Field-Caught Culex erythrothorax Larvae Found Naturally Infected with West Nile Virus in Grand County, Utah

Abstract

Culex erythrothorax larvae were collected from a bulrush-cattail marsh near Moab, Grand County, Utah, October 28, 2004, and found positive for West Nile virus (WNV) RNA by real-time reverse-transcriptase polymerase chain reaction (RT-PCR). This demonstrates WNV vertical transmission in this species in the wild and suggests that vertical transmission in overwintering Cx. erythrothorax larvae may contribute to WNV overwintering.