Two common drugs used by veterinarians to control parasites could be effective against bed bugs, with one showing particularly strong potential, according to a new North Carolina State University study examining the drugs linked to controlling resurgent bed bug populations on poultry farms examined.
Fluralaner and ivermectin, which are used to kill fleas and ticks on pets like dogs and cats, among other things, were tested for their effectiveness in killing bed bugs. In a collaboration between entomologists and veterinary scientists at NC State’s College of Veterinary Medicine, researchers tested bed bug mortality rates in separate experiments: after the pests had consumed blood mixed with the drugs on the lab bench, and after bed bugs had bitten and fed chickens either ingested or topically with it been treated with the medication.
Fluralaner is a relatively new, longer-lasting antiparasitic used primarily on pets. However, Europe and Australia have approved its use for the poultry industry. In addition to domestic use, ivermectin has effective antiparasitic uses in human populations, particularly in Africa, as well as in larger animals.
Both drugs showed strong efficacy on the lab bench, killing most bed bugs, although fluralaner was much more effective on bed bugs that showed resistance to common insecticides.
“The drugs affect receptors in the insect’s nervous system,” said Coby Schal, Blanton J. Whitmire Distinguished Professor of Entomology at NC State and corresponding author of an article describing the work.
Fluralener was highly effective at killing bed bugs that fed on chickens given the drug. Ivermectin, on the other hand, was ineffective against bed bugs feeding on dosed chickens.
“We used the recommended dosage of ivermectin, either topical or ingested, but neither were able to kill bed bugs,” said Maria González-Morales, a former Ph.D. Student at NC State and first author of the work.
The researchers say chickens could rapidly metabolize or clear ivermectin from their system.
“The bed bug is an important insect worldwide,” said Schal. “The last few decades have seen a resurgence of bed bugs in households and now we are seeing bed bugs returning to poultry farms. As there is no proven method to stop bed bugs in commercial farms, the potential problems in poultry farms could be massive. We try to be one step ahead by developing technologies that can eliminate bed bugs.”
“The health effects of bed bug infestations on poultry are not well documented, but occasionally poultry farmers see welfare concerns such as stress and anemia that could negatively impact meat or egg production,” González-Morales said.
“There are also concerns for workers on these farms given how easily bed bugs can be transmitted from poultry to humans,” Schal added.
According to the researchers, dosing fluralaner in the drinking water of poultry could be an effective measure against bed bugs. A combination of surveillance, reconnaissance, heat treatments and fluralans could be the key to eradicating bed bugs from infested poultry farms, they add.
The study appears in Parasites & Vectors. Andrea E. Thomson, Olivia A. Petritz, Rocio Crespo, Ahmed Haija, Richard G. Santangelo co-authored the paper. Funding was provided by the Blanton J. Whitmire Endowment of the State of NC, as well as grants from the US Department of Housing and Urban Development’s Healthy Homes program (NCHHU0053-19) and the National Science Foundation (DEB-1754190).
-kulikowski-
Note to the editor: The summary of the work follows.
“Systemic veterinary medicinal products for control of the bed bug Cimex lectularius in poultry farms”
Authors: Maria A Gonzalez-Morales, Andrea E Thomson, Olivia A Petritz, Crisp Dew, Ahmed Haija, Richard G Santangelo and Coby Schal, North Carolina State University
Published: November 17, 2022 in Parasites & Vectors
DOI: 10.1186/s13071-022-05555-6
abstract:
Background: The common bed bug, Cimex lectularius L., is a hematophagous ectoparasite that was a common pest in poultry farms until the 1960s. Dichlorodiphenyltrichloroethane (DDT) and organophosphates eradicated most pests, but concurrent with their global resurgence as human ectoparasites, bed bug infestations have reappeared on poultry farms. Although the effects of bed bugs on chicken health have not been quantified, frequent biting and blood feeding are expected to cause stress, infection and even anemia in birds. Bed bug control options are limited due to the sensitive nature of the poultry environment, limited products labeled to control bed bugs, and the resistance of bed bug populations to a broad spectrum of agents. Veterinary drugs are commonly used to control internal and external parasites in animals. In this study, we evaluated the effect of two commonly used veterinary drugs on bed bugs by treating the host with systemic antiparasitic drugs.
Methods: We performed dose-response studies with ivermectin and fluralaner against several bed bug strains using a membrane feeding system. In addition, chickens were administered different doses of these drugs and two delivery methods (topical treatment and ingestion) were used to evaluate the effectiveness of ivermectin and fluralaner on bed bug mortality.
Results: When using an artificial feeding system, both ivermectin and fluralaner caused high mortality in insecticide-susceptible bed bugs, and fluralaner was found to be effective in pyrethroid- and fipronil-resistant bed bugs. Ivermectin was not effective in chickens either by topical treatment or by ingestion, while bed bugs that fed on chickens ingested fluralaner experienced high mortality when feeding on these chickens up to 28 days after treatment.
Conclusions: These results suggest that systemic ectoparasitic drugs have great potential for practical use to control bed bug infestations in poultry farms. These results also demonstrate the effectiveness of fluralaner (and possibly other isoxazolines) as a potent new drug in bed bug control.
