New trends in chloroquine efficacy in the treatment of malaria: significance of low (scanty) parasitaemia in an endemic area, with emerging chloroquine-resistant P. falciparum.

In a continuous malaria therapy surveillance, using in vivo (WHO) seven-day-test, extended to 14 days follow up, we evaluated the significance of low (scanty) parasitaemia, in an area with chloroquine resistance P. falciparum (CRPF), where self-medication is widely practised. We found that 30.9 pc of the patients screened had Plasmodium species, and 71.4 pc of these had low parasite counts of less than 500 parasites/mm3, whole blood. Eight pc of these were febrile and 41.7 pc of the parasite strains were not susceptible to chloroquine. Parasite strains from four of the patients were also resistant to other antimalarials. These patients gave psychosomatic symptoms, and were seen by a psychiatrist. We conclude that 41 pc of the patients with low parasite counts consist of patients with CRPF and/or multiple-drug resistant P. falciparum in this area. These do not only cause chronic anaemia, but also may be responsible for moderate psychosomatic symptoms in all ages.