The continent-wide daily average was 10,300 last week, down from 11,000 the week before.
The director of Africa CDC, Dr John Nkengasong, said it was a “sign of hope”.
Africa has recorded 1,147,369 cases, more than half of which are in South Africa, and about 26,000 deaths.
Dr Nkengasong said he was hopeful “that we are beginning to bend the curve slowly” but added that “it’s very, very early – we are dealing with a very delicate virus that spreads rapidly”.
“We take this news with cautious optimism,” he said, explaining that he didn’t want people to get complacent and stop trying to prevent the spread of the virus.
“We really want our population not to show what we call ‘prevention fatigue’, where we slow down on the measures that we are putting in place.”
He urged people to continue their efforts to prevent the spread of the virus, specifically saying that people needed to continue to wear masks, to maintain social distance and that more testing is needed.
Dr Nkengasong also said that more than one million tests had been conducted across the continent, with South Africa being one of the main countries to test people.
Recorded cases and deaths are relatively low compared to other parts of the word such as parts of Europe, Latin America and the US, which alone has more than 5,500,000 cases, but some experts warn that there may be many more cases than are recorded in Africa because of the lack of testing.
The spread of the virus appeared to be relatively slow in Africa in the early stages of the pandemic but the recorded rate of infection gradually accelerated, especially in South Africa.
South Africa has 596,060 cases of coronavirus, according to data from Johns Hopkins University. That is more than half the cases across Africa and the fifth-most cases in the world.
The country’s cases have been falling, and this has been driving the fall in cases across the continent. At its peak, there were more than 12,000 daily confirmed new cases and that has fallen to an average of 5,000.
The next African country to feature on the list is Egypt, in 31st place in the world with 96,914 cases.