RICHMOND, Va. — There are now 28 confirmed cases of hepatitis A in Virginia linked to Egyptian strawberries used by Tropical Smoothie Cafe franchises, and lawsuits are being filed.

The Virginia Department of Health traced the source of the hepatitis A virus to frozen strawberries imported from Egypt and consumed in July or early August. The department also confirmed that all potentially contaminated berries were pulled from the 96 Tropical Smoothie Cafe locations in Virginia no later than Aug. 8 or Aug. 9.

There are more than 500 of the smoothie franchises across the country, and Virginia is not the only state affected. Two others have reported recent hepatitis A outbreaks among people exposed to products from a Tropical Smoothie Cafe, said VDH spokeswoman Marian Hunter. The CDC is working with those states to determine if the cases are related to Virginia’s outbreak. Hunter did not identify the states.

The hepatitis A virus affects the liver, and symptoms can emerge relatively slowly, from 15 to 50 days after infection. They include yellowing of the skin or eyes, stomach and chest pain, fever and nausea.

That makes it crucial to provide timely alerts about possible outbreaks, because a vaccine or immune globulin must be administered within two weeks of exposure to be effective at preventing the disease, according to a release from the VDH.

Tropical Smoothie Cafe CEO Mike Rotondo issued a video apology on YouTube, and said “we voluntarily and immediately removed all of those strawberries from all of our cafes. We have sourced new strawberries for every location.”

Some afflicted customers are seeking class-action status for their lawsuits against Tropical Smoothie Cafe. Their lawyers will be closely examining how quickly the company took action to stop the outbreak, said attorney William D. Marler of Seattle-based Marler Clark LLP, which specializes in food poisoning cases.

“We’ve been contacted by five people who are hepatitis A positive, and a dozen or so people got shots to try to prevent getting sick,” Marler said.

Separately, Constantinos A. Raptis of Olney, Maryland, said he was hospitalized for four days after consuming smoothies from a Tropical Smoothie Cafe restaurant in Purcellville. His lawsuit seeks $100,000.