The mosquito electrocuting trap as an exposure-free method for measuring human-biting rates by Aedes mosquito vectors

Abstract

Background: Entomological monitoring of Aedes vectors has largely relied on surveillance of larvae, pupae and non-host-seeking adults, which have been poorly correlated with human disease incidence. Exposure to mosquitoborne diseases can be more directly estimated using human landing catches (HLC), although this method is not recommended for Aedes-borne arboviruses. We evaluated a new method previously tested with malaria vectors, the mosquito electrocuting trap (MET) as an exposure-free alternative for measuring landing rates of Aedes mosquitoes on people. Aims were to (i) compare the MET to the BG-sentinel (BGS) trap gold standard approach for sampling hostseeking Aedes vectors; and (ii) characterize the diel activity of Aedes vectors and their association with microclimatic conditions. Methods: The study was conducted over 12 days in Quinindé (Ecuador) in May 2017. Mosquito sampling stations were set up in the peridomestic area of four houses. On each day of sampling, each house was allocated either a MET or a BGS trap, which were rotated amongst the four houses daily in a Latin square design. Mosquito abundance and microclimatic conditions were recorded hourly at each sampling station between 7:00-19:00 h to assess variation between vector abundance, trapping methods, and environmental conditions. All Aedes aegypti females were tested for the presence of Zika (ZIKV), dengue (DENV) and chikungunya (CHIKV) viruses. Results: A higher number of Ae. aegypti females were found in MET than in BGS collections, although no statistically significant differences in mean Ae. aegypti abundance between trapping methods were found. Both trapping methods indicated female Ae. aegypti had bimodal patterns of host-seeking, being highest during early morning and late afternoon hours. Mean Ae. aegypti daily abundance was negatively associated with daily temperature. No infection by ZIKV, DENV or CHIKV was detected in any Aedes mosquitoes caught by either trapping method. Conclusion: We conclude the MET performs at least as well as the BGS standard and offers the additional advantage of direct measurement of per capita human-biting rates. If detection of arboviruses can be confirmed in MET-collected Aedes in future studies, this surveillance method could provide a valuable tool for surveillance and prediction on human arboviral exposure risk.

Serological biomarker for assessing human exposure to Aedes mosquito bites during a randomized vector control intervention trial in northeastern Thailand

“…As a consequence, Aedes females are often interrupted in the course of seeking a blood meal and can often feed on multiple hosts per gonotrophic cycle [21][22][23]. Other methods to sample adult Aedes include various versions of passive and active trapping devices (e.g., gravitraps, sticky traps, mechanical battery-operated aspirators, and mosquito electrocuting trap) [24], each presenting differing levels of efficiency [25]. However, they do not measure the inter-individual heterogeneity of exposure influenced by human attraction exerted on mosquitoes and individual host behaviors (e.g., use of personal protections).…”

Diel activity patterns of two distinct populations of Aedes aegypti in Miami, FL and Brownsville, TX

“…To our knowledge, only two studies have previously used sampling procedures not based on human landing catches to study the biting activity patterns of Ae. aegypti ; the study by Ortega-Lopez et al 6 used mosquito electrocuting traps, and the study by Smith et al 7 used a mechanical rotator mosquito trap. In the present study, the use of BG-Sentinel II traps had the advantage that it was specifically designed to capture female host-seeking Ae.…”

“…aegypti showed an atypical biting activity rhythm in the dry season, and biting activity was throughout the night and peaking at midnight 5 . A recent study by Ortega‑López et al 6 used BG‑Sentinel traps and Mosquito electrocuting traps to study host-seeking activity of Ae. aegypti in Quinindé, Ecuador.…”

A Literature Review of Host Feeding Patterns of Invasive Aedes Mosquitoes in Europe

“…Further information on the blood feeding patterns of these mosquito species could be obtained by exposing different hosts (e.g., humans or other animals) to mosquito attacks [89,90]. The novel mosquito electrocuting trap may allow researchers to identify the risk of exposure of humans to mosquito bites, including invasive Aedes species [91].…”