Why 60% of cases went undetected for months in a gold-mining town: Rare Ebola strain, no vaccine, delayed testing, and deep community mistrust are making this Central African outbreak nearly impossible to stop. New York Times correspondent Declan Walsh reports from the epicenter in the DRC where barely-equipped hospitals face both disease and violent resistance from locals who believe the virus is a conspiracy. The Bundybudyo Ebola strain circulated undetected for 2-3 months before diagnosis because initial tests screened for the more common Zaire strain, allowing hundreds of infections to spread unchecked.