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SAN DIEGO -- The deadly hepatitis A (HAV) outbreak in San Diego reflects a national spike in cases over the past 15 months and a larger threat to homeless people across the country, health officials said.
There is evidence linking the San Diego HAV outbreak to cases elsewhere in California and in Arizona, Rhode Island, Colorado and Utah, Eric C. McDonald, MD, deputy public health officer with San Diego County, said at the annual IDWeek conference, sponsored jointly by the Infectious Diseases Society of American (IDSA), the Pediatric Infectious Diseases Society (PIDS), the Society for Healthcare Epidemiology of America (SHEA), and the HIV Medicine Association (HIVMA).
While the general population is not at significant danger, "there should probably be vaccinations" for homeless people who face high risk because of their living conditions, he told MedPage Today.
According to California health officials, the San Diego outbreak is the largest in the nation that's not linked to food contamination since the HAV vaccine was introduced in 1995.
As of October 2, 17 people died in cases linked to San Diego County's hepatitis A outbreak. Since the outbreak began in early 2017, 481 cases and 337 (70%) hospitalizations have been reported, according to county health officials.
Like some other U.S. outbreaks of HAV over the past 15 months, the one in San Diego is linked to person-to-person contamination instead of the more typical infection route through food, said CDC epidemiologist Monique A. Foster, MD.
Before the routine HAV vaccination of children, cases in the U.S. topped 21,000 a year, largely in kids, Foster said. Since then, the annual number of cases dipped by 95%. However, the CDC reported more than 1,400 outbreak cases since July 2016, she said.
Three of the five outbreaks over the last 15 months were not linked to transmission via food, she said, which is unusual. There were no non-foodborne outbreaks of HAV from 2003 through 2015.
Another unusual characteristic was the finding that the recent HAV cases were predominantly genotype 1B, which is rarely seen out outside of the Mediterranean and North Africa, she said. HAV genotype 1A is more common in North America and South America, she said.
There is no evidence that genotype 1B is more virulent, Foster told MedPage Today.
In San Diego, almost all the cases are among homeless people and/or illegal drug users. Officials believe the virus is transmitted person-to-person and "through contact with a fecally contaminated environment" -- polite terminology for the feces left in public places by the homeless who've had few restrooms to use.
McDonald reported that more than 54,000 people recently received HAV vaccinations in the San Diego. However, local officials did not begin a major push for public restrooms and hand-washing stations until a local news outlet in September exposed how red tape and inertia had delayed action.
Thus far officials have installed portable restrooms and 66 hand-washing stations in areas where homeless people congregate.
Officials also distributed "hygiene kits" and started power-washing streets and sidewalks with a bleach solution to address fecal contamination. In addition, the city is opening an outdoors "safe camp" that can serve 200 homeless people.
The homeless population in San Diego, the nation's eighth-largest city, became more visible in recent years for reasons that are unclear. Transients live on sidewalks throughout downtown (where the IDWeek conference is being held), erecting tents and covering their belongings with tarps.
Other California cities like San Francisco, San Jose, Los Angeles and Santa Ana in Orange County are also dealing with highly visible homeless populations.
McDonald, who didn't address the local controversy over the public health response, in his presentation, noted that five health care workers were infected with HAV cases linked to the outbreak, including four who worked in patient areas. The HAV outbreak also spread in jails, he said, and a law enforcement worker was infected.
While the CDC recommends that illicit drug users get vaccinated against HAV, there are no guidelines regarding homeless people. They haven't been considered an at-risk group, Foster said, and there's little known about HAV in the transient population.
McDonald said he expects the CDC might add homeless people to its vaccination guidelines.
According to news reports, HAV outbreaks linked to San Diego also affected homeless populations in Salt Lake City, Los Angeles and Santa Cruz, Calif.