Health systems in Africa hobbled by shortages of oxygen and other resources are struggling with COVID-19's "second wave,”pushing the fatality rate above the global average, the continent's health watchdog said Thursday.

Africa has so far recorded around 3.3 million cases of COVID-19 and nearly 82,000 deaths, according to the Africa Centres for Disease Control and Prevention (Africa CDC).

These figures represent small fractions of the global totals, but cases have increased by an average of 14 percent each week for the past month.

Africa CDC director John Nkengasong told a press conference Thursday that the continent-wide case fatality rate was now 2.5 percent above the global average of 2.2 percent.

That is a break from earlier in the pandemic when death rates on the continent were on average lower than the rest of the world, Nkengasong said.

"During the second wave, we are beginning to see that reverse. So I think that is one of the remarkable characteristics of the second wave, which we must fight hard,” Nkengasong said.

A total of 21 African countries have so far recorded death rates higher than 2.2 percent, Nkengasong said.

"That also means you're overwhelming the ability of nurses, doctors to manage patients. Because of that, there will be inadequate attention and care… to patients because we have limited beds, limited supplies,” Nkengasong explained.

He also cited the need for more oxygen supplies, which he said was becoming “critical.”

In Nigeria, Africa's most populous country, health officials have described being forced to "decide which patients to manage and which not to manage,” Nkengasong said.

Last week the African Union announced it had secured 270 million doses of coronavirus vaccines, which will complement those secured via Covax, the globally-pooled vaccine procurement and distribution effort.