Though endemic foci of scrub typhus are present in Indonesia, no information is
available on the burden of this disease. However, several serological and entomologicalstudies carried out in the Eighties clearly illustrated the presence of vectors in rural
settings. L. deliense was identified in central Sulawesi as a vector of scrub typhus and
the prevalence of antibodies against the O. tsutsugamushi antigen was 23% in the
sampled rat sera (18). Similarly, a preliminary serological survey carried out in Sumatra in
1982 revealed that human and rodent samples were seropositive against scrub typhus
12% and 43% respectively. Two species of chigger vectors, L. deliense and L. fletcheri
were found in the area studied (19). O. tsutsugamushi was isolated from L. arenicola
chiggers and three species of rats in an area of scrub and sedge along the Bay of
Jakarta. This is the only finding in Indonesia of a cycle of the agent of scrub typhus
associated with L. arenicola (20). A survey of small mammals and their ectoparasites
conducted on the islands of Biak and Owi in August 1976 found L. deliense and
L. flectcheri as vectors and O. tsutsugamushi was isolated from local rodents (21). The
favoured ecotype of the chigger and rat hosts of O. tsutsugamushi appeared to be
coarse, low-lying native vegetation on a porous coralline soil