Flu season officially started on 22 April and there is a general expectation that up to 40% of South Africans will get the virus, the National Institute for Communicable Diseases says.

South Africa is in "flu season", which began on 22 April. The National Institute for Communicable Diseases said there were no indications that this year's flu was worse than before.

Dr Sibongile Walaza, the head of epidemiology at the National Institute for Communicable Diseases (NICD) Centre for Respiratory Diseases and Meningitis, said 20-40% of South Africa's population is infected with influenza every year.

"It is still too early to tell how severe the current influenza season will be. However, from the surveillance programme data we have at the moment, there are no indications that the current influenza season is more severe than previous ones."

She said hospital admissions (and deaths) were expected to increase during the flu season. Previous data estimates are that on an annual basis in South Africa, "an estimated 56,000 individuals are hospitalised with influenza", she added.

Flu season starts when the three-week moving average (adding all the cases over three weeks and dividing by 21) remains above a certain number for two consecutive weeks. These cases are taken from in-patient programmes monitored by the NICD.

According to the latest surveillance report published by the NICD, 1,798 samples were taken from patients in surveillance programmes from the...