Gynae: blood borne viruses

Question 1

What is the risk of acquiring the common blood borne viruses after exposure?

Answer 1

• Hep B: 1:3
• Hep C: 1:30
• HIV: 1:300

Question 2

What are the risks of vertical transmission in untreated HIV mothers?

What intranatal, post-partum and post-partum measures are recommended to reduce risk of vertical transmission?

Answer 2

-23-30%

Reducing vertical transmission:

-Anti-retroviral therapy (HAART – should be started as soon as patient is diagnosed) during pregnancy and delivery
-Avoidance of breastfeeding (increases risk of viral transmission, all HIV +ve women are recommended to bottle feed).
-Neonatal post-exposure prophylaxis
*Collectively reduce risk of transmission from ¼ to 1%

Question 3

What are the criteria for a vaginal delivery in a HIV positive patient?

Answer 3

• MDT based decision based on CD4+ count and viral load at 36 weeks and previous pregnancies
• Patient can delivery vaginally if taking HAART, have viral load below 50 and CD4+ count above 350

Question 4

What is the U=U campaign?

Answer 4

-Undetectable = untransmittable: undetectable viral load (for minimum 3 months) when being compliant with medication has been shown to stop transmission completely.

Question 5

What is HIV PEP?

Answer 5

• Post-exposure prophylaxis – started packs of triple anti-retroviral drugs
• Lasts for 28 days, ideally start within 24h but can be taken within 72

Question 6

What is HIV seroconversion illness?

Answer 6

• Period where immune system mounts an immune response and develops Abs against HIV. Lasts 203 weeks
• Causes flu like symptoms: fever, malaise, arthralgia, headache, sore throat, lymphadenopathy, rash (most common sx)
• Less common symptoms: NS involvement (meningitis, encephalitis, peripheral neuropathy, myelopathy)

Question 7

What is AIDS? Name 3 cancers associated with AIDS

Answer 7

• When a patient’s CD4+ count drops below 200 and the patient suffers from opportunistic infections due to immunosuppression
• Non-hodgkins lymphoma, Kaposi’s sarcoma, cervical cancer

Question 8

What prophylaxis is available for Hepatitis B and C?

Answer 8

• Hep B: booster immunisation, HBIg (incompletely vaccinated, poor responder and if source of blood contamination is HBsAg +ve (acute Hep B infection)
• Hep C: no prophylaxis available

Question 9

What is Hep C? Describe the progression of the infection

Answer 9

• RNA virus transmitted via blood borne (IVDU, needlestick, transfusion), vertical (5% risk) or sexual transmission
• Clinical features: usually asymptomatic or mild, incubation lasts approx. 6/52
• 20% clear the infection and 80% progress to chronic infection (risk factor for cirrhosis and hepatocellular carcinoma

Question 10

What tests are available to diagnose Hep C? How do you interpret them?

Answer 10

• Anti-HCV (total): used for initial screening – becomes +ve 4-10 weeks after exposure. Only indicates whether there is current or past infection.
• HCV RNA: distinguishes between current and past infection – if HCV RNA is +ve patient is infected and infectious

Question 11

How do you treat Hep C?

Answer 11

• NO vaccine, PEP or immunoglobulin available
• Cure exists: 3/12 of treatment will clear Hep C but does not prevent re-infection

Question 12

What is Hep B? Describe the 3 basic components of the Virus and what they mean

Answer 12

-DNA virus (80% clear infection and 20% progress to chronic infection)

3 Basic components:

• Surface antigen: if +ve tells us the patient has Hep B
• Core antibody: tells us if the patient has been exposed (vaccine or infected) to Hep B – remains +ve for life
• Surface antibody: if +ve tells us patient has acquired immunity (vaccination or natural clearance) and if –ve tells us patient has chronic infection – tells of chronicity

Question 13

Attempt to fill out the table. Options are +ve or -ve. Answers on the back

Answer 13