Last Friday, Oct. 13, governor Jerry Brown of California declared a state of emergency after hepatitis A cases in San Diego, Santa Cruz, and Los Angeles counties hit record highs.
In the past 11 months, 569 people have been infected and 17 have died of the virus in southern California. The US Centers for Disease Control reported that in 2015, there were a total (pdf) of 1,390 country-wide. This is now the second-largest outbreak in the US in the last 20 years. (The largest was over 10 years ago in Pennsylvania due to contaminated onions.)
Hepatitis A is a virus that damages the liver and causes it to swell. Many of the initial symptoms look like a stomach flu, but hep A can also cause the skin and the whites of your eyes to turn yellow, because the liver stops being able to filter out toxins in the blood. It spreads easily between people—especially through shared needles—or through contaminated food or drinking water. It’s an unpleasant virus whose symptoms usually last up to two months, but is only fatal about 1% of the time.
However, in San Diego, which is experiencing the worst of the California epidemic with almost 500 cases alone, most who have become sick are currently homeless. There are over 9,000 people who are homeless in San Diego, and they’re a particularly high-risk population for hepatitis A outbreaks. They don’t have access to clean water or basic sanitation, and are living in close proximity to one another. Many are also drug users. Without access to healthcare many have untreated liver conditions (like lingering hepatitis B or C infections, viruses similar to hep A but spread differently), which can make a new hep A infection lethal. Although there’s an effective vaccine for hep A, most of these people haven’t had it.
Brown declared a state of emergency in part to increase the supply of vaccines available to the homeless, and other efforts to curb the outbreak are already underway. Last month, San Diego started bleaching city streets to try to disinfect them, and city councilmen have also called for testing to ensure drinking water isn’t being contaminated with feces. In other cities affected by the outbreak, local government representatives have put in requests for port-a-potties as a way of improving sanitation on the streets to stop the spread of the virus.
Some 81,000 vaccines have already been distributed across the state this year; affected areas can now purchase additional vaccines from the federal government thanks to the state of emergency. Since last November, San Diego health officials have distributed thousands of extra vaccines to those who are homeless and those who work closely with them, like healthcare providers. Cities in Orange County have started preemptively giving vaccinations to hundreds of other people who are homeless, even though there have only been only two reported cases there so far.
The outbreak is not yet so bad that everyone in affected areas needs to get one. “The general population—if you’re not in one of those specific risk groups—is at very low risk,” Eric McDonald, the deputy public health officer for San Diego, told the LA Times.
Officials farther north in San Francisco and Oakland have said they’re concerned the outbreak with reach their cities if its progress isn’t curbed soon, and it’s likely that it will continue to spread for months ahead. “It’s not unusual for them to last quite some time—usually over a year, one to two years,” Monique Foster, an epidemiologist at the CDC, told the Times.