Younger, less dense populations and hot, humid climates are being cited as key reasons why Africa has been spared a surge in coronavirus cases.

As Europe and the Americas battle high case numbers, infections have been declining in many African countries.

On top of social and environmental factors in the continent's favour, the World Health Organization praised the "decisive" action by African nations.

Some countries, however, are still seeing rises in cases.

According to the WHO, in the past four weeks in Africa, 77,147 cases were recorded, down from 131,647 in the previous four weeks.

"Africa has not witnessed an exponential spread of Covid-19 as many initially feared," said Dr Matshidiso Moeti, the WHO's Regional Director for Africa.

"The downward trend that we have seen in Africa over the past two months is undoubtedly a positive development and speaks to the robust and decisive public health measures taken by governments across the region," she said.

In a statement, the WHO said "a mix of socio-ecological factors such as low population density and mobility, hot and humid climate, lower age group, interacting to accentuate their individual effects" were most likely to be behind the decline.

Latest tallies show that nearly 1.5 million people in Africa have been confirmed as contracting coronavirus, with around 35,000 deaths.

The US - the world's worst affected country - has had nearly seven million cases and over 200,000 deaths.

Low levels of testing remains a concern in Africa, with a handful of countries responsible for the bulk of those carried out.

The WHO is urging African countries to maintain public health measures and warns against complacency, with Ivory Coast and Cameroon bucking the trend by seeing a slight increase in cases.