IMPROVED SURVEILLANCE OF AEDES TRISERIATUS USING THE BG-PRO TRAP: IMPLICATIONS FOR SAMPLING HOST-SEEKING LA CROSSE VIRUS VECTORS.

Abstract

La Crosse virus (LACV) is responsible for the majority of pediatric arboviral encephalitis in the United States. At present there are limited options for host-seeking surveillance for the primary vector (Aedes triseriatus) and, to a lesser extent, two invasive species (Ae. albopictus and Ae. japonicus) capable of transmitting LACV. We evaluated four host-seeking trap configurations (Centers for Disease Control and Prevention [CDC] Light trap, BG-Pro with BG lure, and BG-Sentinel 2 with and without BG lure) via two 4 × 4 Latin square field studies. Over the course of 128 trap-days, 436 mosquitoes were collected with the two most common species being Aedes triseriatus (n = 156, 35.8% of total) and Ae. albopictus (n = 182, 41.7% of total). The BG-Pro, on average, collected approximately 3 times more female Ae. triseriatus than the CDC light trap or the BG-Sentinel with BG lure. Similarly, the odds of collecting Ae. triseriatus with the BG-Pro trap were 3.02 times (95% CI: 1.96-4.67) than the CDC light trap; statistically greater than any other trap. There was no statistical difference in the odds of collecting Ae. triseriatus by the BG-Sentinel 2 (irrespective of lure presence) when compared to the CDC light trap as the reference. There was no difference in the odds of collecting Ae. albopictus using the BG-Sentinel 2 (OR: 4.62, 95% CI: 2.76-7.74) or the BG-Pro (3.06, 95% CI: 1.78-5.24) when compared to the CDC light trap as the reference. The limited collection of Ae. japonicus precluded any meaningful comparisons. Taken together, the BG-Pro trap should be considered for the surveillance or collection of the primary LACV vector, Ae. triseriatus.