In Uganda, a 42-day countdown has now begun before it can officially be declared Ebola-free, as long as no new infections emerge.
“It demonstrates that with early detection, prompt treatment and a strong health system, Ebola can be defeated,” the health minister said.
Nevertheless, his ministry has urged people to “remain vigilant”.
“If you develop symptoms such as fever, vomiting, diarrhoea or unexplained bleeding, seek immediate medical care,” it said in a statement on X.
In all, Uganda recorded 20 confirmed cases, mostly among visitors from DR Congo, and two deaths.
Uganda has experienced several Ebola outbreaks over the last two decades and now has well established protocols to deal with the virus. These include isolation of suspected cases and contact tracing as well as targeted public health messages.
There have been more than 2,000 confirmed infections and 796 deaths in DR Congo, according to government data.
But it is thought that it could have been in the community undetected for months before the outbreak was officially declared two months ago.
“About two-thirds of deaths are occurring in communities, among people who never receive care in a health facility,” the AFP news agency quotes Tedros as saying at a briefing at the WHO headquarters in Geneva.
Earlier this week, a WHO official said the true number of infections could be four times larger than recorded.
There are currently no vaccines or approved treatments for this Bundibugyo species of Ebola and health workers in DR Congo are playing catch up with not enough beds for the ill, not enough contact tracing and testing.
They also face suspicion from local communities, in a region with active armed conflict.
The WHO wants $115m (£85m) to tackle the outbreak – so far it has received just $45m.
“This is not charity, it’s an investment in national security,” Tedros said, asking donor countries to step up.
In response to the latest situation, the US has announced that citizens who have been in DR Congo and want to return home must spend 21 days in a third country before being allowed into America.
Previously, they had been able to enter at select airports, where they went through a screening process.
The new rule could affect recruitment of US medics who want to work in Ebola-affected areas and the scale of operations, Franklin Graham, the CEO of an organisation that runs Ebola treatment centres, told the Reuters news agency.
Ebola is caused by a virus which attacks the body’s immune system and organs.
It normally infects animals, typically fruit bats, but outbreaks among humans can sometimes start when people handle infected animals. It is spread through bodily fluids like blood.
Additional reporting by Swaibu Ibrahim in Kampala and Imogen Foulkes in Geneva