Patterns of resistance and DHFR/DHPS genotypes of Plasmodium falciparum in rural Tanzania prior to the adoption of sulfadoxine–pyrimethamine as first-line treatment

• Published in: Transactions of the Royal Society of Tropical Medicine and Hygiene 2004-06, Vol.98 (6), p.347-353
• Main Authors: Eriksen, J, Mwankusye, S, Mduma, S, Kitua, A, Swedberg, G, Tomson, G, Gustafsson, L.L, Warsame, M
• Format: Article
• Language: English
• Subjects: Animals; Antimalarials - therapeutic use; Biological and medical sciences; Child, Preschool; Chloroquine; Chloroquine - therapeutic use; Developing Countries; Dihydropteroate Synthase - genetics; Drug Combinations; Drug resistance; Drug Resistance - genetics; Female; Genotype; Human protozoal diseases; Humans; Infant; Infectious diseases; Malaria; Malaria, Falciparum - drug therapy; Malaria, Falciparum - parasitology; Male; Medical sciences; Medicin och hälsovetenskap; Molecular markers; Parasitic diseases; Plasmodium falciparum; Plasmodium falciparum - drug effects; Plasmodium falciparum - genetics; Plasmodium falciparum/drug effects/genetics; Point Mutation; Policy change; Protozoal diseases; Pyrimethamine - therapeutic use; Rural Health; Sulfadoxine - therapeutic use; Sulfadoxine–pyrimethamine; Tanzania; Tetrahydrofolate Dehydrogenase - genetics
• ISSN: 0035-9203; 1878-3503
• DOI: 10.1016/j.trstmh.2003.10.010

A study was carried out to assess the patterns of resistance and occurrence of DHFR/DHPS genotypes of Plasmodium falciparum prior to the adoption of sulfadoxine–pyrimethamine (SP) as first-line treatment for uncomplicated malaria in Tanzania. Children under five years ( n=117) with clinical, uncomplicated malaria were randomly allocated to standard treatments of either chloroquine (CQ) (25 mg/kg) or SP (25 mg sulfadoxine and 1.25 mg pyrimethamine/kg). Patients were monitored for 28 days. Clinical recovery was achieved in 98% ( n=58) and 90% ( n=59) of the patients in the SP and CQ groups, respectively. Parasitologically, 14% of the patients in the SP group and 51% in the CQ group exhibited RII/RIII resistance. When relating pre-treatment blood drug levels to treatment outcome and the degree of parasite resistance to the number of mutations, no relationships could be detected. There was an overall significant increase in haemoglobin levels from day 0 to day 28 in both patient groups. Sulfadoxine–pyrimethamine produced an acceptable clinical response but the high degree of parasitological resistance (RII/RIII) observed two years prior to the introduction of the drug as first-line treatment is of concern, especially considering the long half-lives of sulfadoxine and pyrimethamine.