Two polio virus strains detected in Cape Town wastewater – NICD

The National Institute for Communicable Diseases (NICD) has detected two polio virus strains (VDPV3 and nOPV2-L) in wastewater samples from a treatment plant in Cape Town, Western Cape.

The NICD said it had informed the Department of Health of its findings.

Testing

According to the Department of Health, the detection was part of the NICD’s routine environmental and wastewater testing aimed at proactive, population-wide disease tracking.

“This entails analysing municipal sewage and water resources to detect emerging outbreaks and viral variants before clinical cases appear,” said health department spokesperson Foster Mohale.

“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.”

Polio

Polio is a vaccine-preventable disease, and South Africa was officially certified polio-free by the World Health Organisation’s African Regional Certification Commission (ARCC) in September 2019.

This suggests that the viruses detected in wastewater are likely from imported cases involving people vaccinated with vaccines different from those used in South Africa.

Mohale said this does not amount to an outbreak.

“The department, working closely with the NICD, has activated appropriate health response activities, including strengthening surveillance and increasing the frequency of environmental sampling of wastewater.

“South Africa continues to maintain outbreak preparedness plans, especially given the sporadic outbreaks of this disease in other countries and cross-border movements,” Mohale said.

Symptoms

Mohale stressed that while there is no cause for concern. The public is urged to remain vigilant and report any suspected polio symptoms promptly to the nearest healthcare provider.

“These symptoms include progressive muscle or joint weakness and pain, fatigue, muscle wasting, breathing or swallowing problems, and sleep-related breathing disorders. However, these are common symptoms for other health conditions.”