A transmission electron micrograph of a small cluster of the ribonucleic acid (RNA) hepatitis A virus. (Centers for Disease Control and Prevention Public Health Image Library)

The hepatitis A outbreak that has spread across 18 states, infecting over 15,000 people, has crept into Virginia.

According to the state’s Department of Health, there have been 45 cases reported in Virginia as of the beginning of this week, a 132 percent increase in cases compared to this time last year.

The nationwide outbreak has been going on since 2016. Of the 15,000 cases, 57 percent required hospitalizations, and 140 deaths resulted from the virus, according to the Centers for Disease Control and Prevention.

Largely, those impacted have been high-risk populations like drug users, people experiencing homelessness, men who have sex with men and people who are or were recently incarcerated.

That’s what makes this outbreak different from others the state has experienced in the past (like the one related to frozen strawberries in 2016), explained Marshall Vogt, epidemiologist with the Department of Health’s Division of Immunization: it’s spreading from person to person and isn’t tied to a food source.

Hepatitis A is primarily spread by the “fecal-oral route,” Vogt said — like when people use the bathroom and don’t thoroughly wash their hands. Then, the virus can spread through close interactions with others or through sexual contact. It can also be spread intravenously.

Hepatitis A is acute, meaning it doesn’t become chronic like hepatitis B or C. An inflammation of the liver, the virus typically lasts a few months before it runs its course. There is no treatment other than supportive care and monitoring for the disease, which often causes jaundice — the yellowing of the skin or eyes. Other symptoms include fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, joint pain, dark urine and clay-colored stools. Symptoms develop 15-50 days after exposure to the virus.

Southwest Virginia saw the increase in cases first, Vogt said, possibly due to the fact that West Virginia, Kentucky and Tennessee are also dealing with the outbreak. But now the Department of Health has seen cases statewide.

The best defense for the virus is vaccination, though good hand hygiene helps as well. According to the CDC, children are routinely vaccinated between their first and second birthdays, but the vaccine has only been available since 1995, so some adults may not have received it.

In Virginia, the vaccine is not required for school entry, so there is no statewide data on how well-immunized the population is. Vogt said that’s a frustrating limitation, but the outbreak related to frozen strawberries may have prompted many adults across the state to get their vaccination already, though there’s no way to know that for sure.

But, fortunately, the vaccination is very effective, he said.

“One dose is 95 percent effective, and after two doses, protection reaches almost 100 percent, with minimal side effects,” Vogt said. “Vaccination is one of the most effective ways to protect from this, and that’s why we want to raise attention of the importance of people checking their vaccination status.”

The old adage often heard by mothers, he added, would also help: frequent and thorough hand washing.

Local health departments are conducting a vaccination campaign that began in January and is focused on high-risk groups.