STI Pathologies

Question 1

Please see general info regarding STIs before we start:

Answer 1

• Most people with STIs are asymptomatic most of the time - hence they are still rife
• Delay in diagnosis can lead to an increased chance of transmission and complications
• Having an STI can be psychologically traumatising for many people. Often more damaging than the physical effects.
  
  • Patients need information, a sensitive approach and appropriate follow up.
• If you diagnose someone with say chlamydia but haven’t made arrangements for their sexual contact(s) to be treated then you haven’t finished the job.
• STI control is a multidisciplinary field

Question 2

Gonorrhea

What is causative organism?

Answer 2

• Neisseria gonorrhoeae

Question 3

Gonorrhoea

SSx?

Answer 3

Male:

• 10% of males have no symptoms though might have clinical signs if examined. Thick, profuse yellow discharge, dysuria. Rectal and pharyngeal infection often asymptomatic.

Female:

• >50% have no symptoms.
• vaginal discharge, dysuria or intermenstrual/post-coital bleeding

Question 4

Gonorrhoea

Complications?

Answer 4

Male:

• Epididymitis

Female:

• PID, Abscess

Both

• Acute monoarthritis usually elbow or shoulder. Disseminated Gonococcal Infection: skin lesions - pustular with halo

Question 5

Gonorrhoea

What is the incubation period?

Answer 5

Average 5-6 days

Question 6

Gonorrhoea

Epidemiology?

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

Gonorrhoea

How do we make Dx?

Answer 7

• Nucleic Acid amplification test (NAAT) on urine or swab from affected site (vagina, rectum, throat)
• 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

Gonorrhoea

Rx?

Answer 8

• Blind treatment with ceftriaxone 500mg im once plus Azithromycin 1g.
• Can also treat according to antibiotic sensitivities

Question 9

Gonorrhoea

Follow up?

Answer 9

Test of cure at 2 weeks and test of reinfection at 3 months

Question 10

Chlamydia

Caused by?

Answer 10

Chlamydia trachomatis serovars D to K

Question 11

Chlamydia

SSx?

Answer 11

Men:

• >70% asymptomatic
• Slight watery discharge, dysuria,

Female:

• >80% asymptomatic
• vaginal discharge, dysuria, intermenstrual/post-coital bleeding.

Both

• Conjunctivitis

Question 12

Chlamydia

Complications?

Answer 12

Male:

• Epididymitis

Female:

• 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 13

Chlamydia

Epidemiology?

Answer 13

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

Question 14

Chlamydia

How do we make Dx?

Answer 14

• First void urine in men.
• Self-taken or clinician-taken swab from cervix, urethra, rectum as appropriate.
• All specimens tested using a NAAT

Question 15

Chlamydia

Rx?

Answer 15

• Azithromycin 1g po once.
• Doxycycline 100mg bd 1 week if rectal infection.

Question 16

Chlamydia

Follow up?

Answer 16

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

Question 17

Herpes

Caused by?

Answer 17

Herpes Simplex Virus types 1 and 2

Question 18

Herpes

SSx?

Answer 18

• 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 19

Herpes

Complications?

Answer 19

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

Question 20

Herpes

Incubation period?

Answer 20

About 5 days to months. Some people never report symptoms

Question 21

Herpes

Epidemiology?

Answer 21

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 22

Herpes

How do we make Dx?

Answer 22

• Clinical impression.
• Swab from lesion tested using PCR.

Question 23

Herpes

Rx?

Answer 23

• 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 24

Trichomoniasis

Causative organism?

Answer 24

Trichomonas vaginalis

Question 25

Trichomoniasis SSx?

Answer 25

* Men: usually asymptomatic * Women: 10-30% asymptomatic * Profuse thin vaginal discharge - greenish, frothy and foul smelling. Vulvitis.

Question 26

Trichomoniasis Epidemiology?

Answer 26

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

Question 27

Trichomoniasis Complications?

Answer 27

Miscarriage and preterm labour

Question 28

Trichomoniasis How do we make Dx?

Answer 28

* PCR on a vaginal swab. NB not on urine yet so no test for men. * Point of Care - Microscopy of wet preparation of vaginal discharge.

Question 29

Trichomoniasis Rx?

Answer 29

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

Question 30

Anogenital Warts Caused by?

Answer 30

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

Question 31

Anogenital warts SSx?

Answer 31

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

Question 32

Anogenital warts Epidemiology?

Answer 32

\>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 33

Anogenital warts Complications?

Answer 33

None common

Question 34

Anogenital warts How do we make Dx?

Answer 34

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

Question 35

Anogenital warts Rx?

Answer 35

* Podophyllotoxin (brands warticon and condyline), imiquimod (brand Aldara). Both home treatments. Others – cryotherapy * Bulky warts – diathermy, scissor removal.

Question 36

Syphilis Causative organism?

Answer 36

Treponema pallidum subspecies pallidum

Question 37

Syphillis SSx? Stages?

Answer 37

Very diverse presentation Often entirely asymptomatic or mild symptoms which go unreported. * Primary stage: Local ulcer * Secondary: Rash, mucosal ulceration, neuro symptoms, patchy alopecia * Early latent: no symptoms but \<2 yrs since diagnosis * Late latent: no symptoms but \>2yrs since diagnosis * Tertiary: Neurological, cardiovascular or gummatous – skin lesions, (all v rare).

Question 38

Syphillis Epidemiology?

Answer 38

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

Question 39

Syphillis Complications?

Answer 39

neurosyphilis – cranial nerve palsies are commonest, cardiac or aortal involvement. Congenital syphilis _(extremely rare in Scotland)_.

Question 40

Syphillis How do we make Dx?

Answer 40

* Clinical signs * Serology for TP IgGEIA, TPPA and RPR PCR on sample from an ulcer

Question 41

Syphillis Rx?

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