Aseptic Meningitidis On An Indian Reservation: An Epidemic Associated With Echo 9 Virus.

This epidemic took place in the summer of 1959 on the Mescalero Apache Reservation. There were 40 cases, occurring in three waves between mid-July and mid-September, apparently transmitted by personal contact in this poorly sanitated population. The overall attack rate was 3.7 cases per 100 persons, with the highest rates among infants and young children (21% and 9% respectively). Multiple family cases were common, a study group of infected families having a secondary attack rate of 7.8%. The incubation period seemed to range as high as 7 to 11 days. The unusual manifestations of this epidemic are felt to be related either to strain characteristics of the infective agent or to the interaction of variant characteristics in both the host and the parasite. There seems to be distinct variations in the manifestations of some virus diseases from one outbreak to another. Perhaps both the strain of virus and strain of host may dictate this. Bar chart. Map. Tables. Bibliography.