TABLE 2.

Malaria-related clinical outcomes during the 9-month study period, by age group

OutcomeValue for age groupValue for all individuals (n = 225)P valuea
2-4 yr (n = 73)5-7 yr (n = 52)8-10 yr (n = 51)18-25 yr (n = 49)
Malaria incidence (mean ± SD)b1.99 ± 1.251.94 ± 1.210.98 ± 1.050.08 ± 0.281.33 ± 1.30<0.001
No. of cases of severe malariac41005
Time to first malaria episode for those who experienced malaria (days [median])d1011141301531150.02
No. (%) of individuals with at least one malaria episode63 (86.3)45 (86.5)31 (60.8)4 (8.2)143 (63.6)<0.001
Level of parasitemia at first malaria episode (no. of parasites/μl) (geometric mean [95% CI])34,374 (24,955-47,348)15,687 (9,623-25,574)10,433 (5,079-21,427)8,816 (4,082-19,037)19,625 (15,004-25,668)0.04
  • a P values were derived by using Fisher's exact test for categorical variables and the Kruskal-Wallis test for continuous variables.

  • b A malaria episode was defined as a temperature of >37.5°C, asexual parasitemia of >5,000 parasites/microliter, and nonfocal physical examination.

  • c According to WHO definition of severe malaria.

  • d Days since study enrollment.