CAPE TOWN - The National Institute for Communicable Diseases says environmental surveillance remains a key tool in its efforts to eliminate and eradicate polio.
The NICD has alerted the Health Department after detecting two different polio virus strains in wastewater samples.
The samples were collected from a treatment plant in Cape Town as part of routine monitoring.
NICD's Dr Kerrigan McCarthy said this discovery was an early warning for them.
"When we detect polio in wastewater, we know that someone in the community is infected and is secreting the virus into the community. Now, the problem is we don't know how widespread this infection is when detected in wastewater.
"It's actually a very early warning system that tells us that something might be happening. It's ongoing. It is one of our routine surveillance systems that we keep maintained through government and grant funding.
"It allows us to monitor polio in accordance with the World Health Organization guidelines. So, environmental surveillance is a component of polio elimination and eradication," McCarthy said.