Hepatitis A

Question 1

route of Hep A transmission

Answer 1

faecal-oral usually

HAV may also be present in serum and saliva. However, blood transmission of HAV occurs only in extremely rare cases because HAV viremia is transient; therefore, donated blood is not screened for HAV.

Question 2

risk factors for transmission of Hep A

Answer 2

Contaminated water and food (e.g., raw shellfish)
Risk groups: international travelers, nursing home residents, prison inmates, men who have sex with men, IV drug users.

Question 3

infectious period for Hep A

Answer 3

2 weeks before onset of illness until 1 week after onset of illness

Question 4

labs for Hep A

Answer 4

increased serum transaminases levels
AST / ALT ratio < 1
raised total bilirubin and urine bilirubin
raised ALP and GGT

if AST / ALT ratio is > 1, this is a sign of fulminant hepatitis

Question 5

confirmatory testing for Hep A

Answer 5

↑ Anti-HAV IgM antibodies: present in patients with active infection
Usually detectable 5–10 days after exposure and 5–10 days before clinical symptoms develop

↑ Anti-HAV IgG antibodies
Develop during active infection and persist indefinitely after infection or vaccination

HAV RNA can be detected in still and serum samples using PCR

Question 6

Anti-HAV IgM antibodies indicate

Answer 6

present in patients with active infection
Usually detectable 5–10 days after exposure and 5–10 days before clinical symptoms develop
Levels peak commonly ∼ 1 month after infection.
May persist for up to 6 months after infection

Question 7

Anti-HAV IgG antibodies indicate

Answer 7

Develop during active infection and persist indefinitely after infection or vaccination
Production begins within 2–3 weeks of infection.

Question 8

how to tell between active infection and immunity in HAV

Answer 8

The presence of anti-HAV IgM antibodies or HAV RNA confirms active hepatitis A. Detection of anti-HAV IgG antibodies in the absence of anti-HAV IgM antibodies indicates immunity against HAV due to prior infection or vaccination.

Question 9

treatment of hep A

Answer 9

Hepatitis A is generally self-limited.
Offer supportive care
Consider symptomatic treatment, e.g., antiemetics.
Inability to maintain hydration with oral fluids can be an indication for parenteral fluid therapy and hospitalization.
Recommend alcohol avoidance.
Use medications that are metabolized by the liver with caution (e.g., acetaminophen).
More intensive treatment may be required in rare cases in which hepatitis A leads to acute liver failure.

Question 10

is Hep A a notifiable disease

Answer 10

yes

Question 11

hep A post exposure prophylaxis

Answer 11

Postexposure prophylaxis is indicated for all previously unvaccinated individuals who have been in contact with an individual with serologically confirmed hepatitis A within the past two weeks.