The pattern of infection and in vivo response to Chloroquine by uncomplicated Plasmodium falciparum malaria in northwestern Nigeria

The pattern of infection and in vivo response of uncomplicated Plasmodium falciparum malaria to Chloroquine as first line drug and Quinine, Halofantrine or Sulfadoxine-Pyrimethamine as second line medications was evaluated at nested sentinel points, including Government and Private Practices, for three consecutive months. 559 cases were evaluated of which 22.5% failed on Chloroquine therapy. The age range of P. falciparum malaria cases was 4 months to 48 years, with a mean and median age of 9.2 and 3 years, respectively. There were significantly more female patients than male. Also, ages 5 years and below accounted for 63.2% of cases and as a group had an increased risk of treatment failure with Chloroquine compared to older patients. In general, male patients also had a higher relative risk of treatment failure on Chloroquine. Patients treated in Government practices were more likely to fail than those treated in Private practices. All cases of failure to Chloroquine treatment responded to Quinine, Halofantrine or Sulfadoxine-Pyrimethamine.