NICD detects two polio strains in Cape Town wastewater what Joburg readers should know

What happened

The National Institute for Communicable Diseases (NICD) detected two polio virus strains VDPV3 and nOPV2-L in wastewater samples from a treatment plant in Cape Town, the Citizen reported on 22 May 2026. The NICD informed the Department of Health of the findings, the report said.

Why the detections were made

According to the Citizen, the detections were part of the NICD’s routine environmental and wastewater testing, a programme described by the Department of Health as a proactive, population-wide way to track disease by analysing municipal sewage and water resources.

What authorities say

Department of Health spokesperson Foster Mohale explained the purpose of the surveillance in a statement published in the Citizen:

“This entails analysing municipal sewage and water resources to detect emerging outbreaks and viral variants before clinical cases appear.”

The Citizen also reported that these detections are referred to as “vaccine events” because no actual cases of the virus have been detected in a human being.

Public health response

Per the Citizen, 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. The department said this does not amount to an outbreak and that no additional vaccination campaign is required, the Citizen reported.

Context and what Joburg readers should know

Polio is vaccine-preventable; South Africa was certified polio-free by the World Health Organization’s African Regional Certification Commission in September 2019, the Citizen noted. Health officials said the viruses detected in wastewater are likely linked to imported cases involving people vaccinated with different vaccines from those used in South Africa, the Citizen reported.

Symptoms and vigilance

The Department of Health urged the public to remain vigilant and to report any suspected polio symptoms to the nearest healthcare provider. Symptoms cited in the Citizen report included progressive muscle or joint weakness and pain, fatigue, muscle wasting, breathing or swallowing problems, and sleep-related breathing disorders, though officials noted these symptoms can occur with other conditions.

What comes next

The Citizen said the Department of Health and the NICD are maintaining outbreak preparedness plans, and have increased environmental sampling as part of their response. For now, authorities describe the situation as a surveillance finding rather than an outbreak.