Tanzania is refusing to provide detailed information on suspected Ebola cases, the World Health Organization (WHO) said, a rare public rebuke as the region struggles to contain an outbreak already declared a global health emergency. Transparency and speed are keys to combating the deadly hemorrhagic fever because the disease can spread rapidly. Contacts of any potentially infected person must be quarantined and the public warned to step up precautions like handwashing.

WHO said in a statement released 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 one.

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