DRUG-RESISTANT AND MIXED-SPECIES MALARIA INFECTIONS IN MPUMALANGA, SOUTH-AFRICA

Malaria infections in South Africa have surged to alarming levels over the last few years. This study was undertaken to establish the occurr ence of antifolate-resistant parasites and of mixed-species malaria in fections in the Mpumalanga province of South Africa. Blood samples fro m infected patients were subjected to molecular screening methods base d on parasite nucleic acid properties. The assays consisted of restric tion enzyme analyses specific for point mutations in the polymerase ch ain reaction (PCR) amplified gene of the antifolate target enzyme, dih ydrofolate reductase (DHFR), which are known to confer drug resistance , Concurrently, the infective species were identified using PCR amplif ication of the small-subunit ribosomal RNA genes. Of the 56 samples an alysed, sir (12%) showed mired-species infections, four being P. falci parum-P. ovale and two P. falciparum-P. vivax mixtures, Analyses of re sistance to the antifolates revealed that out of 21 single P. falcipar um-infected samples tested, 43% contained parasites resistant to pyrim ethamine treatment. The mutations were located in codon 108 and all we re substitutions of Ser to Asn. Despite the relatively small sample si ze, these results suggest that malaria resistance to antifolates in th e Mpumalanga province, which includes the Kruger National Park, could significantly influence the chemotherapeutic regimens employed for the prophylaxis and treatment of the disease.