D3329: Human landing collections can be replaced by an effective mosquito trap

Human landing collections (HLC) were the gold standard in the Singapore Armed Forces for monitoring populations of Anopheles and other vector mosquito populations, but ethical concerns regarding exposure of collectors to mosquito-borne diseases have led to the abandonment of this sampling method. In the search for an alternative to HLCs, the BG-Pro trap in 2 configurations (upright and inverted) was compared with HLCs to gauge its effectiveness as a replacement. Collections were made at 4 military training sites in Singapore over 25 days between December 2020 and February 2021 using a 3x3 Latin square design.

A total of 11469 mosquitoes representing 46 species in 7 genera were identified. The two trap configurations collected more species per night than HLC. The mean number of species collected per night in inverted traps was 9.8, upright 8.3 and HLC 6. Mean Anopheles catch rates per night were substantially higher in both traps compared to the HLC (inverted 34.6, upright 23.1 and HLC 2.4) as were Culex (inverted 138.4, upright 110 and HLC 28). For important vector species, results were similar: Aedes albopictus (inverted 2.92, upright 1.24, HLC 0.36); Cx. quinquefasciatus (inverted 17,72, upright 7.48, HLC 0.00); An. sinensis (inverted 9.16, upright 2.6, HLC 3.52); and An. eprioticus (inverted 3.96, upright 0.68, HLC 2.0).

Using BG-Pro traps as a substitute for human landing collections eliminates the ethical concerns of disease exposure risk to field personnel, eliminates collector bias, frees up personnel for other tasks, and provides a time saving, standardized and reproducible collection method.