Infection Rate of Typhus Fever in Rats at High Risk Areas - การศึกษาอัตราการติดเชื้อกลุ่มไข้รากสาด (Typhus Fever) ของหนูในพื้นที่เสี่ยงสูง

Abstract

        The objective of this survey research was to study the prevalence of typhus fever and species of redents and its ectoparasites in high risk areas. The total number of 1,567 traps were laid in seven chosen areas; and serum and ectoparasites of all trapped rodents were collected and tested for antibody by indirect immunofluorescent antibody medthod. It was found that the total number of 192 rodents were trapped which was 12.3% trap success. Genus typing of rat groups (78.1%) revealed Rattus spp.(72.0%)
Banticota spp.(23.3%) and Mus spp.(4.7%). Other rodents were Tupaia glis, Crocidura murinus, Menetes berdmorei consularis, T. minor, Callosciurus notatus and C. erythraeus. The prevalence of rickettsial diseases in the serum samples was 50.9%. There were 73.3% antibody detection for Rickettsia honei, 41.7% for Orientia tsutsugamushi and 6.7% for Rickettsia tyhpi. Ectoparasites were detected in 65 of 122 rodents (55.3%). Majority of them were chigger mite which included genus Ascoschoengastia spp., genus
Gahrliepia (Walchia) spp., genus Leptotrombidium spp., genus Helenicula spp. and genus Schoengastia spp. Other ectoparasites detected were tropical rat mite (Laelaps spp.), rat flea (Nosopsyllus fasciatus), tick (genus Haemaphysalis spp. and Amblyomma spp.). The study indicated the need for continued vector surveillance to detect the occurrence typhus fever, and to educate the public on disease prevention especially the tourists visiting those high risk areas.
Key words: infection rate, typhus fever, rat, high risk areas