Insects like flies and cockroaches are “unlikely” to transmit the coronavirus to humans, at least that’s what a study by scientists at Texas A&M AgriLife Research (USA) published in the Journal of Medical Entomology suggests.
“We took insect samples from homes with recent human Covid-19 cases, some of which also had dogs and cats that were actively infected with SARS-CoV-2. We hypothesized that these were high-risk environments where insects could become infected with the virus if they came into contact with infected humans, animals, or contaminated surfaces. Instead, we found no evidence of the virus in insect samples from these households,” the experts said.
Previous experimental studies by other researchers had shown that both infectious virus and viral RNA were detectable in house flies after exposure to SARS-CoV-2 in a laboratory setting but not in natural living environments.
As part of the study, they processed the contents of 133 insect traps in 40 households, each with at least one confirmed coronavirus case. The sticky traps collected more than 1,345 individual insects representing 11 different species of flies and cockroaches.
Insects were tested using quantitative reverse transcription PCR. Fluid in additional trap types was also tested for RNA concentration. The individual insects were divided into 243 groups and all tested negative for SARS-CoV-2.
In addition, 14 traps were set in seven households on the same day that the dog or cat samples tested positive for the virus, further increasing the opportunity for the insects to come into contact with contaminated animals or surfaces.
“This study provides further evidence for reducing SARS-CoV-2 transmission routes and evaluates different methods for new surveillance techniques. It was teamwork that allowed us to quickly deploy these traps in high-risk environments to directly assess the role of insects in the Covid-19 pandemic,” they established.