Public health officials are trying to contain a multistate outbreak of hepatitis A that is spreading rapidly between people via close personal contact, not a contaminated food source.
The outbreak is being driven by high rates of infection among homeless people and drug users, who are unlikely to seek out or have access to health care. Close proximity among people in unsanitary living conditions also is fueling the spread of viral disease.
In Michigan, 837 cases have been documented since 2016. Of those, 80 percent of the infected have been hospitalized, and 27 people have died.
Last year, Southern California saw a large outbreak — particularly in San Diego County, which recorded 20 deaths, 588 infections and 403 hospitalizations.
“There’s been very much a shift, starting in 2015 or 2016, in the kinds of hepatitis A outbreaks that we’re seeing in the country,” said Jay Fiedler, an epidemiologist with the Michigan Department of Health and Human Services. “We’re now seeing these larger community-acquired outbreaks, and that’s very much what they saw in San Diego, in Utah. It’s what we’re seeing in Michigan.”
Hepatitis A is highly contagious and spread by ingesting feces-contaminated food or liquids.
Typically, health departments investigating an outbreak can pinpoint the source as an infected food worker or food item, and treat those people who were in close contact. In August 2016, a multistate outbreak of hepatitis A was linked to tainted frozen strawberries from Egypt.
But this latest outbreak took health officials by surprise. When health workers couldn’t tie the rising infection rates to a specific source, they focused on communities with conditions that fuel viral spread.
“I can’t specifically say that it is tied directly to the increase in opioid use or the opioid epidemic in the country right now,” Mr. Fiedler said. “I would say the two are correlated, but I don’t have direct proof of evidence.”
While the specific strain of hepatitis A is different between San Diego, Utah and Michigan, outbreak infections are traveling across state-lines in the Midwest.
In Nashville, Tennessee, the Metro Public Health Department said a rising number of infections are consistent with outbreaks in Indiana, which in turn blamed its increasing infections on a larger outbreak in Louisville, Kentucky.
West Virginia is the latest state to record an increase in infections, with a total of 121 cases since January, including 84 hospitalizations and one death. The strain identified in the state is linked to cases in Kentucky and California, the state health department said on its website.
The virus causes inflammation of the liver, but not everyone gets symptoms, which can present anywhere between five and 50 days after infection. Symptoms include fever, fatigue, nausea, loss of appetite, yellowing of the eyes (jaundice), stomach pains, vomiting, dark urine, pale stools and diarrhea.
“With hepatitis A being very infectious and having a long incubation period, it makes it very good at spreading person-to-person this way,” Mr. Fiedler said.
At least three vaccines are highly effective, but there are “constrained supplies” at the Centers for Disease Control and Prevention, meaning states requesting doses are given a limited amount.
“We have very much experienced the vaccine constraint that’s in place from CDC,” Mr. Fiedler said. “We have had to do certain things in terms of prioritizing.”
This means offering the vaccine for free to the most at-risk populations: the homeless, injection and non-injection drug users, men who have sex with men, people recently in prison, individuals co-infected with hepatitis C and those in the food service industry.
While most of the hepatitis A vaccines require multiple dosages, health officials are advising that at least one dose offers enough protection.
Awareness among the general public is low, said Mr. Fiedler, who urged people to get vaccinated if they’ve been exposed.
“The vaccine is very safe and its very effective and we cannot urge people enough to use it when it’s appropriate for you,” he said.