MONDAY, Aug. 1, 2022 (HealthDay News) — You may not have even considered the possibility, but new research finds that flies and cockroaches are unlikely to spread COVID-19.
Although public health professionals and officials now have a better understanding of how COVID-19 spreads, concerns remain about whether it can be spread indirectly through contaminated surfaces, animals, or insects.
According to study co-author Gabriel Hamer, an AgriLife Research entomologist in the Department of Entomology at Texas A&M, insects are known to transmit a variety of infectious diseases to people, so determining their potential contribution to disease transmission SARS-CoV-2 it was given priority in the early stages of the pandemic.
“We took insect samples from households with recent human cases of COVID-19, some of which also had dogs and cats actively infected with SARS-CoV-2,” Hamer explained in a university news release. “We suspected that these were high-risk environments where insects could become contaminated with the virus if they were in contact with infected humans, animals or contaminated surfaces. Instead, we detected no evidence of the virus in the insect samples from these households.”
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The research team had previously found that households with confirmed positive cases of COVID-19 in humans experienced transmission of SARS-CoV-2 from humans to dogs and cats. And the team has recently been investigating Transmission of COVID-19 among Texas white-tailed deer.
In earlier studies by other researchers, after being exposed to SARS-CoV-2 in a laboratory, houseflies showed signs of both the virus and viral RNA. Still, the AgriLife study did not conclude that these insects were obtaining viral RNA from SARS-CoV-2 in domestic settings.
According to Hamer, mechanical transmission would involve the pathogen spreading to a person through infectious particles in an insect’s body. With biological transmission, the pathogen would enter the insect, develop, and then multiply before being spread through the insect’s saliva or feces.
In the new study, Hamer’s team processed the contents of 133 bug traps that were placed in 40 homes that each had at least one confirmed human case of COVID-19. From June to September 2020, the sticky traps captured more than 1,345 insects, including 11 different species of flies and cockroaches.
The researchers used PCR tests to assess insects. Each of the 243 individual insect groups tested negative for SARS-CoV-2.
The day after dog or cat samples tested positive for the virus, 14 more bug traps were set up in seven homes, increasing the likelihood that bugs would come into contact with contaminated animals or surfaces.
According to the findings, recently published in the Journal of Medical Entomology, Neither cockroaches nor biting or non-biting flies are likely to spread the virus.
“This study provides more evidence to help reduce the transmission routes of SARS-CoV-2 and evaluates different methods for new surveillance techniques,” said Hamer. “It was a team effort that allowed us to rapidly deploy these traps in high-risk settings to directly assess the role of insects in the COVID-19 pandemic.”
The US Centers for Disease Control and Prevention has more about how covid spreads.
SOURCE: Texas A&M AgriLife Research, news release, July 28, 2022