Factors associated with malaria parasitemia in individuals with sickle cell anemia at the outpatient clinic and during hospitalization
| Clinical feature . | OPD clinic (n = 10 491) . | Hospitalization (n = 691) . | ||||||
|---|---|---|---|---|---|---|---|---|
| No malaria parasitemia [n = 10 415 (99.3)] . | Malaria parasitemia [n = 76 (0.72)] . | OR (95% CI) . | P . | No malaria parasitemia [n = 670 (96.9)] . | Malaria parasitemia [n = 21 (3.04)] . | OR (95% CI) . | P . | |
| Male, n/n (%) | 4 916/10 415 (47.2) | 32/76 (42.1) | 0.81 (0.52-1.28) | .38 | 308/670 (45.9) | 13/21 (4.1) | 1.9 (0.78-4.67) | .16 |
| Age, y, GM ± SD | 12.5 ± 8.0 | 10.7 ± 7.9 | 0.97 (0.94-1.00) | .06 | 10.6 ± 8.3 | 14.3 ± 12.3 | 1.04 (0.99-1.09) | .05 |
| Physical signs | ||||||||
| Febrile (> 37.5°C), n/n (%) | 184/10 152 (1.8) | 6/74 (8.1) | 4.78 (2.05-11.15) | < .01 | 197/661 (29.8) | 7/21 (33.3) | 1.18 (0.47-2.96) | .73 |
| SpO2, GM ± SD | 97.2 ± 3.15 | 98.1 ± 2.8 | 1.13 (1.02-1.25) | .02 | 98.1 ± 2.4 | 98.9 ± 1.9 | 1.24 (0.94-1.62) | .12 |
| Hypoxia (SpO2 ≤ 95%), n/n (%) | 229/9 952 (2.3) | 1/71 (1.4) | 0.61 (0.08-4.39) | .62 | 7/681 (1.0) | 0 | ||
| Spleen palpable on examination, n/n (%) | 953/9 761 (9.8) | 13/67 (19.4) | 2.23 (1.21-4.09) | .01 | 146/648 (22.5) | 6/20 (30) | 1.47 (0.56-3.90) | .44 |
| Liver palpable on examination, n/n (%) | 173/7 206 (2.4) | 3/38 (7.9) | 3.48 (1.06-11.44) | .04 | 80/604 (13.3) | 2/19 (10.5) | 0.77 (0.17-3.39) | .73 |
| Laboratory features | ||||||||
| WBC count, × 109/L, GM ± SD | 14.7 ± 6.3 | 21.8 ± 11.7 | 1.07 (1.05-1.09) | < .01 | 23.3 ± 13.6 | 28.8 ± 19.9 | 1.02 (0.99-1.05) | .09 |
| High WBC count (> 17.7 × 109/L), n/n (%)* | 2 250/9 656 (23.3) | 38/69 (55.1) | 4.03 (2.50-6.49) | < .01 | 390/623 (62.6) | 11/20 (55.0) | 0.73 (0.29-1.79) | .49 |
| Hb, g/dL, GM ± SD | 7.5 ± 1.3 | 6.7 ± 1.4 | 0.64 (0.54-0.75) | < .01 | 6.59 ± 1.8 | 5.56 ± 2.1 | 0.74 (0.58-0.93) | .01 |
| Severe anemia (Hb < 5 g/dL), n/n (%) | 305/9 658 (3.16) | 8/70 (11.4) | 3.96 (1.88-8.34) | < .01 | 114/623 (18.3) | 11/21 (52.38) | 4.91 (2.04-11.84) | .01 |
| MCV, fL, GM ± SD | 80.4 ± 9.3 | 85.8 ± 12.9 | 1.06 (1.04-1.09) | < .01 | 81.2 ± 10.1 | 87.9 ± 10.2 | 1.07 (1.02-1.11) | < .01 |
| Macrocytosis (MCV > 93 fL), n/n (%) | 763/9 602 (7.9) | 19/70 (27.1) | 4.32 (2.54-7.35) | < .01 | 58/606 (9.57) | 6/21 (28.6) | 3.78 (1.41-10.12) | < .01 |
| Reticulocyte count, %, GM ± SD | 13.7 ± 8.8 | 15.2 ± 7.6 | 1.01 (0.99-1.01) | .20 | 13.5 ± 6.7 | 16.4 ± 5.4 | 1.06 (0.99-1.12) | .05 |
| AST level, IU/L, GM ± SD | 45.9 ± 23.4 | 48.4 ± 23.4 | 1.0 (0.98-1.02) | .66 | 65.7 ± 50.4 | 117.57 ± 83.4 | < .01 | |
| High AST level (> 97.2 IU/L), n/n (%)* | 83/3 586 (2.3) | 1/18 (5.6) | 2.48 (0.33-18.87) | .38 | 85/546 (15.6) | 8/19 (42.1) | 3.94 (1.54-10.09) | < .01 |
| Death during admission, n/n (%) | 14/668 (2.1) | 2/21 (9.5) | 4.9 (1.04-23.20) | .04 | ||||
| Clinical feature . | OPD clinic (n = 10 491) . | Hospitalization (n = 691) . | ||||||
|---|---|---|---|---|---|---|---|---|
| No malaria parasitemia [n = 10 415 (99.3)] . | Malaria parasitemia [n = 76 (0.72)] . | OR (95% CI) . | P . | No malaria parasitemia [n = 670 (96.9)] . | Malaria parasitemia [n = 21 (3.04)] . | OR (95% CI) . | P . | |
| Male, n/n (%) | 4 916/10 415 (47.2) | 32/76 (42.1) | 0.81 (0.52-1.28) | .38 | 308/670 (45.9) | 13/21 (4.1) | 1.9 (0.78-4.67) | .16 |
| Age, y, GM ± SD | 12.5 ± 8.0 | 10.7 ± 7.9 | 0.97 (0.94-1.00) | .06 | 10.6 ± 8.3 | 14.3 ± 12.3 | 1.04 (0.99-1.09) | .05 |
| Physical signs | ||||||||
| Febrile (> 37.5°C), n/n (%) | 184/10 152 (1.8) | 6/74 (8.1) | 4.78 (2.05-11.15) | < .01 | 197/661 (29.8) | 7/21 (33.3) | 1.18 (0.47-2.96) | .73 |
| SpO2, GM ± SD | 97.2 ± 3.15 | 98.1 ± 2.8 | 1.13 (1.02-1.25) | .02 | 98.1 ± 2.4 | 98.9 ± 1.9 | 1.24 (0.94-1.62) | .12 |
| Hypoxia (SpO2 ≤ 95%), n/n (%) | 229/9 952 (2.3) | 1/71 (1.4) | 0.61 (0.08-4.39) | .62 | 7/681 (1.0) | 0 | ||
| Spleen palpable on examination, n/n (%) | 953/9 761 (9.8) | 13/67 (19.4) | 2.23 (1.21-4.09) | .01 | 146/648 (22.5) | 6/20 (30) | 1.47 (0.56-3.90) | .44 |
| Liver palpable on examination, n/n (%) | 173/7 206 (2.4) | 3/38 (7.9) | 3.48 (1.06-11.44) | .04 | 80/604 (13.3) | 2/19 (10.5) | 0.77 (0.17-3.39) | .73 |
| Laboratory features | ||||||||
| WBC count, × 109/L, GM ± SD | 14.7 ± 6.3 | 21.8 ± 11.7 | 1.07 (1.05-1.09) | < .01 | 23.3 ± 13.6 | 28.8 ± 19.9 | 1.02 (0.99-1.05) | .09 |
| High WBC count (> 17.7 × 109/L), n/n (%)* | 2 250/9 656 (23.3) | 38/69 (55.1) | 4.03 (2.50-6.49) | < .01 | 390/623 (62.6) | 11/20 (55.0) | 0.73 (0.29-1.79) | .49 |
| Hb, g/dL, GM ± SD | 7.5 ± 1.3 | 6.7 ± 1.4 | 0.64 (0.54-0.75) | < .01 | 6.59 ± 1.8 | 5.56 ± 2.1 | 0.74 (0.58-0.93) | .01 |
| Severe anemia (Hb < 5 g/dL), n/n (%) | 305/9 658 (3.16) | 8/70 (11.4) | 3.96 (1.88-8.34) | < .01 | 114/623 (18.3) | 11/21 (52.38) | 4.91 (2.04-11.84) | .01 |
| MCV, fL, GM ± SD | 80.4 ± 9.3 | 85.8 ± 12.9 | 1.06 (1.04-1.09) | < .01 | 81.2 ± 10.1 | 87.9 ± 10.2 | 1.07 (1.02-1.11) | < .01 |
| Macrocytosis (MCV > 93 fL), n/n (%) | 763/9 602 (7.9) | 19/70 (27.1) | 4.32 (2.54-7.35) | < .01 | 58/606 (9.57) | 6/21 (28.6) | 3.78 (1.41-10.12) | < .01 |
| Reticulocyte count, %, GM ± SD | 13.7 ± 8.8 | 15.2 ± 7.6 | 1.01 (0.99-1.01) | .20 | 13.5 ± 6.7 | 16.4 ± 5.4 | 1.06 (0.99-1.12) | .05 |
| AST level, IU/L, GM ± SD | 45.9 ± 23.4 | 48.4 ± 23.4 | 1.0 (0.98-1.02) | .66 | 65.7 ± 50.4 | 117.57 ± 83.4 | < .01 | |
| High AST level (> 97.2 IU/L), n/n (%)* | 83/3 586 (2.3) | 1/18 (5.6) | 2.48 (0.33-18.87) | .38 | 85/546 (15.6) | 8/19 (42.1) | 3.94 (1.54-10.09) | < .01 |
| Death during admission, n/n (%) | 14/668 (2.1) | 2/21 (9.5) | 4.9 (1.04-23.20) | .04 | ||||
GM indicates geometric mean; SpO2, peripheral oxygen saturation; WBC, white blood cell; Hb, hemoglobin; MCV, mean corpuscular volume; and AST, aspartate transaminase.
The following values were the 97.5 percentile for the SCA population (from well clinic visits) and were considered the upper limit of normal in this study population: WBC count greater than 17.7 × 109/L and AST level greater than 97.2 IU/L. The denominators denote available data.