Accession Number : AD0617695

Title :   STUDIES ON LARVAL TROMBICULID MITES (CHIGGERS) FROM MALAYA AND BORNEO.

Descriptive Note : Progress rept. for 1 Jul 64-15 Feb 65,

Corporate Author : MARYLAND UNIV COLLEGE PARK DEPT OF ZOOLOGY

Personal Author(s) : Anastos,George

Report Date : 15 FEB 1965

Pagination or Media Count : 25

Abstract : The major effort during the contract year was on investigations in Pakistan, undertaken as a colloborative project ancillary to studies on viral and rickettsial infections in Asia. It is pointed out that preliminary observations in 1962, based upon a study of trombiculid mites and their hosts in parts of West Pakistan, indicated that scrub typhus may be present in highly unusual types of terrain and in unexpected geographical areas. In 1963 it was shown that such indeed was the case and isolations of scrub typhus rickettsiae (R. orientalis) were made from tissues of Rattus from the plains of Lahore and elsewhere in that District, where established vector chiggers, such as Leptotrombidium deliensis, have never been found, but where related species, new to Science, do occur. Likewise in 1963 it was demonstrated that natural infection with Rickettsia orientalis occurred in Rattus rattoides and in Apodemus flavicollis (a field mouse) in the Kaghan Valley of the Himalayas at 8000 feet elevation, where snow is present on the ground eight months of the year. The 1964 program verified and extended the above observations, and it appears that scrub typhus may be endemic in a vast area that had been assumed to be free of infection, and that it may occur in desert regions, and in alpine or artic-alpine zones in the Himalayas. A minimum of 54 species of trombiculid mites were collected in Pakistan, including at least ten that are apparently new to science, are discussed. The mammal-hosts and their habitats are considered.

Descriptors :   (*MITES, ASIA), DISEASE VECTORS, RICKETTSIA, PARASITES, MAMMALS, LARVAE, VIRUS DISEASES, ECOLOGY, SIPHONAPTERA, PAKISTAN, BORNEO, MALAYA, THAILAND, TABLES(DATA)

Distribution Statement : APPROVED FOR PUBLIC RELEASE