Seroprevalence of Rickettsial Infection in Commensal
Rodents and Shrews Trapped in the Bangkok Metropoli
tan Area
SONTANA SIRITANTIKORN, Dr.rer.nat*, VICHAI SANGKASUWAN, MD**,
CHIRAPA EAMSILA, MSc**, CHANTRA SINGCHAI, DVM***,
WANNEE KANTAKAMALAKUL, PhD*, PILAIPAN PUTHA VA THANA, PhD*
Affiliation : * Depanment of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University. Bangkok 10700.
** Armed Forces Research Institute of Medical Sciences, Army Medical Depanment, Bangkok 10400,
**"' Division of Veterinary Public Health. Department of Health, Bangkok Metropolitan Administration, Bangkok 10400.
Thailand.
AbstractMurine typhus and scrub typhus are important human rickettsial diseases in Thailand. Small
mammals, including many species of rodents and shrews, serve as the reservoir host of rickettsial
diseases. Rickettsia typhi can be transmitted to humans by fleas causing murine typhus, while infection
with Orientia tsutsugamushi causing scrub typhus in humans is transmitted by chiggers. The prevalence
of rickettsial infection depends on the geographic area. The seroprevalence of antibody to R. typhi and
0. tsutsugamushi was studied in commensal rodents and shrews trapped in markets in the Bangkok
Metropolitan Area (BMA). R. typhi and 0. tsutsugamushi antigen prepared in the yolk sac of embryo
nated eggs were used to determine the specific antibody in trapped animals' sera by using fluorescein
isothiocyanate (FITC)-anti rat immunoglobulins as a second antibody. Antibody toR. typhi was found in
25 (5%) of 500 sera tested and no antibody to 0. tsutsugamushi was detected. R. typhi antibody titer
ranged from 40-1280 and was found in Rattus norvegicus (4.2%), Rattus rattus (0.4%), Rattus exulans
(0.2%), and Mus musculus (0.2%) trapped in 8 of 47 markets in the BMA. R. typhi antibody was com
monly found in R. norvegicus. The authors concluded that murine typhus is an important rickettsial
disease and R. norvegicus is an important reservoir species of rodents found in markets of the BMA.
Keywords : Murine typhus, Scrub typhus, Orientia tsutsugamushi, Rickettsia typhi, Rattus norve
gicus, Bangkok Metropolitan Area
All Articles
Download
