MATERIALS AND METHODS

Clinical materials. Autopsy specimens for virus isolation were collected at the Children's, Police, Wachira, Prapinklao, Pramongutklao and Siriraj Hospitals in Bangkok and Thonburi from April, 1962, through December, 1964. After the patient expired, the body was usually moved into a refrigerator until autopsy permission. The interval between death and autopsy was measured in the first 46 study cases and is shown in Table 1. These cases were all autopsied at the Children's Hospital. Organ sections were placed in separate containers and transferred to the Virus Laboratory on wet ice. They were then frozen and stored at-700C. Venous blood was obtained from some patients with hemorrhagic fever who subsequently died. Collection of these specimens has been described.'In other instances heart blood was drawn immediately after the patient expired, placed at 40C. and brought to the laboratory. If not already hemolysed, the red cells were separated from serum. Serum was quick frozen in a dry-ice-alcohol bath and stored at-70 C. until tested.