Africa's coronavirus case fatality rate stands at 2.5%, higher than the global level of 2.2%, a trend that is alarming experts, the head of the continent's disease control body said on Thursday.

Earlier in the pandemic, Africa's death rate had been below the global average, the Africa Centres for Disease Control and Prevention (CDC) head John Nkengasong told reporters.

"The case fatality rate is beginning to be very worrying and concerning for all of us," he said.

The number of African nations with a death rate higher than the current global average is growing, he added. There are 21 countries on the continent with a death rate of above 3%, including Egypt, the Democratic Republic of Congo, and Sudan.

Over the past week, cases decreased by nearly 7% compared to the previous week while deaths increased 10%, according to Africa CDC data. Africa has recorded 3.3-million coronavirus infections and 81 000 deaths as of Thursday, it says.

The continent reported 207 000 new cases in the past week, with South Africa alone reporting 100 000 of those new cases, Nkengasong said.