Ivermectin as a Rodent Feed-Through Insecticide for Control of Immature Sand Flies (Diptera: Psychodidae)

Abstract

Ivermectin was evaluated as a potential rodent feed-through for the control of immature stages of Phlebotomus papatasi. The survival of sand fly larvae fed feces of Syrian hamsters (Mesocricetus auratus) that had been fed a diet containing 0, 2, 6, 10, 20, 60, or 100 ppm ivermectin was measured. Sand fly larvae fed the feces of ivermectin-treated hamsters had significantly reduced survival, with 100% mortality of larvae fed feces of hamsters fed a diet containing 20, 60, and 100 ppm ivermectin. The results of this study suggest that a control strategy using rodent baits containing ivermectin to control phlebotomine sand flies may be possible. Because rodent reservoirs and sand fly vectors of Leishmania major live in close association in many parts of the Middle East, the control of transmission of the agent of zoonotic cutaneous leishmaniasis also may be possible.

Effects of Ivermectin on Blood-Feeding Phlebotomus papatasi, and the Promastigote Stage of Leishmania major

“…Although these methods could not expect to achieve serum drug levels comparable to SC dosing, and outright lethality to the biting flies, they could, by virtue of a gradual feed-through effect, deliver targeted IVM levels through feces that have profound and potentially long-term toxic effect against the more vulnerable larval stages of the sand flies. Strong (1993) drew attention to feces as the main elimination route of avermectin and the broad adverse effects of the active drug residues on pastureland ecology, but Mascari et al (2008) demonstrated serious potential of this approach for Middle Eastern Leishmania control. Hamsters fed a diet containing 20-100 ppm of IVM IVERMECTIN EFFECT ON L. major AND P. papatasi 49 excreted sufficient levels of the active drug in their feces to cause high mortality when fed to P. papatasi larvae.…”

Ivermectin: panacea for resource-poor communities?

“…Ivermectin is more effective in killing promastigotes compared with rifampicin, nystatin, and erythromycin [74]. Ivermectin has also been proposed as a possible rodent-bait feed-through insecticide to help control the Phlebotomine sandflies that transmit Leishmania parasites [75].…”

Ivermectin: enigmatic multifaceted ‘wonder’ drug continues to surprise and exceed expectations

“…62 Leishmaniasis Ivermectin has been proposed as a possible rodent-bait feed-through insecticide to help control the Phlebotomine sandfly vectors that transmit Leishmania parasites. 63,64 Experiments to test the impact of ivermectin on one blood-feeding sandfly vector, Phlebotomus papatasi, demonstrated that they die if the blood feed is 1-2 days post treatment. Although Leishmania major promastigotes have been shown to die or lose their infectivity after exposure to ivermectin, it does not have a major impact against L. major.…”