Laboratory evidence that dinotefuran, pyriproxyfen and permethrin combination abrogates <i>Leishmania infantum</i> transmissibility by sick dogs

Abstract

<jats:title>Abstract</jats:title><jats:p>Dogs are reservoir hosts of leishmaniasis caused by <jats:italic>Leishmania infantum</jats:italic> and transmitted by phlebotomine vectors. The effect of dinotefuran, pyriproxyfen and permethrin spot‐on solution (Vectra®3D, Ceva Santé Animale, Libourne, France) on <jats:italic>Leishmania</jats:italic> transmissibility by naturally infected dogs via reared <jats:italic>Phlebotomus perniciosus</jats:italic>, was assessed. Dogs affected by leishmaniasis were submitted to xenodiagnosis and 6 infecting &gt;10% of insects were treated topically on day 0. Antifeeding, insecticidal and anti‐transmissibility effects were evaluated through xenodiagnoses performed on days 1, 7 and 28, using individual pre‐treatment parameters as control. Feeding and mortality rates were assessed at 24 h, whereas promastigote infection, maturation and burden were assessed up to 96 h post blood meal (potentially infectious rate). On day 1, the anti‐feeding efficacy was &gt;95% in 4 dogs, insecticidal efficacy 100% in 4 dogs, and anti‐transmissibility effect 100% in 6 dogs. Efficacy rates recorded on day 7 were very similar to day 1. On day 28, anti‐feeding and insecticidal efficacy values were much broader, ranging 32.6–100% and 7.7–94.4%, respectively. Potentially infectious insects were recorded from two dogs, with sharp decrease in transmissibility rate as compared with pre‐treatment condition. Altogether, Vectra®3D abrogated by &gt;98% the potential <jats:italic>Leishmania</jats:italic> transmissibility by the examined pool of infected dogs over 1 month.</jats:p>