Abstract:
Background: After years of disuse of chloroquine (CQ) as first-line anti-malarial drug in Ghana, reports from
molecular studies conducted in parts of the country indicate varying prevalence of T76 mutation in the pfcrt gene.
This situation has several health implications, one being that mutations that confer resistance to CQ have been
reported to show substantial cross-resistance to other anti-malarial drugs. It is important to identify some of the
factors contributing to the continuous presence of CQ resistance markers in the country. This study determined
the prevalence of T76 mutation in pfcrt gene of Plasmodium falciparum isolates collected from selected areas of
the Central region of Ghana and correlated with the level of CQ use in these areas.
Methods: Plasmodium falciparum DNA was extracted from collected blood-blot filter paper samples in the study
sites. The prevalence of T76 point mutation in pfcrt gene was assessed using nested PCR followed by RFLP.
CQ from pharmacy and chemical shops was obtained using mystery buying method. The extent of CQ use by
the participants was determined by measuring the level of the drug in their urine samples using the Saker-Solomon
method.
Results: Of the 214 P. falciparum isolates analysed, 71.9% were found to have T76 mutation of pfcrt gene. The study
revealed that 14.49% of community pharmacies and chemical shops had stocks of CQ for sale while 16.9% of the
participants had CQ in their urine samples. There is five times more risks of becoming infected with CQ resistant
strain for staying in an area where CQ is stocked for sale [RR = 0.20, p < 0.0001] and thirteen times more risks of
having CQ-resistant mutant from those who still use CQ than non-users [OR = 0.08, p < 0.0001].
Conclusion: This study has shown that high variation in the prevalence of T76 mutations of P. falciparum is linked
with the level of CQ stocking and usage within study area.
