Repurposing isoxazoline veterinary drugs for control of vector-borne human diseases
Miglianico, Marie ; Eldering, Maarten ; Slater, Hannah ; Ferguson, Neil ; Ambrose, Pauline ; Lees, Rosemary S. ; Koolen, Karin M.J. ; Pruzinova, Katerina ; Jancarova, Magdalena ; Volf, Petr ; Koenraadt, Constantianus J.M. ; Duerr, Hans Peter ; Trevitt, Graham ; Yang, Baiyuan ; Chatterjee, Arnab K. ; Wisler, John ; Sturm, Angelika ; Bousema, Teun ; Sauerwein, Robert W. ; Schultz, Peter G. ; Tremblay, Matthew S. ; Dechering, Koen J. - \ 2018
Proceedings of the National Academy of Sciences of the United States of America 115 (2018)29. - ISSN 0027-8424 - p. E6920 - E6926.
Insecticide - Isoxazoline - Malaria - Vector control - Zika fever
Isoxazolines are oral insecticidal drugs currently licensed fo ectoparasite control in companion animals. Here we propose thei use in humans for the reduction of vector-borne disease incidence Fluralaner and afoxolaner rapidly killed Anopheles, Aedes, an Culex mosquitoes and Phlebotomus sand flies after feeding on drug-supplemented blood meal, with IC50 values ranging from 33 to 575 nM, and were fully active against strains with preexist ing resistance to common insecticides. Based on allometric scalin of preclinical pharmacokinetics data, we predict that a single hu man median dose of 260 mg (IQR, 177–407 mg) for afoxolaner, o 410 mg (IQR, 278–648 mg) for fluralaner, could provide an insecti cidal effect lasting 50–90 days against mosquitoes and Phleboto mus sand flies. Computational modeling showed that seasona mass drug administration of such a single dose to a fraction of regional population would dramatically reduce clinical cases o Zika and malaria in endemic settings. Isoxazolines therefore rep resent a promising new component of drug-based vector control.
Effects of imidacloprid on the ecology of sub-tropical freshwater microcosms
Sumon, Kizar Ahmed ; Ritika, Afifat Khanam ; Peeters, Edwin T.H.M. ; Rashid, Harunur ; Bosma, Roel H. ; Rahman, Md Shahidur ; Fatema, Mst Kaniz ; Brink, Paul J. Van den - \ 2018
Environmental Pollution 236 (2018). - ISSN 0269-7491 - p. 432 - 441.
Bangladesh - Freshwater ecosystem - Insecticide - Neonicotinoid
The neonicotinoid insecticide imidacloprid is used in Bangladesh for a variety of crop protection purposes. Imidacloprid may contaminate aquatic ecosystems via spray drift, surface runoff and ground water leaching. The present study aimed at assessing the fate and effects of imidacloprid on structural (phytoplankton, zooplankton, macroinvertebrates and periphyton) and functional (organic matter decomposition) endpoints of freshwater, sub-tropical ecosystems in Bangladesh. Imidacloprid was applied weekly to 16 freshwater microcosms (PVC tanks containing 400 L de-chlorinated tap water) at nominal concentrations of 0, 30, 300, 3000 ng/L over a period of 4 weeks. Results indicated that imidacloprid concentrations from the microcosm water column declined rapidly. Univariate and multivariate analysis showed significant effects of imidacloprid on the zooplankton and macroinvertebrate community, some individual phytoplankton taxa, and water quality variables (i.e. DO, alkalinity, ammonia and nitrate), with Cloeon sp., Diaptomus sp. and Keratella sp. being the most affected species, i.e. showing lower abundance values in all treatments compared to the control. The observed high sensitivity of Cloeon sp. and Diaptomus sp. was confirmed by the results of single species tests. No significant effects were observed on the species composition of the phytoplankton, periphyton biomass and organic matter decomposition for any of the sampling days. Our study indicates that (sub-)tropical aquatic ecosystems can be much more sensitive to imidacloprid compared to temperate ones.
Effect of insecticide-treated bed nets on house-entry by malaria mosquitoes : The flight response recorded in a semi-field study in Kenya
Spitzen, Jeroen ; Koelewijn, Teun ; Mukabana, W.R. ; Takken, Willem - \ 2017
Acta Tropica 172 (2017). - ISSN 0001-706X - p. 180 - 185.
Anopheles - Bed net - House-entry - Insecticide - Insecticide-treated nets - Mosquito flight
Insecticide-treated nets are currently a major tool to reduce malaria transmission. Their level of repellency affects contact of the mosquito with the net, but may also influence the mosquito's entry into the house. The response of host-seeking malaria mosquitoes approaching the eave of an experimental house was recorded within a large screen house. We compared entry- and exit rates in relation to the presence in the house of different insecticide-treated bed nets (ITNs) with an untreated net. Mosquitoes were lured towards the house by dispensing a synthetic host-odour blend from within the net in the house. Complementary WHO bioassays revealed that the treated nets caused high knock-down- and mortality responses to the Anopheles gambiae sensu stricto strain tested. The proportion of mosquitoes that came into view of the cameras and subsequently entered the house did not differ between treated nets and the untreated net. Treated nets did not affect proportions of mosquitoes that exited the house and departed from view around the eave. However, the percentage of house-leaving and re-entering mosquitoes when an insecticide- treated net was present, was lower than in the presence of an untreated net. Our results indicated that there was no spatial repellent effect from pyrethroid-treated nets that influences house-entry at eave level. It is argued that the toxic effect of treated bed nets resulted in a reduced number of mosquitoes re-entering the house, which could thereby affect malaria transmission in neighbouring, unprotected houses.