NAIROBI - The number of COVID-19 cases in Africa has surged at an unprecedented pace as the continent grapples with a third wave that has posed a dire threat to public health infrastructure, a World Health Organization (WHO) official said Thursday.

Matshidiso Moeti, WHO regional director for Africa, said the continent is grappling with a surge in COVID-19 infection fuelled by the easing of containment measures, cold weather and the presence of new variants.

"The third wave is picking up speed, spreading faster, hitting harder. With rapidly rising case numbers and increasing reports of serious illness, the latest surge threatens to be Africa's worst yet," Moeti said in a statement.

She said the continent can avert the worst outcomes as it struggles with the third COVID-19 wave of infections, subject to strict adherence to public health protocols combined with speedy vaccine roll-out.

Statistics from Africa Centre for Disease Control and Prevention (Africa CDC) indicate the continent had 5,288,323 COVID-19 cases and 139,226 fatalities as of Thursday.

Five countries including South Africa, Morocco, Tunisia, Egypt and Ethiopia accounted for 62 percent of all cases reported in the continent as three major variants drive the uptick.

Moeti said that COVID-19 infections have been on an upward trajectory in Africa in the last five weeks since the onset of the third wave on May 3 adding that a 21 percent increase could delay flattening the curve.

She said the pandemic was on resurgence in 12 countries citing unrestricted social interactions and the presence of mutated versions for powering the virus's spread.

According to Moeti, the delta variant that was initially reported in India has been detected in 14 African countries and in the last one month, it has been identified in the majority of samples sequenced in Uganda and the Democratic Republic of the Congo (DRC).

She said WHO has deployed experts to some of the countries experiencing unprecedented surges including Uganda and Zambia to boost mitigation measures including timely diagnosis and treatment.

Moeti said boosting the capacity of the continent's laboratories to monitor and sequence variants of concern has been prioritized in a bid to reduce the intensity of the third wave.