LUSAKA, March 6 (Xinhua) -- Authorities in Zambia have imposed an immediate ban on the importation of risky food products like processed meat from South Africa following an outbreak of listeriosis in that country, a senior government official said on Tuesday.

South African authorities confirmed over the weekend that the source of the listeriosis outbreak has been linked to consumption of polony manufactured by a food processing company from Polokwane.

Minister of Health Chitalu Chilufya has since directed all South African chain stores in Zambia to remove such risky foods from their shelves.

The ministry has strengthened port health systems to monitor food imports into the country, he added.

According to him, a Disease Surveillance and Intelligence team as well as health inspectors have been directed to diligently investigate all suspicious food products and take appropriate action including destruction of contaminated or suspicious products.

Listeria bacteria may cause fever and diarrhea, with pregnant women being more likely to become infected.