Abstract
Quadruple mutations in the
Plasmodium falciparum
dihydrofolate reductase (PFDHFR) enzyme give rise to the highest level of pyrimethamine resistance leading to treatment failures. We describe here the presence of these quadruple mutations in a majority of
P. falciparum
isolates from Car Nicobar (Andaman and Nicobar) Island, India. Isolates from the mainland, however, continue to show a prevalence of double PFDHFR mutations and some with triple but none with quadruple mutations. In conclusion, the antifolate drug pressure is very high in the island, which should be a cause of concern for the malaria control program in the country.