Data from: Potential interaction between clorsulon and ivermectin for malaria vector control

Mass ivermectin (IVM) treatment of livestock (MITL) is under consideration
as a malaria control tool as IVM-treated livestock are lethal to
blood-feeding Anopheles mosquitoes. MITL is routinely used as a
prophylaxis in livestock to reduce the burden and transmission of helminth
infections. Recently, there has been a shift in the veterinary IVM market
in Southeast Asia wherein nearly all standard IVM formulations are now
co-formulated with clorsulon (CLO). CLO is used to treat the trematode
liver fluke, Fasciola hepatica. Thus, the co-administration of IVM and CLO
simultaneously targets multiple livestock infections. Additionally, F.
hepatica frequently afflicts human populations in endemic areas, making
control of F. hepatica in livestock beneficial for One Health. CLO
interrupts glycolysis in F. hepatica, but its potential effect against
Anopheles mosquitoes has never been evaluated. Anopheles dirus mosquitoes
were blood-fed CLO across a range of concentrations (1 – 10,000 nM; 0.38 -
3,807 ng/ml)) and mosquito survival was monitored for ten days. Co-feeding
experiments were also performed with An. dirus blood-fed on IVM at two
concentrations (4 and 6 ng/ml) without and with CLO corresponding to peak
concentration in cattle (Cmax) (2,700 ng/ml) and five times the Cmax
(13,500 ng/ml), and mosquito survival was monitored for ten days. CLO had
no mosquito-lethal effect on An. dirus. The IVM and CLO co-feed experiment
did not indicate any altered effect of IVM on mosquito survival when
co-fed with CLO. IVM-CLO livestock co-formulations would not likely alter
the Anopheles mosquito-lethal effect of MITL. The use of MITL-CLO for
malaria control would have health benefits for livestock, treating
helminth and liver fluke infections, and additional One Health benefits by
reducing transmission risk of liver flukes to humans.