Calculations suggest flea and tick medications for pets could benefit people by controlling mosquitoes

Killing mosquitoes helps control infectious diseases. A new study finds that two compounds used to protect dogs from fleas and ticks could be repurposed as human oral drugs to kill disease-spreading mosquitoes when they bite treated people. Led by TropIQ Health Sciences’ Koen Dechering and California Institute for Biomedical Research’s Peter Schultz and Matthew Tremblay, the team conducted modeling studies and found that in areas at risk, giving people these drugs would substantially reduce incidences of malaria and Zika (Proc. Natl. Acad. Sci. USA2018, DOI: 10.1073/pnas.1801338115). The two compounds, known as isoxazolines, kill mosquitoes by attacking an insect-specific ion channel. Because dog and human cells clear these isoxazolines in a similar way, the team predicted that the drugs would remain in human bloodstreams as long as they did in dogs’ blood. Based on this information and other factors, such as the number of mosquitoes present in a region, modeling studies suggest that giving a single dose of the compounds to 30% of an at-risk population could reduce the clinical cases of malaria and Zika fever by 70% and 97%, respectively. The team plans to conduct human trials in one to two years.