Dutch public health authorities declared that one of two Dutch doctors feared to have been infected with the deadly Ebola virus in Sierra Leone has malaria.
"She's being treated for malaria," Harald Wychgel, spokesman for the National Institute for Health and the Environment (RIVM), told AFP of Erdi Huizenga.
"We have carried out tests to see if she's also infected with Ebola. The results show that for the time being she does not have Ebola," said Wychgel.
Doctors Huizenga and Nick Zwinkels last week put themselves into voluntary quarantine for two weeks after they returned from Sierra Leone on September 14.
They had been working in a clinic their charity runs in the central town of Yele.
The incubation period for the virus is between two and 21 days.
They showed no symptoms of Ebola, a virus which has killed almost 3,000 people in west Africa so far this year in an epidemic international organisations say is running out of control.
Zwinkels and Huizenga came into contact with Ebola-infected patients in the Sierra Leone clinic, which mostly treats malaria cases, where one other staff member had died of the virus.
The RIVM said that another Dutchman who had recently travelled to infected zones and been hospitalised last week is also being treated for malaria.
"He has not been infected with Ebola," spokesman Wychgel said, after the incubation period passed.
Around 15 people have been tested for Ebola in the Netherlands in recent weeks, and all the tests have come back negative, the RIVM said.
Several Western health workers have been flown home after being contaminated and given experimental drugs to combat the disease. Most have recovered.
Sierra Leone, Guinea and Liberia are the hardest-hit countries.
Although no vaccine is commercially available, early treatment involving constant rehydration and medication to alleviate fever increases the chances of survival.