Table 2 Individual risk of transfusion-transmitted malaria infection according to the transmission level hypothesis (low, medium or high)
Douala | Cameroon | |||||
|---|---|---|---|---|---|---|
Variables | Low | Medium | High | Low | Medium | High |
Population (estimation in 2010) | 1 907 479 | 19 406 100 | ||||
Estimated proportion of transfusion (u) | 0.0027 | 0.0045 | 0.0067 | 0.0027 | 0.0036 | 0.0045 |
Estimated N° of transfusion per year | 5,150 | 8,559 | 12, 838 | 52,396 | 69,734 | 87,072 |
Estimated Prevalence among donor- P (vi) | 0.121 | 0.124 | 0.143 | 0.13 | 0.29 | 0.45 |
Estimated N° of infections per year | 623 | 1,061 | 1,836 | 6,550 | 20,049 | 39,182 |
Unsafe transfusion proportion (not screened in an malaria risk context)-P (u) | 0.97 | 0.98 | 0.99 | 0.97 | 0.98 | 0.99 |
Probability for exposure to infected blood units-P (E) = P (vi)*P (u) | 0.1173 | 0.1215 | 0.1416 | 0.1212 | 0.2818 | 0.4455 |
Probability for malaria transmission following blood transfusion-P (t) | 0.98 | 0.99 | 0.99 | 0.98 | 0.99 | 0.99 |
Partially immune population | 0 | 0.025 | 0.05 | 0 | 0.025 | 0.05 |
Probability for recipient susceptibility to malaria-P (s) | 0.95 | 0.975 | 1 | 0.975 | 1 | 0.95 |
Individual risk of receiving a transfused infected blood unit every year-P (I); P (I) = 1-[1-P (S)*P (t)*P (e)] u | 3.1238 × 10−4 | 5.5965 × 10−4 | 1.0268 × 10−3 | 1.1399 × 10−3 | 2.6423 × 10−3 | 3.2335 × 10−4 |