STI's Flashcards
What is the most common STI?
Chlamydia
What % of women and men with chlamydia are asymptomatic?
70% of women.
50% of men
What type of bacterium is chlamydia?
Gram -ve
How can chlamydia be transmitted?
Vaginal, oral or anal
Who is the highest incidence of chlamydia in?
20-24 year olds, both male and female.
What is the % of women with chlamydia who develop PID estimated at?
9%
What are the risks of an episode of PID?
Risk of ectopic pregnancy increases 10-fold.
Risk of tubal factor infertility of 15-20%.
How does chlamydia present in males?
- Urethral discharge (clearer than in gonorrhoea).
- Dysuria.
- Urethritis.
- Epididymo-orchitis.
- Proctitis (LGV).
How does chlaymdia present in females?
(often asymptomatic)
- Post coital or intermenstrual bleeding (this is the most common red flag)
- Lower abdominal pain
- Dyspareunia (painful sex)
- Mucopurulent cervicitis
What % of cases of PID does CT account for?
50%
What problems can arise as a result of tubal damage?
- Infertility
* Ectopic pregnancy
How may CT transmitted to the neonate present?
17% conjunctivitis
OR
20% pneumonia.
What is the triad of symptoms in Reitiers?
- Conjunctivitis
- Urethritis
- Arthritis
Tayside is the worst area in Scotland for Chlamydia rates
Ooops
‘Piano string adhesions’ is the classic sign of?
Fitz-Hugh-Curtis Syndrome (Perihepatitis)
What is responsible for LGV?
L1-3 serovars of chlamydia trachomatis
What has happened to the rates of LGV?
They have been increasing from 2003.
Who mostly gets LGV?
MSM
What are the symptoms of LGV?
- Rectal pain.
- Discharge.
- Bleeding.
With LGV, what is there a high risk of?
Concurrent STI’s (67% HIV).
When is the test for chlamydia done?
14 days following exposure
What tests are done for chlamydia in i) females ii) males iii) MSM?
i) NAAT – vulvovaginal swab.
ii) NAAT – first void urine.
iii) MSM – first void urine PLUS rectal swab if has had receptive anal intercourse.
How is chlamydia treated?
Doxycycline 100mg BD x 1 week
Describe the ‘test for cure in chlamydia’.
Not done routinely, but is done 3 weeks after treatment in pregnant women or for those with rectal infection.
Describe the bacteria in gonorrhoea.
Gram negative INTRACELLULAR diplococcus
What are the primary sites of infection in Gonorrhoea?
The mucous membranes of the urethra, endocervix, rectum and pharynx.
What is the incubation period of urethral infection in men?
Usually short – 2-5 days
What is the risk of transmission from an INFECTED WOMAN to MALE partner?
20%
What is the risk of transmission from INFECTED MAN to FEMALE partner?
50-90%
Who is gonorrhoea most common in?
Under 25’s
Is the presentation of gonorrhoea in men likely to be asymptomatic?
No - ≤10% of males with gonorrhoea have no symptoms
What is the most common sx? In what % of people with gonorrhoea does this occur?
Urethral discharge - >80%.
Describe urethral discharge in gonorrhoea.
Mucopurulent
What other urogenital sx is this often associated with?
Dysuria.
Pharyngeal/rectal infections are mostly asymptomatic in gonorrhoea
TRUE
What % of females with gonorrhoea will be asymptomatic?
Up to 50%
What sx may gonorrhoea present with in females?
- Increased/altered vaginal discharge – 40%.
- Dysuria.
- Pelvic pain - <5%.
In what % of i) females ii) males do complications of gonorrhoea occur?
i) 3%.
ii) <1%.
Outline some upper genital tract complications of gonorrhoea.
- Endometritis
- PID
- Hydrosalpinx
- Infertility
- Ectopic pregnancy
- Prostatitis
Outline some lower genital tract complications of gonorrhoea.
- Bartholinitis
- Tysonitis
- Periurethral abscess
- Rectal abscess
- Epididymitis
- Urethral stricture
What is the screening test and gold standard for the dx of gonorrhoea?
NAATS >96% sensitivity (both symptomatic and asymptomatic)
What are the other options (minus NAAT’s`) for the diagnosis of gonorrhoea?
Microscopy
- Urethral 90-95% sensitivity
- Endocervical 37-50% sensitivity
Culture
- > 95% sensitivity (male urethra)
- 80-92% sensitive (female endocx)
What is the first line treatment for gonorrhoea?
Ceftriaxone 500mg IM
OR
Cefixime 400mg oral (only if IM injection is contra-indicated or refused by pt)
What is gonorrhoea co-treated with?
Azithromycin 1g (regardless of Chlamydia result) given at the same time as gonorrhoea treatment.
Why is gonorrhoea co-treated with Azithromycin?
- Helps clear gonorrhoea.
* Given because of high rates of co-infection with chlamydia
What should be done in all patients who are diagnosed with chlamydia?
Test for cure !!!
Many strains of gonorrhoea are resistant to antibiotics
What do you need to decide in someone with genital herpes?
- Primary infection.
- Non-primary first episode.
- Recurrent infection
What is the intubation period of genital herpes?
3-6 days.
What is the duration of the herpes virus?
14-21 days
How does genital herpes present?
- Blistering and ulceration of the external genitalia.
- Pain.
- External dysuria.
- Vaginal or urethral discharge.
- Local lymphadenopathy.
- Fever and myalgia (prodrome).
When diagnosing genital herpes, where should swabs be taken from?
Open lesions
With what type of HSV are recurrent episodes more common?
HSV 2
Why is herpes often overlooked/misdiagnosed?
It is often mistaken for ‘thrush’ – mild, localised anogenital tingling, burning or soreness.
What do recurrent episodes of HSV usually present like?
As unilateral small blisters and ulcers
Describe systemic symptoms is HSV.
Are minimal and resolve within 5-7 days
How is genital herpes investigated?
Swab base of ulcer for HSV PCR.
What is the causative virus in genital herpes?
HSV
How is genital herpes treated?
- Give oral antiviral treatment – acyclovir. (shortens current episode and relieves sx)
- Consider topical Lidocaine 5% ointment if very painful.
- Saline bathing.
- Analgesia.
Is viral shedding more common following infection with HSV 1 or 2?
2
When is viral shedding more common in genital herpes infection?
In the first year of infection.
Who does viral shedding in HSV occur more in?
Individuals with frequent recurrences.
What is viral shedding in genital herpes reduced by?
Suppressive therapy.
What is the most common VIRAl STI in the UK?
HPV
What is the lifetime risk of acquiring HPV?
Up to 80%.
How many different genotypes of HPV are there?
> 170
What are the low risk genotypes of HPV?
6,11,42,43,44
What are the high risk genotypes of HPV?
16,18,31,33,35,45,51,52,58 and 66
What genotypes of HPV cause anogenital warts?
Types 6 and 11
What genotypes of HPV cause cancer?
Types 16 and 18
What genotypes of HPV causes palmar and plantar warts?
Types 1 and 2
What % of the population will be exposed to HPV?
80%
What % of the population probably harbour detectable infection of HPV?
10%
What % of people will develop anogenital warts?
1%.
Who are people most likely to have acquired HPV from?
An asymptomatic partner
What is the incubation period of HPV?
3 weeks to 9 months
Subclincial disease of HPV is common where?
On all anogenital sites.
Transmission of more than one HPV type is common
True
What % of people with anogenital warts experience spontaneous clearance of warts?
20-34%
What % of people with anogenital warts experience clearance with treatment?
60%
What % of people with anogenital warts experience persistence despite treatment?
20%
What are >90% of anogenital warts caused by?
HPV 6 and 11
What are the 4 options of treatment of HPV?
- Podophyllotoxin (Warticon).
- Imiquimod (Aldara).
- Cryotherapy.
- Electrocautery.
Who is offered the HPV vaccine?
MSM and people living with HIV.
What is - Podophyllotoxin (Warticon), in the treatment of genital warts?
- Cytotoxic.
* Not licensed for extra-genital warts, but widely used.
What is - Imiquimod (Aldara), in the treatment of genital warts?
- Immune modifier.
* Can be used on all Anogenital warts.
What is the causative organism in syphilis?
Treponema pallidum (spirochete)
What is syphilis usually transmitted through?
- Sexual contact.
- Trans-placental/during birth.
- Blood transfusions.
- Non-sexual contact – healthcare workers.
How is syphilis categorised?
- CONGENITAL.
or - ACQUIRED.
What is the intubation period of primary syphilis?
From 9-90 days (mean of 21 days).
What is the lesion traditionally known as in primary syphilis?
A primary chancre (painless).
Where do primary lesions in syphilis occur?
At the site of inoculation.
Describe the primary sites in syphilis.
Sites are genital in 90% and extra-genital in 10%.
As what as a primary chancre, what else may there be?
Non-tender local lymphadenopathy.
What is the intubation period in secondary syphilis?
6 weeks to 6 months.
Outline how secondary syphilis may present.
- On skin as a macular, follicular or pustular rash on palms + soles.
- Lesions on mucous membranes.
- Generalized lymphadenopathy.
- Patchy alopecia.
- Condylomata lata (most highly infectious lesion in syphilis, exudes a serum TEEMING with TREPONEMES).
Outline how a diagnosis of syphilis can be confirmed. Mention the 2 categories of ix.
Demonstration of Treponema Pallidum (from lesions or infected lymph nodes)
- Dark Field Microscopy
- PCR (polymerase chain reaction)
Serological Testing
- Detects antibody to pathogenic treponemes
Give 2 examples of non-treponemal serological tests.
VDRL – Venereal Disease Research Laboratory.
RPR – Rapid Plasma Reagin.
Give 4 examples of treponemal serological tests.
- TPPA (Treponemal Pallidum Particle Agglutination)
- ELISA/EIA (Enzyme Immunoassay)
- INNO-LIA (Line immunoassay)
- FTA abs (Fluorescent Treponemal Antibody absorbed)
Name a screening test for syphilis.
ELISA/EIA (Enzyme Immunoassay).
How is early syphilis treated?
2.4 MU Benzathine penicillin x 1
How is late syphilis treated?
2.4 MU Benzathine penicillin x 3
For early/late syphilis, when should follow-up be done?
Until RPR is negative or serofast
If early syphilis is successfully treated, what should happen to titres?
They should decrease four-fold by 3-6 months.
If there is serological relapse/reinfection, what happens to titres?
They increase by fourfold.
This STI is known as the “great imitator” because its symptoms resemble those of other infections
Syphilis
The vaccine for HPV is currently recommended for females (HIV negative) ages …
11-13
