DAR ES SALAAM (Reuters) - Tanzania is refusing to provide detailed information on suspected Ebola cases, the World Health Organization (WHO) said in a rare public rebuke as the region struggles with an outbreak already declared a global health emergency.

Transparency and speed are key to combating the deadly hemorrhagic fever because it can spread rapidly. Anyone deemed to have been in contact with potentially infected people must be quarantined and the public warned to step up precautions such as handwashing.

WHO said in a statement late on Saturday that it was made aware on Sept. 10 of the death of a patient in Dar es Salaam, and unofficially told the next day that the person tested positive for Ebola. The woman had died on Sept. 8.

“Identified contacts of the deceased were unofficially reported to be quarantined in various sites in the country,” the statement said.

WHO said it was unofficially told that Tanzania had two other possible Ebola cases. One had tested negative and there was no information on the other.

Officially, the Tanzanian government said last weekend it had no confirmed or suspected cases of Ebola. The government did not address the death of the woman directly and did not provide further information.

Despite several requests, “clinical data, results of the investigations, possible contacts and potential laboratory tests performed ... have not been communicated to WHO”, the U.N. agency said.

“The limited available official information from Tanzanian authorities represents a challenge.”

Officials in Tanzania’s health ministry could not be reached for comment.

Authorities in east and central Africa have been on high alert for possible spillovers of Ebola from the Democratic Republic of Congo, where a year-long outbreak has killed more than 2,000 people.

The WHO was heavily criticized by experts during West Africa’s 2014-2016 Ebola epidemic, which claimed more than 11,300 lives in Guinea, Liberia and Sierra Leone, for not moving more quickly to contain the outbreak, which remains the world’s worst.

FEARS SPREAD

Last week the U.S. health secretary, Alex Azar, criticized Tanzania for failing to share information on the possible outbreak. The next day he sent a senior health official to Tanzania.

Uganda has already recorded several cases after sick patients crossed the border from Congo. A quick government response there prevented the disease spreading.

The 34-year-old woman who died in Dar es Salaam had traveled to Uganda, according to a leaked WHO document circulated earlier this month. She showed signs of Ebola including headache, fever, rash and bloody diarrhea on Aug. 10 and died on Sept. 8.

Tanzania relies heavily on tourism and an outbreak of Ebola would likely discourage visitors.

WHO spokesman Tarik Jasarevic said the organization stood ready to help Tanzania should an outbreak be confirmed and that its country office in Tanzania had been reinforced with experts in patient care, infection prevention and other specialities.

“WHO is standing by to facilitate the delivery of various supplies, including vaccines and therapeutics. This will occur upon request by the government,” Jasarevic said, adding there were enough supplies of vaccine to provide if needed.

The Geneva-based agency had also shipped 1,000 sets of protective equipment to Tanzania 10 days ago.

WHO’s statement is not the first time international organizations have queried information from the government of President John Magufuli, nicknamed The Bulldozer.

Earlier this year, the World Bank and the International Monetary Fund contradicted the government’s economic growth figure for 2018.