COPENHAGEN, Aug. 18 (Xinhua) -- The number of confirmed cases of infection caused by the deadly bacteria listeria has risen to 24 in Denmark, health authorities said Monday.
According to Denmark's State Serum Institute (SSI), the number includes four more Danes who were confirmed to have been infected with listeria from cold-cut sausages.
In addition, another three individuals are being tested for the bacteria.
A Hedehusene-based sausage company has proved to be the main source of infection, SSI said.
Although the company is closed and all suspected products have been recalled, SSI expects that more cases may continue to pop up in the coming weeks as it typically takes several weeks for listeriosis symptoms to surface, it said in a statement.
A total of 12 people are believed to have died as a result of the listeria outbreak so far.
Some 30 products, including variations of cold-cut sausages, salami and hot dogs have been withdrawn from the market.
Regulatory control over listeria is now tightened with more extensive controls directed against listeria in companies, according to the country's Ministry of Food, Agriculture and Fisheries.
Listeria is a bacteria found in soil, water and in the intestines of some animals. The bacteria can also live in food processing plants. Unlike other germs, it can survive refrigeration.
It is one of the most virulent food-borne pathogens, with 20 to 30 percent of clinical infections resulting in death. Symptoms of listeria include weakness, vomiting, diarrhea and fever.