Hepatitis A virus infections associated with berry and pomegranate mix
Posted Jun 19 2013 12:00am
Hepatitis A virus is a member of the picornavirus family, which also contains poliovirus and rhinovirus. The virion is a naked, icosahedral particle containing a single strand of positive-sense RNA. Infection is typically acquired by ingestion of food contaminated by feces containing the virus. In one scenario, food is contaminated by an HAV-infected food handler who does not practice good hand hygiene. After ingestion, the virus enters the gastrointestinal tract and then passes to the blood. It then replicates in the liver leading to jaundice and elevated serum levels of liver enzymes. After replicating in the liver, HAV passes into the intestine via the bile canaliculi and is then shed in feces. The incubation period of the disease is on average 4 weeks, but infectious particles are present in feces about two weeks before the onset of clinical symptoms. The virus is most likely to be transmitted during this period as the infected individual does not display clinical symptoms.
There are six genotypes of HAV that circulate worldwide. According to the CDC, the virus strain causing this outbreak is HAV genotype 1B, which is often found in North Africa and the Middle East but is rarely isolated in the Americas. Genotype 1b caused a 2013 European outbreak linked to frozen berries, and a 2012 British Columbia outbreak in which a frozen berry blend was implicated. In the BC outbreak the berry blend contained pomegranate seeds from Egypt. This is likely why Townsend Farms recalled the berry mix when they found that it contained pomegranate seeds processed in Turkey.