Natural Focus of Tsutsugamushi Fever

摘要

As a result of zoologo-parasitological investigations it was established that the fauna of small mammals and trombiculid mites of Southern Primorye is analogous to the fauna of carriers and vectors of R. tsutsugamushi in North Korea and Japan. It is made up mainly by the following species: Apodemus agrarius, Micromys minutus, Rattus norvegious caraco, Cricetulus triton, Microtus fortis, Crocidura lasiura and Leptotrombidium palida, L. orientalis, L. pavlovskyi, Neotrombicula japonica, N. tamiyai, N. mitamura. Three positive results were obtained during the investigation of 128 sera of A. agrarius in the reaction of complement fixation with specific antigen from R. tsutsugamushi (Gilliam strain). Strains of rickettsia were isolated in 6 out of 17 biotests on Ap. agrarius, in 1 out of 7 biotests from M. fortis, in 1 test out of 1 investigation from C. triton, in 1 test out of 2 in C. lasiura. All told 9 strains of rickettsia were isolated from the stated animals. An analogous causative agent was isolated in 6 biotests out of 41 from the larvae of trombiculid mites, represented by species of Leptotrombidium pallida, L. pavlovskyi, L. orientalis, Neotrombicula japonica. Based on morphological, tinctorial, biological and serological properties, the isolated strains were identical to R. tsutsugamushi. On the basis of the data obtained, it is apparent that the region studied is a potential natural focus of infection, identical to tsutsugamushi. (Author)