Department confirms detections likely from imported cases vaccinated abroad.
The National Institute for Communicable Diseases (NICD) has detected two polio virus (VDPV3 and nOPV2-L) strains. Picture: iStock
There is no need for the public to be concerned after the detection of two different polio virus strains from wastewater sampled from a treatment plant, says department of health spokesperson Foster Mohale.
The National Institute for Communicable Diseases (NICD) informed the department on Friday of the positive detection of the two different polio virus strains from a wastewater treatment plant in Cape Town.
Two polio virus strains found in wastewater treatment plant
Mohale said his was part of the NICD’s routine environmental and wastewater testing to conduct proactive, population-wide disease tracking.
“This entails analysing municipal sewage and water resources to detect emerging outbreaks and viral variants before clinical cases appear.
“These detections are called vaccine events because no actual cases of the virus have been detected in a human being.
“These events need a public health response, are not high risk and no additional vaccination campaign is required,” he said.
Polio was a vaccine-preventable disease, Mohale said, adding that South Africa was officially certified polio-free by the World Health Organisation in September 2019.
SA polio-free since September 2019
“This suggests that the viruses detected in wastewater are likely from imported cases of people vaccinated with different vaccines from those used in South Africa.
“This does not translate to an outbreak,” he said.
Water scientist Ayesha Laher said while SA wastewater plants were in an extremely poor state, according to the latest Green Drop report, it had no connection with the detection of polio.
“The question was why polio was found in wastewater, because it means that there were people carrying polio in the community, which is a health risk,” Laher added.
University of Stellenbosch Faculty of Science spokesperson Wiida Fourie-Basson said researchers found evidence of genetic material from two major bacterial groups, commonly known to exhibit highrisk resistance profiles in wastewater samples from the City of Tshwane.
