Sexually Transmitted Infections Flashcards
What is the most commonly reported bacterial STI in sexual health clinics?
Chlamydia
What percentage of women and men with chlamydia are asymptomatic?
70-80% of women, 50% of men
Chlamydia is a gram ____ ______ ______ bacterium
Chlamydia is a gram negative obligate intracellular bacterium
How is chlamydia transmitted?
Vaginal, oral or anal sex
Which age group have the highest incidence of chlamydia?
20-24 years
Chlamydia is very small, stain _____ with gram stain have a typical ___ wall of gram ___ bacteria
Cell wall lacks ________
Chlamydia is very small, stain poorly with gram stain have a typical LPS wall of gram negative bacteria
Cell wall lacks peptidoglycan
The percentage of women with chlamydia who develop PID is estimated at _%
The percentage of women with chlamydia who develop PID is estimated at 9%
An episode of PID increases the risk of ectopic pregnancy ___ fold and carries a risk of tubal factor infertility of __-__%
An episode of PID increases the risk of ectopic pregnancy ten fold and carries a risk of tubal factor infertility of 15-20%
What is the primary target of chlamydia?
Mucosal epithelial cells, replicates within vacuole in cytoplasm of host cell
How can some people clear chlamydia infection?
Good TH1 and gamma interferon response, some have abnormal immune response which confers damage
How does chlamydia present in females?
- post coital or intermenstrual bleeding
- lower abdominal pain
- dyspareunia
- mucopurulent cervicitis
How does chlamydia present in males?
- Urethral discharge
- Dysuria
- Urethritis
- Epididymo-orchitis
- Proctitis (LGV)
What are the complications of CT?
- PID 50%
- tubal damage
- chromic pelvic pain
- transmission to neonate
- conjunctivitis
- pneumonia
- SARA- sexually acquired reactive arthritis
- reiters syndrome (commoner in men)
- hugh-curtis syndrome
- perihepatitis
Who should be tested for chlamydia?
Women who have had chlamydia trachomatis in the past year
1 in 5 women who are diagnosed and treated for chlamydia are estimated to become infected within __ months after initial treatment
1 in 5 women who are diagnosed and treated for chlamydia are estimated to become infected within 10 months after initial treatment
What is LGV?
Serovars of chlamydia trachomatis (L1-L3)
How does LGV present?
in MSM
Rectal pain, discharge and bleeding
Describe the testing for CT?
Test 14 days following exposure
NAAT (nucleic acid amplification test)- females (vulvovaginal swab), males (first void urine)
MSM (add rectal swab if has receptive anal intercourse)
What is the treatment for chlamydia trachomatis?
Doxycycline 100mg BD x 1 week
Azithromycin 1G stat followed by 500mg daily for two days
What is associated with mycoplasma genitalium?
Non gonococcal urethritis (15-25%) and PID
How is mycoplasma genitalium tested for?
NAAT test (same sample sites as GC/CT
Why is mycoplasma genitalium so easily spread?
It has asymptomatic carriage
Gonorrhoea is a gram _____ _________ _______
The primary sites of infection are; (4)
Gonorrhoea is a gram negative intracellular diplococcus
The primary sites of infection are;
- Mucous membranes of urethra
- endocervix
- rectum
- pharynx
What is the incubation period of gonorrhoeal urethral infection?
Short in men (3-5 days)
__% risk of gonorrhoea transmission from infected woman to male partner
__-__% risk from infected man to female partner
20% risk of gonorrhoea transmission from infected woman to male partner
50-90% risk from infected man to female partner
How does gonorrhoea present in males?
Asymptomatic (<10%)
Urethral discharge >80%
Dysuria
Pharyngeal/rectal infections- mostly asymptomatic
How does gonorrhoea present in females?
Asymptomatic (up to 50%)
Increased/altered vaginal discharge (40%)
Dysuria
Pelvic pain (<5%)
Pharyngeal and rectal infection are usually asymptomatic
Complications of gonorrhoea favour _____:______
_% females: <_% males
Complications of gonorrhoea favour females:males
3% females: <1 % males
What are the lower genital tract complications of gonorrhoea?
Bartholinitis
Tysonitis
Periurethral abscess
Rectal Abscess
Epiididymitis
Urethral stricture
What are the upper genital tract complications of gonorrhoea?
Endometritis
PID
Hydrosalpinx
Infertility
Ectopic pregnancy
Prostatitis
What is tysonitis
inflammation of Tyson’s glands (preputial glands).
How is gonorrhoea diagnosed?
NAATs (screening test) >96% sensitivity
How is gonorrhoea tested for if symptomatic
Microscopy
Urethral (90-95% sensitivity)
Endocervical 37-50% sensitivity
What are the advantages of gonorrhoea testing via
- microscopy
- culture
- NAAT
Microscopy
- Near Pt diagnosis*
- Timely treatment*
Culture
Always allows antibiotic sensitivity and monitoring
NAAT
- Non invasive*
- Less problems with transport, media and storage*
What are the disadvantages of gonorrhoea testing via
- Microscopy
- Culture
- NAAT
Microscopy
- Invasive test*
- Low sensitivity*
- Requires confirmation*
Culture
- Invasive test*
- Requires specific media and incubation*
NAAT
- Risk of false positive*
- Positive result should be confirmed by NAAT with different targer*
What is the first line treatment for Gonorrhoea?
Ceftriaxone 500mg IM
What is the second line treatment for Gonorrhoea?
Cefixime 400mg oral (only if IM injection is contraindicated or refused by patient )
What is the most important aspect of gonorrhoea testing in all patients
Test of a cure
What are the three variations of genital herpes?
Primary infection
Non-primary first episode
Recurrent infection
Genital herpes (primary infection)
Incubation- _- _ days
Duration- __-__ days
Genital herpes (primary infection)
Incubation- 3- 6 days
Duration- 14-21 days
What are the symptoms of genital herpes primary infection?
- Blistering and ulceration of the external genitalia
- pain
- external dysuria
- vaginal or urethral discharge
- local lymphadenopathy
- fevel and myalgia (prodrome)
Recurrent episodes of herpes symptoms are common with which HSV?
HSV 2
Describe recurrent episodes of HSV2
Often overlooked/misdiagnosed
Usually unilateral, small blisters and ulcers
minimal systemic symptoms, resolves within 5-7 days
How should herpes be investigated and managed?
- Swab base of ulcer for HSV PCR
- Give oral antiviral treatment (aciclovir 400mg TDS x5/7)
- Consider topical lidocaine 5% ointment if very painful
- saline bathing
- analgesia
Viral shedding following HSV _ is consistently higher than for HSV _
Viral shedding following HSV 2 is consistently higher than for HSV 1
How can viral shedding be reduced?
By supressive therapy
What should be done if herpes is diagnosed within 5 weeks of EDD
Inform O+G
What is the mose common viral STI in the UK
HPV
How many hpv genotypes are there?
>200
What are the high risk HPV types
16, 18
31, 33, 25, 52, 58
Which HPV genotype presents with;
- anogenital warts
- palmar and plantar warts
- cellular dysplasia/intraepithelial neoplasia
Which HPV genotype presents with;
- anogenital warts= 6/11
- palmar and plantar warts= 1/2
- cellular dysplasia/intraepithelial neoplasia = 16/18
Who are you most liekly to have acquired HPV from?
Asymptomatic partner
What is the incubation period of HPV?
3 weeks to 9 months
Where is subclinical HPV common?
On all anogenital sites
HPV immunology
Spontaenous clearance of warts: __-__%
Clearance with treatment: __%
Persistence despite treatment: __%
HPV immunology
Spontaenous clearance of warts: 20-34%
Clearance with treatment: 60%
Persistence despite treatment: 20%
What is the treatment for HPV
Podophyllotoxin (Warticon)
- cytotoxic*
- Not licensed for extragenital warts- but widely used*
Imiquimod (aldara)
- Immune modifier*
- Can be used on all anogenital warts*
Cryotherapy
cytolytic can require repeat treatments
Electrocautery
Who gets HPV vaccine?
MSM
Women
Adolescent boys
What causes syphilis?
Treponema pallidum (spirochete)
How is syphillis transmitted?
Sexual contact
Trans-placental/during birth
Blood transfusions
Non-sexual contact- healthcare workers
What are the classifications of syphilis?
Congenital
Acquired
What are the phases of early infectious acquired sphilis?
Primary
Secondary
Early latent
What are the phases of late non-infectious acquired sphilis?
Late latent
tertiary
What is the incubation period of primary syphilis?
From 9-90 days (mean of 21 days)
What is the primary syphilis lesion known as?
Chancre (painless)
Where to chancres appear?
At the site of inoculation
What percentage of chancres are genital?
90%
Primary syphilis presents with a chancre and what else?
Non-tender local luymphadenopathy
What is the incubation period for secondary syphillis?
6 weeks to 6 months
Describe the presentation of secondary syphillis?
- Skin (macular, follicular or pustular rash on palms + soles)
- Lesions of mucous membranes
- Generalised lymphadenopathy
- Patchy alopecia
- Condylomata lata
What are condylomata lata?
Most highly infectious lesion in syphilis, exudes a serum teeming with treponemes
How is syphillis diagnosed?
Demonstration of treponema pallidum
From lesions or infected lymph nodes
Techniques;
- Dark field microscopy
- PCR (Polymerase Chain Reaction)*
Serological testing
- detects antibody to pathogenic treponemes
What are the non-treponemal serological tests for syphillis?
VDRL (venereal disease research laboratory)
RPR (rapid plasma reagin)
What are the treponemal serological tests for syphillis?
TPPA (treponemal pallidum partical agglutination)
ELISA/EIA (enzyme immunoassay) Screening test
INNO-LIA (line immunoassay)
FTA abs (fluorescent treponemal antibody absorbed)
What is the treatment for early and late syphilis?
Early
- 2.4 MU Benzathine penicillin x 1
Late
- 2.4 MU Benthatine penicillin x 3
What is the serological follow up for early/late syphillis?
Until RPR is negative or serofast
- titres should decrease fourfold by 3-6 months in early syphillis
- there is serological reslapse/reinfection if titres increase fourfold
