After informed consent was obtained, the cadaver was stored at 4uC and underwent autopsy about 18 h after death. The autopsies were done following conventional protocols with strict adherence to biosafety procedures [48] . Twenty-four tissues were collected from respiratory, digestive, nervous, urinary and lymphatic organ systems. Duplicate tissue samples were collected; one sample was fixed in diethylpyrocarbonate (DEPC) treated 10% formalin for pathologic analyses, while a second sample was frozen at 280uC for virus isolation and molecular analyses.