Incidence of uncomplicated falciparum malaria and anemia stratified for hemoglobin genotypes
| β-Globin genotype . | Malaria . | Anemia . | ||||||
|---|---|---|---|---|---|---|---|---|
| Events . | PYAR . | Rate (per year) . | IRR (95%CI) . | Events . | PYAR . | Rate (per year) . | IRR (95% CI) . | |
| HbAA | 1327 | 1108.7 | 1.2 | 1 | 787 | 1217.7 | 0.6 | 1 |
| HbAC | 193 | 149.1 | 1.3 | 1.08 (0.93-1.26)* | 121 | 163.2 | 0.7 | 1.15 (0.95-1.39) |
| HbCC | 0 | 3.4 | 0.0 | — | 3 | 3.4 | 0.9 | 1.38 (0.44-4.28) |
| HbAS | 153 | 164.3 | 0.9 | 0.78 (0.66-0.92)† | 59 | 179.7 | 0.3 | 0.51 (0.39-0.66)‡ |
| HbCS | 7 | 16.4 | 0.4 | 0.36 (0.17-0.75)§ | 18 | 17.3 | 1.0 | 1.61 (1.01-2.57) |
| HbSS | 4 | 7.6 | 0.5 | 0.44 (0.17-1.18) | 40 | 7.0 | 5.7 | 8.84 (6.43-12.1)‖ |
| β-Globin genotype . | Malaria . | Anemia . | ||||||
|---|---|---|---|---|---|---|---|---|
| Events . | PYAR . | Rate (per year) . | IRR (95%CI) . | Events . | PYAR . | Rate (per year) . | IRR (95% CI) . | |
| HbAA | 1327 | 1108.7 | 1.2 | 1 | 787 | 1217.7 | 0.6 | 1 |
| HbAC | 193 | 149.1 | 1.3 | 1.08 (0.93-1.26)* | 121 | 163.2 | 0.7 | 1.15 (0.95-1.39) |
| HbCC | 0 | 3.4 | 0.0 | — | 3 | 3.4 | 0.9 | 1.38 (0.44-4.28) |
| HbAS | 153 | 164.3 | 0.9 | 0.78 (0.66-0.92)† | 59 | 179.7 | 0.3 | 0.51 (0.39-0.66)‡ |
| HbCS | 7 | 16.4 | 0.4 | 0.36 (0.17-0.75)§ | 18 | 17.3 | 1.0 | 1.61 (1.01-2.57) |
| HbSS | 4 | 7.6 | 0.5 | 0.44 (0.17-1.18) | 40 | 7.0 | 5.7 | 8.84 (6.43-12.1)‖ |
PYAR indicates person-years at risk; and —, not applicable.
Trend of an agonistic epistatic effect by α+-thalassemia toward susceptibility: IRR HbAC plus αα/αα = 0.98; 95% CI, 0.82-1.18; IRR HbAC plus α/αα = 1.43; 95% CI, 1.11-1.84.
P < .005 (Poisson regression). Relative risk estimate significantly different from that of HbAC (test of interaction, z = 2.83, P < .005). Trend of an antagonistic epistatic effect by α+-thalassemia against protection: IRR HbAS plus αα/αα = 0.76; 95% CI, 0.63-0.93; IRR HbAS plus α/αα = 0.82, CI 0.58-1.16.
P < .001 (Poisson regression). Relative risk estimate significantly different from that of HbAC (test of interaction, z = 4.91, P < .001).
P < .01 (Poisson regression).
P < .001 (Poisson regression).