Seasonal distribution and diel biting patterns of culicine mosquitoes in Costa Marques, Rondônia, Brazil

A study of peridomestic man-biting culicines in the Amazon Basin was conducted from January through December, 1987. Fifteen species of mosquitoes from six genera were collected by volunters in all-night human-bait indoor and outdoor collections at five hoses in and near the town of Costa Marques, Rondônia, Brazil. Culex quinquefasciatus and members of the Mansonia titillans/indubitans Group comprised 61 and 33%, respectively, of all culcines collected from human-bait outside houses and 62 and 35%, respectively, of those collected from volunteers inside houses in the town. In rural areas, Cx. quinquefasciatus was less abundant and only comprised 2 and 5% of the culcines, respectively, collected inside and outside houses. Mansonia titillans/indubitans Group comprised 75% and 86% of the culicines collected inside and outside houses, respectively, from rural residences. Culex quinquefasciatus and members of Mn. titillans/indubitans Group were more endophilic than other culcines collected. Nocturnal and seasonal biting rhythms for the more common culcines are described

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

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 phospate, 15 mg, was administered concurrently at h 0 and 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 inffective 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 administred concurrently with chloroquine to reduce vivax malaria transmission.

Assessment of immunity induced in mice by glycoproteins derived from different strains and species of Leishmania

A comparative study was undertaken on the immunogenic properties of 63kDa glycoproteins obtained from five different strains/species of Leishmania and assessed in C57BL/10 mice. The humoral immune response was assessed by ELISA against the five different antigens of the immunized animals. The cellular immune response was derived from Leishmania. The response was found to be species-specific in all of determined by means of the cytokine profiles secreted by the spleen cells of immunized animals. The presence of ³-IFN and IL-2, and the absence of IL-4 in the supernatants of cells stimulated by L. amazonensis antigen established that the cellular response is of Th1 type. The five glycoproteins tested were equally effective in protecting C57BL/10 mice against challenge by L. amazonensis. About 50% of the immunized animals were protected for six months.

Zymodeme and Serodeme Characterization of Leishmania Isolates Obtained from Costa Rican Patients

Thirty-four Leishmania isolates obtained from Costa Rican patients, from different geographical areas, were characterized by isoenzyme electrophoresis and indirect immunofluorescense with monoclonal antibodies. Thirty-two were characterized as L. panamensis strains and two were L. braziliensis variants. We confirm the evident predominance of L. panamensis as the main etiological agent of leishmaniasis in Costa Rica and the existence of L. braziliensis in the country.

Possible hybridization of Brazilian planorbid snails and its importance in population dynamics

This study focuses on the possibility of experimental hybridization among host snail species for Schistosoma mansoni in Brazil, with morphological characterization of the hybrids found. By using albinism as a genetic marker, intraspecific crossbreedings were performed between two strains of each species involved, in addition to interspecific crossbreedings; the only viable crossbreeding was between pigmented Biomphalaria glabrata (Paulista, PE) and albino B. tenagophila (Joinville, SC), with the formation of F1 and F2 generations. All offspring in F1 displayed black eyes and a renal ridge on the mantle, while F2 displayed dissociated morphological traits. With regard to reproduction, F1 was more efficient than F2. The experiment's results suggest post-zygotic reproductive isolation.

Description of Lutzomyia bianchigalatiae n. sp. a sand fly within the subgenus Pintomyia Costa Lima 1932 (Diptera; Psychodidae)

A new sand fly species is described based on males collected in Bananal, municipality of Mariana and the female from Sabará city, State of Minas Gerais, Brazil. Taxonomic remarks, geographic distribution and the description of new species are presented. The name Lutzomyia (Pintomyia) bianchigalatiae is in honour of Dr Eunice Aparecida Bianchi Galati, friend and researcher at the Faculdade de Saúde Pública, Universidade de São Paulo.