RESUMEN
The sporontocidal activity of four dihydroacridine-diones (WR-233602, WR-243251, WR-250547, and WR-250548) and three fluoroquinolones (WR-279135, WR-279298, and WR-279288) was determined against naturally circulating isolates of Plasmodium vivax. Laboratory-reared Anopheles dirus mosquitoes were infected with P. vivax by feeding them on gametocytemic volunteers reporting to local malaria clinics in Kanchanaburi and Tak provinces, Thailand. Four days after the infectious feed, mosquitoes were re-fed on uninfected mice treated 90 minutes previously with a given drug at a dose of 100 mg base drug/kg mouse body weight. Sporontocidal activity was determined by assessing both oocyst and sporozoite development. None of the fluoroquinolones exhibited sporontocidal activity against P. vivax, whereas all 4 dihydroacridine-diones affected sporogonic development to some degree. WR-233602 affected oocyst development, but had no impact on sporozoite production, WR-250548 affected oocyst development and had a limited effect on sporozoite production, and WR-243251 and WR-250547 had a marked impact on all phases of sporogony. These data demonstrate that experimental dihydroacridine-diones are capable of interrupting the sporogonic development of P. vivax. These compounds may be useful in preventing malaria transmission.
Asunto(s)
Acridinas/farmacología , Anopheles/parasitología , Antiinfecciosos/farmacología , Antimaláricos/farmacología , Malaria Vivax/parasitología , Plasmodium vivax/efectos de los fármacos , Acridinas/uso terapéutico , Adulto , Animales , Antiinfecciosos/uso terapéutico , Antimaláricos/uso terapéutico , Femenino , Fluoroquinolonas , Humanos , Malaria Vivax/tratamiento farmacológico , Malaria Vivax/prevención & control , Masculino , Ratones , Microscopía de Contraste de Fase , Plasmodium vivax/crecimiento & desarrollo , Distribución Aleatoria , Glándulas Salivales/parasitología , TailandiaRESUMEN
Laboratory and field tests of the repellents diethyl methylbenzamide (deet), 1-(3-Cyclohexen-1-yl-carbonyl)-2-methylpiperidine (AI3-37220), and (2-hydroxymethylcyclohexyl) acetic acid lactone (CIC-4) were conducted against Anopheles dirus Peyton & Harrison, the principal malaria vector in Thailand. In the laboratory, An. dirus was more sensitive to CIC-4 than either AI3-37220 or deet. The duration of protection provided by each repellent in laboratory tests increased with higher concentrations of repellents and when exposed in cages containing fewer mosquitoes. A field study in Chanthaburi Province, southeastern Thailand, during November 1993 tested 25% (wt:wt) ethanol solutions of each repellent against An. dirus. In contrast to the laboratory experiments, protection provided by AI3-37220 was significantly better than either deet or CIC-4 and there was no significant difference between deet and CIC-4. Protection provided by deet and CIC-4 fell to below 95% 2 h after repellent application, whereas AI3-37220 provided > 95% protection for 4 h. The protection provided by all repellents fell to < or = 65% 7 h after repellent application.
Asunto(s)
Anopheles , Cromonas , DEET , Repelentes de Insectos , Control de Mosquitos , Piperidinas , Aedes , Animales , Femenino , Humanos , TailandiaRESUMEN
Laboratory tests were conducted to study the response of Anopheles dirus and Aedes albopictus to repellent formulations containing diethyl methylbenzamide (deet) and dimethyl phthalate. Anopheles dirus was tolerant of low concentrations of deet (5-20%), and formulations containing < or = 35% deet provided protection for < or = 90 min. In contrast, Ae. albopictus was sensitive to these formulations, which provided > or = 180 min protection from bites.
