STIs

Question 1

List the most common STIs (descending order).

Answer 1

Chlamydia 
Genital warts
Gonorrhea 
Genital herpes 
Syphilis 
HIV

Question 2

What causes chlamydia? What symptoms do Serovars D-K and Serovars L1-3 cause?

Answer 2

Caused by chlamydia trachomatis
Serovars D-K:
- Males = urethritis, epididymitis, prostatitis
- Females = cervicitis, PID, Fitz-Hugh Curtis
- Neonate = conjunctivitis + pneumonia

Serovars L1-3:

• lymphogranuloma venereum (chronic infection of lymphatic system)
  
  • Buboes = swollen inflamed lymph nodes
  • Proctitis = inflammation of the rectum/anus

Question 3

What are the complications and treatment options for chlamydia?

Answer 3

Complications:

• reactive arthritis
• infertility

Treatment options:

• Azithromycin
• Doxycycline
• Tetramycine

Question 4

What causes genital warts? Which strains of the virus are carcinogenic? What is the treatment?

Answer 4

Human papilloma virus 
Carcinogenic strains = 16, 18, 31, 33
Treatment: HPV vaccine 
- topical podophyllotoxin 
- imiqimod (cream)
- cryotherapy

Question 5

What causes gonorrhoea? What are the S+S in males, females and neonates?

Answer 5

Cause: Neisseria gonorrhoea
Males: urethritis, prostatitis, sore throat, epididymitis
Females: cervicitis, PID, peri-hepatitis, septic abortion
Neonate: conjunctivits

Question 6

What are the complications associated with gonorrhoea? How it is treated?

Answer 6

Complications:

• septic arthritis
• blindness
• infertility
• septicaemia (meningitis, endocarditis)

Treatment:
Ceftriaxone

Question 7

What is the difference between HSV 1 + 2? What are the important features of Herpes virus? How is it managed?

Answer 7

HSV1 = oral
HSV2 = genital
Important features:
- there is a latency phase - virus lives in trigeminal/sacral ganglia
- reactivation phase (ill, stressed etc) - symptomatic, lesion can appear on mouth + genitals
- or asymptomatic

Management (no cure!!):

• aciclovir
• famciclovir
• valaciclovir

Question 8

What causes syphilis? What is the treatment?

Answer 8

Treponema pallidum
Treatment:
- penicillin
- doxycycline

Question 9

What are the signs + symptoms of primary syphilis and secondary syphilis?

Answer 9

Primary:

1. Chancre (genital ulcer disease) - usually a single, painless ulcer; can occur anywhere at site of infection; heals within a few weeks = no scar
2. Lymphadenoapthy
   * Dark ground/Dark field microscopy will be positive - will show lil’ squiggly worm thingies

Secondary:

• rash
• fever
• lymphadenopathy
• condyloma lata (genital warts)
• serology will be +ve

Question 10

What is primary HIV? How quickly do symptoms arise? What is the differential diagnosis?

Answer 10

Known as acute retroviral syndrome
there will be increased viral replication and reduced CD4 count
75% of patients will develop symptoms within 2-6 weeks of infection
Differential diagnosis: glandular fever, flu-like illness

Question 11

What are the common features of primary HIV?

Answer 11

• Headache
• Lymphadenopathy
• Oral/genital ulceration
• Pharyngitis
• Nausea
• Rash
• myalgia

Question 12

How does HIV cause disease?

Answer 12

HIV infects CD4+ cells (t helper), macrophages + dendritic cells

• in acute HIV there is massive loss of CD4+ cells
• in chronic HIV there is ongoing loss of CD4+ cells, reduced immune function and progressive immunosuppression

Question 13

What are the direct and indirect effects of HIV?

Answer 13

Direct: wasting, diarrhoea, neurological problems
Indirect: allow invasion by opportunistic infection:
can cause malignancies: lymphoma, cervical carcinoma

Question 14

What are the different forms of antiretroviral drugs?

Answer 14

• Nucleoside reverse transcriptase inhibitors (NRTIs)
• Non-NRTIs
• Protease inhibitors (PIs)
• Fusion inhibitors
• Integrase inhibitors
• Co-receptor antagonists

*always combine at least 3 from 2 classes
these drugs act during viral replication - prevent production of new HIV particles

Question 15

What are the short-term and long-term issues with HAART?

Answer 15

Short-term:

• Nausea
• Vomiting
• Headache
• Sleep disturbance

Long-term:

• Lipodystrophy
• Renal dysfunction
• Renal dysfunction
• Peripheral neuropathy
• Lactic acidosis

Question 16

What is IRIS?

Answer 16

Immune reconstitution inflammatory syndrome
- collection of inflammatory disorders associated with paradoxical worsening of preexisting infectious processes following the initiation of antiretroviral therapy (ART) in HIV-infected individuals

Question 17

What doe PrEP, PEP and PEPSE stand for? What are the indications for these precautionary treatments?

Answer 17

PrEP = pre-exposure prophylaxis 
PEP = post-exposure prophylaxis 
PEPSE = PEP after sexual intercourse 

Indications =

• high risk sexual exposure <72 hours
• needle stick

Question 18

How is HIV managed in pregnancy? By how much does this reduce the risk of transmission?

Answer 18

• Early screening for HIV
• Antiretroviral therapy for mother :
  a. immediate and continued if low CD4
  b. 2nd trimester + discontinued if high CD4
• elective c-section (vaginal delivery if undetectable HIV load)
• antiretroviral therapy for infant
• no breastfeeding

Reduces risk of transmission from 25% to 1%