Ectoparasites of commensal rodents in Sulawesi Utara, Indonesia, with notes on species of medical importance

Ectoparasite records are presented for four species of commensal murid rodents (Rattus rattus palelae Miller & Hollister, R.argentiventer (Robinson & Kloss), R.exulans (Peale) and Mus musculus castaneus Waterhouse) in Sulawesi Utara, with particular reference to the potential for these arthropods to bite and transmit pathogens to humans. The flea, Xenopsylla cheopis (Rothschild), was most common on R.r.palelae and is capable of transmitting plague and other pathogens to humans although no current foci for these diseases are known in Sulawesi. Hoplopleura pacifica Ewing and Polyplax spinulosa (Burmeister) sucking lice parasitized all three Rattus species although H.pacifica was mainly associated with R.exulans and P.spinulosa with R.r.palelae. These lice do not bite humans but may be intramurid vectors of murine typhus and other zoonoses. The mites Laelaps echidnina Berlese and L.nuttalli Hirst were both collected; the latter was recorded from all four murid species, mainly R.exulans. The mite Ornithonyssus bacoti Hirst was rare. Only one chigger mite, Walchiella oudemansi (Walch), was retrieved from murids (from R.exulans) and a single Leptotrombidium deliense (Walch) chigger was taken from a human subject. Although L.deliense is a significant vector of scrub typhus, a disease known from Sulawesi, the L.deliense-R.argentiventer relationship frequently noted in the ecology of this rickettsial disease, was not evident in this survey. Other ectoparasites collected from murids were the ticks, Ixodes granulatus Supino (first record for Sulawesi), Haemaphysalis sp. and Dermacentor sp., the mites Myocoptes musculinus (Koch) and Listrophoroids cucullatus (Trouessart), acarids and a uropodid. Additional ectoparasites noted on humans were the tick Amblyoma babirussae (Schulze), the scabies mite Sarcoptes scabiei L. and the head louse Pediculus humanus capitis De Geer.