The correlation between platelet count and parasite density in children with malaria infection

ObjectiveTo assess the correlation between platelet count and parasite density.MethodsA cross-sectional study of febrile children was conducted in Batubara Regency, North Sumatra, Indonesia. We used rapid diagnostic tests and blood smears to identify children with malaria infection. Platelet counts and measurement of parasite density were performed manually using a microscope.ResultsA total of 72 children with positive malaria infection were enrolled in the study. Sixty one children had Plasmodium vivax, two children had Plasmodium falciparum, and nine children had mixed infection. The mean platelet count from all patients was (230 940.00 ± 96 611.53)/µL and the mean parasite density was (2 254.83 ± 1 432.55)/µL. There was a weak negative correlation between the platelet count and the parasitemia count (r = –0.145). The platelet count in the mixed infection group was significantly lower [(175 444.44 ± 48 093.95)/µL] than that in the vivax malaria group [(231 927.87 ± 99 475.28)/µL] (P = 0.024). Children with splenomegaly had a significantly lower platelet count [(189 655.56 ± 80 115.76)/µL versus (245 230.77 ± 98 380.74)/µL, P = 0.04] and a higher parasite density [(3 635.78 ± 1 623.70)/µL versus (1 789.88 ± 927.29)/µL, P < 0.000 1] than those without splenomegaly.ConclusionsThere was a weak negative correlation between the platelet count and parasite count.