STI learning guide Flashcards
What is an STI?
infection which is predominantly sexually transmitted; for example Chlamydia trachomatis or HIV. Other infections can be sexually transmissible but aren’t usually classed as STIs eg hepatitis A, hepatitis C, Zika and giardiasis. Another term sometimes used is ‘sexually transmitted disease’ (STD). This is often used interchangeably with ‘STI’ but is strictly speaking slightly different. An STI is the infection, eg Human Papilloma Virus, whereas an STD is the disease(s) it causes; eg warts.
What is gonnorhea caused by?
Neisseria gonorrhea
What are the symptoms of gonorrhoea?
Men 10% of males have no symptoms though might have clinical signs if examined.
Thick, profuse yellow discharge, dysuria. Rectal and pharyngeal infection often asymptomatic.
Women >50% have no symptoms.
vaginal discharge, dysuria or intermenstrual/post-coital bleeding
What are the complications of gonorrhea?
Male: Epididymitis
Female: Pelvic inflammatory disease. Bartholin’s abscess. [Gonococcal ophthalmia neonatorum.]
Both: Acute monoarthritis usually elbow or shoulder. Disseminated
Gonococcal Infection: skin lesions - pustular with halo. (both v rare).
What is the incubation period of gonorrhea?
Average 5 to 6 days. Range 2 days to 2 weeks (if get symptoms at all).
What is epidemiology of gonorrohea?
Approx 150 cases/yr in Grampian. Much less common than chlamydia. Most cases are in men, often in men who have sex with men (MSM).
How is gonorrhea diagnosed?
Nucleic Acid Amplification Test (NAAT) on urine or swab from an exposed site – vagina, rectum, throat. Could be self-obtained or clinician-obtained.
Gram stained smear from urethra/cervix/rectum in symptomatic people.
Culture of swab-obtained specimen from an exposed site using highly selective lysed blood agar in a 5% CO2 environment. Should be done for all confirmed cases to assess antibiotic sensitivity.
What is the treatment of gonorrhea?
Blind treatment with ceftriaxone 1g im. Can also treat according to antibiotic sensitivities.
What is chlaymdia caused by?
Chlaymdia trachomatis serovars D to K
What are the symptoms of chlaymdia?
Men: >70% asymptomatic
Slight watery discharge, dysuria,
Women: >80% asymptomatic
vaginal discharge, dysuria, intermenstrual/post-coital bleeding.
Both: Conjunctivitis
What are the complications of chlaymdia?
Men Epididymitis.
Women: PID and hence ectopic pregnancy, pelvic pain and infertility. Probably only ~1% of women who get chlamydia will develop a problem with their fertility
Both: Reactive arthritis/ Reiter’s syndrome – urethritis/cervicitis + conjunctivitis + arthritis
What is the epidiology of chlaymdia?
Common. Approx 2000/yr in Grampian. Most cases in people under 25, especially sexually active teenage women.
How diagnosis of chlaymdia done?
First void urine in men. Self-taken or clinician-taken swab from cervix, urethra, rectum as appropriate.
All specimens tested using a NAAT
What is the treatment of chlaymdia?
Doxycycline 100mg bd 1 week
Azithromycin 1g po once if pregnant
When is chlaymdia followed up?
Test for reinfection at 3-12 months. Earlier test of cure not needed unless symptoms persist.
What is herpes caused by?
Herpes simplex virus type 1 and 2
What are the symptoms of herpes?
80% have no symptoms. The rest have recurring symptoms – monthly, annually.
Burning/itching then blistering then tender ulceration.
Tender inguinal lymphadenopathy. Flu-like symptoms.
Dysuria, Neuralgic pain in back, pelvis and legs,
What are the complications of herpes?
Autonomic neuropathy (urinary retention), neonatal infection, secondary infection.
What is the incubation period of herpes?
About 5 days to months. Some people never report symptoms
What is the epidiomolgy of herpes?
Very common ~ 15-20% of UK population has it. Both strains equally common in genital infection. Roughly equal between sexes. HSV2 is important co-factor for HIV transmission.
What is the diagnosis of herpes?
Clinical impression.
Swab from lesion tested using PCR.
What is the treatment of herpes?
Primary outbreak: Aciclovir: various regimens – eg 400mg tds for 5 days
Lidocaine ointment
Infrequent recurrences: Lidocaine ointment. Aciclovir 1.2g once daily until symptoms gone (1-3 days)
Frequent recurrences: Aciclovir 400bd long-term as suppression.
WHat is trichomoniasis caused by?
Trichomonas vaginalis
What are the symptoms of trichomoniasis?
Men: usually asymptomatic
Women: 10-30% asymptomatic
Profuse thin vaginal discharge - greenish, frothy and foul smelling. Vulvitis.
What is the epidomology of trichomoniasis?
Uncommon, approx 100/yr in Grampian. More common in middle aged women than some other STIs are.
What are the complications of trichomoniasis?
Miscarriage and preterm labour
How is the diagnosis of trichominiasis done?
PCR on a vaginal swab. NB not validated on urine yet so no test for men.
Point of Care - Microscopy of wet preparation of vaginal discharge.
What is the treatment for trichominasis?
Metronidazole 400mg po bd for 5 days or 2g single dose.
What is anogenital warts caused by?
Human Papilloma Virus types 6 and 11 (and occasionally type 1). (NB different strains from those that cause cervical cancer.
What are the symptoms of anogenital warts?
Lumps with a surface texture of a small cauliflower. Occasionally itching or bleeding especially if perianal or intraurethral.
What is the epidiomolgy of anogenital warts?
>90% of UK population have a genital HPV infection at some point in their life. Only about 20% of those infected with a wart-causing strain of human papilloma virus get warts. A drop in cases is anticipated in response to quadrivalent HPV vaccine.
What are the complications of anogenital warts?
None common. Neonatal laryngeal papillomatosis.
What is involved in the diagnosis of anogenital warts?
Appearance. Biopsy if unusual – to exclude intraepithelial neoplasia, but this is rarely needed.
What is the treatment of anogenital warts?
Podophyllotoxin (brands warticon and condyline), imiquimod (brand Aldara). Both home treatments.
Others – cryotherapy
Bulky warts – diathermy, scissor removal.
What is syphillis caused by?
Treponema pallidum subspecies pallidum
What are the symptoms/stages of syphillis?
Diverse – “He who knows Syphilis knows medicine” – Osler.
Often entirely asymptomatic or mild symptoms which go unreported.
Primary Local ulcer (chancre)
Secondary Rash, mucosal ulceration, neuro symptoms, patchy alopecia, other symptoms.
Early latent no symptoms but <2years since caught.
Late latent no symptoms but >2 years since caught.
Tertiary Neurological, cardiovascular or gummatous – skin lesions, (all v rare).
What is the epidiology of syphillis?
Approx 20 cases/yr in Grampian. >90% of cases in Scotland are in men who’ve had sex with men.
What are the complications of syphillis?
neurosyphilis – cranial nerve palsies are commonest, cardiac or aortal involvement.
Congenital syphilis (extremely rare in Scotland).
What is the incubation period?
9 to 90 days until appearance of chancre. But can be asymptomatic.
How is the diagnosis of syphilis done?
Clinical signs
Serology for TP IgGEIA, TPPA and RPR
PCR on sample from an ulcer
What is the treatment of syphillis?
Early (<2 yrs and no neurological involvement):
Benzathine penicillin 2.4 MU im once
Or Doxycycline 100mg bd po 2 weeks
Late (>2 years) and no neurological involvement
Benzathine penicillin 2.4MU im weekly for 3 doses
Doxycycline 100mg bd po 28 days
