BackgroundIn sub-Saharan Africa where sickle cell trait (SCT) and malaria is prevalent, significant proportions of blood donors may be affected by one or more of these abnormalities. The haemato-biochemical properties of SCT and asymptomatic malaria in donor blood have not been evaluated. This study evaluated the haemato-biochemical impact of SCT and asymptomatic malaria infections in citrate-phosphate-dextrose-adenine (CPDA-1) stored donor blood units.MethodsFifty-milliliters of sterile CPDA-1 anti-coagulated blood were drained into the sample pouch attached to the main blood bag. Ten units each of sickle cell/malaria negative, sickle cell and malaria positive blood were analyzed. Baseline and weekly haematological profiling and week 1, 3 and 5 concentrations of plasma haemoglobin, % haemolysis, sodium, potassium and chloride and lactate dehydrogenase (LDH) were assayed. Differences between baseline and weekly data were determined using one-way analysis of variance (ANOVA) and Kruskal-Wallis test, whereas differences between baseline parameters and week 1–3 data pairs were determined using paired t-test. P-value < 0.05 was considered statistically significant.ResultsStorage of SCT and malaria infected blood affected all haematological cell lines. In the SCT donors, red blood cells (RBC) (4.75 × 1012/L ± 1.43baseline to 3.49 × 1012/L ± 1.09week-5), haemoglobin (14.45 g/dl ± 1.63baseline to 11.43 g/dl ± 1.69week-5) and haematocrit (39.96% ± 3.18baseline to 33.22% ± 4.12week-5) were reduced. In the asymptomatic malaria group, reductions were observed in RBC (5.00 × 1012/L ± 0.75baseline to 3.72 × 1012/L ± 0.71week-5), haemoglobin (14.73 g/dl ± 1.67baseline to 11.53 g/dl ± 1.62week-5), haematocrit (42.72% ± 5.16baseline to 33.38% ± 5.80week-5), mean cell haemoglobin concentration (35.48 g/dl ± 1.84baseline to 35.01 g/dl ± 0.64week-5) and red cell distribution width coefficient of variation (14.81% ± 1.54baseline to 16.26% ± 1.37week-5). Biochemically, whereas plasma LDH levels significantly increased in asymptomatic malaria blood donors (319% increase at week 5 compared to baseline), SCT blood donors had the most significant increase in plasma potassium levels at week 5 (382% increase). Sodium ions significantly reduced in SCT/malaria negative and sickle cell trait blood at an average rate of 0.21 mmol/L per day. Moreover, elevations in lymphocytes-to-eosinophils and lymphocytes-to-neutrophils ratios were associated with SCT and malaria positive blood whilst elevation lymphocytes-to-basophils ratio was exclusive to malaria positive blood.ConclusionSevere storage lesions were significant in SCT or malaria positive donor blood units. Proper clinical evaluation must be done in prospective blood donors to ensure deferral of such donors.Electronic supplementary materialThe online version of this article (10.1186/s12878-018-0128-x) contains supplementary material, which is available to authorized users.