Malariometric survey in Keoudom District, Laos: sensitivity of Plasmodium falciparum to anti-malarials and automedication with chloroquine.

ABSTRACT

A malariometric survey was conducted in the Keoudom District, in the northern part of Vientiane Province, Laos, where an artificial dam-lake on the Nam River is located. The parasite rate of the whole cohort representing 1,105 subjects was 2.44% with the predominance of Plasmodium vivax (70%), while P. falciparum represented 30% with the average parasite density index 3. The low spleen rate (2.3%) characterized the study area as a hypoendemic zone. IFAT antibodies were examined in 419 subjects. The seropositivity of 195 persons < 15 years was 13.7% while in > 15 year old subjects seropositivity was 61.6% with a low GMRT in both groups (140148). Automedication with aminoquinoline was assayed by urinary analysis in 125 outpatients. Of these, 36 (28.8%) were positive, 89 (71.2%) negative. The frequency of positive blood films for P. falciparum was higher in subjects with aminoquinoline in the urine (36.1%) than in those without (10.1%). Chloroquine sensitivity assay of 15 strains of P. falciparum displayed resistance in 39.3%.