The Department of Health has been informed that two different strains of the poliovirus have been detected in Cape Town sewage. (Photo: Gemini)
The National Institute for Communicable Diseases (Nios) has informed the Department of Health that two different strains of the poliovirus have been detected in Cape Town’s sewage water.
However, the department responded quickly and stressed that there was no reason to panic, as no cases of polio had been confirmed in humans.
Foster Mohale, spokesperson for the national department of health, says the detection of the two strains, specifically known as VDPV3 and nOPV2-L, was made during routine tests at a waste water treatment plant in Cape Town.
“This proactive testing is part of Nios’ comprehensive population-wide disease monitoring system. By regularly analyzing municipal sewage and water sources, scientists can determine future outbreaks and new virus variants long before any clinical symptoms appear in humans.”
According to Mohale, these specific detections are simply part of preventive public health management.
“These detections are officially described as ‘vaccine events’ because no actual cases of the virus have been detected in any human so far. Although this occurrence (of the virus) does require a public health response, it is not a high-risk situation and no additional vaccination campaigns are necessary at this stage,” says Mohale.
Possible overseas origin
Already in September 2019, South Africa was officially declared polio-free by the World Health Organization’s African Regional Certification Commission (ARCC). Polio is a disease that can be fully prevented by vaccines, and the country’s status remains unchanged. The presence of the virus in the sewage therefore indicates an external source rather than local transmission.
Mohale confirmed that the detection does not indicate a domestic crisis.
“This indicates that the viruses detected in the waste water probably came from people who were vaccinated in other countries with different types of polio antibodies than those used in South Africa. However, this does not mean at all that there is an outbreak of the disease in the country.”
Department monitors situation
Despite the low risk, health authorities are taking the situation seriously and further monitoring has already been introduced. The Department of Health is now working with Nios to step up surveillance and conduct more frequent sewage testing.
South Africa’s preparedness plans for possible outbreaks remain in place in the meantime, especially because polio still occurs sporadically in other countries and people constantly travel across national borders.
“The department, in close collaboration with Nios, has already taken the necessary health measures. This includes the tightening of surveillance and more frequent environmental monitoring and waste water tests,” says Mohale.
Be alert, but calm
Although there is no reason to panic, South Africans are encouraged to remain vigilant.
The department encourages the public to report any suspicious symptoms to their nearest healthcare provider immediately. These symptoms include progressive muscle or joint weakness, muscle pain, fatigue, muscle atrophy, as well as breathing or swallowing problems and sleep-related breathing disorders. However, many of these symptoms also occur with other common medical conditions.