REVERSE TRANSCRIPTION PCR DETECTION OF LACROSSE VIRUS IN MOSQUITOS AND COMPARISON WITH ENZYME-IMMUNOASSAY AND VIRUS ISOLATION

A reverse transcription-PCR (RT-PCR) assay was developed and compared with enzyme immunoassay (EIA) and virus isolation for detecting LaCros se virus (LAC) in mosquito pools. All three techniques were able to de tect a single LAC-infected mosquito in a pool of 99 negative mosquitoe s. Virus isolation was the most sensitive of the three techniques; it was possible to isolate virus immediately following intrathoracic inoc ulation of mosquitoes. RT-PCR was second in sensitivity; LAC RNA was d etected 1 day postinfection. EIA detected LAC antigen 2 days postinfec tion. Additionally, RT-PCR and EIA were able to detect LAC RNA and pro tein, respectively, from mosquito samples which were subjected to seve n freeze-thaw cycles, and RT-PCR was able to detect LAC RNA from mosqu ito samples which remained at room temperature for up to 7 days.