Hepatitis A virus
From IDWiki
Background
Microbiology
- Non-enveloped RNA virus within the Picornavirus family
- Three genotypes, I through III
- Difficult to kill: needs higher temperatures and lower pH than other viruses, or bleach- or ammonium-based cleaners
Epidemiology
- Fecal-oral transmission with person-to-person spread (including sex)
- Can be transmitted by contaminated food and water, as well
- Most often linked to travel or to household contacts
Clinical Presentation
- Incubation period is from 15 to 50 days, with an average of 28 days
Diagnosis
Serology
| IgM | IgG | Interpretation |
|---|---|---|
| – | – | No recent infection (unless in the incubation period). No prior infection or vaccination. |
| – | + | No infection. Prior infection or vaccination. |
| ? | + | Cannot rule out active infection. Prior infection or vaccination. |
| + | +/– | Acute or recent infection. IgM positive from 2 weeks until 3-12 months. IgG positive from 8-12 weeks and remains positive for lifetime. |
