Detection of filarial larvae in mosquitoes with oligonucleotide probe

To investigate a new way to detect filarial larvae in mosquitoes and apply it to the surveillance of filariasis. An oligonucleotide probe that was species-specific to W. malayi was synthesized and marked with 32P using molecular biological technique. Then the probe was tested with dot hybridization in detection of W. malayi filarial larvae from mosquitoes. The minimal detectable limit was found to be 2 ng DNA of filarial larvae or microfilaria (Mf.), with no cross reaction with other animal filariae. A single larva can be detected when infected mosquitoes were tested one by one. One infected mosquito can be detected from a group of 20 mosquitoes tested together. Our probe is sensitive and specific. It is practical to apply our probe to mosquito surveillance in Brug's filariasis endemic areas.