ASHEVILLE — Buncombe County Department of Health officials are investigating the outbreak of a rare strain of salmonella that experts believe originated in the county from an unknown food source. They are also concerned the number of infections will climb.
As of Friday afternoon, 29 possible cases had been identified in connection with the outbreak of salmonella paratyphi B, a bacteria spread through food products and, primarily, through person-to-person contact.
Buncombe County health director Gibbie Harris said it could be early next week before the original food source could be identified through lab results, and no restaurant or food vendor has been identified as a source.
“We do know at this point that the outbreak involves both person-to-person and food-product modes of spreading,” Harris said. “But we can’t know until we get test results what the original source is.”
Almost all cases have been in residents of, or visitors to, Buncombe County since Feb. 28, she said, and cases have also been reported in Tennessee and New York.
Harris said that because of an unusually long incubation period of up to 30 days, the infection may have spread to many more than the 29 suspected cases, and it could be weeks before the peak of the outbreak is reached.
Symptoms of salmonella paratyphi B usually begin about six days after exposure but may not begin for as long as 30 days. Symptoms may include gradual onset of high fever and fatigue, headache, loss of appetite, diarrhea and stomach pain, and usually last between four and seven days.
The strain is not considered life-threatening or dangerous to long-term health, though the elderly, infants and those with a compromised immune system can become seriously ill and may need to be hospitalized.
State epidemiologist Dr. Megan Davies said that of the thousands of “typical” salmonella cases seen in North Carolina each year, only a handful are the paratyphi strain and that a cluster of cases is “very unusual.”
Harris confirmed that multiple people who have been infected are restaurant workers in the area, but that they will undergo stringent testing before returning to work. She said it is DOH policy not to disclose the identities of individuals infected, and the department will not name any restaurants involved as long as proper control measures are being taken.
“If we had a specific restaurant or food to tell people to avoid, we absolutely would,” Davies explained. “But in this case, person-to-person contact is definitely the primary problem.”
Most salmonella cases are not treated with antibiotics, but the health department is recommending them for this strain, Harris said.
Salmonella is a “family” of bacteria and different types of salmonella cause slightly different symptoms, including onset and severity, method of transmission and how long a person is contagious. Davies said the strain in Buncombe can be more severe and is transmitted more easily than typical salmonella strains.
Any food can become contaminated at any point in the food chain, including at home or in restaurants. Contamination can occur when an infected person handles food and does not wash their hands well after using the bathroom.
Food can also become contaminated if cutting boards or counters are used to prepare contaminated foods and are not disinfected before preparing food that doesn’t get cooked, such as salads or fresh fruits.
“The best thing that people can do at this point is to be very diligent and thorough about hand washing, be sure to see a doctor if you’re experiencing symptoms and try to stay away from anyone who has been infected,” Davies said.
“But Buncombe County does have an extremely strong health department working on this,” Davies said. “People in Asheville should feel very fortunate to have this team.”