Abstract

Chloroquine is still a first-line antimalarial drug in uncomplicated falciparum malaria. Increasing resistance to chloroquine has been reported in many parts of Nigeria. Clinical and parasitological responses and classes of resistance to chloroquine in falciparum malaria in five communities in Delta region, southern Nigeria were assessed. Chloroquine was administered to 218 patients with uncomplicated P. falciparummalaria. The levels of parasitemia, clinical response and classes of resistance were monitored for 7 days. High levels of therapeutic failures of chloroquine in P. falciparummalaria were recorded in the region. The frequencies of clinical and parasitological failure of chloroquine were 25.7% and 55%, respectively. These frequencies were significantly lower in children below 5 years than older people. R2 and R3 resistance occurred in 37.2% and 17.4% of the patients, respectively.  The therapeutic failure of chloroquine was not gender dependent. We conclude that chloroquine is still effective in the treatment of uncomplicated P. falciparum malaria in some communities in Delta region of Nigeria. However, resistance to chloroquine is likely. These results may be used as an important indicator of the significant level of therapeutic failure of uncomplicated P. falciparum malaria to chloroquine in Nigeria.

Keywords: Chloroquine, falciparum malaria, resistance, clinical failure, parasitological failure.