Pathogenesis of acute avian malaria. IV. Immunologic factors in nephritis of acute Plasmodium gallinaceum infections of chickens.

Study of urinary waste of chickens with acute Plasmodium gallinaceum malaria indicated that serum proteins of the globulin and albumin classes were passed. Protein extravasation did not begin until globulin-associated serum antigen and its antibody were detected in the blood. Both serum antigen and antibody were found in the wastes for as long as the antigen was present in the blood. Extracts of kidney tissues contained serum proteins that were not present in extracts from normal kidneys, and serum antigen and its antibody were both present. Frozen kidney sections reacted strongly with fluorescein-conjugated antibody to serum antigen, showing diffuse granular immunofluorescence characteristic of immune complex nephritis. Sections from chickens with nephritis induced by injections of malarious plasma also showed deposits of extravasated antigen. The experiments suggested that complexes of serum antigen and antibody served as a permeability factor, or activated other permeability factors and may have caused the glomerulonephritis associated with acute avian malaria. The passing of serum proteins in the urinary wastes after chickens had recovered from acute malaria suggested that persisting damage may have resulted.

Culex nigripalpus: a natural vector of wild turkey malaria (Plasmodium hermani) in Florida.

Durking 1977 and 1978, more than 21,000 female mosquitoes of 15 species were live-trapped in south Florida where high numbers of wild turkeys (Meleagris gallopavo) are known to harbor malarial infections. By inoculation of mosquito extracts into uninfected domestic poults, the presence of sporozoites of Plasmodium hermani was demonstrated in Culex nigrapalpus. This mosquito, previously shown to be a competent experimental vector, is believed to be the primary natural vector of wild turkey malaria in Florida.

Mechanism of spring relapse in avian malaria: effect of gonadotropin and corticosterone.

Previous work demonstrated that corticosterone induces relapse of avian malaria, and that this effect varies markedly from winter to spring. In the present study, English sparrows with latent Plasmodium relictum infections were treated in winter with corticosterone, gonadotropin, corticosterone + gonadotropin, or a control regimen consisting of the oil vehicle. Gonadotropin neither induced relapse nor potentiated the induction of relapse by corticosterone. These data cast doubt on the hypothesis that spring relapse in malarial infections is mediated by seasonal changes in reproductive hormone levels.

Culex saltanensis Dyar, 1928--natural vector of Plasmodium juxtanucleare in Rio de Janeiro, Brazil.

Searching for the natural vector of Plasmodium juxtanucleare in an enzootic locality: Granjas Calábria (33% of the chickens infected), Jacarepaguá, in Rio de Janeiro, Brazil, 13 comparative captures of mosquitoes were carried out, simultaneously on man (out-doors) and on chicken (in a poultry-yard), between 6 and 9 p.m., from September 1988 to March 1989. Culex saltanensis was the most frequent species in captures on chicken, accounting for 41.7% of the mosquitoes collected on this bait, showing to be highly ornithophilic (90% captured on chicken versus 10% on man). Seven specimens of Cx. saltanensis were found naturally infected in Granjas Calábria: five with mature pedunculate oocysts and two with sporozoites (one in the haemocoele and one in the salivary glands). These sporozoites produced an infection by P. juxtanucleare in a chick, which had parasitemia on day 41 after inoculation. One Cx. coronator was found with mature pedunculate oocysts. Culex saltanensis was regarded as primary vector of P. juxtanucleare in Rio de Janeiro for being highly ornithophilic and in enough density to maintain the transmission, having been found with infective sporozoites in its salivary glands, and being susceptible to the parasite and able to transmit experimentally it by the bite.

Culex saltanensis Dyar, 1928: natural vector of Plasmodium juxtanucleare in Rio de Janeiro, Brazil

Searching for the natural vector of Plasmodium juxtanucleare in an enzootic locality: Granjas Calábria (33% of the chickens infected), Jacarepaguá, in Rio de Janeiro, Brazil, 13 comparative captures of mosquitoes were carried out, simultaneously on man (out-doors) and on chiken ( in a poultry-yard), between 6 and 9 p.m., from September to March 1989. Culex saltanensis was the most frequent species in captures on chicken, accounting for 41.7% of the mosquitoes collected on this bait, showing to be highly ornithophilic (90% captured on chicken versus 10% on man). Seven specimens of Cx. saltanensis were found naturally infected in granjas Calábria: five with mature pedunculate oocysts and two with sporozoites (on in the haemocoele and one in the salivary glands). These sporozoites porudced an infection by P. juxtanucleare in a chick, which had parasitemia on day 41 after inoculation. One Cx. coronator was found with mature pedunculate oocysts. Culex saltanensis was regarded as primary vector of P. juxtanucleare in Rio de Janeiro for being highly ornithophilic and in enough density to maintain the transmission, having been found with infective sporozoites in its salivary glands, and being susceptible to the parasite and able to transmit experimentally it by th bite