RESUMO
The presence of malaria parasites and the serological antibody responses against whole Plasmodium falciparum and the Pf155 antigen were studied in the population of a small rural locality in Haiti in December 1985. Only 7 (1.5%) of the individuals were found to be infected with P. falciparum, the only species observed. Antibodies to P. falciparum were detected in an ELISA in 38.2% of the sera, the positivity rates being age-related. Anti-Pf155 antibodies were detected in 12.5% and 13.6% of individuals by two different techniques used. The anti-Pf155 positivity rates increased only after 25 years of age. No trends were detected for a clear-cut protective value of Pf155 antibodies against clinical malaria and further longitudinally conducted field surveys are needed to satisfactorily assess the potential protective effect of Pf155 antibodies.
Assuntos
Anticorpos Antiprotozoários/análise , Antígenos de Protozoários/imunologia , Malária/imunologia , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Feminino , Haiti , Humanos , Lactente , Malária/epidemiologia , Masculino , Plasmodium falciparumRESUMO
Between 1981 and 1983, in vivo and in vitro studies were conducted in Haiti to assess the responsiveness of Plasmodium falciparum to chloroquine. The standard tests successfully performed included 92 WHO standardized in vivo field tests and 160 in vitro tests (64 macrotests, 33 microtests, and 63 48-hr tests). No clearcut evidence of chloroquine resistance was detected. In 3 in vivo and 5 in vitro tests, a decreased susceptibility to the drug was suggested, but these isolated findings failed to be corroborated by parallel alternate tests. In addition, during the initial trial of an alternate monitoring system, 339 simplified 7-day in vivo tests were successfully performed, with no suggestion of resistance detected. This simplified 7-day in vivo test potentially represents an efficient low cost method for monitoring drug resistance in many developing countries.
Assuntos
Cloroquina/farmacologia , Malária/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Animais , Cloroquina/uso terapêutico , Resistência a Medicamentos , Haiti , Humanos , Malária/parasitologia , Plasmodium falciparum/crescimento & desenvolvimentoRESUMO
Eighteen patients with Plasmodium falciparum infection were studied in Port-au-Prince, Haiti, to monitor the response of the malaria parasite to sulfadoxine-pyrimethamine. In all infections the parasitaemia was cleared rapidly following treatment with standard dose of the drug combination; no recrudescence was observed during follow-up periods of 1 week (4 patients) and 4 weeks (14 patients). Parallel in vitro tests indicated that 5 of the 16 isolates successfully tested were resistant to pyrimethamine alone.
Assuntos
Malária/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Pirimetamina/farmacologia , Sulfadoxina/farmacologia , Sulfanilamidas/farmacologia , Adolescente , Adulto , Criança , Pré-Escolar , Resistência a Medicamentos , Quimioterapia Combinada , Feminino , Haiti , Humanos , Lactente , Malária/parasitologia , MasculinoRESUMO
In January and February 1982, in vivo and in vitro studies of the chloroquine sensitivity of Plasmodium falciparum were conducted in Port-au-Prince, Haiti. Of 19 infections tested in vivo using the WHO extended test, all but one were susceptible to the drug; the remaining case showed a recurrence of parasitaemia on day 28. Of the 19 corresponding 48-hour in vitro tests, 16 provided interpretable results; 12 tests demonstrated sensitivity to the drug, while in the remaining 4, parasite multiplication was inhibited only at drug concentrations higher than that previously accepted as indicative of sensitivity. (These four included the isolate from the patient who had a recurrence of parasitaemia on day 28.) While these results provide no absolute demonstration of chloroquine resistance, they underline the need for close monitoring of the susceptibility to chloroquine of P. falciparum in Haiti.