STIs

Question 1

What is the most common type of sexually transmitted infection?

Answer 1

Herpes Simplex Virus (HSV)

Question 2

Gonnhoroea mode of transmission

Answer 2

Gonorrhoea is transmitted by contact with exudates from mucous membranes of infected people, almost always as the result of sexual activity. Gonococcal conjunctivitis can occur in neonates who have had contact with the mother’s infected birth canal during childbirth

Question 3

What type of pathogen is Syphilis? (Treponema pallidum)

Answer 3

Helically coiled, Gram-negative, spirochaete bacterium

Question 4

HIV mode of transmission

Answer 4

Contact between broken skin, wounds, or mucous membranes and HIV-infected blood or blood-contaminated body fluids. Deep, open-mouth kissing if both partners have sores or bleeding gums and blood from the HIV-positive partner gets into the bloodstream of the HIV-negative partner. HIV is not spread through saliva

Question 5

Treatment of syphylis

Answer 5

Benzathine penicillin 1.8 g (= 2.4 million units) IM, as a single dose

If penicillin sensitivity > Docycycline

Question 6

Treatment of Trichomoniasis

Answer 6

metronidazole 2g single dose

or

tinidazole 2g single dose (use metronidazole if pregnant or breastfeeding)

Treat sexual partner also

In cases of relapse: metronidazole 400 mg orally, 12-hourly for 5 days.

Question 7

Syphilis mode of transmission

Answer 7

Most cases of syphilis are transmitted by sexual contact (vaginal, anogenital and orogenital),

Can also be spread congenitally (in utero or less commonly during passage through the birth canal).

Rare cases of acquisition through blood products and organ donation have also been reported, as have cases resulting from occupational and other exposures.

Question 8

Chlamydia mode of transmission

Answer 8

Chlamydia is passed primarily during anal or vaginal sex. It is less likely to be transmitted through oral sex. It can be passed when the mucous membrane secretions or semen of an infected person.

Question 9

Symptoms of Chlamydial infection:

Answer 9

Most people infected are asymptomatic (asymptomatic infections are common in women)

Symptoms are similar to those of a urinary tract infection

i. e: urethritis,
complications: pelvic inflammatory disease, ectopic pregnancy, neonatal pneumonia, and neonatal conjunctivitis

Question 10

At what CD4 count does HIV become AIDS?

Answer 10

200

Question 11

Treatment of HIV

Answer 11

Antiretroviral Therapy

(ART)

Question 12

Symptoms of HSV infection:

Answer 12

Blisters in the skin and mucosa of mouth, lips (predominantly HSV-1) and genitals (predominantly HSV-2).

Lesions appears 3-7 days after infection and ulcerating and painful vesicles take up to 2 weeks to heal with scab formation

Local lymphadenitis, fever and malaise observed.

Can also cause dysuria and pain on micturition.

Encephalitis is very rare

Question 13

What type of pathogen is Chlamydia? (Chlamydiae trachomatis)

Answer 13

Non-motile, gram-negative, obligate bacteria (live and replicate within host cells)

Question 14

Treatment of HSV

Answer 14

aciclovir 400 mg orally, 8-hourly for 5 days

OR

famciclovir 250 mg orally, 8-hourly for 5 days [Note 3]

OR

valaciclovir 500 mg orally, 12-hourly for 5 days.

Question 15

Symptoms of Trichomoniasis infection:

Answer 15

Men usually asymptomatic / can cause urethritis and prostatitis

Women – symptomatic – vaginitis.

‘Frothy’, greenish vaginal discharge and erythematous cervix

May infect urinary tract, fallopian tubes, and pelvis and can cause pneumonia, bronchitis, and oral lesions

Complications - preterm delivery, low birth weight, and increased mortality as well as predisposing to HIV infection, AIDS, and cervical cancer

Question 16

Symptoms of Syphylis infection:

Answer 16

Primary syphilis - painless ulcer (chancre) develops 10 days to 90 days post exposure and heals spontaneously

Secondary syphilis - generalised rash that resolves without treatment. Rash on the palms and soles can occur. Systemic manifestations such as fever, malaise, and lymphadenopathy (“The Great Imitator”)

Tertiary syphilis affects 30% of untreated patients causes cutaneous, cardiovascular or neurologic complications

Question 17

Symptoms of Gonorrhoeal infection:

Answer 17

Asymptomatic infection is common in males and females

Untreated infection cause disseminated gonorrhoea infection, septic arthritis, pelvic inflammatory disease and possible infertility due to the resulting scarring

Question 18

HSV-1

Answer 18

frequently acquired through mucosal infection during early childhood (“cold sore”). Can also be spread through sexual transmission due to increase in oralgenito-sexual practices.

Question 19

HSV mode of transmission

Answer 19

Transmission of HSV infections occurs through close contact with a person shedding virus from a peripheral site, at a mucosal surface, or in genital or oral secretions.

Question 20

Metronidazole:

Mechanism of Action

Metabolism

Excretion

Answer 20

Metabolised into the active form (liver).

Thought to interfere with DNA synthesis.

Renal excretion but dosage does not usually need to be adjusted for renal impaired patients when short-course of treatment.

In patients with hepatic impairment, particularly those who also have impaired renal function, dose needs to be adjusted.

Question 21

What type of pathogen is Gonorrhoea? (Neisseria gonorrhoeae)

Answer 21

Non-motile, gram-negative, non-spore forming, faculative, intracellular diplococci (can only replicate within host cells)

Question 22

What type of pathogen is Trichomonas? (Trichomonas vaginalis)

Answer 22

Anaerobic, flagellated protozoan (eukaryote)

Question 23

HSV-2

Answer 23

spread by sexual contact (“genital herpes”)

Question 24

Method of Dx of Chlamydia?

Answer 24

Can be detected by direct microscopy by direct fluorescence antibody test (DFA) using fluorescence labelled monoclonal antibodies.

Chlamydia is detected using DNA-based tests in conjunction with N. gonorrhoea as co-infection is common

Question 25

Treatment of Gonorrhoea

Answer 25

Ceftriaxone 500 mg in 2 mL of 1% lignocaine IM, or 500 mg IV, as a single dose [Note 9]

PLUS

Azithromycin 1 g orally, as a single dose.

Question 26

Symptoms of HIV infection:

Answer 26

Early stage:

Flu-like symptoms, fatigue and headache, lymphadenopathy, arthralgia/myalgia, rash, nausea/vomiting/diarrhoea, pharyngitis, dry cough, night sweats

Question 27

Method of Dx of Gonorrhoea?

Answer 27

Chocolate agar culture with CO2 supplementation

Question 28

Treatment of Chlamydia

Answer 28

Azithromycin

Adult, child, oral 20 mg/kg (maximum 1 g) as a single dose.

or

Doxycycline

Question 29

Trichomoniasis mode of transmission

Answer 29

Trichomonas vaginalis is typically transmittedthrough vaginal, oral, or anal sex with an infected individual. It can also be passed from a mother to her baby at birth, as evidenced by the discovery of the parasite in the newborn’s lungs.

Question 30

Method of Dx of Trichomoniasis

Answer 30

Cervical smear (wet mount) - “corkscrew” motility observed

PCR diagnosis

Question 31

What is the most reliable way to detect Syphilis? (Treponema pallidum)

Answer 31

Syphilis is visible in dark field illumination, however, serologic tests are the mainstay of diagnosis.