STI Flashcards
What is the most commonly reported bacterial STI in sexual health clinics in the UK?
Chlamydia
Do people tend to present with symptoms in chlamydia?
70-80% of woman are asymptomatic
50% of men are asymptomatic
What type of bacterial is chlamydia?
Gram negative obligate intracellular bacterium
How can chlamydia be transmitted?
Vaginal
Oral
Anal
In what age group is chlamydia most common?
20-24 years
What percentage of women with chlamydia will develop PID?
9%
What is the sequelae of PID infection?
Increases the risk of ectopic pregnancy ten fold
Carries a risk of tubal factor infertility of 15-20%
How does chlamydia present in females?
Post coital or intermenstrual bleeding
Lower abdo pain
Dyspareunia
Mucopurulent cervicitis
How does chlamydia present in men?
Urethral discharge Dysuria Urethritis Epididymo-orchitis Proctitis (LGV)
What are the complications of CT?
PID Tubal damage (infertility, ectopic pregnancy), chronic pelvic pain, transmission to neonate (conjunctivitis and pneumonia), adult conjunctivitis, sexually acquired reactive arthritis, Fitz-Hugh-Curtis Syndrome
What is Fitz-Hugh-Curtis Syndrome?
Development of perihepatitis in association with pelvic inflammatory disease
Who should you test for CT?
Should stop testing women over 25 who present with vaginal discharge
Women who have had CT in past year
One in 5 women with diagnosed and treated chlamydia are estimated to become re-infected within 10 months after initial treatment
What is LGV?
Servoras L1-3 of chlamydia
Diagnosed in MSM
What are the symptoms of LGV?
Rectal pain
Discharge
Bleeding
High risk of concurrent STIs
When can CT be diagnosed?
Test 14 days post exposure
NAAT
If MSM add rectal swab if receptive anal intercourse
What is the difference between NAAT testing in men and women?
Women; vulovaginal swab
Men; first void urine
What is the treatment of chlamydia?
Doxycycline 100mg BD x 1 week
Azithromycin 1G stat followed by 500mg daily for 2 days
What is mycoplasma genitalium associated with?
Non gonococcal urethritis
PID
Is mycoplasma genitalium always symptomatic?
Majority is asymptomatic
BUT high levels of macrolide resistance
What is the gram stain of gonorrhoea?
Gram negative intracellular diplococcu s
Where can the primary sites of infection for gonorrhoea be found?
Mucous membranes of urethra
Endocervix
Rectum
Pharynx
What is the incubation period for gonorrhoea?
In men with a urethral infection; 2-5 days
How is gonococcus transmitted?
20% risk from infected woman to male partner
50-90% risk from infected man to female partner
How does gonorrhoea present in men?
Asymptomatic <10%
Urethral discharge >80%; tends to be green/yellow and purulent
Dysuria
Pharyngeal/ rectal infections
How does gonorrhoea present in women?
Asymptomatic in up to 50%
Increased/ altered vaginal discharge in 40%
Dysuria
Pelvic pain
Pharyngeal and rectal infection usually asymptomatic
Complications of gonorrhoea in lower genital tract?
Bartholinitis Tysonitis Periurethral abscess Rectal abscess Epididymitis Urethral stricture
Complications of gonorrhoea in upper genital tract?
Endometritis PID Hydrosalpinx Infertility Ectopic pregnancy Prostatitis
How is gonorrhoea diagnosed?
NAAT; screening test
If symptomatic; microscopy
If microscopy positive or known contact of GC; do culture to look for antibiotic sensitivities
What is the treatment for gonorrhoea?
1st line: ceftriaxone 1g IM
2nd line: cefixime 400 mg PO and azithromycin 2g PO (only if IM CI or refused)
When should a test of cure be performed in gonorrhoea?
2 weeks
What are the different types of genital herpes?
Primary infection
Non-primary infection
Recurrent infection
Which episode will be the worst in genital herpes?
Primary
What is the incubation period of primary genital herpes?
3-6 days
What is the duration of primary genital herpes?
14-21 days
What are the symptoms of a primary genital herpes infection?
Blistering and ulceration of external genitalia Pain External dysuria Vaginal or urethral discharge Local lymphadenopathy Fever and myalgia (prodrome)
With what strain of HSV are recurrent episodes more common?
HSV-2; usually unilateral, small blisters and ulcers
How long will recurrent genital herpes tend to last?
5-7 days with minimal systemic upset
What investigations should be done to diagnose HSV?
Swab base of ulcer for HSV PCR
What is the treatment for genital herpes?
Oral antiviral treatment (aciclovir 400mg TDS x 5/7)
Topical lidocaine 5% ointment
Saline bathing
Analgesia
Which strain of HSV is more prone to viral shedding?
HSV 2
More frequent in first year of infection
What treatment can be given to people with 6+ recurrent episodes a year?
Aciclovir
What is important regarding genital herpes and pregnancy?
If 1st primary episode in 3rd trim or within 6 weeks of EDD; need to review birth plan as HSV in neonate can cause a disseminated infection, encephalitis and death
Why is it important to distinguish between primary and non-primary genital herpes in pregnancy?
If non-primary; then antibodies will cross placenta and protect the baby
What is the most common viral STI in the UK?
HPV
What is the lifetime risk of acquiring HPV?
80%
What HPV genotypes cause genital warts?
6 and 11
What HPV genotypes cause cervical cancer?
16 and 18
What strains of HPV are the new vaccines protecting against?
6, 11, 16, 18, 31, 33, 45, 51, 58
Which HPV strains are assoc with anogenital warts, palmar and plantar warts and cellular dysplasia?
Anogenital warts = 6 /11
Palmoplantar = 1/2
Cellular dysplasia = 16/18
How is HPV transmitted?
Likely to have acquired HPV from asymptomatic partner
Incubation period is 3 weeks to 9 months
Subclinical disease is common on all anogenital sites
HPV strains come in packs
How many people will have spontaneous clearance of anogenital warts?
20-34%
What is the treatment of HPV warts?
Podophyllotoxin
Imiquimod
Cryotherapy
Electrocautery
What has been the impact of HPV vaccination?
79% reduction in CIN1
88% reduction in CIN 2
89% reduction in CIN 3
What causes syphilis?
Treponema Pallidum
What will treponema pallidum look like on dark light microscopy?
Spirochetes
How is syphilis transmitted?
Sexual contact
Trans-placental/ during birth
Blood transfusion
Non-sexual contact; health care
What are the different classifications of syphilis infections?
Congenital
Acquired
What are the early forms of acquired syphilis?
Primary
Secondary
Early latent
What are the late forms of acquired syphilis?
Late latent
Tertiary
What is the incubation period of primary syphilis?
9-90 days (mean of 21)
What is the main lesion of primary syphilis?
Primary chance; painless
At site of sexual inoculation
Non-tender local lymphadenopathy
What is the incubation period of secondary syphilis?
6 weeks to 6 months
What are the sequelae of secondary syphilis?
Skin; macular, follicular or pustular rash on palms + soles Lesions of mucous membranes Generalized lymphadenopathy Patchy alopecia Condylomata lata Proctitis Ophthalmology
How is syphilis diagnosed?
Demonstration of treponema; dark field microscopy or PCR from lesions or infected lymph nodes
Serological testing; detects antibodies to pathogeic treponemes
What test show the marker of syphilis disease activity?
VDRL
RPR; used in tayside
What is the screening serological test for syphilis?
ELISA
What test is done post +ve ELISA ?
TPPA
What is the treatment for early and late syphilis?
Early; 2.4 MU Benzathine penicillin x1
Late: 2.4 MU Benzathine penicillin x3
What is the follow up foro syphilis?
Follow up serologically until RPR is negative
Titres should decreased fourfold by 3-6 months in early syphilis
Serological relapse/ reinfection if titres increase by fourfold
