The response of Plasmodium falciparum to chloroquine and mefloquine in Bandar-Abbas and Minab areas, Hormozgan Province, southern Iran.

In-vivo and macro and micro in-vitro assessments of the response of P. falciparum to chloroquine and mefloquine were carried out in the malarious areas of Bandar-Abbas and Minab, Hormozgan Province, southern Iran, during 1986-1987. The susceptibility tests indicated a considerable resistance of P. falciparum to chloroquine in Bandar-Abbas but almost satisfactory sensitivity of the parasite to the drug in Minab. A rather high number of the chloroquine-resistant cases were found among Afghans and Pakistani immigrants and tourists who most probably have introduced and established the resistant strains of the parasite in such malarious areas in Iran. In the micro in-vitro test, P. falciparum was generally sensitive to mefloquine in both Bandar-Abbas and Minab. However, in a few sporadic cases the growth of the parasites occurred in the presence of rather higher doses of the drug, up to 3.2 mumol/l blood, which could be considered to result from innate mefloquine tolerant or resistant strains of P. falciparum in the areas studied.