Flashcards in Repro 6 STIs and PID Deck (105):
Why is the term STI instead of STD used?
STI - symptomatic and asymtomatic infection - still potential problems and potential to spread it
STD - symptomatic infection only
Where is the national data for STIs collected from?
GUM clinics - Gentio Urinary Medicine, which notify STDs centrally
Why is there a gradual and sustained increase in STI prevalence from 1995 to 99?
Acceptability of GUM services
Greater public awareness
Development in diagnostic methods
Behavioural, socio-economic, healthcare provision and biological factors all contribute
What is the suspected reason for the fall in STI diagnosis prior to 95?
Thought to reflect changes in behaviour in response to the HIV epidemic
Why is data from GUM clinics an underestimation of the true incidence of STIs?
Patients may be seen in other settings e.g. GP or family planning clinics
Many infections are asymptomatic and only approx 10% of cases attend GUM
Who are the at risk groups in society of contracting STIs?
Ethnic minority (stigma)
Low socio-economic status
Teenage mothers (at risk behaviour)
What factors contribute to the risk of contracting STIs?
Age at first intercourse
Total number of sexual partners
Frequency of change of partners
Sexual orientation (with other factors)
Practice of unsafe sex
Lack of skills ad confidence to negotiate safe sex
What STIs might cause genital ulcers?
HSV (herpes simplex virus)
Chanchroid (Haemophilus ducreyi)
What STIs might cause vesicles of bullae?
When might an STI cause genital papules? Give some examples.
Transient manifestation of STIs - condylomata acuminata (anogenital warts), umbilicated lesions of Molluscum contagiosum virus
What should aspects of genital ulcers should be assessed?
What are the various types of urethritis and what might cause them?
NGU (nongonococcal urethritis) - chlamidia trachomatis, ureaplasma, mycoplasma, trichomonas HSV
What is vulvovaginitis and what might cause it?
Vaginal infection - candidias, trichomoniasis, staphylococcal, foreign body, HSV
What might cause cervicitis?
C. trachomatis, N. gonorrhoeae, HSV, HPV
What is bartholinitis and what might cause it?
Inflammation of one or both of the bartholin glands. Caused by polymicrobial infections with endogenous flora or rarely STIs
What are the symptoms of bacterial vaginosis?
How is bacterial vaginosis diagnosed?
Vaginal pH >4.5
Pungent odour with KOH (whiff test)
Presence of clue cells on a wet mount lacking many PNMs
What is the cause of bacterial vaginalis?
Thought to be the result of a synergistic infection involving the overgrowth of normal flora including gardnerella vaginalis
What are the potential pregnancy related causes of infections of the female pelvis?
Peurperal ovarian vein thrombophlebitis
What are the different types of prostatitis?
Chronic pelvic pain syndrome
What are the different types of epididymitis?
What are the causes of orhchitis?
(inflammation of the testes)
Viral (mumps, coxsackie B)
Why do chlamydia trachomatis not grow on routine lab media?
They are obligate intracellular bacteria
What is the infective form of chlamydia trachomatis?
Elementary body which develops within the host cell into the reticulate body
What does the reticulate body of chlamydia trachomatis do?
Replicates eventually reverting back to elementary bodies which leave the cell to infect other cells
Where in the female reproductive tract does chlamydia replicate?
Epithelium of the cervix and urethra
What are the consequences of an infection of C. trachomatis?
An ascending infection with involvement of the upper genital tract occurs and can result in clinical or subclinical PID presenting as endometritis or salpingitis. Perihepatitis is a rare complication (more likely from gonorrhoea)
What results from a cervical infection of C. trachomatis?
The majority of infections are symptomatic but it is an important cause of muopurulent cervicitis
What are the manifestations of a urethral infection of chlamydia?
Acute urethral syndrome - dysuria and frequency (most common in young sexually active women)
What are the common symptoms of chlamydia infection in males?
What ar epotential complication of chlamydia infection in males?
What is Reiters syndrome?
Urethritis, conjunctivitis, and arthritis are the classical triad f clinical manifestations
Predominantly occurs in male patients affected with chlamydia
Where other than the genital tract may there be a manifestation of chlamydia?
Eye - ocular infections
What is the cause of chlamydia in neonates?
Cervical infection in pregnant women
What are the manifestations and complications of chlamydia in neonates?
How are specimen collected from males to test for chlamydia?
Urethral swab or first catch urine
How are specimen collected from females to test for chlamydia?
Endocervical swab. It is important that any pus is first removed from the cervix and that good quality cellular material is obtained
What are the pros and cons for urine samples as a specimen collection for chlamydia testing?
Less sensitive than swabs
Patients may provide their own samples whereas swabs are time consuming and requires a trained member of staff to take the specimen and is less acceptable to the patient
How are specimens collected from neonates to test for chlamydia?
Eye swab - remove pus, invert eyelid and scrape conjunctiva surface to obtain cellular material
For pneumonia, serology is useful. A differential on a WCC may show eosinophilia
How are diagnoses of chlamydia made?
Used to employ tissue culture but this is expensive and requires highly specialised labs
Antigen detection (immunofluorescence)
Enzyme Immunoassays (EIA)
Molecular methods (PCR)
Nucleic acid amplification from first void urine
Describe the method of antigen detection in diagnosing chlamydia.
Specimens may be fixed to a slide and stained with a monoclonal antibody that is tagged with fluorescein
Slides are examined under a UV microscope
What are the drawbacks and advantages to antigen detection in diagnosing chlamydia?
Results are subject to observer error and the method is time consuming (only suitable for small number of specimens)
Quality of specimen can be assessed
Describe the advantages and disadvantages of EIA in assessing specimens for chlamydia.
Allow a large number of specimens to be processed relatively easily
Comercial kits may vary in sensitivity and specificity
What are the advantages and disadvantages to molecular methods use in diagnosing chlamydia?
High sensitivity and specificity
Clinical specimens may contain inhibitors that will interfere with the assay
Commercial kits may yield significant false positives and negatives
What is the mainstay treatment for chlamydia?
(Typically used for atypical resp infection)
Why are systemic antibiotics used in the treatment of chlamydia?
Conjunctivitis is part of a more widespread infection
Why are beta lactam antibiotics not used in the treatment of chlamydia?
Chlamydia trachomatis contain relatively little peptidoglycan
Classify the gonorrhoea bacteria.
Gram-negative diplococci that only grow on enriched media
Where do gonococcal infections generally occur in the female?
What are the clinical manifestations of gonococcal infection?
Urethral syndrome where the urethra is infected (male and female)
What are the potential complications of gonococcal infection?
PID (occasionally with tubo-ovarian abscess)
Disseminated gonococcal infection (male and female)
What is a disseminated gonococcal infection?
Bacteraemia. A rare complication that affects women more than men
Common symptoms: pain on joints (lesions), tensynovitis and rash
How should specimens for testing of gonorrhoea be taken?
Taken and plated directly on to media at the bedside as it is a fragile organism and does not survive transportation well
Where are specimen collected from in males and females to test for gonorrhoea?
Female - endocervical, urethral, rectal or pharyngeal swab
Male - Urethral, rectal and pharyngeal swabs
Smear and culture
How are gonococcal infections diagnosed in the lab?
Gram stain - gram-negative diplococci
Culture is more sensitive than microscopy - biochemical tests must be done to confirm potential neisseria on a culture
Why is sensitivity testing important for gonococcal infections?
Antibiotic resistance patterns are valuable in guiding future management guidelines
What is the treatment for a gonococcal infection?
Neisseria gonorrhoea may vary in its sensitivity. Initial therapy is usually guided by severity of symptoms an local knowledge of sensitivity patterns. Penicillin resistance common
Ceftriaxone (IM) is now mainstay treatment. Used to be ciprofoxacin but resistance built
What is the most commonly diagnosed STI?
Genital warts caused by HPV
How many types of HPV are there?
Do all individuals infected with HPV develop warts?
What are the risks carried with HPV?
Difficult to treat
Certain high risk types are associated with cervical carcinoma (HPV 16 and 18)
What are the methods of HPV screening?
Cervical pap smear cytology
Colposcopy and acetowhite test
Cervical swab - HPV hybrid capture -> high/intermediate risk of differentiation
What are the symptoms of HPV?
Verucous epithelia or mucosal outgrowths
How is HPV diagnosed?
Clinical biopsy + genome analysis
What is the treatment for HPV?
No treatment - spontaneous resolution
Why should patients presenting with one STI be screened for others, including BBV?
Multiple infections are common - at risk behaviour, identical transmission mode, long-term asymptomatic and chlamydia is common
What type of microorganism is Trichomonas vaginalis?
What are the clinical presentations of Trichomonas vaginalis?
Thin, frothy, offensive discharge
How is a diagnosis of trichomonas vaginalis made?
Vaginal wet preparation +/- culture enhancement
WHat is the treatment of trichomonas vaginalis?
Metronidazole (active against anaerobes and protozoa)
What is the name of the bacterium causing syphilis?
How is the disease of syphilis described?
Multi-stage disease - progressive, manifests in different ways
'The great pretender'
Describe the stages of syphilis.
1. Indurated painless ulcer (chancre)
2. 6-8 weeks later: fever, rash, lymphadenopathy, mucosal lesions
(can be latent and symptom free for years)
3. Chronic granulomatous lesions
4. CVS and CNS pathology
How is syphilis diagnosed?
Serology, dark field microscopy
What is the treatment of syphilis?
Penicillin and 'test of cure' follow up
What are the 2 types of HSV?
Exposure to type 1 provides some immunity to type 2
What are the clinical presentations of type 2 HSV?
Extensive, painful genital ulceration
Urinary retention common in women
Recurrent = asymptomatic -> moderate
How is herpes diagnosed?
Smear and swab (viral culture) of vesicle fluid and/or ulcer base
How is HSV treated?
Primary and severe with aciclovir (only active in infected cells - activated by virus)
May need hospitalised if severe primary disease
What is the most common cause of vulvovaginal candidiasis?
Candida albicans - normal flora of the GI and genital tracts
What are risk factors for the development of vulvovaginal candidiasis?
What are the clinical presentations of vulvovaginal candidiasis?
Profuse, whites, curd like discharge
How is a diagnosis of vulvovaginal candidiasis made?
High vaginal smear and culture
What is the treatment of vulvovaginal candidiasis?
Topical azoles or nystatin
What causes bacterial vaginosis?
perturbed normal flora - garderella, anaerobes, mycoplasmas
How is bacterial vaginosis treated?
What treatment is generally given when a diagnosis of Neisseria gonorrhoea has been made?
Ceftriaxone IM + doxycycline for 7 days for possible chlamydial infection or azithromycin if pregnant of unlikely to be complient
What is Fitz-Hugh-Curtis syndrome?
Right upper quadrant pain from perihepatitis (inflammation of the liver capsule or diaphragm) following the transabdominal spread from PID. Adhesions form between the liver and abdominal wall or diaphragm, classically called violin strings
What causes Fits-Hugh-Curtis syndrome?
Most commonly, chlamydia, less commonly, gonorrhoea
What advice should patients with STIs be given?
Abstinence during treatment
Tell recent sexual partners
Advice to decrease STI risks
Return visit to test for cure
Sexual health education
How does the illness iceberg relate to STIs?
Many asymptomatic unknown cases - higher prevalence than known
What conditions in the vagina will promote growth of candida?
Warmth and humidity
OC and pregnancy
Menstrual cycle association
Why does the OC increase risk of development of thrush?
High oestrogen levels promote overgrowth of the yeast
What is PID?
Infection ascending from the endocervix, causing endometritis, salpingitis, parmetritis, oophoritis, tubo-ovairan abscess and/or pelvic peritonitis
Who gets PID?
Sexually active women
High incidence in urban areas
Peak incidence 20 per 1000
Highest incidence in 20-24yr olds
What microorganisms can cause PID?
Garderella, mycoplasma and anaerobes also implicated
What are the chances of concurrent infection?
What are the risk factors for PID?
Type of contraception used - IUCD carries risk of infection for 1st week of insertion (foreign body), COCP considered protective
What are the clinical features of PID?
Pyrexia (>38 degrees)
Abnormal vaginal discharge
Abnormal vaginal bleeding
What pain is associated with PID?
Bilateral lower abdominal tenderness
Tenderness on cervical excitation
What investigations should be carried out for PID?
Ultrasound, laproscopy, endocervical swabs, swabs from peritoneum if laproscopy done
*Positive swabs confirm but negative do not exclude
How would you manage a patient with PID?
analgesia, antibiotics/antimicrobial against specific organisms and broad spectrum antibiotics with good anaerobic coverage
bed rest. If hospitalised adopt semi fowler position to drain pus out of pelvis
What are the potential complications of PID?
Chronic pelvic pain
How can patients prevent PID?
Safe sex - barrier contraception
STI screening and partner
Early STI treatment