STI and BBV Passmed Flashcards
Gonorrhoea is caused by the Gram-negative diplococcus Neisseria gonorrhoae.
How does it present differently in men and women?
What local complications can arise?
males: urethral discharge, dysuria
females: cervicitis e.g. leading to vaginal discharge
Local complications that may develop include urethral strictures, epididymitis and salpingitis
What is the major systemic complication of gonorrhea? How does it present?
Disseminated gonococcal infection (DGI)
Initially there may be a classic triad of symptoms: tenosynovitis, migratory polyarthritis and dermatitis.
Later complications include septic arthritis, endocarditis and perihepatitis (Fitz-Hugh-Curtis syndrome)
It is the most common cause of septic arthritis in young adults
How is gonorrhea treated?
The first-line treatment is a single dose of IM ceftriaxone 1g
(But if the organism is sensitive to ciprofloxacin then oral ciprofloxacin 500mg should be given)
if ceftriaxone is refused (e.g. needle-phobic) then oral cefixime 400mg + oral azithromycin 2g should be used
All patients with gonorrhoea should have ‘test of cure’ due to high abx resistance. What is used for this?
with NAAT if asymptomatic or cultures if symptomatic
How can genital herpes be diagnosed?
clinical diagnosis or viral PCR swab from lesion
How should genital herpes in pregnancy be managed?
Elective C-section at term is advised if a primary attack of herpes occurs at greater than 28 weeks gestation (3rd trimester)
Oral aciclovir 400 mg TDS (three times daily) should be taken until delivery
Women with recurrent herpes who are pregnant should be treated with suppressive therapy and be advised that the risk of transmission to their baby is low
How is asymptomatic bacteriuria in pregnancy managed?
Immediate tx with abx
HIV seroconversion occurs about 3-12 weeks after initial infection. How does it present if symptomatic?
Like glandular fever
sore throat
lymphadenopathy
malaise, myalgia, arthralgia
diarrhoea
maculopapular rash and mouth ulcers
rarely meningoencephalitis
antibodies to HIV may not be present
HIV PCR and p24 antigen tests can confirm diagnosis
When should asymptomatic patients be screened for HIV?
4 weeks following potential exposure
What is the first line for HIV testing?
combination tests (HIV p24 antigen and HIV antibody) are now standard for the diagnosis and screening of HIV
- if the combined test is positive it should be repeated to confirm the diagnosis
Name some key AIDS defining illnesses
Kaposi’s sarcoma (caused by human herpes virus 8)
PCP
CMV
Candidiasis (oesophageal or bronchial)
Lymphoma
TB
How can HIV be monitored?
CD4 count ( 500-1200 is normal, under 200 is end stage /AIDS)
Viral Load
How should HIV be managed?
Antiretroviral therapy (ART) involves a combination of at least 3 drugs, typically 2 nucleoside reverse transcriptase inhibitors (NRTI) and either a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI).
This combination both decreases viral replication but also reduces the risk of viral resistance emerging
patients should start ART as soon as they have been diagnosed, rather than waiting until a particular CD4 count
NRTI: zidovudine (AZT), abacavir, emtricitabine, didanosine, lamivudine, stavudine, zalcitabine, tenofovir
PI: indinavir, nelfinavir, ritonavir, saquinavir
NNRTI: nevirapine, efavirenz
What is a chancre?
Painless indurated lesion characteristic of the primary stage of syphilis
Most common complication of gonorrhoea?
Infertility secondary to PID
Most common cause of PID?
Chlamydia
(gonorrhoea second)
Common causes of genital ulcers?
painful: herpes much more common than chancroid
painless: syphilis more common than lymphogranuloma venereum
Most common cause of genital warts (90%)?
HPV 6 & 11
What is BV?
Bacterial vaginosis (BV) is an overgrowth of predominately anaerobic organisms e.g. Gardnerella vaginalis which = a fall in aerobic lactobacilli that produce lactic acid→ raised vaginal pH
Fishy/offensive discharge or can be asymptomatic
Risk factors for BV?
multiple sexual partners
excessive vaginal cleaning
recent abx
smoking
copper coil
How can BV be investigated?
vaginal pH testing from swab - above 4.5 = BV
vaginal swab for microscopy = clue cells
How can BV be treated?
metronidazole orally or by vaginal gel
Complications of BV?
increased risk of getting STIs
complications in pregnancy:
miscarriage
preterm delivery / PPROM
low birth weight
chorioamnionitis
Man returns from trip abroad with maculopapular rash and flu-like illness→
think HIV seroconversion
Tx for pubic lice (Phthirus pubis)?
malathion lotion or permethrin cream (insecticides)
Both should be applied to the whole body and washed off after 12 hours
repeat after a week
Chlamydia is the most prevalent STI in the UK and is caused by Chlamydia trachomatis.
How does it present in men and women?
Investigation?
Tx?
women: cervicitis (discharge, bleeding), dysuria
men: urethral discharge, dysuria
often ASYMPTOMATIC
Investigation:
for women: the vulvovaginal swab is first-line
for men: the urine test is first-line
Chlamydia testing should be carried out two weeks after a possible exposure
Tx: doxycycline (7 day course)
if pregnant then azithromycin, erythromycin or amoxicillin may be used (azithromycin 1g stat preferable)
Findings on examination of chlamydia?
pelvic or abdo tenderness
cervical motion tenderness
inflamed cervix
purulent discharge
Complications of infection with chlamydia?
PID
chronic pelvic pain
infertility, ectopic pregnancy
conjunctivitis
lymphogranuloma venerum
reactive arthritis
What is lymphogranuloma venerum ?
condition affecting lymphoid tissue around area infected w chlamydia
commonest in MSM
painless ulcer > lymphadenitis > proctitis
Supportive management of genital herpes?
saline bathing
analgesia
topical anaesthetic agents e.g. lidocaine
What PEP should be given post hep B and hep C exposure?
Hep B
known responder to vaccine : booster vaccine
non-repsonder to vaccine : hepatitis B immune globulin (HBIG) and booster
Hep C
monthly PCR - if seroconversion then interferon +/- ribavirin
What PEP should be given post HIV exposure?
low-risk incidents such as human bites don’t require post-exposure prophylaxis
high-risk incidents like needle stick injuries should be treated with a combo of oral antiretrovirals (e.g. Tenofovir, lopinavir and ritonavir) ASAP for 4 weeks with serological testing at 12 weeks following completion
Where should swabs for chlamydia and gonorrhoea in women be taken from?
the vulvo-vaginal area (introitus)
Fever, loin pain, nausea and vomiting →
Management?
acute pyelonephritis
obtain a MSU sample and then start on cefalexin for 14 days ( or IV ceftriaxone in hospital)
Appropriate next step after needlestick injury?
Bleed and wash the wound
Ask a colleague to complete a risk assessment and take the patient’s blood as they will be able to be objective
Inform occupational health
What is Trichomonas vaginalis?
Presentation?
Tx?
STI caused by flagellated protozoan parasite
vaginal discharge: offensive, yellow/green, frothy
strawberry cervix
pH > 4.5
in men is usually asymptomatic but may cause urethritis
tx: metronidazole for 5-7 days
HIV + proctitis ?
Lymphogranuloma venereum
most common non-immune cause of foetal hydrops in pregnancy? what is the immune cause?
Parvovirus B19
(Immune is Rh disease)
Painless genital pustule → ulcer → painful inguinal lymphadenopathy → proctocolitis =
lymphogranuloma venereum
- caused by three serovars of Chlamydia trachomatis
When should reinfection with syphilis be suspected?
if the RPR rises by 4-fold or more
Urethritis in a male, negative for Gonorrhoea and Chlamydia →
?Mycoplasma genitalium
Vaginal candidiasis or thrush refers to a vaginal yeast infection, most commonly with Candida albicans. What are the risk factors?
pregnancy
poorly controlled diabetes
immunosuppression
broad spectrum abx
How does candidiasis present?
thick, white ‘cottage cheese’ discharge
vulval / vaginal itching or soreness
dyspareunia
What pH would you expect in candidias?
<4.5 (as opposed to >4.5 in trichomonas or BV)
How can candidiasis be treated?
antifungal cream e.g. clotrimazole (with applicator)
antifungal pessary e.g. clotrimazole
oral antifungal e.g. fluconazole
can use Canesten Duo (OTC tablet + cream)
What is mycoplasma genitalium? How is it investigated and managed?
STI that causes non-gonococcal urethritis
Ix:
NAAT - first urine sample in men, vaginal swabs in women
Mx:
doxycycline 100mg BD for 7 days, then azithromycin
Syphilis is a sexually transmitted infection caused by the spirochaete Treponema pallidum. What are the primary features?
chancre - painless ulcer at the site of sexual contact
local non-tender lymphadenopathy
What are the secondary features of syphilis?
occurs 6-10 weeks after primary infection
systemic symptoms: fevers, lymphadenopathy
rash on trunk, palms and soles
buccal ‘snail track’ ulcers
condylomata lata (painless, warty lesions on the genitalia )
What is Argyll-Robertson pupil?
tertiary feature of syphilis
suggests neurosyphilis
constricted pupil that accommodates when focusing on near objects but does not react to light
How can syphilis be treated?
single dose IM benzathine benzylpencillin
Risk factors for HIV?
multiple sexual partners, high-risk sexual practices such as ‘chemsex’, history of other STI
IVDU
from area with high HIV prevalence
MSM / female sexual contacts of MSM
trans women
sex workers
blood transfusions, transplants, or other risk-prone procedures in countries without rigorous procedures for HIV screening
occupational exposure such as a needle stick injury
