DETROIT — The first signs that something was amiss surfaced in the weeks before the 2016 election, when public-health officials began to notice one patient after another walking into a clinic, or hospital emergency room in the Detroit metropolitan area complaining of the same symptoms: nausea and vomiting, pains in their stomach and joints, fatigue, fever, loss of appetite, yellowing of the skin and eyes, dark urine, and pale-colored feces.

It didn’t take long for the medical community to hone in on the culprit: hepatitis A.

For the roughly 21-month period between Aug. 1, 2016 to June of 2018, more than 846 cases of hepatitis A have been reported in Michigan, with more than 80 percent occurring in the southeast portion of the state that revolves around Detroit and its closest suburbs. For the sake of comparison, that is nearly triple the number of hepatitis A cases reported in Michigan for the 60-month period between 2011 and 2015. Twenty-seven of those infected with the virus have died, and nearly 650 have been hospitalized.

James Koopman, a retired epidemiologist at the University of Michigan in Ann Arbor, told MintPress:

This has gotten pretty big. It’s a significant outbreak and it’s surprising to me.”

What’s happening in Michigan is the largest outbreak of hepatitis A in the state’s history. But Michigan is hardly unique: In nearby Ohio, Indiana and Kentucky — and as far away as San Diego, Salt Lake City, and New York City — the number of hepatitis A cases is spiking sharply. It has, by at least one estimate, increased by nearly 50 percent over the past two years.

Hepatitis A is a curable but highly contagious disease of the liver caused by the hepatitis A virus or HAV, which is found in human excrement. You can contract the virus through contaminated food or water, unprotected sexual intercourse — particularly a combination of anal and oral sex — living with an infected person, or merely touching a doorknob after someone infected with the virus. It can take as long as 50 days for people infected with the disease to develop symptoms, and in rare cases it is fatal. The most effective safeguard is a vaccine, and public health experts recommend frequent hand washing with soap and warm water before cooking, or after using the bathroom, or changing a diaper.

A disease of poverty and isolation

While the spread of the disease from one person to another can vary widely, hepatitis A — like HIV and cholera — thrives on poverty and isolation, and sharp increases typically reflect broader tears in the social fabric. Laura Hanen, the head of governmental affairs at the National Association of County and City Health, told the Huffington Post:

We’re continuing to have an affordable-housing crunch, which means you have more homeless people. And oftentimes communities close the public bathrooms because of the opioid epidemic and people overdosing. Some of that is likely contributing to what we’re seeing.”

Michigan public-health officials warn state residents that they are most at-risk if they have a history of drug use, homelessness, transient housing and incarceration, or are men who have sex with men. The state appropriated more than $7 million at the end of 2017 to subsidize additional staffing, outreach, and vaccine purchases at local health departments to combat the spread of the disease.

With the fourth largest homeless population in the country, San Diego County seemed last year to slow the momentum of an outbreak of hepatitis A that infected 580 people, killing 20, between November 2016 and March of 2018 by spending $9.5 million on a public-health campaign that included scrubbing Skid Row streets with bleach, handing out plastic bags for homeless people to “poop” in, and providing vaccinations for San Diego’s homeless population. Meanwhile, health officials in Louisville, Kentucky report roughly 400 hepatitis A cases since November of 2017, or more than 10 times as many as the city typically reports over a similar period.

“My guess is that we’re closer to the beginning than the end” of fighting the outbreak in Kentucky, said Dave Langdon, a public information officer for the Louisville Metro Department of Health and Wellness.

Kentucky’s hepatitis A outbreak has spread across its northern border to southern Indiana, infecting 148 Hoosiers since November of last year; typically, health officials say, hepatitis A infects about 20 people in the state annually. Experts attribute the growth in infections to a growing homeless population, and widespread opioid use, particularly in southern Indiana.

In New York City, the health department is investigating an increase in hepatitis A cases among men who have sex with men, most of whom did not report recent international travel. Typically, that demographic produces no more than three hepatitis A in the five boroughs annually, but reported 45 infections between January through August of 2017.

An acutely political disease

While the Centers for Disease Control reports only a 5.4 percent increase in hepatitis A cases in 2017, an analysis of CDC and California’s Department of Health data by the Huffington Post found a 48.7 percent increase in hepatitis A cases from 2016 to 2017. Journalists with the Huffington Post say that the CDC is downplaying their numbers to avoid a panic.

The numbers of the homeless increased nationwide last year for the first time since the nadir of the Great Recession in 2010, and public health experts note that the homeless are particularly vulnerable because they lack proper sanitation. Also vulnerable are users of illicit drugs, whose numbers are rising and who often don’t have access to medical care.

Doctor Koopman told MintPress that Michigan’s outbreak seems to be a different viral strain from that reported in other states, and the failure of health authorities to pinpoint its origin to a fast-food worker or a single person who has infected multiple sex partners, is alarming. Said Koopman.

There’s something unique about what we’re seeing in Michigan, and what makes hepatitis A so tricky is the long incubation period. It usually takes about a month from the time you’re infected for you to start developing symptoms.”

Similar to HIV 35 years ago, hepatitis A is an acutely political disease, affecting some of the most marginalized people in society. “It’s difficult to keep public health, and especially public health for poor disenfranchised people, on the frontlines of public consciousness,” Dr. Jeff Duchin, the public health officer for Seattle told the Huffington Post.

Top Photo | Christine Wade sits among her children in front of their donated tent in the city-sanctioned encampment on a parking lot in San Diego. They are, from left, Shawnni, 12, Roland, 4, Rayahna, 3, Jaymason, 2, Brooklyn, 8, and Shaccoya, 14. The Wade family is among several hundred people living in the city’s first campground open for the homeless, set up to curb the worst Hepatitis A outbreak in the United States in decades. Gregory Bull | AP

Jon Jeter is a published book author and two-time Pulitzer Prize finalist with more than 20 years of journalistic experience. He is a former Washington Post bureau chief and award-winning foreign correspondent on two continents, as well as a former radio and television producer for Chicago Public Media’s “This American Life.”