There were 11 cases with hemorrhagic fever occurred in Aksakmaral area of Bachu County in 1965 and 8 cases were found in the next year. From April 1967 a large number of people came there for (reclaimation) of waste land but no cases occurred in this year neither in the natives nor in the strangers. In 1968 two native herdsmen suffered from hemorrhagic fever. In the winter of 1966 the weather of this area was inclemancy, the atmospheric temperature under-10℃ continued as long as one month. It might be the r...