South America is a new COVID-19 'epicentre', African deaths still low: WHO

South America has become a new epicentre of the COVID-19 pandemic with Brazil hardest-hit, while cases are rising in some African countries that so far have a relatively low death toll, the World Health Organization (WHO) said on Friday.

"In a sense South America has become a new epicentre for the disease," Dr. Mike Ryan, WHO's top emergencies expert, told a news conference, adding Brazil is "clearly the most affected".

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Ryan noted Brazilian authorities have approved broad use of the anti-malarial drug hydroxychloroquine for treatment of COVID-19. He reiterated that current clinical evidence does not support the unproven drug's widespread use against the new disease, given its risks.

Some nine African countries had 50% rises in cases in the past week, while others have seen a decline or have stable rates, Ryan said. The low mortality rate may be due to half of the continent's population being 18 years old or younger, he said, adding he still is worried the disease will spread on a continent with "significant gaps" in intensive care services, medical oxygen and ventilation.