STIs Flashcards
What is the most common bacterial STI?
Chlamydia
Are more males or females with chlamydia infection asymptomatic?
More women are asymptomatic
=> 70-80% of women
=> 50% of men
Through what types of sex is chlamydia transmitted?
Vaginal, oral or anal sex
The highest incidence of chlamydia is in what age group?
20-24 years (♂+♀)
What complication of chlamydia infection can cause FURTHER complications in females?
- Pelvic inflammatory disease (PID)
- PID increases risk of ectopic pregnancy ten
- PID also carries risk of tubal factor infertility (15-20%).
If females ARE symptomatic, then how do they present with chlamydia?
- Post coital or intermenstrual bleeding
- Lower abdominal pain
- Dyspareunia (painful sex)
- Mucopurulent cervicitis
If males are symptomatic with chlamydia, then how do they present?
- Urethral discharge
- Dysuria
- Urethritis
- Epididymo-orchitis
- Proctitis (infl. of rectal lining)
What are the various complications of chlamydia infection?
- PID
- reactive arthritis
- abdominal “piano string” like adhesions
- conjunctivitis
What patient group is it important to test when considering chlamydia infection?
- women who have had CT in past year
as 1 in 5 treated women become re-infected within 10 months after initial treatment
What can the L1-3 serovars of chlamydia potentially cause?
LGV - Lymphogranuloma Venereum
LGV is more common in what group?
Men who have sex with men (MSM)
What symptoms would make you consider LGV due to chlamydia?
- Rectal pain
- discharge
- bleeding
There is a high risk of other STI infections with LGV frmo chlamydia. TRUE/FALSE?
TRUE - other STIs = high risk
(67% HIV)
What tests are used to diagnose chlamydia and how soon can these be done?
- Test 14 days following exposure
- NAAT
females (vulvovaginal swab)
males (first void urine) - Test sites of sexual contact (oral, vaginal, rectal)
e. g. If MSM add rectal swab
How is chlamydia now treated?
Doxycycline 100mg BD x 1 week
How was chlamydia previously treated and why has this changed?
Single dose azithromycin
- changed due to increasing macrolide resistance against Mycoplasma Genitalium
What symptoms/other conditions are associated with Mycoplasma Genitalium?
- Non Gonococcal Urethritis (15-25%)
- PID
Patients carrying Mycoplasma Genitalium are often asymptomatic. TRUE/FALSE?
TRUE
How is Mycoplasma Genitalium tested for and diagnosed?
NAAT test (same sample sites as chlamydia)
What are the primary infection sites in Gonorrhoea?
- mucous membranes => urethra => endocervix => rectum => pharynx.
What is the typical incubation period of gonorrhoea?
2-5 days
A male partner is more likely to pass chlamydia to a female partner than vice versa. TRUE/FALSE?
TRUE
50-90% transmission from male -> female
What age groups have the highest incidence of gonorrhoea?
MALE - 20-24
FEMALE - <20
How do males usually present with symptoms of gonorrhoea?
- *MOST = SYMPTOMATIC** (Asymptomatic <10%)
- Urethral discharge – >80%
- Dysuria
- Pharyngeal/rectal infections – mostly asymptomatic
What sex is diagnosed more with chlamydia and what sex is diagnosed more with gonorrhoea?
chlamydia - more females diagnosed
gonorrhoea - more males diagnosed
Which sex is more likely to experience complications of gonorrhoea?
Females (3% vs <1% in males)
How is gonorrhoea tested and diagnosed?
- NAATs
- Microscopy ( If symptomatic)
- Urethral
- Endocervical (less sensitive)
- Culture
- Urethral
- Endocervical
How is gonorrhoea treated?
1st: Ceftriaxone 1G IM
2nd: Cefixime 400 mg oral (If IM injection = contra-indicated/ refused)
After 2 wks do Test of cure in all patients
What is the difference between Primary infection, Non- primary first episode and Recurrent infection with regards to genital herpes?
Primary - never been exposed to virus before, no Ab formed
Non-Primary First Ep - first symptomatic episode but Ab already present
Recurrent - latent infection causes episodes to reoccur
What is the normal incubation period for a genital herpes infection?
Incubation - 3-6 days
How long does the first symptomatic attack of genital herpes normally last?
Duration - 14-21 days (usually the longest and most severe exposure)
What symptoms are common in genital herpes?
- Blistering/ulceration of external genitalia
- Pain
- External dysuria
- Vaginal or urethral discharge
- Local lymphadenopathy
- Fever and myalgia (flu-like illness)
What is genital herpes often overlooked or misdiagnosed as?
Thrush
- due to itching and discharge
Recurrent episodes are more common with what HSV type?
- HSV-2
- Recurrent episode = minimal systemic symptoms, resolves within 5-7 days (shorter than initial)
How is genital herpes diagnosed?
- Swab base of ulcer for HSV PCR
How is genital herpes treated and how are discomforting symptoms treated?
- Oral antivirals (Aciclovir 400mg TDS x 5/7)
- Topical Lidocaine 5% ointment if very painful
- Saline bathing
Is viral shedding of genital herpes higher for HSV type 1 or 2?
Type 2
- and this is most frequent in first year of infection
Why is it important to work out if a pregnant female has had genital herpes prior to the existing episode?
If she has had previous epsiode and developed Ab then these will have crossed placenta to immunise baby
- If NOT then baby is at risk of neonatal herpes during birth
What is the most common viral STI in the UK?
HPV (genital warts)
What subtypes of HPV are covered in the current quadrivalent vaccine?
Low risk - 6,11 (cause anogenital warts)
High Risk - 16,18 (cause cancers)
How many HPV subtypes will be included in the new vaccine?
Nanovalent Vaccine => 9 strains
including 4 current strains + 31, 33, 45, 52, 58
What strains of HPV would cause palmar and plantar warts?
Types 1 and 2
Transmission of HPV is likely to have been acquired from an asymptomatic partner. TRUE/FALSE?
TRUE
Subclinical disease = common on all anogenital sites
=> patients may not know they carry the disease
What is the typical incubation period of HPV?
Between 3 weeks to 9 months
Multiple HPV subtypes can be transmitted at the same time. TRUE/FALSE?
TRUE
Describe the outcomes of HPV with (or without) treatments
Spontaneous clearance (no Tx) = 20-34% Clearance with treatment = 60% Persistence despite treatment = 20%
Describe the typical appearance of anogenital warts
“cauliflower like”
- may be pedunculated => hang from a narrow connection to skin
What treatments are available for genital warts?
Podophyllotoxin (Warticon)
- Cytotoxic
Imiquimod
- immune modifier
Cryotherapy
Electrocautery/ minor surgical procedure
Who is eligible for the HPV vaccine?
- Girls aged 11-13
- Men who have sex with men (high uptake of vaccine)
- will also eventually be rolled out to teenage boys
What type of organism is syphilis and how is it transmitted?
Spirochete organism
Transmitted via:
- Sexual contact
- Trans-placental/during birth (=> deemed as congenital)
- Blood transfusions
- Non-sexual contact – healthcare workers
What is the incubation period of PRIMARY syphilis?
Between 9-90 days (mean of 21 days)
What is the primary lesion in syphilis called?
Chancre (painless lesion)
- at site of inoculation (90% genital, 10% extra-genital)
What is the typical incubation period of SECONDARY syphilis?
6 wks to 6 months
How does secondary syphilis normally present?
“the great imitator”
- disseminated infection => presents EVERYWHERE
- Skin (rash on palms + soles)
- Lesions of mucous membranes
- Lymphadenopathy
- Alopecia
- Condylomata Lata (highly infectious lesion in syphilis)
How is syphilis tested and diagnosed?
Dark Field Microscopy
PCR (polymerase chain reaction)
Serological Testing
What serological test are specific to Treponema (syphilis)?
TPPA (Treponemal Pallidum Particle Agglutination)
ELISA/EIA (Enzyme Immunoassay) SCREENING TEST
What serological tests are not syphilis specific but give an indication of inflammation and therefore infection?
VDRL (Venereal Disease Research Laboratory)
RPR (Rapid Plasma Reagin)
What treatment is used in both early and late stage syphilis?
Long acting Penicillin inj.
more doses req’d in late syphilis
How should you follow up syphilis serology after treatment and what would indicate reinfection?
- Check RPR until negative
- Titres should decrease by 3-6 months in early syphilis.
- Relapse/reinfection if titres increase by fourfold