The World Health Organization indicated Saturday it’s concerned that Tanzania may be hiding Ebola cases. In a public statement on Saturday, WHO said it learned of unofficial reports that a woman suspected to have the disease died in Dar es Salaam and that people she was in contact with were quarantined. But Tanzanian authorities have not responded to requests from WHO for more information, and have apparently declined to do a second round of testing that would confirm whether or not several patients had the hemorrhagic fever that has killed 2,000 people in the Democratic Republic of Congo.