • Cardiovascular: 10-30 years later, uncomplicated and complicated aortitis, +++ spirochaetes, +++ inflammation
  • Neurosyphilis: most common in HIV +ve, 20-30 years later, meningovascular, general paresis of the insane, tabes dorsalis, gumma, spirochaetes in CSF, small vessel vasculitis, Argyll-Robinson pupil (accommodates but doesn't react)

80

What is the treatment for syphilis and what is a caution to be aware of?

  • Single IM dose of benzathine penicillin
  • Doxycycline if allergic
  • Monitor RPR, need to see four-fold reduction to say successful
  • NB: Jarish Heimer reaction: fever, headache, myalgia, sometimes exacerbation of syphilitic smyptoms
    • Common, develops within hours of Abx and clears within 24h

81

How does congenital syphilis occur and what are the features?

  • May occur during pregnancy or birth
  • Often develop features over the first couple of years including hepatosplenomegaly, rash, fever, neurosyphilis and pneumonitis
  • Late congenital syphilis can occur in 40%

82

What causes chancroid, what does it look like and how do you diagnose it?

  • Haemophilus ducreyi - gram negative coccobacillus (like Hib)
  • Tropical ulcer disease mainly in Africa; rare in UK
  • Often multiple ulcers, frequently painful
  • Diagnosis: culture (chocolate Agar), PCR

83

What causes Donovanosis, where is it common, what does it look like, and how is it diagnosed and treated?

  • Klebsiella granulomatis - gram negative bacillus
  • Africa, India, PNG, Australian aboriginal communities
  • Large, expanding ulcers that start as a papule or nodule that breaks down; beefy red appearance
  • Diagnosis: Giemsa stain of biopsy or tissue crush, Donovan bodies
  • Treat with azithromycin

84

How do enteric pathogens spread to cause STIs and which commonly do so?

  • Oro-anal contact
  • Shigella
  • Salmonella
  • Giardia (protozoan)
  • Occasionally others e.g. Strongyloidesrre

85

What causes trichomoniasis, what are its features and how is it diagnosed and treated?

  • Caused by T vaginalis (flagellated protozoan)
  • Diagnosis: wet prep microscopy, PCR
  • Asymptomatic or urethritis in men
  • Discharge in women
  • Associated with increased risk of HIV acquisition
  • Treat with metronidazole

86

What causes BV?

  • Abnormal vaginal flora, polymicrobial, low lactobacilli
  • Discharge, odour
  • Sexually associated not transmitted
  • May be associated with hygiene practices

87

How is BV diagnosed?

  • Microscopy of gram stain
  • Raised pH
  • Whiff test
  • Clue cells

88

What obstetric complication is BV associated with?

Preterm delivery

89

What causes candidasis, what are teh features and how is it treated?  What causes recurrence?

  • Usually candida albicans (a yeast)
  • If symptomatic: white discharge, itching, soreness, redness
  • Commonly vulvovaginitis in women, balanitis in men
  • Not sexually transmitted - can be a normal part of flora
  • Treated with topical or oral antifungals e.g. clotrimazole, fluconazole
  • Recurrence may be associated with immunodeficiency or hygiene practices

90

What causes molluscum contagiosum and how does it appear/spread in adults and children?  How is it treated?

  • Pox virus - dsDNA
  • Adults: causes genital lesions, spread by sexual contact
    • Facial molluscum in an adult is HIV until proved otherwise
    • Giant lesions in immunocompromised
  • Children: hands and face, spread by skin to skin contact
  • Treatment is destructive with cryotherapy if wanted

91

What's the difference between a yeast and a mould?

Yeast usually unicellular, mould multi, but some fungi exist as both e.g. yeast during infection, mould in nature

92

How do you diagnose a superficial fungal infection?

Woods lamp

93

What causes tinea and what varieties are common?

Dermatophyte infection e.g. Trichophyton rubrum.  E.g. athlete's foot, ringworm

94

What causes pityriasis and what forms are there which are fungal infections?

Malassezia globosa/furfura.  Seborrhoeic dermatitis, T. versicolor (depigmetnation in those with darker skin).

95

In whom are candida infections deep-seated and how would you diagnose this?

Immunocompromised.  Diagnose with culture, mannan, antibodies

96

How does deep seated aspergillus infection present and how is it diagnosed?

Spectrum from allergy to invasion, presents as a pneumonia in the immunocompromised in particular with high mortality.

Diagnosis: ELISA, PCR, beta-glucan test

97

How does deep seated cryptococcus infection present and how is it diagnosed?

In immunocompromised, especially HIV, causes meningitis with (in HIV) insidious onset.

Diagnosis: cryptococcal antigen in serum/CSF

98

What's an example of a polyene antifungal, what does it target and what's an indication for its use?

E.g. amphotericin.  Targets cell membrane integrity.  Used for yeasts

99

What's an example of a azole antifungal, what does it target and what's an indication for its use?

E.g. fluconazole.  Targets cell membrane synthesis.  Used for yeasts

100

Terbinafine - what does it target and what's an indication for its use?

Targets cell membrane.  Used for mould vs dermatophyte

101

What is the target of flucytosine?

Fungal DNA synthesis

102

What's an example of an echinocandin antifungal, what does it target and what's an indication for its use?

E.g. capsofungin.  Targets the cell wall, used for yeast (less toxic side effects)

103

How do you treat cryptococcal meningitis and invasive fungal infection?

Amphotericin B

104

What are the common features of HSV1 and HSV 2?

  • Both neurotropic
  • dsDNA
  • No animal reservoir
  • Persistent latent phase in DRG
  • Lytic infection of fibroblasts and epithelial cells
  • Transmitted via mucocutaneous contact

105

What are the characteristics of oral HSV infection?

  • Incubation 2-12/7
  • Severe painful ulceration, tendency to coalesce, erythematous base
  • Fever and submandibular lymphadenopathy
  • DDx: herpangina (Coxsackie A)

106

What are the characteristics of genital HSV infection?

107

What are the characteristics of ocular HSV infection?

  • Herpetic keratitis - unilateral/bilateral conjunctivitis and pre-auricular LNs
  • Acute retinal necrosis if immunocompetent
  • If immunosuppressed, progressive outer retinal necrosis (PORN) - also caused by VZV, EBV, CMV

108

When do neonates get herpes infections and when is the greated risk?  How should it be managed?

  • Primary infections (HSV1+2) in 1st and 2nd trimesters not associated with risks to foetus
  • Primary infection in 3rd trimester associated with greatest risk of transmitting infection
  • Treatment: oral/iv aciclovir 6 weeks before EDD; C section if primary
  • Transmission is most often at delivery and more rarely in utero
  • Postnatally: mum with cold sores kissing baby

109

What are the features of neonatal herpes infection?

  • Foetal loss
  • Skin, eye, mouth (SEM) lesions 7-12/7; long term ocular and neural sequelae
  • Disseminated disease +/- vesicles (4-11/7 post-partum); risk of fulminant hepatitis or multi organ failure 80%
  • Neurological disease +/- SEM 17-18/7 post partum; 50%

110

What are the features of herpes encephalitis?

  • 90% HSV-1
  • Flu like prodrome 2/52, focal neurology, fever, confusion, behavioural change, decreased consciousness, seizures, nausea and vomiting, coma, death
  • Half of cases in patients >60 years

111

What is Mollaret's meningitis?

Benign recurrent aseptic meningitis usually HSV-2

112

What are some investigation findings in herpes encephalitis?

  • Fronto temporal and parietal lobes - lesions on CT/MRI
  • CSF: lymphocytic pleiocytosis, cytology may be normal, normal glucose, high protein
  • Negative PCR doesn't exclude

113

How is herpes encephalitis treated?

  • IV aciclovir stat
  • Don't want for test results
  • 10mg/kg tds then oral ACV for a total of 2-3/52

114

What skin infections can be caused by herpes simplex infection?

  • Herpes gladiatorum (scrum pox) - painful blisters, inguinal lymphadenopathy, rugby players
  • Herpetic whitlow (painful red finger)
  • Erythema multiforme
  • HS dermatitis
  • Eczema herpeticum
  • Zosteriform (painless)

115

How do you diagnose herpes skin infections?

Clinical, culture, ELISA, swab PCR (or blood PCR if disseminated)

116

What is the treatment for herpes skin infections?

  • Actclic nucleoside analogues: aciclovir, valaciclovir, famiciclovir
  • Ganciclovir (pro drug valganciclovir)
  • Foscarnet (pyrophosphate analogue)
  • Cidofovir

117

What are the characteristics of the varicella zoster virus?

  • dsDNA
  • Droplet spread
  • Viral replication in lymph nodes then in liver and spleen then vesicular rash (rash ~48 hours after infection)

118

What are the clinical features of chickenpox?

  • Fever, malaise, headache
  • Followed by characteristic crops of rash (dew on a rose petal)
  • Lesions scab after 1/52 (no longer contagious)

119

What are the possible complications of chickenpox?

  • Scarring, pneumonitis, haemorrhage, eye involvement
  • Reye's syndrome
  • Neurological: acute cerebellar ataxia, Guillain Barre, Ramsay Hunt syndrome - facial palsy and vesicles in ear - geniculate ganglion of CN8 (hearing loss and vertigo)
  • Encephalitis (vasculopathy)
  • Post-herpetic neuralgia

120

How do you diagnose varicella zoster?

  • Exam - vesicles
  • Cytology - scrapings for multinucleated giant cells (Tzanck cells)
  • Immunofluorescence cytology - cells from vesicles
  • PCR - especially if the rash is old, CNS and ocular disease

121

What are the features of varicella infection in pregnancy?

  • Congenital varicella snydrome; risk os low in early pregnancy (0.4%) if <12/40, 2% if 12-20/40; scarring, hypoplastic limbs, coritcal atrophy, psychomotor retardation, choreoretinitis, cataracts
  • Risk of disseminated varicella infection if occurs +/- 7 days from delivery

122

How do you treat varicella zoster and who should be treated?

  • Aciclovir 800mg PO tds 7/7 or valaciclovir 1g tds
  • Indications:
    • All adults with chickenpox (at risk of complications), neonates, immunocompromised, eye involvement, all patients presenting with pain
  • Post exposure prophylaxis: VZIG (immunocompromised, pregnant)
  • Live vaccine against varicella - attenuated Oka strain (contraindicated in pregnancy)

123

What are the features of shingles?

  • VZV reactivation 
  • Caused by stress, decreased immunity (compromised by something or age >50)
  • Painful rash in a specific dermatome

124

How is shingles treated and who should be treated?

  • Aciclovir 800mg PO 5x daily or farniciclovir 250mg PO tds or valaciclovir 1000mg po tds
  • Topical eye drops and oral for ophthalmic
  • Treatment should be for smyptomatic children or (if <24 hours rash) healthy adult smokers, chronic lung disease, of >20/40 gravid
  • PEP 7-9/7 for immunocompromised

125

How many CMV infections are asymptomatic?

80%

126

Which herpes viruses are epitheliotropic?

CMV and roseola virus

127

What are the features of congenital CMV infection?

  • IUGR/jaundice/hepatosplenomegaly/chorioretinitis/encephalitis including microcephaly, thrombocytopenia and death
  • Late progressive sensorineural deafness, impaired IQ
  • Cytomegalic inclusion disease 13%

128

What is CMV mononucleosis similar to clinically?

EBV

129

What are the features of CMV infection in the immunocompromised?

  • Fever, hepatitis
  • GI - colitis
  • Retinitis - AIDS
  • Pneumonitis - BMT patients
  • Bone marrow suppression
  • Addisons disease
  • Radiculopathy

130

Which cells does CMV infect?

  • Macrophages
  • Endothelial cells
  • B + T lymphocytes
  • Bone marrow stem cells

131

How is CMV infection diagnosed?

  • Blood PCR
  • Histopathology
  • Tissue immunofluorescence
  • Cell culture in human fibroblasts (owl's eye inclusions), serology
  • Immunocompetent: serology - CMV IgM and IGG (IgG low avidity if primary infection)
  • Immunocompromised: serology has limited diagnostic value
  • Heterophile Abs: Paul Bunnel/monospot - clumping of sheep RBCs

132

What is the treatment for CMV infection?

Ganciclovir (valganciclovir - prodrug)

Cidofovir

Foscarnet

133

What are the features of roseola virus infection?

  • Causes roseola infantum (=exanthum subitum, Sixth disease)
  • 3/7 fever, then transient rash
  • Abx often given for fever then they get the rash and the child is branded penicillin allergic
  • Most common cause of febrile convulsions
  • Latent in monocytes/macrophages
  • Can cause pneumonitis, hepatitis, encephalitis in BMT

134

How is roseola virus infection diagnosed and treated?

  • Dx: blood PCR
  • Rx: ganciclovir, foscarnet, cidofovir

135

What infections can EBV cause?

  • Infectious mononucleosis
  • Burkitt's lymphoma
  • Nasopharyngeal cancer
  • Post-transplant lympho-proliferative disease

136

What are the features of infectious mononucleosis and how is it diagnosed?

  • Triad of fever, pharyngitis, lymphadenopathy (incubation 4-6/52 + maculopapular rash)
  • Dx: blood film, monospot agglutination, EBV antibodies

137

What is the problem with EBV causing post-transplant lymphoproliferative disease and how is this managed?

  • Predisposes to lymphoma
  • Treatment: reduce immunosuppression and give rituximab (anti CD20 monoclonal Ab)

138

How is HHV8 transmitted and what is it associated with?  How is it treated?

  • Genitally transmitted
  • Kaposi's sarcoma
  • Primary effusion lymphoma (associated with EBV coinfection)
  • Castleman's disease (non cancerous growth in lymph nodes)
  • Treated with ganciclovir and foscarnet

139

Which herpes viruses are lymphotropic?

EBV and HHV8

140

What defines pyrexia of unknown origin?

>38.3 fever on several occasions persisting for >3/52 without diagnosis despite >1/52 of intensive investigations

141

What should the workup for PUO include?

  • Observe fever and if possible withhold therapy until a diagnosis is reached
  • Febrile neutropenia: empirical treatment should be started after taking samples for culture unless pt is unstable; try to identify source to guide Abx choice
  • Vasculitis screen: pANCA, cANCA, Rho, La (rheum review if arthritis)
  • Bence jones protein/electrophoresis (myeloma)
  • Dip urine/casts
  • Familial diseases: FMF, Fabry's, cyclic neutropenia
  • Fever in returning traveller

142

What are the characteristisc of 'classical' PUO and what are some examples of causes?

  • As PUO + 3/7 in hospital, or >3 OP visits with ambulatory investigations
  • Infections
  • Neoplasms
  • Connective tissue diseases
  • Undiagnosed conditions
  • Abscesses, endocarditis, TB, complicated UTI

143

What defines hospital acquired PUO and what are some of its causes?

  • PUO develops in a patient after >24 hours in hospital
  • Surgery
  • Drugs (vancomycin, penicillins, serotonergics)
  • Medical devices (catheter, IV line bacteraemia)
  • LRTI (including ventilator associated in ITU)
  • C diff colitis
  • Immobilisation

144

What defines neutropenic PUO and what are some of its causes?

  • Fever concomitant with neutropenia (<500/uL) and subsequent lack of cellular response - an emergency
  • Chemotherapy
  • Haematological malignancies
  • Look for conditions that require neutrophils (e.g. fungal, aspergillus, bacterial sepsis)

145

What are some of the causes of HIV associated PUO?

  • Seroconversion
  • TB
  • Kaposi's sarcoma
  • Bacterial
  • Disseminated MAI
  • PCP
  • CMV
  • Cryptococcus
  • Toxoplasmosis
  • Lymphoma
  • Histoplasmosis
  • Drug fever

146

What are some potential causes of fever in the returning traveller?

  • Malaria - ask about prophylaxis
  • Dengue - rash
  • Typhoid
  • Rickettsia
  • Bacterial diarrhoea
  • UTI
  • Pneumonia
  • HIV seroconversion
  • Brucella
  • Viral haemorrhagic fever (ebola/lassa/etc)

147

What is the causative organism of typhoid?

Salmonella typhi and paratyphi - anaerobic gram negative bacillus

148

What are the clinical features of typhoid?

  • Enteric fever infecting Peyer's patches
  • Transmitted by food and water
  • Fever, headache, abdo pain
  • Diarrhoea or constipation
  • Rose spots (30%)
  • Relative bradycardia (non specific, <50%)
  • Hepatosplenomegaly (50%)
  • Chronic carriage: gallstones, immunosuppression

149

How is typhoid diagnosed and managed?

  • Dx: history, blood cultures, stool
  • Management:
    • IV fluid
    • Oral or IV antibiotics
    • Notifiable disease

150

What transmits malaria?

Female anopheles mosquito. Bites at night, attracted by heat and carbon dioxide.  Needs blood proteins for eggs.

151

What are the pathological features of P falciparum infection and what's the treatment for it?

  • Very severe - >2% parasitaemia
  • 48hr (tertian) rhythm
  • Blood film: young trophozoits (rings) in the absence of mature trophozoites and schizonts; crescent shaped gametozytes
  • If stable, quinine 7/7 then doxy/clinda/fansidar

152

What are the pathological features of P vivax infection and what's the treatment for it?

  • Chronic liver stage (hypnozoites)
  • 48 hr rhythm
  • Blood film: Schüffner's dots, >20 merozoites/schizonts
  • Treatment: chloroquine, then primaquine

153

What are the pathological features of P ovale infection and what's the treatment for it?

  • Chronic liver stage (hypnozoites)
  • 48 hour rhythm
  • Blood film: schüffner's dots
  • Treatment: chloroquine then primaquine

154

What is the severity and rhythm length of P malariae, and what morphology is it similar to?

Benign, 72 hr (quartan) rhythm.  Similar to P knowlesi

155

What are the investigation findings in falciparum malaria?

  • Thick film - find parasitaemia
  • Thin film - find the species
  • WCC rarely raised
  • 70% have low platelets
  • 50% have deranged LFTs
  • 30% have anaemia

156

How is malaria treated?

  • MILD
    • Quinine + doxy/clinda
    • Malarone (Atovoyuone/proguanil)
    • Riamet (artemether and lumefantrine)
  • SEVERE
    • ACT or
    • quinine + doxy/clinda

 

Remember, G&Ts are good for you (quinine) + doxyCYCLIne - can get malaria from CYCLIng in the tropics

157

What are the features of severe malaria?

  • Impaired consciousness or seizures
  • Renal impairment
  • Acidosis (pH < 7.3)
  • Hypoglycameia <2.2
  • Pulmonary oedema or ARDS
  • Anaemia <8
  • Spontaneous bleeding/DIC
  • Shock (BP<90/60)
  • Haemoglobinuria (without G6PDD)
  • Other indications for parenteral therapy: parasitaemia >2%, pregnancy, vomiting

158

What are the features of clostridium botulinum and how do you treat it?

  • Canned and vacuum packed foods e.g. honey, beans
    • BOTulinum - foods that a roBOT has packed
  • Ingestion of preformed toxin (inactivated by cooking)
  • Blocks Ach release from peripheral nerves -> paralysis
    • CLOSTRidium - descending paralysis makes you feel CLOSTR-ophobic (I know that's misspelled)
  • Descending paralysis unlike GBS
  • Treat with antitoxin

159

What are the features of clostridium perfringens?

  • Reheated meats
  • Superantigen enterotoxin (bind directly to TCR and MHC outside peptide binding site -> massive cytokine production by CD4
    • PERFringens - it's the PERFect toxin
  • Systemic toxicity and suppression of adaptive response
  • Acts on small bowel, 8-16 hours incubation
  • Watery diarrhoea and cramps lasting 24 hours
  • Also causes gas gangrene

160

What are the features of bacillus cereus infection?

  • Reheated rice (spores germinate)
  • Sudden vomiting
  • Superantigen - short incubation (4 hrs)
  • Increased cAMP - long incubation (18 hours)
  • Watery non bloody diarrhoea

161

What are the features of staph aureus GI infection?

  • Main virulence factor - protein A catalase, coagulase positive
    • Staph Aureus -> protein A catalase
  • Appears in tetrads, clusters on gram stain
  • Beta haemolytic on blood agar
  • Produces enterotoxin, an exotoxin that acats as a superantigen releasing IL-1 and IL-2 -> prominent vomiting, and watery non bloody diarrhoea

162

What kind of bacteria is E coli and what are its subspecies causing GI infection?

  • Gram negative enterobacteriae - think E coli - gram nEgative, Enterobacteriae
    • Facultative anerobes, oxidase negative
  • ETEC - Toxigenic, Traveller's diarrhoea
    • Heat labile LT stinulates adenyl cyclase and cAMP
    • Heat stable ST stimulates guanylate cyclase
    • Acts on jejunum, ileum, not on colon
  • EIEC - Invasive dysentery
  • EHEC - Haemorrhagic, caused by verotoxin
  • HUS - anaemia, thrombocytopenia, renal fialure (0157:H7 toxin)
  • EPEC - infantile diarrhoea (Paeds)

163

How can you treat E coli GI infection and what are the sources?

  • Human faeces, contaminated food/water
  • Self limiting but can treat with ciprofloxacin

164

What are some clues that a bacteria is Salmonella?

  • O, H, V antigens
  • TSI agar
  • XLD agar
  • Selenite A broth (think broth like chicken broth, salmonella is from chickens)

165

What are the features of salmonella typhi/paratyphi infection and how is it treated?

  • Only transmitted by humans
  • Multiplies in Peyer's patches
  • 3% are carriers (in gallbladder)
  • Slow onset fever + constipation, relative bradycardia, splenomegaly, rose spots, anaemia, leukopenia
  • Cefriaxone or ciprofloxacin
    • Cs - like Chickens - again, salmonella from chickens (not in this case)

166

What are the features of salmonella enteritides infection and how is it treated?

  • Poultry, eggs, meat
  • Invades small and large bowel
  • Bacteraemia infrequent
  • Self limiting non bloody diarrhoea
  • Treat with cef or cipro if needed (AGAIN - Cs - Chickens)

167

How are the features of shigella infection and how is it treated?

  • Mainly distal ileum and colon -> mucosal inflammation, fever, pain, bloody diarrhoea
  • Shiga enterotoxin
  • Avoid antibiotics but cipro if needed

168

What are the features of yersinia enterocolitis infection?

  • Enterocolitis, mesenteric adenitis with necrotising granulomas, associated reactive arthritis and erythema nodosum
    • YERsinia - YER gonna get autoimmune type features
  • Transmitted via food contaminated with domestic animals' excreta
    • yerSINia - have you SIN (seen?) my lovely cat
  • Prefers 4C - 'cold enrichment'
    • Animals like to be outside

169

Which type of GI infecting bacteria are:

  • Anaerobic
  • Aerobic
  • Lactose fermentors
  • Non lactose fermentors

Which type of GI infecting bacteria are:

  • Anaerobic - clostridium - (if you're CLOSTrophobic there isn't much air)
  • Aerobic - Bacillus cereus (cereus-ly respiring) and staph aureus (often on skin -> lots of air on skin)
  • Lactose fermentors - E coli - cows?  cows make milk?
  • Non lactose fermentors - Salmonella (chickens don't make milk), Shigella (kinda sounds like salmonella), Yersinia enteroclitis (weird one)

170

What are the features of C diff infection and how is it treated?

  • 2 exotoxins (A + B)
  • Pseudomembranous colitis
  • Caused by antibiotics - cephalosporins, fluoroquinolones
  • Treat with metronidazole, vancomycin PO
    • Think it's a really serious infection so you need to VANquish it (VANComycin), like with someone powerful like TRON (meTRONidazole)

171

What is vibrio cholera like as a bacteria?  What are the features of cholera infection?

  • Comma shaped, late lactose fermentors, oxidase positive
    • Comma shaped, Cholera.  Late lactose fermentor - think developing countries get cholera, still developing ability to lactose ferment.  Oxidase positive.... something like oxygen, fresh air, windows, vibrio sounds a bit like a window maybe?
  • Rice water stool
  • Tranmitted by human faeces e.g. in shellfish
  • Increased cAMP opens Cl- channel at apical membrane of enterocytes -> efflux of Cl- to lumen (loss of H2O and electrolytes)
  • Massive diarrhoea without inflammation

172

What are the features of vibrio parahaemolyticus infection and how is it treated?

  • Ingestion of raw/undercooked seafood (common in Japan)
  • 3/7 diarrhoea whic his often self limiting
  • Doxycycline

173

What are the features of vibrio vulnificus infection and how is it treated?

  • Cellulitis in shellfish handlers
  • Fatal septicaemia with D+V in HIV positive patients
  • Doxy

174

What are the features of campylobacter jejuni infection and how is it treated?  What's it associated with?

  • Drinking unpasteurised milk, food e.g. poultry
  • Prodrome of headache and fever, abdo cramps, bloody (foul smelling) diarrhoea
  • Curved, S shaped, microaerophilic, oxidase positive, motile, sensitive to nalidixic acid (1st quinolone)
  • Assoc with GBS, Reiter's
  • Erythromycin or cipro if first 4-5/7

175

What are the features of listeria monocytogenes infection and how is it treated?

  • V or L shaped, beta haemolytic, aesculin positive, tumbling motility
  • Watery diarrhoea, cramps, headache, fever little vomiting
  • Perinatal infection, immunocompromised
  • Outbreaks of febrile gastroenteritis
  • Refrigerated food (unpasteurised dairy, vegetables)
  • Ampicillin, ceftriaxone, cotrimoxazole

176

What are the features of entamoeba histolytica infection and how is it treated?

  • EMG: MSM, food, water, soil
  • Motile torphozoite in diarrhoea
  • Non motile cyst in non-diarrhoeal illness
  • 4 nuclei and no animal reservoir
  • Colonises the colon
  • Makes a flask shaped ulcer on histology
  • Symptoms: dysentery, wind, tenesmus, chronic weight loss and RUQ pain due to liver abscess
  • Do stool microscopy
  • Metronidazole and paromomycin if luminal disease

177

What are the features of giardia infection?

  • Travellers, hikers, MSM, mental hospitals
  • Pear shaped trophozoite
  • 2 nuclei
  • Torphozoites/cysts found in stool
  • Ingesting cysts from faecally contaminate dwater
  • Malabsopriton of protein and fat -> foul smelling non bloody diarrhoea
  • Diagnose with ELISA string test
  • Metronidazole

178

What are the features of cryptosporidium parvum infection?

  • Infects the jejunum
  • Severe diarrhoea in the immunocompromised
  • Oocytes seen in stool by modified Kinyoun acid fast stain
  • Paromomycin, nitazoxanide in kids

179

Which bugs cause secretory diarrhoea?

  • Rotavirus <6 years
  • Adenovirus: types 40, 41 cause non bloody diarrhoea <2 years
  • Norovirus - adult outbreaks, vomiting
  • Poliovirus
  • Enteroviruses - coxsackie, ECHO

180

Which protozoa commonly cause GI infection?

  • Entamoeba histolytica
  • Giardia lamblia
  • Cryptosporidium parvum

181

What are the distinguishing features of these types of GI infection and what are the causative bugs?

  • Secretory diarrhoea
  • Inflammatory diarrhoea
  • Enteric fever

  • Secretory diarrhoea
    • No fever or low grade fever, no WBC in stool sample
    • Vibrio cholerae, ETEC, EaggEC, EPEC, EHEC
  • Inflammatory diarrhoea
    • Fever, WBCs in stool sample (neutrophils)
    • Campylobacter jejuni, shigella spp, non typhoidal salmonella serotypes, EIEC
  • Enteric fever
    • fever, WBCs in stool sample (mononuclear cells)
    • Typical salmonella serotypes, enteropathogenic yersinia spp, brucella spp

182

Which 3 antibiotics commonly predispose to C diff infection?

  • 3 Cs
  • Clindamycin (often used in penicillin allergic patients with cellulitis)
  • Cephalosporins
  • Ciprofloxacin

183

Which organisms commonly causethe following HAIs:

  • UTI
  • Bacteraemia
  • Surgical site infection

  • UTI
    • ESBL, catheters, commonly E coli but also Klebsiella, Proteus, Pseudomonas
  • Bacteraemia
    • MRSA, coagulase negative staph, E coli
  • Surgical site infection
    • MRSA, coagulase negative staph

184

What is the pathophysiology of prion disease?

  • Prion protein gene on Chr20 - predominantly expressed in CNS
  • Codon 129 polymprphism and specific PRNP mutations
  • Normal protein structure PrP but abnormal PrPsc abnormally folds into a beta sheet configuration and is protease/radiation resistant
  • Seed of PrPsc acts as a template which promotes irreversible conversion of PrP to insoluve PrPsc

185

How do you treat CJD?

  • Symptomatic: clonazepam
    • Myoclonus - valproate, levetiracetam, piracetam
  • Delaying prion 'conversion' - quinacrine, pentosan, tetracycline

186

What are the investigation findings in sporadic CJD?

  • Serial EEG - periodic triphasic changes
  • MRI - normal/highlighting basal ganglia
  • CSF: 14-3-3 protein positive
  • No PRNP mutations
  • Most cases 129 codon MM
  • Western blot PrPsc - types 1-3
  • Spongiform vaculoation and PrP amyloid plaques at post mortem

187

What are the investigation findings in variant CJD?

  • Non specific slow waves on EEG
  • Posterior thalamus highlighte don MRI - T2 (pulvinar sign)
  • CSF: 14-3-3, can be normal
  • No PRNP mutations
  • ALL cases aer 129 codon MM
  • Western blot PrPsc - type 4t from tonsillar biopsy (100% sensitive and specific)
  • PrPsc 4t detectable in CNS and lymphoreticular tissue, florid plaques at post mortem

188

What are the investigation findings in iatrogenic CJD?

  • No PRNP mutations
  • Most cases are 129 codon homozygous (MM or VV)
  • Types 1-3 on western blot PrPsc

189

What are the investigation findings in inherited CJD?

  • Non specific EEG
  • Sometimes high signal in basal ganglia on MRI
  • PRNP - mutations present and diagnostic
  • 129 codon homozygosity may mean earlier onset

190

What are the features of sporadic CJD?

  • 80% of CJD
  • Either somatic PRNP mutation or spontaneous conversion of PrPc to PrPsc and subsequent seeding
  • Rapid, progressive dementia with myoclonus, cortical blindness, akinetic mutism and LMN signs
  • Mean onset is 45-75 years and mean survival time is within 6/12 of symptoms starting

191

What are the features of variant CJD?

  • Exposure to bovine spongiform encephalopathy (BSE)
  • Younger age of onset, typically 30
  • Mean survival 14/12
  • Psych symptoms at first (anxiety, paranoia, hallucinations) followed by neuro symptoms (peripheral sensory symptoms, ataxia and myoclonus)
  • Later symptoms include chorea, ataxia, dementia

192

What are the features of iatrogenic CJD?

  • Inoculation with human prions most commonly from surgery
  • Progressive ataxia initially
  • Dementia and myoclonus later stages
  • Speed of progression depends on route of inoculation (CNS route fastest)

193

What are the features of kuru?

  • Exposure to human prions from cannabilistic feasts
  • Progressive cerebellar syndrome (death within 2 years) following 45 year incubation
  • Dementia is late or absent
  • Epidemic in 50s/60s

194

What are the features of inherited CJD?

  • 15% of CJD
  • Familial CJD, GSS, FFI, various atypical dementias
  • PRNP mutations
  • Gerstmann-Straussler-Scheinher syndrome
    • AD
    • Develops 20-60 years, mean survival 5 years
    • Dysarthria progressing to cerebellar ataxia ending in dementia
  • Fatal Familial Insomnia
    • Insomnia and paranoia progressing to hallucinations and weight loss
    • Then a mute period
    • Death 1-18/12 after start of symptoms

195

Which diseases do mice transmit?

  • Hantan viruses (fleas)
  • Lyme
  • Ehrlichia
  • Bartonella
  • Lymphocytic choriomeningitis

196

Which diseases do rats transmit?

  • Rabies
  • Leptospirosis
  • Lassa fever
  • Hantan viruses
  • Plague
  • Pasteruellosis
  • Haverhill fever (rat bite)

197

Which diseases do cats transmit?

  • Bartonellosis (cat scratch fever)
  • Leptospirosis
  • Q fever
  • Rabies
  • MRSA
  • Ringworm
  • Toxocariasis

198

Which diseases do dogs transmit?

  • Hydatid disease
  • Leptospirosis
  • Brucellosis
  • Q fever
  • Rabies
  • MRSA
  • Ringworm
  • Toxocariasis

199

Which diseases do small ruminants transmit?

  • Anthrax
  • Brucellosis
  • Q fever
  • Cryptosporidiosis
  • Enzootic abortion
  • Louping ill
  • Orff virus
  • Rift Valley fever
  • Toxoplasmosis

200

Which diseases do swine transmit?

  • Brucellosis
  • Leptospirosis
  • Erysipeloid
  • Cysticerocsis
  • Trichinella
  • HEV
  • Influenza A
  • Streptococcal sepsis

201

Which diseases do cattle transmit?

  • Anthrax
  • Leptospirosis
  • Brucella
  • Bovine TB
  • Anaplasmosis
  • Toxoplasmosis
  • E coli 0157
  • Rift Valley
  • Ringworm

202

Which diseases do birds transmit?

  • Psitticosis
  • Influenza
  • Cryptococcus
  • Influenza A
  • Poultry - salmonella, west nile

203

Which infections can you get from water sports?

  • Leptospirosis
  • HAV
  • Giardia
  • Toxoplasmosis
  • Mycobacterium marinum/ulcerans
  • Burkholderia pseudomallei
  • E coli

204

Which infections are commonly water borne?

  • Campylobacter
  • Salmonella
  • VTEC 0157
  • cryptosporidium

205

How is infective endocarditis treated?

  • Empirical
    • Prosthetic valve: vanc + gent + rif (VGR -> Vessels Got Rekt)
    • Native valve: acute -> fluclox (get things FLowing), indolent -> pen and gent
  • Strep viridans: benpen and gent (BEN's VIRIle, not a GENT)
  • MSSA endocarditis: fluclox for 4/52
  • MRSA endocarditis: vanc + gent/rif/fucidin
  • Enterococcal: ampicillin + gent

206

What are the indications for surgery in infective endocarditis?

  • >2 serious systemic embolus/high risk
  • Uncontrolled infection
  • Significant valve dysfunction
  • Lack of response to antibiotics
  • Local suppurative complication e.g. perivalvular abscess
  • Congestive heart failure
  • Prosthetic valve endocarditis

207

Which valves are commonly affected by infective endocarditis?

Mitral and aortic most commonly

Tricuspid in 50% ICDUs (S aureus or polymicrobial)

208

What are the causative organisms for subacute bacterial endocarditis, acute bacterial endocarditis, culture negative endocarditis and HACEK?

  • Subacute - low virulence Strep (often strep viridans)
  • Acute - S aureus, coagulase negative staph if prosthetic
  • Culture -ve - most commonly due to culture after antibiotics but can be aspergillus, brucella, coxiella, chlamydia, mycoplasma
  • HACEK: Haemophilus parainfluenzae, aggregatibacter/actinobacillus, cardiobacterium hominis, eikenella corrodens, kingella kingae

209

What kind of bacteria is brucella and where do you get it from?

  • Gram negative aerobic bacilli (facultative intracellular)
  • Inahaltion, skin or mucous membrane contat, consumtpino of contaminated food (milk.dairy), animal contact or environmental contamination, also lab acquired

210

What are the features of brucellosis & what are its complications?

  • Symptoms
    • Fever, clasically undulent which peaks in evening and normal by morning
    • Malaise
    • Rigors
    • Sweating
    • Myalgia
    • Arthralgia
    • Tiredness (incubation 3-4/52)
  • Signs:
    • Arthritis, spinal tenderness
    • Lymphadenopahty, splenomegaly, hepatomegaly
    • Epididymo-orchitis
    • Rarely jaundice, CNS abnormalities, cardiac murmur, pneumonia
  • Complications: endocarditis, osetomyelitis, occasionally meningo-encephalitis

211

How do you investigate and treat brucellosis?

  • Investigations
    • Serology - anti-O-polysaccharide antibody titres >1:160
    • WCC usually normal
    • Leucocytosis rare, significant number of patients are neutropenic
  • Treatment
    • 4-6/52 tetracycline or doxycycline combined with streptomycin
    • Or PO doxycycline and rifampicin 8/52

212

What is the pathognomonic feature of rabies encephalitis?  How do you test for rabies and how do you treat it?

  • Negri bodies
  • IFA for rabies antigen in brain tissue
  • Serology: neutralisation tests/ELISA for specific IgM
  • Treatment - rabies IgG post exposure

213

What kind of bacteria is Yersinia pestis and how do you treat plague?

  • Gram negative lactose fermenter
  • Streptomycin, doxycycline, gentamicin, chloramphenicol in meningitis

 

214

Which bacterium causes leptospirosis, what are the clinical features and how do you treat it?

  • L interrogans: Gram negative obligate aerobic motile spirochaete
  • High spiking temperature, headache, conjunctival haemorrhage, jaundice, malaise, myalgia, meningism, carditis, renal failure, haemolytic anaemia
  • Water exposure - 10-14/7 incubation
  • Treat with amoxicillin, eryhtromycin, doxycycline, ampicillin

215

What are the features of anthrax and how do you treat it?

  • Cutaneous - painless round black lesions with a rim of oedema
  • Pulmonary (Woolsorters disease): massive lymphadenopathy and mediastinal haemorrhage, pleural effusion and respiratory failure
  • Treat with cipro/doxy

216

What causes Q fever, what are its features and how do you treat it?

  • Coxiella burnetii
  • Looks like atypical pneumonia
  • Cattle/sheep infection
  • 2-5/52 post infection - fever ,dry cough, fatigue, pleural efufsion and diarrhoea with no rash
  • Treat with doxy

217

What causes lyme disease, what are the clinical features and how do you treat it?

  • Borrelia burgdorferi (spirochaete) - borne by ixodes tick
  • Early localised
    • Cyclical fevers, non specific flu like symptoms, erythema chronica migricans (bullseye rash)
  • Early disseminated
    • Malaise, lymphadenopathy, hepatitis, carditis, arthritis
  • Late persistent
    • Arthritis, focal neurology, neuropsychiatric disturbance, ACA (acrodermatitis chronic atrophicans)
  • Dx: biopsy edge of ECM and ELISA for lyme Abs
  • Treat: doxy 2-3/52 (also amoxicillin, cephalosporins)
    • If CNS issues give IV ceftriaxone 2-4/52
    • Post Rx few patients get ME type symptoms

218

Which types of leishmania cause what?

  • cutaneous - L major, L tropica (ulcer, Type IV reaction)
  • Diffuse cutaneous if immunodeficient
  • Mucocutaneous - L braziliensis - ulcers in mucous membranes later)
  • Visceral - L donovani, L infantum (L chagasi in south america) - abdo problems, weight loss
    • Leishmani donovani - invasion of reticuloendothelial system -> hepatosplenomegaly, BM invasion, later disfiguring dermal disease

219

When aer the peaks for the different kinds of influenza?

  • Influenza A (H1) - beginning of January
  • H1N1 - end of december
  • Influenza B - March

220

What antivirals can you use for influenza?

  • Amantadine - influenza A only
    • Targets M2 ion channel but a single AA mutation (S31N) in M2 gives resistance which is now in many flu A strains including H1N1
  • Neuraminidase inhibitors - oseltamivir (Tamiflu), Zanamivir (Relenza), Sialic acid
    • Effective only if given <48 hours after infection

221

What treatments are there for herpes viruses and when should you use them?

  • Aciclovir - HSV
  • Ganciclovir - CMV, EBV, HHV-6
    • If CMV is resistant to ganciclovir or severe side effects use foscarnet
  • Cidofovir - CMV retinitis
  • HSV that is genital, oral, encephalitis, disseminated - Act Very Fast:
    • Aciclovir (if serious IV immediately)
    • Valaciclovir
    • Foscarnet
  • Foscarnet/cidofovir for resistant herpes infectoin

222

How do you treat EBV?

  • Pegylated interferon alpha 2a (subcut)
  • Neucleos(t)ide analgoues e.g. entecavir, tenofovir
  • 1st line is IFN + Entecavir + tenofovir

223

How do you treat HCV?

PegIFN alpha 2b/2a + ribavirin

224

How do you treat respiratory viruses?

  • Influenza  NA inhibitors: Zanamivir (INH), oseltamivir (PO), amantadine (PO)
  • RSV/parainfluenza: ribavirin

225

What are the common bugs for surgical site infections and how do you treat them?

  • Staph aureus, E coli, pseudonomas, haemolytic strep
  • Treat with fluclox

226

Which bugs cause septic arthritis and how do you treat them?

  • Staph aureus (46%), then strep, less commonly various gram negatives like E coli
  • Treat: IV antibiotics (ceph or fluclox), MRSA - vanc and drain joint

227

Which organisms cause osteomyelitis and how do you treat it?

  • Staph aureus
  • Debride

228

Which bugs cause prosthetic joint infection and how do you treat it?

  • Staph, gram negatives
  • Treat - replace joint, single or second stage revision, and use antibiotic impregnated cement

229

Which bugs cause UTI and how do you treat it?

  • E coli
  • Proteus
  • Klebsiella
  • Staphylococcus saprophyticus
  • Trimethoprim or nitrifurantoin
  • If pyelonephritis - broad spectrum IV Abx e.g. co amoxiclav +/- gent; cefuroxime +/- gent

230

Which bugs cause congenital infection?

TORCH

  • Toxoplasmosis
  • Other (HIV, HBV)
  • Rubella
  • CMV
  • HSV

231

Which bugs cause neonatal (<6 weeks) infecton and how do you treat it?

  • Early onset - first 48 hours
    • GBS, E coli, Listeria
    • Treat: BenPen + gent, amox/ampicillin if listeria
  • Late onset
    • Coagulase negative staph + GBS, E coli, Listeria
    • Treat:
      • 1st line - fluclox + gent
      • 2nd - tqazocin + vanc
      • Late onset from community - amoxicillin + cefotaxime - listeria + community meningitis (BenPen given in GP)

232

Which bugs cause bacterial meningitis in children?

  • Neisseria
  • Strep pneumoniae - <2 year
  • Haemophilus influenzae 0 <3 months _ unvaccinated
  • GBS, E coli, Listeria - common 1-3 months

233

Which bugs cause UTI in children?

  • E coli
  • Proteus
  • Klebsiella
  • Enterococcus

234

Which bugs cause meningitis?  How do you treat bacterial meningitis

  • Bacteria - N meningitidis (G-ve), Strep pneumo (G+ve)
    • Neonates - GI flora - GBS, listeria, E coli
    • Elderly - GBS, listeria, mycobacterium TB (subacute)
    • Resuscitate + cef + corticosteroids
      • Cover Listeria with ampicillin
  • Viral - enteroviruses e.g. coxsackie, mumps, HSV2 + echovirus
  • Fungal: cryptococcus neoformans

235

How do you interpret a CSF result if ?meningitis?

  • Normal
    • 0-5 WCC
    • Protein 0.15-0.4
    • Glucose 2.2-3.3 (>50% serum)
  • Glucose low, WCC high, with polymorphs - think bacterial infection
  • Glucose normal, WCC high with polymorphs - think partially treated bacterial infectoin
  • Glucose normal, WCC high with mononuclear cells - think viral meningitis/encephalitis
  • Protein high, WCC high with mononuclear cells - think mycobacterium TB or cryptococcus

236

How do you treat meningoencephalitis?

Aciclovir + ceftriaxone

237

What antibiotic should you use against staphylococcal skin infection?

Flucloxacillin - unless allergy or MR negative

238

What antibiotic should you use against beta haemolytic strep pharyngitis infection?

Benpen

239

What antibiotic should you use against mild and severe community acquired pneumonia?

  • Mild - amoxicillin
  • Severe - cefuroxime + clarithmycin

240

How do you treat hospital acquired pneumonia?

Cefuroxime

241

How do you treat bacterial meningitis?

Ceftriaxone - amoxicillin if listeria likely/young/old

242

How do you treat UTI?

  • Community - trimethoprim (3 days)
  • Nosocomial - augmentin or cephalexin

243

How do you treat sepsis?

  • Severe - cefuroxime, metronidazole +/- gentamicin
  • Neutropenic - tazocin + gentamicin

244

How do you treat C diff colitis?

Metronidazole PO (stop Ceph!)

245

Which classes of antibiotics inhibit cell wall synthesis and what are some examples of them?  what are the indications for use?

  • Beta lactams: cephalosporins, penicillins, carbapanems
    • Benpen, ceftriaxone, meropenem
    • Indications: gram positive, gram negative - 3rd gen cephs
  • Glycopeptides
    • Vancomycin, teicoplanin
    • MRSA, C diff

246

Which classes of antibiotics inhibit protein synthesis and what are some examples of them?  what are the indications for use?

  • ATMCO - Make All The Cells Obsolete 
  • Aminoglycosides - gentamicin
    • Gram negative sepsis
  • Tetracyclines - doxycycline
    • Intracellular - chlamydia
  • Macrolides - erythromycin
    • Gram positives (penicillin allergy)
  • Chloramphenicol - eye drops
    • Bacterial conjunctivitis
  • Oxazolidinones - linezolid
    • Gram positive, MRSA positive

247

Which classes of antibiotics inhibit DNA synthesis and what are some examples of them?  what are the indications for use?

  • Fluoroquinolones - ciprofloxacin
    • Gram negative
  • Nitroimidazoles - metronidazole
    • Anaerobes and protozoa

248

Which classes of antibiotics inhibit RNA synthesis and what are some examples of them?  what are the indications for use?

Rifamycin - rifampicin.  Mycobacteria

249

Which classes of antibiotics are cell membrane toxins and what are some examples of them?  what are the indications for use?

  • Polymyxin
    • Colistin
    • Gram negatives
  • Cyclic lipopeptide
    • Daptomycin

250

Which classes of antibiotics inhibit folate metabolism and what are some examples of them?  what are the indications for use?

  • Sulphonamides - sulphamethoxazole
    • PCP with trimethoprim = co trimoxazole
  • Diaminopyrimidines - trimethoprim
    • UTI

251

Which commonly used antibiotics are broad spectrum and which are narrow spectrum?

  • Broad spectrum
    • Co-amoxiclav, tazocin, ciprofloxacin, meropenem
  • Narrow spectrum
    • Flucloxacillin, metronidazole, gentamicin

252

What are the 4 methods of drug resistance in bacteria?

BEAT drug action

  • Bypass antibiotic sensitive step in pathway e.g. MRSA
  • Enzyme mediated drug inactivation e.g. beta lactamases
  • Impairment of Accumulation of the drug e.g. tetracycline resistance
  • Modification of the drug's Target in the microbe e.g. quinolone resistance

253

What are the features of hep A infection?

  • Acute - IgM, previous infection or vaccination - IgG
  • Faecal oral transmission
  • Acute diagnosis - anti HAV IgM; persists for up to 14 weeks
  • Management is supportive
  • 2-6 weeks incubatoin
  • Severe in the elderly
  • RNA virus

254

What are the features of hep B infection?

  • dsDNA
  • Acute <6 months and chronic
  • Latent virus can reactivate in immunocompromised patients
  • Sexual, vertical, horizontal
  • ALT, AST high
  • HBsAg, HBeAG (= infectivity), HBcAb (acute IgM, chronic is IgG)
  • Management: pegIFN2alpha, lamivudine, tenofovir
  • Later: fibrosis, cirrhosis, HCC
  • 2-6 months incubation

255

What are the features of hep C  infection?

  • RNA virus
  • Acute, 80% progress to chronic
  • Blood products
  • ALT, anti HCV for diagnosis
  • PegIFN2b, ribavirin
  • Cirrhosis

256

What is hep D?

RNA virus that can only infect hep B patients

257

What is Hep E?

RNA virus transmitted faecal oral route

258

What are the features of parvovirus B19 infection in pregnancy?

  • Resp/blood borne transmission, 6-8 days incubatoin
  • Stmptoms: asymptomatic or fever, malaise, erythema infectiosum (slapped cheek), transient aplastic crisis (especially if sickle cell, spherocytosis)
  • Foetus:
    • Infection <20w has 3% risk of hydrops fetalis
    • Treatment is intrauterine transfusion (no risk after 20w)

259

What are the features of rubella infection in pregnancy?

  • RNA virus, resp transmission, incubation 12-21 days
  • Symptoms: 20-50% subclinical infection; classically flu like symptoms followed by pinpoint macular papular rash and lymphaenopathy
  • Diagnosis via serology of saliva swabs
  • Foetus:
    • Congenital rubella syndrome (90%) develops if infected <10 weeks - cataracts, glaucoma, heart disease, los sof hearing, retinopathy, splenomegaly, mental retardatoin and meningoencephalitis
    • 20% risk of spontaneous abortion if infected before 8 weeks
    • If 13-18 weeks may have hearing defects and occasionally retinopathy
    • If >20 weeks no documented risk

260

What are the risks of influenza infection in pregnancy?

  • 5x risk stillbirth
  • 3x risk preterm delivery
  • No congenital abnormalities
  • Recommended that pregnant women get vaccinated

261

What are the risks of measles infection in pregancny?

  • IUDmiscarriage
  • Preterm delivery
  • Maternal morbidity increased

262

What are the different types of vaccine?

  • Live attenuated
    • MMR
    • VZV
    • Yellow fever
  • Inactivated
    • Rabies
    • HAV
  • Recombinant proteins
    • HBV
  • Subunit
    • Influenza
    • Typhoid
  • Conjugate
    • Men C

263

Which common bacteria are gram positive?

  • cocci
    • Staph (clusters)
      • Coagulase positive - aureus
      • Coagulase negative - epidermis
    • Streptococcus
    • Enterococcus
  • Rods
    • Actinmyces
    • Bacillus: cereus, anthracis
    • Clostridium difficile, perfringens, botulinum, tetani
    • Diphtheria
    • Listeria

264

Which common bacteria are gram negative?

  • Cocci
    • Neisseria meningitidis + gonorrhoeae, moraxella catarrhalis
  • Rods
    • Enterobacteriaceae (coli), salmonella, shigella, klebsiella, yersinia
  • Coccobacilli
    • H influenza/ducreyi, Bordtaella pertussis, pseudomonas aeruginosa, chlamydia trachomatis
  • Spirochaetes
    • Treponema pallidum, leptospirosis, borrelia

265

Which common organisms are obligate intracellular microbes?

  • Bacteria: chlamydia trachomatis, rickettsia, coxiella, mycobacteria leprae
  • Protozoa: toxoplasma, cryptosporidium, leishmania spp
  • Fungi e.g. PCP