Hematological parameter changes are the most common complications in malaria. We aimed to determine the hematological parameters and hemozoin-containing leukocytes and their association with disease severity in malaria infected children aged between 1 and 15 years. A facility-based cross-sectional study was conducted at Pawe General Hospital from July 31 to December 30, 2014. Demographic and clinical data were collected using structured questionnaire. Blood specimen was collected from each study participant for hematological investigations. Data were analyzed using SPSS version 20. The overall prevalence of anemia was 40.3%, most of which were mildly anemic. Leukocytosis was found in 15.4% of study participants. More than a fourth (27%) of the children had severe malaria. Hemozoin-containing monocytes and neutrophils were found in 80.1% and 58.9% of the study participants, respectively. Under-five years of age (AOR = 3.01, 95% CI: 1.83–7.39,
Malaria is one of the infectious diseases that may affect hematological parameters. Anemia, thrombocytopenia, leukocytosis, and leukopenia are the most common hematological complications associated with malaria [
Hematological changes are the most common complications in malaria and play major role in disease outcomes. In malaria endemic areas, severe malarial anemia (SMA) is one of the major factors contributing to anemia resulting in morbidity and mortality among children [
Although there are several factors that increase mortality due to malaria in Ethiopia, the absence of reliable diagnosis and management of SM is the most important. In health facilities in Ethiopia, SM is usually diagnosed by counting the number of asexual parasitaemia in peripheral blood smear of the patients [
A facility-based cross-sectional study was conducted at Pawe General Hospital from July 31 to December 30, 2014. Pawe General Hospital is found in Metekel Zone of Benishangul Gumuz Regional State, located 557 kms northwest of Addis Ababa. The hospital serves an estimated 300,000 people in the region, with bed capacity of 180. The geographical coordinates of the area are approximately 11°19′N latitude and 36°25′E longitude, with altitude range of 1050–1250 meters above sea level. The annual mean rainfall is 1150 mm with average temperature of 32°C. The area is characterized by hot and humid climatic condition with stable, year-round transmission of malaria. Even though there is perennial transmission of malaria in the study area, the transmission peaks from September to December, following the main rainy season from June to September [
A total of 377 children diagnosed with malaria by peripheral smear microscopy at the hospital were included in this study. The sample size was estimated using single population proportion formula considering 43% expected prevalence of malarial anemia [
The following exclusion criteria were considered in this study: (1) positivity for intestinal parasite(s) as screened by microscopic examination of wet mount and formol-ether concentrated stool sample; (2) HIV-1/2-seropositivity as screened by the HIV rapid diagnostic tests (KHB
Demographic and clinical data of the children were collected by a trained public health officer using structured questionnaire. Moreover, laboratory data including complete blood count (CBC), blood film examination for hemoparasites, and HCLs were generated in this study. Approximately 4 mL of venous blood was aseptically collected into ethylene diamine tetra acetic acid- (EDTA-) containing vacationer tube. The blood samples were analyzed for CBC and thin and thick blood smears prepared for microscopic examination of malaria parasites. The CBC was analyzed using CELLDYNE 1800® (Abott Laboratories Diagnostics Division, USA) within two hours of sample collection. Thick and thin blood films were prepared on single slide for each study participant. Thin blood smears were methanol-fixed before staining. The slides were stained using 10% Giemsa stain (PH 7.2) for 10 minutes, with the Giemsa stain being prepared immediately before use. The blood smears were examined for malaria parasites, and HCLs were enumerated.
To ensure quality of the data generated in the study, data collectors were trained prior to commencement of the study. Control samples were utilized to ensure accuracy of outputs of the hematology analyzer. Two independent blinded laboratory technologists examined the blood films. In case of discrepancy between the two readings, a third person was involved in reading the slide. Moreover, 10% of the slides were randomly selected and reexamined by the third laboratory technologist.
Children with at least one of the clinical symptoms: prostration, severe malarial anemia, and hyperparasitemia were classified to have SM [
The collected data were checked for completeness regularly during the course of data collection. The data were entered, cleaned, and analyzed using SPSS version 20.0 (SPSS Inc., Chicago, IL). Descriptive statistics including frequency, mean, and standard deviation were utilized to summarize demographic profile of the children and some of the clinical data. Bivariate and multivariable logistic regressions were used to assess association of the independent variables with the dependent variables. Variables with
Ethical clearance was obtained from Jimma University Ethical Review Board. Permission was obtained from the Regional Health Bureau. Voluntary participation of the children and their parents/guardians was ensured. Written informed consent was obtained from the parents/guardians of the children before enrollment in the study. Confidentiality of all the clinical information obtained from the children was strictly maintained. All the children who were involved in the study were treated for malaria according to the Malaria Treatment Guidelines [
A total of 377 malaria infected children aged 1 to 15 years were included in this study. The mean age of the study participants was 8.5 ± 4.9 years. A third of the study participants (33.7%,
Demographic and clinical characteristics of the study participants, Pawe General Hospital, 2014.
Variables | Categories | Frequency | Percent (%) |
---|---|---|---|
Age (years) | <5 | 127 | 33.7 |
≥5 | 250 | 66.3 | |
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Sex | Male | 218 | 57.8 |
Female | 159 | 42.2 | |
| |||
Axillary temperature | <37.5°C | 151 | 40.1 |
≥37.5°C | 226 | 59.9 | |
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| | 283 | 75.1 |
| 57 | 15.1 | |
Mixed | 37 | 9.8 | |
| |||
Malaria severity | Uncomplicated malaria | 275 | 72.9 |
Severe malaria | 102 | 27.1 |
Mean values of the hematological parameters are presented in Table
Comparison of mean values of hematological parameters and hemozoin-containing leukocytes with malaria severity among the study participants, Pawe General Hospital, 2014.
Parameters | Total mean (SD) | UM | SM | | |
---|---|---|---|---|---|
Hb concentration (g/dL), | 11.7 (2.2) | 12.1 (1.9) | 10.6 (2.4) | 6.310 | <0.001 |
Hct (%), | 32.9 (5.6) | 34.02 (4.8) | 30.05 (6.6) | 5.538 | <0.001 |
RBC count (×1012/L), | 4.4 (0.7) | 4.51 (0.6) | 4.18 (0.9) | 3.237 | 0.002 |
WBC count (×109/L), | 7.7 (3.7) | 7.09 (3.3) | 9.31 (4.3) | −5.436 | <0.001 |
PLT count (×109/L), | 153.0 (91.4) | 151 (80.0) | 160 (116) | −0.735 | 0.464 |
HCMs (%), | 9.7 (9.2) | 7.3 (7.2) | 16.2 (10.9) | −7.618 | <0.001 |
HCNs (%), | 1.7 (2.2) | 1.25 (1.6) | 2.8 (3.1) | −4.685 | <0.001 |
HCMs count (per | 80.6 (34.3) | 48.8 (46.1) | 166.3 (82.1) | −5.327 | <0.001 |
HCNs count (per | 85.8 (37.1) | 56.2 (69.8) | 165.6 (80.5) | −5.140 | <0.001 |
Hb = hemoglobin, Hct = hematocrit, HCMs = hemozoin-containing monocytes, HCNs = hemozoin-containing neutrophils, PLT = platelet, RBC = red blood cell, SD = standard deviation, SM = severe malaria, UM = uncomplicated malaria, WBC = white blood cell, and
Factors associated with severe malaria among the children are demonstrated in Table
Factors associated with of severe malaria among the study participants, Pawe General Hospital, 2014.
Variables | Categories | UM: | SM: | COR (95% CI) | | AOR (95% CI) | |
---|---|---|---|---|---|---|---|
Age (year) | <5 | 70 (55.1) | 57 (44.9) | 3.71 (2.30–5.97) | <0.001 | 3.01 (1.83–7.39) | <0.001 |
≥5 | 205 (82.0) | 45 (18.0) | 1 (ref) | 1 (ref) | |||
| |||||||
Sex | Male | 160 (73.4) | 58 (26.6) | 1.05 (0.67–1.67) | 0.818 | ||
Female | 115 (72.3) | 44 (27.7) | 1 (ref) | ||||
| |||||||
Axillary temperature (°c) | <37.5 | 113 (74.8) | 38 (25.2) | 1 (ref) | |||
37.5–39.4 | 162 (71.7) | 64 (28.3) | 1.24 (0.76–2.04) | 0.235 | 1.03 (0.57–1.84) | 0.960 | |
| |||||||
Anemia | Yes | 93 (61.2) | 59 (38.8) | 2.68 (1.69–4.28) | <0.001 | 1.65 (0.93–2.92) | 0.089 |
No | 182 (80.9) | 43 (19.1) | 1 (ref) | 1 (ref) | |||
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Leukocytosis | Yes | 32 (55.2) | 26 (44.8) | 2.6 (1.46–4.63) | <0.001 | 3.20 (1.65–6.24) | 0.001 |
No | 243 (76.2) | 76 (23.8) | 1 (ref) | 1 (ref) | |||
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Leukopenia | Yes | 33 (84.6) | 6 (15.4) | 0.46 (0.19–1.13) | 0.090 | 0.68 (0.25–1.88) | 0.462 |
No | 242 (71.6) | 96 (28.4) | 1 (ref) | 1 (ref) | |||
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Thrombocytopenia | Yes | 154 (72.0) | 60 (28.0) | 1.12 (0.71–1.78) | 0.623 | ||
No | 121 (74.2) | 42 (25.8) | 1 (ref) | ||||
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HCMs | No HCMs | 70 (93.3) | 5 (6.7) | 1 (ref) | 1 (ref) | ||
0.5–5% | 143 (77.7) | 41 (22.3) | 2.04 (0.63–6.57) | 0.234 | 3.77 (1.39–10.20) | 0.009 | |
>5% | 62 (52.5) | 56 (47.5) | 8.31 (3.23–1.36) | <0.001 | 6.26 (2.14–14.29) | <0.001 | |
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HCNs | No HCNs | 125 (80.6) | 30 (29.4) | 1 (ref) | 1 (ref) | ||
0.5–5% | 143 (73.7) | 51 (26.3) | 1.49 (0.89–2.48) | 0.129 | 0.79 (0.43–1.46) | 0.455 | |
>5% | 7 (25) | 21 (75) | 12.5 (4.86–2.12) | <0.001 | 7.93 (3.09–16.86) | <0.001 | |
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| | 191 (67.5) | 92 (32.5) | 5.56 (1.63–11.12) | 0.006 | ||
| 50 (87.7) | 7 (12.3) | 1.59 (0.38–6.57) | 0.524 | |||
Mixed | 34 (91.9) | 3 (8.1) | 1 (ref) | ||||
| |||||||
High parasitemia | Yes | 117 (65.0) | 63 (35.0) | 2.18 (1.37–3.47) | 0.001 | 1.90 (1.13–3.18) | 0.015 |
No | 158 (80.2) | 39 (19.8) | 1 (ref) | 1 (ref) |
UM = uncomplicated malaria, SM = severe malaria,
After adjusting for all the measured explanatory variables in the multivariable regression model, under-five years of age (AOR = 3.01, 95% CI: 1.83–7.39), leukocytosis (AOR = 3.20, 95% CI: 1.65–6.24), mean HCMs >5% (AOR = 6.26, 95% CI: 2.14–14.29), mean HCNs >5% (AOR = 7.93, 95% CI: 3.09–16.86), and high parasitemia (AOR = 1.90, 95% CI: 1.13–3.18) were associated with SM.
The main aim of this study was to determine the common hematological indices and HCLs among the malaria infected children. Accordingly, the overall prevalence of anemia was 40.3%. Anemia is a common complication associated with malaria [
In this study, nearly half of the children had moderate to mild thrombocytopenia. Low PLT associated with malaria in malaria endemic areas has also been reported previously [
Leukocytosis and leukopenia were found in 15.4% and 10.3% of the study participants, respectively. Moreover, children who had leukocytosis were 3 times more likely to have SM. Other studies also show significant association of leukocytosis with SM [
In this study, it was also revealed that most of the malaria infected children had HCMs and HCNs in their peripheral blood smear. The interaction of HZ with immune cells may result in upregulation or downregulation of immune mediators [
The findings of this study should be interpreted in light of the following limitations. As no locally established reference range for hematological parameters in children was obtained, the WHO reference range was utilized. Although certain bacterial infections can profoundly perturb hematological parameters, thereby affecting their diagnostic value in determining severity of malaria, this study did not investigate any bacterial coinfections.
Over a quarter of the children with malaria had SM. Demographic and hematological parameters significantly affected the malaria disease outcome among the studied children. The presence and quantities of HCLs and other hematological parameters should be considered in the management of children with malaria in the study area. Further longitudinal studies with larger sample size are needed to determine the association of hematological parameters with SMA.
The authors declare that they do not have competing interests.
The authors would like to thank the data collectors for participating in the data collection and Pawe General Hospital for allowing them to use the laboratory facilities of the hospital. The authors are grateful to the study participants and their parents/guardians. The authors thank Jimma University for financially supporting this study.