A survey of ectoparasites from wild rodents and Anourosorex squamipes in Sichuan Province, South-west China

This study was to investigate the populations and species of ectoparasites from Apodemas agrariu s (Rodentia: Muridae; Pallas, 1771), Rattus norvegicus (Rodentia: Muridae; Berkenhout, 1769), Rattus nitidus (Rodentia: Muridae; Hodgson, 1845), Rattus fulavipectus (Rodentia: Muridae; Gray,1847), Mus musculus (Rodentia: Muridae; Linnaeus, 1758), Micromys minutus (Rodentia: Muridae; Pallas, 1771) and Anourosorex squamipes , (Insectivora: Soricidae; Milne-Edwards,1872) which have been identified as the main wild reservoir of disease, trapped from six districts of Sichuan province, southwest China, with the objectives of determining the prevalence of ectoparasites and identifying the potential risk factors associated with human health. Parasitological examination was performed by optical microscopy. Out of 282 A. squamipes and 175 rodents species examined, 70.5% of A. squamipes and 66.4% of rodents species were found to be infested with more ectoparasites (average: 68.45%). A total of 56 species of parasites, including 34 species of chigger mite, 14 species of mesostigmatid (gamasid) mite, six species of flea and two species of sucking louse were examined. The ectoparasites identified in A. squamipes were chigger mite (60.0%), mesostigmatid (gamasid) mite (22.2%), flea (13.3%) and sucking louse (4.4%). In rodents, chigger mite (60.7%), mesostigmatid (gamasid) mite (25.0%), flea (10.7%) and sucking louse (3.6%) were identified also. Both in rodents and A. squamipes , significant variation (p < 0.05) in ectoparasite infestation was observed in relation to body weight between females and males in all ectoparasites and chigger mites. Most species of ectoparasite were relatively uncommon, but a few were abundant. Within this ectoparasite complex, 16 species have previously been reported to be vectors of human disease agents. These mammals would appear therefore to be a natural reservoir for plague bacilli and epidemic haemorrhagic fever (Korean haemorrhagic fever) viruses. The results suggest that parasite viability studies are needed in order to assess the potential risk for human health.