Infection of Anopheles darlingi fed on patients infected with Plasmodium vivax before and during treatment with chloroquine plus primaquine in Costa Marques, Rondônia, Brazil

Abstract

Five patients with asexual and sexual parasites of Plasmodium vivax were treated orally with 600 mg chloroquine diphosphate (hour 0) followed with 300 mg at 8, 24 and 48 h later. Primaquine phosphate, 15 mg, was administered concurrently at h 0 and at 24 h intervals for 14 days. Anopheles darlingi were fed before the first dose (h -0.5) and 0.5, 1, 2, 4, 6, 8, 10, 12, 16, 20, 24, 36, 48, 60 and 72 h later. Mosquitoes were examined for oocysts on day 8 and for sporozoites on day 15 after infection. Four of the five patients studied were still infective to mosquitoes from 1-5 h after the first dose of chloroquine plus primaquine. One of these and one other patient, who vomited 15 min after the first dose, became infective again at hours 10 and 12, respectively. Once produced, oocysts in mosquitoes fed on patients before, during and after chloroquine plus primaquine treatment appeared normal and produced sporozoite infected salivary glands. In view of these data, it is concluded that primaquine demonstrated rapid gametocytocidal activity and should be administered concurrently with chloroquine to reduce vivax malaria transmission.

Efficacy of Three Different Regimens of Primaquine for the Prevention of Relapses of Plasmodium vivax Malaria in the Amazon Basin of Peru

“…2 PQ also eliminates gametocytes in the blood, preventing transmission to mosquitoes. 3 There is evidence that PQ synergizes with CQ to kill the asexual blood stage of P. falciparum and P. vivax, 4 despite the minimal effect of PQ by itself against asexual blood parasites. 5 After treatment, a recurrence of P. vivax in the bloodstream can be classified as recrudescence, relapse, or reinfection.…”

Primaquina y recurrencias de malaria por Plasmodium vivax. Metanálisis de estudios clínicos controlados

“…PQ seems more efficient when it occurs simultaneously with the blood schozonticides 2 and, from all antimalarials, this is the one which has the wider activity spectrum 3 . The PQ has proven highly useful for simple primary and secondary chemoprophylaxis 4 or against recurrences [5][6][7][8] . The total dosis (TD) of 210 mg given in 14 days (210-14), for an adult weighting 60 kg (0.25 mg/kg/day for 14 days), is recommended by the WHO as the stardard in order to avoid recurrences 7 .…”

“…The total dosis (TD) of 210 mg given in 14 days (210-14), for an adult weighting 60 kg (0.25 mg/kg/day for 14 days), is recommended by the WHO as the stardard in order to avoid recurrences 7 . Blocking the transmission of P. vivax through the use of drugs is achieved with the usual PQ dose, which produces, in 4 to 20 hours, the complete loss of transmission to the anopheline 8 . The clinical and parasitary cure, which include avoiding recurrences of the infection by P. cynomolgi and P. vivax is the role of the TD of the 8-AQ 9,10 .…”

Type material of Platyhelminthes housed in the Helminthological Collection of the Oswaldo Cruz Institute/ FIOCRUZ (CHIOC), Rio de Janeiro, Brazil, from 1979 to 2016 (Rhabditophora, Trematoda and Cestoda)

“…CHIOC 36600 a–b collected in the Paraná River (Porto Rico, Paraná State), and 32713–32714, referred to as Nomimoscolex sudobim Woodland, 1935 by Pavanelli and Rego (1992), collected in the Itaipu reservoir (Paraná State). Other paratypes deposited in the BMNH and MHNG collections.…”