Table 2.
Clinical episodes of malaria
| Ethnic groups and comparisons | No. of Pf-positive fever cases | Distribution of Pf-positive fever
cases in different classes of Pf PD, %
|
Geometric mean of PD | Average of clinical episodes with different
Pf PD thresholds
|
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1–100 | 101–400 | 401–1600 | 1601–6400 | 6401–12,800 | 12,801–25,600 | >25,600 | >0 | >6400 | >12,800 | >25,600 | |||
| M | 95 | 7.4 | 11.6 | 15.8 | 22.1 | 9.5 | 16.8 | 16.8 | 3304 | 0.579 | 0.250 | 0.195 | 0.098 |
| RB | 92 | 7.6 | 10.9 | 15.2 | 17.4 | 16.3 | 20.0 | 13.0 | 3069 | 0.497 | 0.243 | 0.162 | 0.065 |
| RD | 21 | 0 | 14.3 | 14.3 | 28.6 | 9.5 | 14.3 | 19.0 | 4345 | 0.618 | 0.265 | 0.206 | 0.118 |
| NF | 208 | 6.7 | 11.5 | 15.4 | 20.7 | 12.5 | 17.8 | 15.4 | 3289 | 0.543 | 0.248 | 0.180 | 0.084 |
| F | 51 | 21.6 | 11.8 | 13.7 | 25.5 | 15.7 | 9.8 | 1.96 | 955 | 0.495 | 0.136 | 0.058 | 0.010 |
| M vs. RB | 0.83 | 0.94 | 0.93 | 0.53 | 0.24 | 0.77 | 0.60 | 0.85 | 0.32 | 0.76 | 0.25 | 0.25 | |
| M vs. RD | 0.35* | 0.72* | 1.0* | 0.57 | 1.0* | 1.0* | 0.76* | 0.68 | 0.72 | 0.80 | 0.73 | 0.57 | |
| RB vs. RD | 0.34* | 0.71* | 1.0* | 0.24 | 0.73 | 0.76* | 0.49* | 0.64 | 0.33 | 0.66 | 0.28 | 0.17 | |
| M vs. F | 0.026 | 0.91 | 0.93 | 0.80 | 0.24 | 0.36 | 0.016 | 0.004 | 0.38 | 0.09 | 0.005 | 0.009 | |
| RB vs. F | 0.032 | 0.81 | 0.96 | 0.35 | 0.89 | 0.20 | 0.061* | 0.004 | 0.97 | 0.15 | 0.052 | 0.06 | |
| RD vs. F | 0.027* | 1.0* | 1.0* | 0.98 | 0.71 | 0.68* | 0.023 | 0.021 | 0.36 | 0.16 | 0.011 | 0.004 | |
| NF vs. F | 0.003* | 0.85 | 0.94 | 0.58 | 0.71 | 0.24 | 0.019 | 0.001 | 0.56 | 0.08 | 0.009 | 0.016 | |
Clinical episodes of malaria were defined by temperature higher than 38.0°C and by different P. falciparum parasite densities recorded during 2 months of active case detection in children (0-10 years) of three ethnic groups. The size of the samples and their mean ages (in years) ± SD were as follows: 164 Mossi from Barkoumbilen, age = 5.0 ± 2.7; 185 Rimaibé from Barkoumbilen, age = 4.9 ± 2.8; 34 Rimaibé from Barkoundouba, age = 4.7 ± 3.0; 383 non-Fulani, age = 4.9 ± 2.8; 103 Fulani from Barkoundouba, age = 4.9 ± 2.7. The lower section of the table lists the various comparisons and the respective P values calculated by Yates-corrected χ2 test (or Fisher’s exact probability test when needed) in case of frequencies, and by Kruskal–Wallis test for means. Pf, P. falciparum; PD, parasite densities; M, Mossi; RB, Rimaibé from Barkoumbilen; RD, Rimaibé from Barkoundouba; NF, non-Fulani; F, Fulani. Ranges indicate number of parasites per μl of blood (PD).
Fisher exact test.