STI learning guide

Question 1

What is an STI?

Answer 1

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.

Question 2

What is gonnorhea caused by?

Answer 2

Neisseria gonorrhea

Question 3

What are the symptoms of gonorrhoea?

Answer 3

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

Question 4

What are the complications of gonorrhea?

Answer 4

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).

Question 5

What is the incubation period of gonorrhea?

Answer 5

Average 5 to 6 days. Range 2 days to 2 weeks (if get symptoms at all).

Question 6

What is epidemiology of gonorrohea?

Answer 6

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).

Question 7

How is gonorrhea diagnosed?

Answer 7

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.

Question 8

What is the treatment of gonorrhea?

Answer 8

Blind treatment with ceftriaxone 1g im. Can also treat according to antibiotic sensitivities.

Question 9

What is chlaymdia caused by?

Answer 9

Chlaymdia trachomatis serovars D to K

Question 10

What are the symptoms of chlaymdia?

Answer 10

Men: >70% asymptomatic

Slight watery discharge, dysuria,

Women: >80% asymptomatic

vaginal discharge, dysuria, intermenstrual/post-coital bleeding.

Both: Conjunctivitis

Question 11

What are the complications of chlaymdia?

Answer 11

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

Question 12

What is the epidiology of chlaymdia?

Answer 12

Common. Approx 2000/yr in Grampian. Most cases in people under 25, especially sexually active teenage women.

Question 13

How diagnosis of chlaymdia done?

Answer 13

First void urine in men. Self-taken or clinician-taken swab from cervix, urethra, rectum as appropriate.

All specimens tested using a NAAT

Question 14

What is the treatment of chlaymdia?

Answer 14

Doxycycline 100mg bd 1 week

Azithromycin 1g po once if pregnant

Question 15

When is chlaymdia followed up?

Answer 15

Test for reinfection at 3-12 months. Earlier test of cure not needed unless symptoms persist.

Question 16

What is herpes caused by?

Answer 16

Herpes simplex virus type 1 and 2

Question 17

What are the symptoms of herpes?

Answer 17

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,

Question 18

What are the complications of herpes?

Answer 18

Autonomic neuropathy (urinary retention), neonatal infection, secondary infection.

Question 19

What is the incubation period of herpes?

Answer 19

About 5 days to months. Some people never report symptoms

Question 20

What is the epidiomolgy of herpes?

Answer 20

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.

Question 21

What is the diagnosis of herpes?

Answer 21

Clinical impression.

Swab from lesion tested using PCR.

Question 22

What is the treatment of herpes?

Answer 22

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.

Question 23

WHat is trichomoniasis caused by?

Answer 23

Trichomonas vaginalis

Question 24

What are the symptoms of trichomoniasis?

Answer 24

Men: usually asymptomatic

Women: 10-30% asymptomatic

Profuse thin vaginal discharge - greenish, frothy and foul smelling. Vulvitis.

Question 25

What is the epidomology of trichomoniasis?

Answer 25

Uncommon, approx 100/yr in Grampian. More common in middle aged women than some other STIs are.

Question 26

What are the complications of trichomoniasis?

Answer 26

Miscarriage and preterm labour

Question 27

How is the diagnosis of trichominiasis done?

Answer 27

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.

Question 28

What is the treatment for trichominasis?

Answer 28

Metronidazole 400mg po bd for 5 days or 2g single dose.

Question 29

What is anogenital warts caused by?

Answer 29

Human Papilloma Virus types 6 and 11 (and occasionally type 1). (NB different strains from those that cause cervical cancer.

Question 30

What are the symptoms of anogenital warts?

Answer 30

Lumps with a surface texture of a small cauliflower. Occasionally itching or bleeding especially if perianal or intraurethral.

Question 31

What is the epidiomolgy of anogenital warts?

Answer 31

>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.

Question 32

What are the complications of anogenital warts?

Answer 32

None common. Neonatal laryngeal papillomatosis.

Question 33

What is involved in the diagnosis of anogenital warts?

Answer 33

Appearance. Biopsy if unusual – to exclude intraepithelial neoplasia, but this is rarely needed.

Question 34

What is the treatment of anogenital warts?

Answer 34

Podophyllotoxin (brands warticon and condyline), imiquimod (brand Aldara). Both home treatments.

Others – cryotherapy

Bulky warts – diathermy, scissor removal.

Question 35

What is syphillis caused by?

Answer 35

Treponema pallidum subspecies pallidum

Question 36

What are the symptoms/stages of syphillis?

Answer 36

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).

Question 37

What is the epidiology of syphillis?

Answer 37

Approx 20 cases/yr in Grampian. >90% of cases in Scotland are in men who’ve had sex with men.

Question 38

What are the complications of syphillis?

Answer 38

neurosyphilis – cranial nerve palsies are commonest, cardiac or aortal involvement.

Congenital syphilis (extremely rare in Scotland).

Question 39

What is the incubation period?

Answer 39

9 to 90 days until appearance of chancre. But can be asymptomatic.

Question 40

How is the diagnosis of syphilis done?

Answer 40

Clinical signs

Serology for TP IgGEIA, TPPA and RPR

PCR on sample from an ulcer

Question 41

What is the treatment of syphillis?

Answer 41

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