As masks and physical distancing become part of everyday living in South Africa, it looks like the traditional winter flu season is struggling to take hold. The lockdown has also kept the virus from spreading.
Flu cases usually start to rise sharply around mid-to-late April, but as of end-May there was still little sign of it according to the National Institute for Communicable Diseases, which collects data from sentinel sites that track respiratory diseases around the country.
The NICD says while cases of two flu strains were detected in the Western Cape, the number of cases has been falling since the first week of April.
There’s an even more marked delay in the onset of seasonal respiratory syncytial virus (RSV), another common pathogen that causes flu-like symptoms, and which can be fatal in young children. South Africa’s RSV season usually starts at the end of February, but by end-May it, too, was nowhere in sight
Flu normally kills over 10,000 South Africans and costs the economy billions of rands every year due to the deaths and absenteeism from sick days. If fewer people catch flu, the country will have a better chance of fighting Covid-19, experts wrote in April.
The drop in international travel could also have contributed, said Richard Lessells, an infectious disease specialist and group leader at the KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP). Seasonal flu has to be introduced into the country by travellers, much like Covid-19 was, he said.
“If there’s nobody coming into the country, you won’t have those feeder events.”
Walaza cautions that people avoiding going to the doctor during lockdown could have contributed to less flu and RSV being detected.
There’s also evidence from other parts of the world to suggest that physical distancing and lockdowns can stop the flu.
The northern hemisphere’s flu season ended about six weeks earlier than normal this year, Nature reported last week.
In Hong Kong, which registered its first Covid-19 case on 23 January, this year’s flu season was 63% shorter than usual.
Source: Business Insider.