Lack of quadruple and quintuple mutant alleles associated with sulfadoxine-pyrimethamine resistance in Plasmodium vivax isolates from Brazilian endemic areas

BACKGROUND AND OBJECTIVE Brazil is responsible for a large number of Plasmodium vivax cases in America. Given the emergence of P. vivax parasites resistant to chloroquine and the effectiveness of antifolates in vivax malaria treatment together with a correlation between mutations in P. vivax dhfr and dhps genes and SP treatment failure, the point mutations in these genes were investigated. METHODS Blood samples from 54 patients experiencing vivax malaria symptomatic episodes in the Amazonian Region were investigated. Genomic DNA was extracted using a DNA extraction kit (QIAGENTM). Nested polymerase chain reaction (PCR) amplification was carried out followed by Sanger sequencing to detect single nucleotide polymorphisms (SNPs). FINDINGS All tested isolates showed non-synonymous mutations in pvdhfr gene: 117N (54/54, 100%) and 58R (25/54, 46%). Double mutant allele 58R/117N (FRTNI, 28%) was the most frequent followed by triple mutant alleles (58R/117N/173L, FRTNL, 11%; 58R/61M/117N, FRMNI, 5% 117N/173L, FSTNL, 4%) and quadruple mutant allele (58R/61M/117N/173L, FRMNL, 2%). A single mutation was observed at codon C383G in pvdhps gene (SGKAV, 48%). CONCLUSION No evidence of molecular signatures associated with P. vivax resistance to SP was observed in the Brazilian samples.

Use of pre-packaged chloroquine for the home of presumed malaria in Malagasy children

Objective: The main objective of this study was to assess the quality of home malaria management with pre-packaged chloroquine in two areas in the Moramanga district of Madagascar. The knowledge; attitude and practices of care providers in terms of home treatment options were evaluated and compared. The availability of treatment options by studying retailers and community-based service providers was also investigated. Methods: A cross-sectional investigation in two communities; in the hamlets and villages located close to carers; retailers; community-based service providers and primary health centres was carried out. Results :Carers in the two districts were equally well aware of the use of pre-packaged chloroquine. Their first response to the onset of fever was to treat children with this antimalarial drug at home. The dose administered and treatment compliance were entirely satisfactory (100) with pre-packaged chloroquine and rarely satisfactory (1.6to 4.5) with non pre-packaged chloroquine. In cases of treatment failure; the carers took patients to health centres. Chloroquine was supplied principally by private pharmacies and travelling salesmen selling unpackaged chloroquine tablets. Non pre-packaged chloroquine was the most common drug used at health centres. The frequency of positive rapid malaria tests (P=0.01) was significantly higher in children treated with non pre-packaged chloroquine (38) than in children treated with pre-packaged chloroquine (1.3). Conclusions: Home malaria management should be improved in Madagascar. Efforts should focus on communication; the training of community-based service providers; access to pre-packaged drugs and the gradual withdrawal of pre-packaged chloroquine and its replacement by pre-packaged artemisinin-based combination therapies