JOHANNESBURG – The National Institute for Communicable Diseases (NICD), in Johannesburg, South Africa, reported 107 case patients have died from Listeria monocytogenes.

The agency, which is a division of the National Health Dept., said 852 listeriosis cases were confirmed between Jan. 1 and Feb. 5, but so far, the source of the outbreak is not known. “Presently no food sources that are contaminated with the outbreak strain have been found, including amongst poultry and poultry products,” the agency said in a statement.

Case patients ranged in age from newborns to 93 years old. NICD reported 344 cases are babies 28 days old or younger. Females accounted for 457 of the 825 cases confirmed so far. Pregnant women are 10 times more likely than other people to get a Listeria infection, according to the Atlanta-based Centers for Disease Control and Prevention (CDC).

NICD said 505 cases have been reported from Gauteng Province, followed by 107 in Western Cape and 63 cases in KwaZuluNatal Province. Cases have been diagnosed in both public and private healthcare sectors.

“Healthcare workers across the country, both in the private and public healthcare sectors, are aware of this outbreak and have been cautioned to be alert for listeriosis in groups of people at high risk of developing severe disease,” NICD said. “When health workers suspect listeriosis, appropriate laboratory tests can be performed (blood culture) and correct antibiotic treatment can be given. The infection is treated with ampicillin, an antibiotic that is widely available.”

The National Health Dept. highlighted steps the agency is taking to address the outbreak. In a statement, the agency said individuals who have been diagnosed with listeriosis are being interviewed to understand what foods they have eaten to identify trends. The agency also is collecting data from food safety agencies to collect samples from food production facilities. The NICD and infectious disease physicians are working together to establish guidelines for diagnosing and treating the disease. Finally, the agency is working to increase public awareness of how to prevent listeriosis.

Symptoms of listeriosis can include headache, stiff neck, confusion, loss of balance and convulsions in addition to fever and muscle aches, according to the CDC. Pregnant women typically experience flu-like symptoms such as fever, fatigue and muscle aches. But an infection can lead to miscarriage, stillbirth, premature delivery or a life-threatening infection of the newborn.

Individuals can be sickened by eating food contaminated with Listeria, however some foods are more vulnerable to Listeria contamination. The CDC has identified queso fresco and other soft cheeses, raw sprouts, melons, deli meats and hot dogs, smoked seafood and unpasteurized milk as foods that are more likely to contain Listeria.