Current status of 4-aminoquinoline resistance markers 18 years after cessation of chloroquine use for the treatment of uncomplicated falciparum malaria in the littoral coastline region of Cameroon.

The onset and rapid spread of chloroquine resistance and the introduction of amodiaquine for the treatment of uncomplicated malaria in Cameroon have influenced the proportion of sensitive and resistant alleles related to 4-aminoquinoline drugs. This study was undertaken to determine the prevalence of resistance markers to antimalarial 4-aminoquinolines in Douala in the Littoral Region, and Buea in the South West Region in June 2020. Dry blood spots were prepared from malaria microscopy positive cases and used for parasite DNA extraction by chelex-100 method. species identification was carried out by PCR amplification/agarose gel electrophoresis of 18srRNA. The and genes were amplified by PCR followed by restriction digestion. The prevalence of single nucleotide polymorphisms (SNPs) was compared between study sites and with previous studies carried out between 2003-2005 and 2009-2011 using the Chi square test. The results showed that was the dominant species occurring as mono-infections (84.6%). The wild type allele of the gene was found in 74.9% of isolates while the wild N86, and D1246 alleles of the gene were found respectively in 87.2%, 89.6% and 100% of field isolates. The results showed a significant reduction in the mutant alleles compared to results obtained in 2003-2005 and 2009-2013. The KNYD haplotype was observed to be the most prevalent. The results indicated that there is a gradual erosion of the mutant and genotype and a gradual return to the sensitive genotype in Cameroon.