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Background and objectives: Voluntary blood donation is the main source of blood and its components globally. Blood transfusion is essential for management of various diseases but remains as one of the most important causes of disease transmission. In this study, we screened donated blood samplesfor haemoparasites in the University of Calabar Teaching Hospital, Nigeria.
Methods: This cross-sectional study was performed on 200 blood samples taken from donors who had been asymptomatic for haemoparasite infections. The blood samples were analyzed microscopically for the presence of malaria parasites using Giemsa stained thin smears and thick smears. The Knott concentration technique was used to detect microfilaria. To evaluate presence of trypanosomes, triple centrifugation was carried out and the resulting sediment was used to prepare wet and smears stained with 10% Giemsa solution.
Results: The prevalence of malaria parasites, microfilaria, and trypanosome was 38% (76/200), 5% (10/200), and nil (0/200), respectively. The prevalence of malaria infection was highest among females, individuals aged 18–25 years and those with O+ blood type. Most donors had malaria parasite density of 200–4000/µl. Microfilaria was only found in males and more common among subjects between 26 and 33 years of age as well as those with O+ blood type.
Conclusion: The findings revealed the presence of malaria and microfilaria infections and the absence of trypanosomes among blood donors in Calabar, Nigeria. This accentuates the need to screen all blood donors for haemoparasites in order to reduce the spread of the parasites and minimize its effects on the recipients.

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Background and objectives: Malaria causes a wide spectrum of hematological and clinical manifestations. This study aimed to identify the alterations in the clinical and hematological parameters in patients infected with Plasmodium vivax, Plasmodium falciparum, and mixed species.
Methods: The study included 126 smear-positive malaria cases, and various hematological parameters were studied.
Results: The frequency of P. vivax, P. falciparum, and mixed species was 53.9%, 36.5%, and 9.6%, respectively. Anemia (hemoglobin <11 gm%) was seen in 79.3% of the cases, and severe anemia (hemoglobin <5g%) was detected in 27.7% of the cases. A decrease in red blood cell count was observed in 67% of P. falciparum and 47% cases of P. vivax cases. Increased red cell distribution width and erythrocyte sedimentation rate were seen in 81% and 78% of the cases, respectively. Leukocytosis and leucopenia were detected in 15% and 16% of all malaria cases, respectively. Thrombocytopenia was associated with 78% of cases infected with P. vivax. The degree of anemia was correlated with the parasite load, and the degree of parasitemia was correlated with the extent of thrombocytopenia. There were also significant variations in the mean corpuscular volume, hematocrit, mean corpuscular hemoglobin concentration, and platelet counts among malarial species (p<0.05).
Conclusion: Malaria is frequently associated with anemia, thrombocytopenia, and leukopenia. Thrombocytopenia is mostly associated with P. vivax infection. On contrary, leukopenia is more prevalent in P. falciparum, followed by P. vivax and mixed parasitemia.