RESUMO
Transfusion-transmitted malaria due to asymptomatic Plasmodium infections is a challenge for blood banks. There is a lack of data on the prevalence of asymptomatic infected blood donors and the incidence of transfusion-transmitted malaria in low endemicity areas worldwide. We estimated the frequency of blood donors harbouring Plasmodium in an area in which asymptomatic infections have been reported. Material and methods. To estimate the frequency of blood donors harbouring Plasmodium weused microscopy and molecular tools. Serological tests were applied to measure the exposure of candidates to Plasmodium antigens. Venous blood was collected from 91 candidates attending the"Pró-Sangue" Blood Centre Foundation in São Paulo, who lived in the municipality of Juquitiba, São Paulo, Brazil, where sporadic autochthonous cases of malaria have been described. Blood samples were used for parasitological, molecular and serological studies...
Assuntos
Humanos , Malária/sangue , Malária/transmissão , Portador Sadio , Transfusão de SangueRESUMO
A study searching for Plasmodium vivax and Plasmodium falciparum DNA among blood donors from the non-endemic area in Brazil reported a rate of 7.41%. This number is at least three times higher than what has been observed in blood donors from the Amazon, an endemic area concentrating >99% of all malaria cases in Brazil. Moreover, the majority of the donors were supposedly infected by P. falciparum, a rare finding both in men and anophelines from the Atlantic forest. These findings shall be taken with caution since they disagree with several publications in the literature and possibly overestimate the actual risk of malaria transmission by blood transfusion in São Paulo city...
Assuntos
Humanos , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/genética , Plasmodium vivax/crescimento & desenvolvimento , Plasmodium vivax/genética , Portador Sadio/sangueRESUMO
Anti-glycosylphosphatidylinositol (GPI) antibodies (Abs) may reflect and mediate, at least partially, anti-disease immunity in malaria by neutralising the toxic effect of parasitic GPI. Thus, we assessed the anti-GPI Ab response in asymptomatic individuals living in an area of the Brazilian Amazon that has a high level of malaria transmission. For comparative purposes, we also investigated the Ab response to a crude extract prepared from Plasmodium falciparum, the merozoite surface protein (MSP)3 antigen of P. falciparum and the MSP 1 antigen of Plasmodium vivax (PvMSP1-19) in these individuals and in Angolan patients with acute malaria. Our data suggest that the Ab response against P. falciparum GPI is not associated with P. falciparum asymptomatic infection in individuals who have been chronically exposed to malaria in the Brazilian Amazon. However, this Ab response could be related to on going parasitaemia (as was previously shown) in the Angolan patients. In addition, our data show that PvMSP1-19 may be a good marker antigen to reflect previous exposure to Plasmodium in areas that have a high transmission rate of P. vivax...