RESUMO
Aotus monkeys are good models for erythrocyte-induced Plasmodium falciparum and P. vivax infections and have been extensively used in malarial drug and vaccine development. Recently, it has been shown that certain species of Aotus can be infected with sporozoites, and that the degree of susceptibility varies among species. We demonstrate here that Panamanian Aotus lemurinus lemurinus are susceptible to a sporozoite-induced infection, opening the possibility that this species of Aotus could be used as models for testing the efficacy of pre-erythrocytic P. falciparum vaccines and drug candidates directed at the pre-erythrocytic stages of P. falciparum and P. vivax malaria. In this species, we compared sporozoite infection rates. Two of four animals splenectomized prior to infection with sporozoites developed patent parasitemias. Seven of eight animals splenectomized either 7 or 35 days after infection became parasitemic. Additionally, we used a P. falciparum-specific polymerase chain reaction (PCR) method to detect the early appearance of parasitized erythrocytes in the blood prior to detection by conventional microscopy, and found that the parasitemia was detected first in five animals by the PCR method, first in three animals by blood film, with one parasitemia detected simultaneously. We also demonstrated the feasibility of infecting monkeys located in Panama with sporozoites isolated at an insectary in Atlanta, thus documenting the feasibility of similar studies where the insectary and monkey colony are not in the same location. A subsequent attempt to infect these monkeys using sporozoites was not successful, suggesting that this model of human malaria is not yet ready for routine use in vaccine or drug efficacy screening. This model merits further study because of the importance of testing pre-erythrocytic P. falciparum malaria vaccines and drugs in animals.
Assuntos
Aotus trivirgatus/imunologia , Modelos Animais de Doenças , Malária Falciparum/veterinária , Plasmodium falciparum/patogenicidade , Animais , Anopheles/parasitologia , DNA de Protozoário/química , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Malária Falciparum/imunologia , Masculino , Hibridização de Ácido Nucleico , Panamá , Parasitemia/sangue , Reação em Cadeia da Polimerase/veterinária , Esplenectomia/veterináriaRESUMO
When 239 (1982) and 361 (1991) five- and nine-year-old children in St. Kitts were assessed for the presence of parasitic infections, there were significant reductions in the prevalence of trichuriasis from 83% to 58%, of ascariasis from 24% to 8.6% and of giardiasis from 15% to 9.4%. Anthelminthic use, which appeared to be the most important responsible intervention tool, remained roughly at the same level at 59-51%. However, the types of anthelminthics used changed over the period. Piperazine citrate, which was used by 66% in 1982, only had 35% usage in 1991. Albendazole which was not used at all in 1982 was taken by 32% of the children in 1991 and at the same time use of laevo-tetramisole increased by 20% from 14%. Suggestions are made for an island-wide mass intervention programme to manage parasitic infections.
Assuntos
Enteropatias Parasitárias/epidemiologia , Anti-Helmínticos/uso terapêutico , Criança , Pré-Escolar , Fezes/parasitologia , Helmintíase/tratamento farmacológico , Helmintíase/epidemiologia , Humanos , Enteropatias Parasitárias/tratamento farmacológico , Prevalência , Infecções por Protozoários/tratamento farmacológico , Infecções por Protozoários/epidemiologia , Fatores de Tempo , Índias Ocidentais/epidemiologiaRESUMO
Thirty-one percent of a group of 49 hospitalized patients or laboratory workers in Guyana showed positive intradermal paracoccidioidin tests in the presence of negative histoplasmin reactions. In 2 patients (4%), the intradermal reactions to paracoccidioidin were greater than 10 mm in diameter. The prevalence of positive reactors in a selected population suggests that paracoccidioidomycosis may be endemic in Guyana although no clinical case has been reported from the country. A further survey in a larger, unselected population would lead to a clearer understanding of the problem.
Assuntos
Proteínas Fúngicas , Paracoccidioidomicose/imunologia , Adolescente , Adulto , Idoso , Criança , Coccidioidina/imunologia , Feminino , Guiana , Histoplasmina/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Testes CutâneosRESUMO
A preliminary survey of the incidence of histoplasmosis in the eastern Caribbean was carried out. The percentages of positive histoplasmin skin test reactors in the populations studied were as follows: Barbados (4%), Trinidad (42%) and Guyana (29%). In Trinidad 69% of individuals under 60 had positive test. However a lower proportion (4%) had serological evidence of past infection with Histoplasma capsulatum. The organism was not isolated from the soil although it had been found previously in Trinidad. On this island five previously diagnosed cases of histoplasmosis were identified. The study confirmed the presence of the infection in the area and further investigations are suggested.
Assuntos
Histoplasmose/epidemiologia , Inquéritos Epidemiológicos , Humanos , Índias OcidentaisRESUMO
A study was made of 127 patients suffering from tuberculosis who were discharged from the Sanatorium after varying periods of treatment. An attempt was made to determine the extent to which patients took drugs at home and the reasons for failure to co-operate analysed. Difficulty in ingesting P.A.S. was not a major factor although it played a part. Inadequate instruction about the need for continuation of treatment seemed to be responsible for a large number failing to take drugs regularly (AU)