The US Food and Drug Administration this week asked more firms to recall products, with items pulled from the shelves of grocery stores, including from Walmart Inc. and Costco Wholesale Corp. Here’s everything you need to know about the hepatitis A outbreak and which products to avoid.

What is hepatitis A?

Hepatitis A is usually a short-term viral infection leading to inflammation of the liver, which does not normally lead to chronic illness or long-lasting organ damage, according to the US Centers for Disease Control and Prevention (CDC). Hepatitis A is not to be confused with the similarly named hepatitis B and C viruses, which can remain in the body long-term and are far more dangerous.

Still, the disease can, in rare instances, be serious. In 2020 there were 179 fatalities in the US where hepatitis A was listed as “a cause of death,” in patients for whom multiple causes were listed. The CDC estimated there were nearly 20,000 cases in the US that year.

How is hepatitis A transmitted?

The virus is highly contagious and spreads when one ingests it, often from contaminated food and water. It can also be spread through close physical or sexual contact.

How does hepatitis A get onto food?

Food can easily be contaminated by the hepatitis A virus, which can be found in the stools and blood of people infected. Failing to wash hands after the bathroom means food handlers can easily contaminate products with the virus at any point in the production process, from growing and harvesting to cooking. Crucially, it can even survive freezing temperatures, meaning contaminated frozen food simply harbors the virus until it is defrosted — often a long way from where it was produced.

In the most recent outbreak, the FDA has linked the virus to frozen organic strawberries imported from Baja California, Mexico. Fresh strawberries from the northern state led to a separate hepatitis A outbreak in the US last year, which infected at least 18 people.

What are the hepatitis  symptoms to watch out for?

Symptoms typically develop two to seven weeks after infection. They can include skin and eyes turning yellow, fatigue, fever, loss of appetite, dark urine or light-colored stools. 

But a person can transmit the disease up to two weeks before symptoms appear, and carriers are sometimes asymptomatic, making detection difficult. The best way to determine whether a patient has hepatitis A, as it can share symptoms with many other conditions, is with a blood test.

Is there a vaccine and is it curable?

Multiple-dose vaccines have been administered for decades, and are proven to be effective against the virus, with generally mild side effects. Combination vaccines are also available and can help protect against both hepatitis A and hepatitis B. There is no specific medication to treat hepatitis A, with patients generally recovering with adequate rest, hydration and nutrition. Once you’ve had it once, you can’t catch it again.

Is it safe to eat frozen fruit?

In general, yes. While the most recent outbreak has caused alarm, it has still affected only a small number of people, with nine cases linked to contaminated strawberries reported across three states. Among those, three people were hospitalized and none of the cases have proved fatal.

How do I find out which products may be contaminated?

The FDA advises people to check their frozen strawberries before they consume them, to ensure they are not on the list of potentially contaminated products. Check out the FDA’s full list of recalled strawberry products here.