Biodiversity of mosquitoes and Mansonia uniformis as a potential vector of Wuchereria bancrofti in Hulu Sungai Utara District, South Kalimantan, Indonesia.

BACKGROUND AND AIM: Lymphatic filariasis, also known as elephantiasis, still remains a problem in Indonesia. The primary causative species of this disease are the filarial worms Wuchereria bancrofti and Brugia spp. This study was conducted to identify the diversity of species and behavior of mosquitoes and to determine the mosquitoes that could be potential vectors of filariasis. MATERIALS AND METHODS: Mosquito samples derived from Hulu Sungai Utara (HSU) district in the 2017 multicenter study conducted in Indonesia were used in this cross-sectional study. The diversity of mosquito species was analyzed using the Shannon-Wiener diversity index. Mosquitoes were identified based on their species, and their DNA was isolated by polymerase chain reaction (PCR). Transcription-insulated isothermal PCR method was used to detect microfilariae/filaria larvae in the mosquitoes. RESULTS: Biodiversity was found in 14 species of mosquitoes belonging to five genera. The maximum number of mosquitoes was recorded from the species Mansonia dives, Culex vishnui, Culex quinquefasciatus, and Mansonia uniformis. W. bancrofti infection was detected in M. uniformis at an infectivity rate of 0.3% (n=311). CONCLUSION: To the best of our knowledge, this is the first report of M. uniformis species as a vector of W. bancrofti in HSU district, Indonesia. More efficient and accurate studies are required to aid in the lymphatic filariasis elimination programs in this subregion.

Rickettsial infections of fleas collected from small mammals on four islands in Indonesia.

Ectoparasites were sampled from small mammals collected in West Java, West Sumatra, North Sulawesi, and East Kalimantan, Indonesia, in 2007-2008 and were screened for evidence of infection from bacteria in the Rickettsaceae family. During eight trap nights at eight sites, 208 fleas were collected from 96 of 507 small mammals trapped from four orders (379 Rodentia; 123 Soricomorpha; two Carnivora; three Scandentia). Two species of fleas were collected: Xenopsylla cheopis (n = 204) and Nosopsyllus spp. (n = 4). Among the 208 fleas collected, 171 X. cheopis were removed from rats (Rattus spp.) and 33 X. cheopis from shrews (Suncus murinus). X. cheopis were pooled and tested for DNA from rickettsial agents Rickettsia typhi, Rickettsia felis, and spotted fever group rickettsiae. R. typhi, the agent of murine typhus, was detected in X. cheopis collected from small mammals in West Java and East Kalimantan. R. felis was detected in X. cheopis collected from small mammals in Manado, North Sulawesi. R. felis and spotted fever group rickettsiae were detected in a pool of X. cheopis collected from an animal in East Kalimantan. Sixteen percent of the X. cheopis pools were found positive for Rickettsia spp.; four (10.8%) R. typhi, one (2.7%) R. felis, and one (2.7%) codetection of R. felis and a spotted fever group rickettsia. These data suggest that rickettsial infections remain a threat to human health across Indonesia.