Blood-borne infections

Question 1

What is the risk of transmission with exposure to HIV, Hep B/C

Answer 1

Hep B ~ 1 in 3

Hep C ~ 1 in 30

HIV ~ 1 in 300

Question 2

How long is HIV PEP?

Answer 2

Starter pack of triple anti-retroviral drugs.
Duration = 28 days.
Start within 72 hours (ideally 1-24 hours)

Question 3

What is the Hepatitis B PEP?

Answer 3

May need booster immunisation

May need HBIG

Question 4

What are the 3 modes of transmission for HIV?

Answer 4

Sexual.

Blood and bodily fluids (IVDU, Needlestick, Transplants).

Vertical (and post-partum during breast feeding).

Question 5

What are the 4 stages of illness with HIV infections?

Answer 5

1. Seroconversion illness - Glandular fever-like illness (Sore throat, Lymphadenopathy, Diarrhoea, Maculopapular rash, Mouth ulcers)
2. Asymptomatic stage of HIV (can last several years)
3. Symptomatic HIV (weakened immune system)
4. Late-stage HIV (AIDS-defining illnesses: Cancer, Tuberculosis, Pneumonia)

Question 6

What are the AIDS defining illnesses?

Answer 6

Tuberculosis
Pneumocystis Jiroveci

Cerebral toxoplasmosis
Cryptococcal meningitis

Kaposi sarcoma (HHV8)

Cytomegalovirus retinitis (CD4 <50)

Question 7

Give 4 risk factors for HIV infection

Answer 7

MSM
Multiple sexual partners
Diagnosed with STI
Group chem sex
Sex partner of known HIV positive
IVDU
People who have paid or been paid for sex
People who have received blood treatment from non-screening countries

Question 8

What do the initial HIV combination assays (EIA) detect?

Answer 8

Detects anti-HIV antibodies
Detects p24 antigen

Question 9

What is the acute presentation of Hepatitis B

Answer 9

Jaundice (30-50%)
Dark urine / Pale stools due to intra-hepatic cholestasis
Rash, Polyarthritis, Fever
Tender hepatomegaly

Question 10

What is the chronic presentation of Hepatitis B

Answer 10

Presentation is either as Compensated or Decompensated chronic liver disease

Question 11

What are the Hepatitis B serology results for Acute Hepatitis B Infection

Answer 11

HBsAg = Positive
HBcAb = Positive (IgM)
HBsAb = Negative

Question 12

What are the Hepatitis B serology results for Chronic Hepatitis B Infection

Answer 12

HBsAg = Positive
HBcAb = Positive
HBsAb = Negative

Question 13

What are the Hepatitis B serology results for Cleared Hepatitis B Infection

Answer 13

HBsAg = Negative
HBcAb = Positive
HBsAb = Positive

Question 14

What are the Hepatitis B serology results for Immunisation against Hepatitis B

Answer 14

HBsAg = Negative
HBcAb = Negative
HBsAb = Positive

Question 15

What is the preventative measures for Hepatitis B in pregnancy?

Answer 15

Mother may require antivirals if high viral load
Vaccinate neonate. Consider HIBG if high risk.

Question 16

What are the clinical features for Hepatitis C infection

Answer 16

Usually asymptomatic or mild
20% clear the infection
80% progress to Chronic infection&raquo_space; Cirrhosis + Hepatocellular carcinoma

Question 17

Outline the Hepatitis C testing/screening process

Answer 17

Anti-HCV (total) for initial screening
- Marks current or past infections
- Note, if antibody is present - reinfection is possible

Next test is&raquo_space; HCV RNA
- To distinguish current from past infection