– Just before July 4th, Trenton Burrell began feeling run-down and achy. Soon he could barely muster the energy to walk. A friend shared an alarming observation: “You’re turning yellow.”

Within days, the 40-year-old landed in the hospital, diagnosed with the highly contagious liver virus hepatitis A, which since 2016, has spawned outbreaks in at least 29 states. It has sickened more than 23,600 people, sent the majority to the hospital and killed more than 230. All but California’s and Utah’s outbreaks are ongoing, and experts expect to see the virus seep into every state.

Like a shadow, it follows the opioid epidemic, spreading mostly among drug users and the homeless. But anyone who hasn’t been vaccinated can get hepatitis A.

“It’s getting into the general public,” said Tracy Rodriguez, communicable disease supervisor for Summit County Public Health. “It’s scary.”

Hepatitis A thrives in unsanitary conditions and spreads as easily as a stomach virus: People ingest minuscule amounts of an infected person’s stool from food, drinks, drug equipment or objects as commonplace as doorknobs. Burrell believes he contracted the virus cleaning up trash left by fellow drug users and not wearing gloves.

The virus has stricken more people in Ohio than any other state but Kentucky, where it infected more than 4,800 people and killed at least 60. Kathleen Winter, a University of Kentucky epidemiologist, said more populous Ohio is on pace to surpass it as her state’s outbreak wanes.

Relentlessly, the virus continues its march across the nation. Pennsylvania declared an outbreak as recently as May. In early August, Florida and Philadelphia declared public health emergencies, which, among other things, signal to health care providers the need to vaccinate the vulnerable. Case counts now exceed 1,000 in six states.

And as in Akron, the virus reaches beyond homeless people and drug users. One in 5 Kentuckians sickened from August 2017 through mid-2019 fit neither group. Nearly 40% of Florida’s cases from 2018 and the first half of 2019 had no or unknown risk factors.

Simon Haeder, an assistant professor of public policy at Pennsylvania State University, said the outbreaks show how the addiction crisis and the diseases it fuels endanger everyone, while also revealing cracks in the nation’s patchwork, poorly funded public health system. A recent report by Trust for America’s Health found only 2.5% of U.S. health spending in 2017 went to public health.

“We have growing homeless and drug-using populations. We have a decreasing investment in public health. It doesn’t make me optimistic looking into the future,” Haeder said. “Once you reach a critical mass, eventually everyone is fair game.”

Hepatitis A, which infects liver cells and causes inflammation, can be mild or severe and in rare cases leads to liver failure and death, especially in older people and those with other liver diseases. There’s no cure; doctors advise rest, nutrition and fluids.

Cases dropped dramatically in the United States after a vaccine came out in 1995. The shots are recommended for babies, and federal figures from 2016 show 61% of children 19- to 35-months old had gotten both of two doses. Only 9.5% of adults 19 and older had gotten the shots.

With so many unprotected adults, the disease roared back in 2016. Public health workers fought it by vaccinating those at greatest risk. In California’s San Diego County, they also opened hand-washing stations, distributed hygiene kits and washed down streets with a bleach solution.

The next year, outbreaks appeared in five more states, including Kentucky, where it would metastasize into the nation’s largest. The virus crept into neighboring Ohio in 2018, gradually infecting people in all but seven of 88 counties.

Rodriguez and her colleagues have mounted an all-out assault in Ohio. They have administered more than 550 vaccinations, targeting people at the jail, syringe services programs, drug treatment centers, post-incarceration support groups and homeless communities. When they identify cases, they work to find and vaccinate their families, friends and close contacts. Sage Lewis, an advocate for the homeless, said “the health department is saving lives.”

News coverage in some places highlights infected restaurant workers, but the Centers for Disease Control and Prevention said transmission to restaurant patrons has been “extremely rare” during these outbreaks because of sanitation practices such as washing hands and wearing gloves.

Controlling the virus has proven especially challenging in rural areas, where there are fewer services such as homeless shelters and homelessness can mean couch-surfing with friends. Many small towns have small health departments, with just a couple of nurses and declining budgets.

A 2018 survey by the National Association of County and City Health Officials found 23% of local health departments serving populations of less than 50,000 — and 19% of all local health departments — expect budget cuts in the next fiscal year.

Against this backdrop, the CDC has injected federal resources. It spent roughly $9.1 million in fiscal 2018 to help curb outbreaks, which includes money for 150,000 federally funded vaccines.

Dr. Monique Foster, a medical officer in CDC’s Division of Viral Hepatitis, said vaccinating those at highest risk remains the best strategy. “Outbreaks will stop when we have effectively vaccinated the vulnerable people,” she said.

With the virus continuing its advance, Penn State’s Haeder said, “it won’t be long before we have it everywhere.”