Transfusion-transmitted malaria in Ghana

Prevalence of Asymptomatic Malaria Parasitemia among Blood Donors in Cape Coast, Ghana: A Cross-Sectional Study

Background

Malaria is an important transfusion-associated infection in many parts of the world, particularly in sub-Saharan Africa, where it is endemic. We studied the prevalence of malaria parasites among blood donors in the Cape Coast Metropolitan Area.

Methods

A malaria parasite examination was added to the blood donor screening protocol for 240 voluntary and replacement blood donors (224 males and 16 females) between December 2020 and July 2021.

Results

Overall, 2.5% (6/240) had Plasmodium falciparum trophozoites detected in their blood sample. The remaining had no parasites detected. Four of the 148 who passed the blood donor screening tests were infected. The remaining two with malaria parasites failed one screening test. These included one donor with "hepatitis B + P. falciparum" and another with "syphilis + P. falciparum" parasite coinfection. All blood donors who had malaria parasites detected in their blood were males. Most donors, 45.8% (110/240), were in the 26-35 age group, with the highest prevalence of 1.3% (3/240). Blood group O was predominant (75.0%, 180/240), followed by B (12.9%, 31/240), A (11.3%, 27/240), and AB (0.8%, 2/240). All malaria parasites detected were among individuals with blood group O. Moreover, 96.3% (231/240) were rhesus-positive and had the highest prevalence of 2.1% (5/240).

Conclusions

Screening of blood donors in Ghana does not include malaria, although there is the potential for transmission through blood products. Malaria transmission via blood transfusion remains an issue of public health concern, as indicated in the results of this current study. We recommend studies on malaria prevention, pretransfusion and posttransfusion, and pathogen reduction technology.

Transfusion-Transmitted Malaria and Mitigation Strategies in Nonendemic Regions

Background

Malaria is a mosquito-borne infectious disease caused by protozoan parasites of the genus Plasmodium. These parasites can be transmitted by blood transfusion especially through Red Cell Blood Concentrates collected from asymptomatic and parasitemic donors. As migration of populations from endemic areas to Europe and overseas recreational travel to endemic regions increase, there is growing risk of transfusion-transmitted malaria (TTM) in nonendemic regions of the world. The present work provides an overview of the mitigation strategies in nonendemic countries and their effectiveness and discusses possible approaches to evolve the strategies in order to maintain both a safe and adequate blood supply.

Summary

The historical and current situation of malaria and TTM in Europe and on the North American continent are described. The infectivity of Plasmodium in blood components and the consequences of TTM are presented, along with the regulations and guidelines for TTM mitigation in Europe, USA, and Canada. The regulations/guidelines currently in place in Europe allow a certain amount of leeway for local policies. A questionnaire was used to survey European countries regarding their current strategies and recent TTM cases. From the questionnaire and published cases, approximately 20 cases of TTM were identified in the past 20 years in the USA and Europe. The vast majority of implicated donors have been former residents of malaria-endemic areas, particularly former residents of hyperendemic areas in Africa. The most recent TTM cases are discussed in detail to provide insight into the gaps in current strategies. The utility and uncertainties of pathogen reduction and serological and molecular testing methods are discussed.

Key Messages

Overall, the risk of transfusion-associated malaria in nonendemic countries is considered to be low and very few TTM cases occurred in these regions in the last 20 years. The questionnaire-based strategy with questions about risk in relation to malaria exposure with or without selective testing based on questioning seems to be relatively effective, although rare and sometimes fatal transmissions still occur. An outstanding question is whether in the future molecular methods may further improve the safety of blood products and help constrain the loss of donors.

Evaluation of the Sysmex XN-31 automated analyser for blood donor malaria screening at Malawi Blood Transfusion Services

Background and Objectives

Balancing blood supply safety and sufficiency is challenging in malaria‐endemic countries where the risk of transfusion‐transmitted malaria (TTM) is ever‐present. In support of reducing this risk, our study aimed at evaluating the performance of the Sysmex XN‐31 analyser in blood donor malaria screening, as compared with current practice in Malawi.

Materials and Methods

This prospective observational study was conducted on remnant venous donor blood samples collected at Malawi Blood Transfusion Service donation sites countrywide for routine blood‐borne pathogen screening. XN‐31 results were compared with routine thick smear malaria microscopy, using expert microscopy (phase 1 and 2) plus qualitative malaria polymerase chain reaction (PCR) (phase 2) to adjudicate discrepancies.

Results

XN‐31 detected malaria in 614 (11.6%) of 5281 study samples compared with 341 (6.5%) for routine microscopy. Of the 273 discrepant samples, 60 smears (phase 1) could not be retrieved for expert microscopic review. Expert microscopy confirmed the XN‐31 positivity in 78.8% (149/189) and 91.7% (22/24) of discrepant samples in phase 1 (n = 4416) and phase 2 (n = 975), respectively, with two cases requiring PCR testing, confirming one each as positive and negative, giving sensitivities of 100% and 75% and specificities of 99.9% and 100%, respectively, for XN‐31 and routine microscopy.

Conclusion

The automated Sysmex XN‐31 analyser's high sensitivity and specificity, ability to detect all Plasmodium species and high throughput with rapid turnaround‐time, overcomes many of the limitations of currently available diagnostic tests, making it well‐suited for malaria screening of donated blood in malaria‐endemic countries in support of TTM risk reduction.

The Use of Screening Algorithm to Defer Blood Donors with Subclinical Malaria

Plasmodium falciparum infection in blood donors is common in malaria endemic countries, including Ghana. To date, there are no established exclusion criteria to defer a donor carrying malaria parasites. Therefore, based on significant independent variables identified in this study, donor malaria screening algorithm was developed to be used by blood banks to screen blood donors for subclinical malaria. Each significant variable was weighted one (1) point and its alternative response was weighted negative one (-1) point. Accumulation of the points determines the risk level of the donor. These weighted points were used to categorize infected donors as having negligible (<2 points), tolerable (3-4 points), undesirable (5-8 points), or intolerable (>9 points) risk. Based on accumulated weight of ≥5 points, the algorithm was 94.7% (54/57) sensitive but 82% (298/364) specific. With this level of specificity, 18% of the blood donors without malaria would have been deferred. Therefore, it is imperative that all donors with accumulated risk ≥5 be screened for malaria using either malaria rapid test kit or microscopy.

Case Report: Could Artemisinin-Based Combination Therapy Prevent Occupational Malaria following Blood Exposure?

Postexposure prophylaxis using artemisinin-based combination therapy (ACT) was prescribed to a malaria-naive nurse who experienced an injury with a hollow needle previously used on a patient admitted for severe imported Plasmodium falciparum malaria (blood parasitemia 10.8%). Artemether-lumefantrine, four tablets twice daily for 3 days, was started 12 hours after exposure, and no side effects were reported. During the six following months, she only developed one episode of fever that was associated with pyelonephritis. Biological follow-up, based on blood smears, molecular biology, and serology, did not evidence P. falciparum malaria. This case suggests that ACT can prevent occupational P. falciparum malaria following needle-stick injury. We found evidence of only one other unpublished similar case where a Turkish resident doctor did not develop malaria after postexposure prophylaxis using ACT. Such a prophylaxis could be prescribed not only in case of occupational exposure to Plasmodium spp. in nonvector-borne laboratory-acquired infections but also following blood exposure in healthcare setting.

Elevated IL-12, TNF-α, and TNF-α/IL-10 Ratios in Stored Plasmodium falciparum-Infected Whole Blood: Implications for Safe Haemotransfusion

Although Plasmodium falciparum infections in blood donors have been reported, the impact of parasitaemia on cytokine levels in stored whole blood has not been explored. This study evaluated the effect of P. falciparum parasitaemia on circulating cytokines and their relationship with haematological parameters in banked blood. In this case-control study, two groups of donor whole blood were recruited: P. falciparum-infected donors (parasitaemia: 515–1877 parasites/μL) and noninfected blood donors (control). At day 0 (baseline), 7, 14, 21, and 35 of banking circulating cytokine levels of tumor necrosis factor alpha (TNF-α), interleukin- (IL-) 12, IL-10, and IL-6 levels and haematological parameters were determined. Kruskal-Wallis test determined differences in weekly cytokine levels while Dunn's post hoc test determined exact significant points. At baseline, the mean TNF-α (33.81 pg/mL vs. 22.70 pg/mL), IL-12 (28.39 pg/mL vs. 16.15 pg/mL), IL-10 (51.04 pg/mL vs. 18.95 pg/mL), and IL-6 (71.03 pg/mL vs. 30.89 pg/mL) levels were significantly higher in infected donor whole blood. Significant rate of increase was observed in TNF-α, IL-12 levels, and TNF-α/IL-10 ratios in infected blood, while decreased levels were observed in IL-10. IL-6 peaked at day 21 and fell below baseline level at day 35. Significant changes in TNF-α, IL-12, IL-10, IL-6 levels, and TNF-α/IL-10 ratios in infected donor blood were observed 7 days after storage. Unlike in noninfected stored whole blood, TNF-α, IL-6, IL-12, and TNF-α/IL-10 ratio levels in infected stored whole blood related inversely to haematological parameters (white cells, red cells, platelets, and haemoglobin levels) during storage. However, in both groups, significant direct relationship was observed in IL-10 and haematological parameters. In conclusion, banking of P. falciparum-infected donor whole blood may lead to infusion of large quantities of inflammatory cytokines with potential adverse immunological response in recipients.

Use of a NAT-based assay to improve the surveillance system and prevent transfusion-transmitted malaria in blood banks

Background

Malaria can be transmitted by blood transfusion through donations collected from asymptomatic donors. Transfusion-transmitted malaria (TTM) poses a great risk to blood services worldwide. A good screening tool for Plasmodium spp. detection in blood banks must have a high sensitivity for prevention of TTM. However, in Brazilian blood banks, screening for malaria still relies on microscopy.

Methods

In Brazil, screening for human immunodeficiency virus type 1 (HIV), RNA/DNA for hepatitis C (HCV) and hepatitis B (HBV) viruses is mandatory for every blood donation and uses nucleic acid amplification testing (NAT). The aim of this study was to evaluate the inclusion of an assay for malaria to identify Plasmodium sp. from total nucleic acid (TNA; DNA/RNA) by targeting the 18S rRNA gene of the parasite.

Results

Considering the limitations of microscopy and the wide availability of the Brazilian NAT platform in the screening of blood units for HIV, HCV, and HBV, a molecular diagnostic tool was validated for detection of Plasmodium sp. in blood banks; a pilot study showed that using this novel NAT assay could reduce the risk of TTM.

Conclusion

The prototype HIV/HCV/HBV/malaria NAT assay was effective in detecting infected candidate donors and has good prospects to be applied in routine screening for preventing TTM.

Characterization of putative drug resistant biomarkers in Plasmodium falciparum isolated from Ghanaian blood donors

BACKGROUND

Plasmodium falciparum parasites, which could harbour anti-malaria drug resistance genes, are commonly detected in blood donors in malaria-endemic areas. Notwithstanding, anti-malaria drug resistant biomarkers have not been characterized in blood donors with asymptomatic P. falciparum infection.

METHODS

A total of 771 blood donors were selected from five districts in the Greater Accra Region, Ghana. Each donor sample was screened with malaria rapid diagnostic test (RDT) kit and parasitaemia quantified microscopically. Dried blood spots from malaria positive samples were genotyped for P. falciparum chloroquine resistance transporter (Pfcrt), P. falciparum multi-drug resistance (Pfmdr1), P. falciparum dihydropteroate-synthetase (Pfdhps), P. falciparum dihydrofolate-reductase (Pfdhfr) and Kelch 13 propeller domain on chromosome 13 (Kelch 13) genes.

RESULTS

Of the 771 blood donors, 91 (11.8%) were positive by RDT. Analysis of sequence reads indicated successful genotyping of Pfcrt, Pfmdr1, Pfdhfr, Pfdhps and Kelch 13 genes in 84.6, 81.3, 86.8, 86.9 and 92.3% of the isolates respectively. Overall, 21 different mutant haplotypes were identified in 69 isolates (75.8%). In Pfcrt, CVIET haplotype was observed in 11.6% samples while in Pfmdr1, triple mutation (resulting in YFN haplotype) was detected in 8.1% of isolates. In Pfdhfr gene, triple mutation resulting in IRNI haplotype and in Pfdhps gene, quintuple mutation resulting in AGESS haplotype was identified in 17.7% parasite isolates. Finally, five non-synonymous Kelch 13 alleles were detected; C580Y (3.6%), P615L (4.8%), A578S (4.8%), I543V (2.4%) and A676S (1.2%) were detected.

CONCLUSION

Results obtained in this study indicated various frequencies of mutant alleles in Pfcrt, Pfmdr1, Pfdhfr, Pfdhps and Kelch 13 genes from P. falciparum infected blood donors. These alleles could reduce the efficacy of standard malaria treatment in transfusion-transmitted malaria cases. Incorporating malaria screening into donor screening protocol to defer infected donors is therefore recommended.

The Incidence of Malaria Parasites in Screened Donor Blood for Transfusion

Malaria is a protozoan parasitic infection of humans resulting from one or more of the five species of the genus Plasmodium and its burden across the world particularly in the tropics is well known. Blood transfusion on the other hand is a necessary intervention in saving lives. However, it can lead to transfusion transmitted infections including malaria if the blood was donated by an infected person. It is therefore important that the blood from donors in malaria prone environment be examined thoroughly for malaria parasites. The objective of this study was to investigate the incidence of malaria parasites in donor blood. A total of 1,500 samples from donors were examined using microscopy, rapid diagnostic test (RDT), and molecular method for malaria parasites. Malaria parasites were detected in forty-eight (48), 49 and 47 of the blood samples using microscopy, RDT, and molecular method respectively. This gave an average prevalence of 3.2%. All the blood groups examined had some malaria positivity except blood group O and A negative. In all the positive samples, the trophozoites of Plasmodium falciparum were detected. There was no association between blood group type and prevalence of the malaria parasites. There was also no association between age and prevalence of malaria parasite. The results attest to the potential risk of blood transfusion transmitted malaria and thus pose a great risk to blood recipients, especially the malaria vulnerable groups of children and pregnant women. Even though the prevalence in this study was not high enough, together with other results from elsewhere, it can be said that the screening of donated blood or donors for malaria parasites is necessary so that measures will be put in place not to transfuse patients at risk.

Assessment of the quality of stored blood for transfusion at Mbarara Regional Referral Hospital, Southwestern Uganda

Aim and objective: To assess the quality of blood stored for transfusion at Mbarara Regional Referral Hospital (MRRH) regarding bacterial contamination, malaria infection, and laboratory audit status. Materials and methods: Whole blood and packed red blood cells at MRRH were critically inspected for visual anomalies, and a portion of this blood was aseptically collected and analyzed for Plasmodium species and bacterial contamination using culture methods. For culture positive samples, drug susceptibility testing (DST) was done using the Kirby-Bauer disc diffusion method. An audit using Stepwise Laboratory quality Improvement Process Towards Accreditation (SLIPTA) quality checklist was conducted. The obtained data were analyzed as frequencies and proportions at 95% confidence interval (CI), and significance levels of relatedness were set at p-values<0.05. Results: Of the 202 samples analyzed, 6 (3%) had bacteria while 3 (1.5%) had Plasmodium falciparum trophozoites. The bacterial isolates were Staphylococcus aureus (N=4, 66.7%); Corynebacterium spp (N=1, 16.7%) and Micrococcus spp (N=1, 16.7%). Staphylococcus aureus showed sensitivity to chloramphenicol, oxacillin, amikacin, and gentamycin. Thirty (14.9%) of these units had visually detectable anomalies, and the laboratory audit score was 53.8%. Conclusion: The quality of some blood stored for transfusion at MRRH was inadequate, and the laboratory quality standard based on SLIPTA was low. Based on this, it is crucial to always insist on aseptic measures at all stages (phlebotomy, processing, transporting, and blood storage) and consider more assessment of the donor risk to minimize transfusion-transmitted malaria. It is plausible to standardize the hospital blood transfusion laboratory and revive hemovigilance by the hospital transfusion committee.

Evaluation of automated malaria diagnosis using the Sysmex XN-30 analyser in a clinical setting

BACKGROUND

Early and accurate diagnosis of malaria is a critical aspect of efforts to control the disease, and several diagnostic tools are available. Microscopic assessment of a peripheral blood smear enables direct visualization of parasites in infected red blood cells and is the clinical diagnostic gold standard. However, it is subjective and requires a high level of skill. Numerous indirect detection methods are in use, but are not ideal since surrogate markers of infection are measured. This study describes the first clinical performance evaluation of the automated Sysmex XN-30 analyser, which utilizes fluorescence flow cytometry to directly detect and quantitate parasite-infected red blood cells.

RESULTS

Residual EDTA blood samples from suspected malaria cases referred for routine diagnosis were analysed on the XN-30. Parasitaemia was reported as a percentage, as well as absolute numbers of infected red blood cells, and scattergrams provided a visual image of the parasitized red blood cell clusters. The results reported by the XN-30 correlated with microscopy and the analyser demonstrated 100% sensitivity and specificity. Measurements were reproducible and storage of samples at room temperature did not affect the parameters. Several Plasmodium species were detected, including Plasmodium falciparum, Plasmodium vivax and Plasmodium ovale. The XN-30 also identified the transmissible gametocytes as a separate cluster on the scattergrams. Abnormal red blood cell indices (low haemoglobin and raised reticulocyte counts), haemoglobinopathies and thrombocytopenia did not interfere with the detection of parasites. The XN-30 also generated a concurrent full blood count for each sample.

CONCLUSIONS

The novel technology of the Sysmex XN-30 provides a robust, rapid, automated and accurate platform for diagnosing malaria in a clinical setting. The objective enumeration of red blood cells infected with Plasmodium species makes it suitable for global use and allows monitoring of the parasite load once therapy has been initiated, thereby providing an early marker of drug resistance. The automated generation of a full blood count for each sample provides an opportunity for detecting unsuspected cases. Asymptomatic carriers can also be identified, which will be useful in blood transfusion centres, and will enable treatment of these individuals to prevent the spread of the disease.

Molecular monitoring of the diversity of human pathogenic malaria species in blood donations on Bioko Island, Equatorial Guinea

BACKGROUND

Malaria can be transmitted by blood transfusion from human to human and it is responsible for the majority of transfusion-transmitted infectious diseases worldwide. In sub-Saharan Africa, it had been estimated that almost a quarter of blood donations contain malaria parasites. Since rapid diagnostic tests and thick blood smear microscopy lack sensitivity for low density parasitaemia, particularly in asymptomatic adults, the most reliable method to assess the problem of transfusion-transmitted malaria are nucleic acid-based molecular approaches such as quantitative polymerase chain reaction. The study was undertaken to determine the prevalence of sub-microscopic malaria parasite infection among blood donors in Malabo, Equatorial Guinea.

METHODS

Between July and August 2017, a total of 200 individual blood samples from blood donors at the Malabo Blood Bank were collected and screened by rapid diagnostic tests and thick blood smear microscopy. Retrospectively, the same samples were analysed for the presence of undetected, low-density malaria parasites using quantitative polymerase chain reaction.

RESULTS

In comparison to 6.5% (13/200) by rapid diagnostic test and 2.0% (4/200) by microscopy, the proportion of Plasmodium falciparum positive blood donations analysed by quantitative polymerase chain reaction was significantly higher (26%, 52/200). Densities of P. falciparum positive blood donations were ranging from 0.06 to 3707.0 parasites/µL with 79.6% below 100 parasites/µL and therefore not detectable by non-molecular malaria diagnostic tests. qPCR based species identification revealed that P. falciparum was the dominating species responsible for 88.1% (52/59) of positive blood donations, followed by Plasmodium malariae (15.3%, 9/59) and Plasmodium ovale (3.4%, 2/59).

CONCLUSIONS

This study confirms that in malaria endemic settings, sub-patent malaria infections among blood donors are prevalent. In blood collected from healthy donors living in Malabo, P. falciparum, P. malariae and P. ovale parasites were identified. Currently widely used malaria diagnostic tools have missed more than 75% of P. falciparum containing blood donations, demonstrating the value of quantitative polymerase chain reaction to reliably detect low density P. falciparum infections. Since the availability of molecular diagnostic methods in malaria endemic countries is still limited, the blood recipients living in malaria endemic countries should be treated following WHO recommendations.

Storage related haematological and biochemical changes in Plasmodium falciparum infected and sickle cell trait donor blood

Background

In 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.

Methods

Fifty-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.

Results

Storage of SCT and malaria infected blood affected all haematological cell lines. In the SCT donors, red blood cells (RBC) (4.75 × 10¹²/L ± 1.43^baseline to 3.49 × 10¹²/L ± 1.09^week-5), haemoglobin (14.45 g/dl ± 1.63^baseline to 11.43 g/dl ± 1.69^week-5) and haematocrit (39.96% ± 3.18^baseline to 33.22% ± 4.12^week-5) were reduced. In the asymptomatic malaria group, reductions were observed in RBC (5.00 × 10¹²/L ± 0.75^baseline to 3.72 × 10¹²/L ± 0.71^week-5), haemoglobin (14.73 g/dl ± 1.67^baseline to 11.53 g/dl ± 1.62^week-5), haematocrit (42.72% ± 5.16^baseline to 33.38% ± 5.80^week-5), mean cell haemoglobin concentration (35.48 g/dl ± 1.84^baseline to 35.01 g/dl ± 0.64^week-5) and red cell distribution width coefficient of variation (14.81% ± 1.54^baseline to 16.26% ± 1.37^week-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.

Conclusion

Severe 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.

Asymptomatic Malaria Infection and Associated Factors among Blood Donors Attending Arba Minch Blood Bank, Southwest Ethiopia

Background

It is well known that malaria can be transmitted via blood transfusion. However, it is not documented in the national donor screening protocol. Magnitude of asymptomatic malaria among donors would be the key to decide on the need of donor screening. Despite this, there is lack of such data in Ethiopia. The aim of this study was thus to estimate the prevalence of asymptomatic malaria and associated factors among blood donors.

Methods

An institution based cross-sectional study was conducted in Arba Minch blood bank from February to June, 2015. Data was collected from donors who passed the clinical donor selection criteria and recruited by systematic random sampling technique. A structured questionnaire was used to capture data on socio-demographic characteristics. Giemsa stained blood films were examined for plasmodium parasites. Magnitude of asymptomatic malaria was calculated and association of factors with malaria was assessed by multivariable logistic regressions using SPSS version 20.0.

Results

A total of 416 donors participated in the study. The proportion of infected donors was 4.1% (17/416). Eight donors were infected with Plasmodium falciparum while 9 donors were infected with Plasmodium vivax. Most positive blood films (13/17) were with parasite loads ranging from 100 – 500 parasites/µl. Donors with blood group O were more susceptible to malaria parasitemia compared to all other ABO blood groups together (AOR=6.899, 95%CI=1.951–24.391, p=0.003).

Conclusion

Magnitude of malaria parasitemia in the present study was high as compared to the national malaria prevalence. Hence, in malaria endemic areas of Ethiopia, blood should be screened before donation.

Transfusional malaria in the neonatal period in Lagos, South-West Nigeria

Background and objectives

Sick neonates in malaria endemic areas are frequently transfused with donor blood unscreened for malaria parasite. Consequently, they are at risk of transfusional malaria which can lead to increased neonatal mortality. The study aimed to determine the burden of transfusional malaria in neonates to help in policy formulation on prevention of transfusional malaria.

Materials and methods

One hundred and sixty four neonates admitted into the neonatal unit of a tertiary hospital over a 10 month period who were scheduled for blood transfusion were screened for malaria parasites pre-transfusion, at three and 14 days post transfusion using Giemsa stained thick and thin films. Donor blood was screened for malaria parasites at the point of transfusion. Neonates who developed malaria parasitaemia post transfusion were followed up for signs of malaria.

Results

All recruited neonates tested negative to malaria parasite pre- transfusion. One hundred and twenty (73.2%) were term neonates with 94(57.3%) aged 1-7days. Four (2.4%) neonates developed malaria parasitaemia three days post transfusion and all four developed fever that resolved on treatment for malaria. Three (1.8%) of 164 donor blood samples had malaria parasitaemia and all three (100%) neonates who were transfused with the infected donor blood developed malaria parasitaemia post transfusion. However, one neonate who developed malaria parasitaemia post transfusion was transfused with non-infected donor blood.

Conclusions

The prevalence of transfusional malaria in this study is low (2.4%). However, 100% of neonates who received malaria infected donor blood developed transfusional malaria. We therefore recommend routine screening of donor pre-transfusion, testing of neonates who develop fever post transfusion and treatment of those who test positive to malaria.

Observation of Blood Donor-Recipient Malaria Parasitaemia Patterns in a Malaria Endemic Region

Background

Asymptomatic malaria parasitaemia has been documented in donor blood in West Africa. However, donated blood is not routinely screened for malaria parasites (MPs). The present study therefore aimed to document the frequency of blood transfusion-induced donor-recipient malaria parasitaemia patterns, in children receiving blood transfusion in a tertiary health-centre.

Methodology

A cross-sectional, observational study involving 140 children receiving blood transfusion was carried out. Blood donor units and patients' blood samples were obtained, for the determination of malaria parasites (MPs). Giemsa staining technique was used to determine the presence of malaria parasitaemia.

Results

Malaria parasites were detected in 7% of donor blood and in 8.3% of the recipients' pretransfusion blood. The incidence of posttransfusion MPs was 3%, but none of these were consistent with blood transfusion-induced malaria, as no child with posttransfusion parasitaemia was transfused with parasitized donor blood. Majority of the blood transfusions (89.4%) had no MPs in either donors or recipients, while 6.8% had MPs in both donors and recipients, with the remaining 3.8% showing MPs in recipients alone.

Conclusion

In conclusion, the incidence of posttransfusion malaria parasitaemia appears low under the prevailing circumstances.

P. falciparum malaria prevalence among blood donors in Bamako, Mali

AIM

Malaria parasite is usually transmitted to humans by Anopheles mosquitoes but it can also be transmitted through blood transfusion. Usually malaria transmission is low in African urban settings. In West Africa where the P. falciparum is the most predominant malaria species, there are limited measures to reduce the risk of blood transfusion malaria. The aim of this study was to evaluate the prevalence of P. falciparum malaria carriage among blood donors in the National Blood Center of Bamako, capital city of Mali.

METHODS

The study was conducted using a random sample of 946 blood donors in Bamako, Mali, from January to December 2011. Screening for malaria was performed by thick smear and rapid diagnostic test (RDT). Blood group was typed by Beth-Vincent and Simonin techniques.

RESULTS

The frequency of malaria infection was 1.4% by thick smear and 0.8% by the RDT. The pick prevalence of P. falciparum malaria was in rainy season, indicating a probable high seasonal risk of malaria by blood transfusion, in Mali. The prevalence of P. falciparum infection was 2% among donors of group O the majority being in this group.

CONCLUSION

There is a seasonal prevalence of malaria among blood donors in Bamako. A prevention strategy of transfusion malaria based on the combination of selection of blood donors through the medical interview, promoting a voluntary low-risk blood donation and screening all blood bags intended to be transfused to children under 5, pregnant women and immune-compromised patients during transmission season using thick smear will reduce the risk of transfusion malaria in Mali.

Alternative transmission routes in the malaria elimination era: an overview of transfusion-transmitted malaria in the Americas

BACKGROUND

Transfusion-transmitted (TT) malaria is an alternative infection route that has gained little attention from authorities, despite representing a life-threatening condition. There has been no systematic review of this health problem in American countries. The aim of this study was to describe the clinical and epidemiological characteristics of TT malaria in the Americas and identify factors associated with lethality based on the studies published in the literature.

METHODS

Potentially relevant papers in all languages were retrieved from MEDLINE and LILACS. Additional articles were obtained from reviews and original papers. Publications on screening of candidate blood donors and on surveillance of TT malaria cases were included. Odds ratios with respective 95% confidence intervals (95% CI) were calculated. Epidemiological characteristics of blood donors of TT malaria cases, including a pooled positivity of different tests for malaria diagnosis, were retrieved.

RESULTS

A total of 63 publications regarding TT malaria from seven countries were included, from 1971 to 2016. A total of 422 cases of TT malaria were recorded. Most TT malaria cases were in females (62.0%) and 39.5% were in the ≥61 years-old age group. About half of all cases were from Mexico (50.7%), 40.3% from the United States of America (USA) and 6.6% from Brazil. Gyneco-obstetrical conditions (67.3%), surgical procedures (20.6%) and complications from neoplasias (6.1%) were the most common indications of transfusion. Packed red blood cells (RBCs) (50.7%) and whole blood (43.3%) were the blood products mostly associated with TT malaria. Cases were mostly caused by Plasmodium malariae (58.4%), followed by Plasmodium vivax (20.7%) and Plasmodium falciparum (17.9%). A total of 66.6% of cases were diagnosed by microscopy. Incubation period of 2-3 weeks was the most commonly observed (28.6%). Lethality was seen in 5.3% of cases and was associated with living in non-endemic countries, P. falciparum infection and concomitant neoplastic diseases.

CONCLUSION

There is an important research and knowledge gap regarding the TT malaria burden in Latin American countries where malaria remains endemic. No screening method that is practical, affordable and suitably sensitive is available at blood banks in Latin American countries, where infections with low parasitaemia contribute greatly to transmission. Lethality from TT malaria was not negligible. TT malaria needs to be acknowledged and addressed in areas moving toward elimination.

Post-exposure serological responses to malaria parasites in potential blood donors

Background

Cases of transfusion-transmitted malaria have been described around the world and highlighted in some studies. Semi-immune individuals are more likely to transmit malaria as they may be asymptomatic. Some countries allow blood donations only based on epidemiological criteria while others reinforce their criteria with serological tests. However, little is known about the longevity of anti-Plasmodium spp. antibodies and its meaning in blood donation. Therefore, this study aims to assess the longevity of different subclasses of anti-Plasmodium spp. antibodies in individuals with previous stays in endemic areas, as well as to assess how those antibodies are related to personal features and travel characteristics. Based on those results, the suitability of the Portuguese blood donors screening method was addressed, i.e. the method to search for an eventual risk of transfusion–transmitted malaria among the population studied.

Results

Statistical associations were found between the presence of total anti-Plasmodium spp. antibodies and some travel characteristics, namely to be born in endemic area versus non endemic and previous episodes of malaria. The intersection between seropositive results and the last year of stay in endemic areas showed a longer longevity of anti-Plasmodium spp. antibodies than previously reported. Those results represented a considerable portion of the individuals having returned from their last stay in endemic areas more than 10 years before enrolment in this study. Considering the study population as potential blood donors, serological results also indicated that if epidemiological criteria alone were applied to screen blood donors, an important percentage of seropositive individuals would be approved for blood donation. Because the nature and meaning of those antibodies in the blood donation context is still not understood, those approved individuals could represent a risk for blood transfusion safety.

Conclusions

The place of birth and past episodes of malaria seem to be related to the serological outcome. Epidemiological criteria to screen potential blood donors are insufficient to guarantee the safety of the blood, if applied alone.

Electronic supplementary material

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Pediatric blood transfusion practices at a regional referral hospital in Kenya

BACKGROUND

Severe anemia in children is a major public health problem in sub-Saharan Africa. In this study we describe clinical and operational aspects of blood transfusion in children admitted to Coast Provincial General Hospital, Kenya.

STUDY DESIGN AND METHODS

This was an observational study where over a 2-year period, demographic and laboratory data were collected on all children for whom the hospital blood bank received a transfusion request. Clinical data were obtained by retrospective review of case notes over the first year.

RESULTS

There were 2789 requests for blood for children (median age, 1.8 years; interquartile range [IQR], 0.6-6.6 years); 70% (1950) of the samples were crossmatched with 85% (1663/1950) issued. Ninety percent (1505/1663) were presumed transfused. Median time from laboratory receipt of request to collection of blood was 3.6 hours (IQR, 1.4-12.8 hr). Case notes of 590 children were reviewed and median pretransfusion hemoglobin level was 6.0 g/dL (IQR, 4.2-9.1 g/dL). Ninety-four percent (186) were transfused "appropriately" while 52% (120) were transfused "inappropriately." There was significant disagreement between the clinical and laboratory diagnosis of severe anemia (exact McNemar's test; p < 0.0001). Antimalarials were prescribed for 65% (259) of children who received blood transfusions but only 41% (106) of these had a positive blood film.

CONCLUSION

In this setting, clinicians often order blood based on the clinical impression of "severe anemia." This has implications for laboratory workload and the blood supply itself. However, the majority of children with severe anemia were appropriately transfused. The use of antimalarials with blood transfusions irrespective of blood film results is common practice.

Treatment of blood with a pathogen reduction technology using ultraviolet light and riboflavin inactivates Ebola virus in vitro

BACKGROUND

Transfusion of plasma from recovered patients after Ebolavirus (EBOV) infection, typically called "convalescent plasma," is an effective treatment for active disease available in endemic areas, but carries the risk of introducing other pathogens, including other strains of EBOV. A pathogen reduction technology using ultraviolet light and riboflavin (UV+RB) is effective against multiple enveloped, negative-sense, single-stranded RNA viruses that are similar in structure to EBOV. We hypothesized that UV+RB is effective against EBOV in blood products without activating complement or reducing protective immunoglobulin titers that are important for the treatment of Ebola virus disease (EVD).

STUDY DESIGN AND METHODS

Four in vitro experiments were conducted to evaluate effects of UV+RB on green fluorescent protein EBOV (EBOV-GFP), wild-type EBOV in serum, and whole blood, respectively, and on immunoglobulins and complement in plasma. Initial titers for Experiments 1 to 3 were 4.21 log GFP units/mL, 4.96 log infectious units/mL, and 4.23 log plaque-forming units/mL. Conditions tested in the first three experiments included the following: 1-EBOV-GFP plus UV+RB; 2-EBOV-GFP plus RB only; 3-EBOV-GFP plus UV only; 4-EBOV-GFP without RB or UV; 5-virus-free control plus UV only; and 6-virus-free control without RB or UV.

RESULTS

UV+RB reduced EBOV titers to nondetectable levels in both nonhuman primate serum (≥2.8- to 3.2-log reduction) and human whole blood (≥3.0-log reduction) without decreasing protective antibody titers in human plasma.

CONCLUSION

Our in vitro results demonstrate that the UV+RB treatment efficiently reduces EBOV titers to below limits of detection in both serum and whole blood. In vivo testing to determine whether UV+RB can improve convalescent blood product safety is indicated.

A Novel Malaria Pf/Pv Ab Rapid Diagnostic Test Using a Differential Diagnostic Marker Identified by Network Biology

Rapid diagnostic tests (RDTs) can detect anti-malaria antibodies in human blood. As they can detect parasite infection at the low parasite density, they are useful in endemic areas where light infection and/or re-infection of parasites are common. Thus, malaria antibody tests can be used for screening bloods in blood banks to prevent transfusion-transmitted malaria (TTM), an emerging problem in malaria endemic areas. However, only a few malaria antibody tests are available in the microwell-based assay format and these are not suitable for field application. A novel malaria antibody (Ab)-based RDT using a differential diagnostic marker for falciparum and vivax malaria was developed as a suitable high-throughput assay that is sensitive and practical for blood screening. The marker, merozoite surface protein 1 (MSP1) was discovered by generation of a Plasmodium-specific network and the hierarchical organization of modularity in the network. Clinical evaluation revealed that the novel Malaria Pf/Pv Ab RDT shows improved sensitivity (98%) and specificity (99.7%) compared with the performance of a commercial kit, SD BioLine Malaria P.f/P.v (95.1% sensitivity and 99.1% specificity). The novel Malaria Pf/Pv Ab RDT has potential for use as a cost-effective blood-screening tool for malaria and in turn, reduces TTM risk in endemic areas.

Selective Testing of At-Risk Blood Donors for Trypanosoma cruzi and Plasmodium spp. in Switzerland

BACKGROUND

Population migrations and overseas recreational travel to regions at risk for tropical diseases are increasing. A major challenge in non-endemic countries is to decrease the number of blood donor deferrals due those tropical disease pathogens, without compromising the high level of blood safety. The protozoans Trypanosoma cruzi and Plasmodium spp., the causative organisms of Chagas disease (CD) and malaria are becoming a major focus in the blood transfusion community.

METHODS

National guidelines of the Blood Transfusion Service of the Swiss Red Cross propose an algorithm for dealing with these pathogens, including a mandatory selective serological testing of donors at risk.

RESULTS

6,978 donors at risk for CD were tested. Three of them were confirmed anti-T. cruzi -positive, and in one case a transfusion-transmitted infection was highly possible. The specificity of the assay was 99.94%. For malaria 12,887 donors were at risk and 178 were confirmed positive. The specificity of the assays was 92.8%.

CONCLUSION

CD and malaria in non-endemic countries may represent a certain risk for blood transfusion. Switzerland chose a selective testing approach. The specificity of the assays is a crucial topic for this approach because it ensures a minimal loss of false-reactive donors and helps towards an easier counselling of implicated donors.

Treatment of Whole Blood With Riboflavin and UV Light: Impact on Malaria Parasite Viability and Whole Blood Storage

Background: Sub-Saharan African countries utilize whole blood (WB) to treat severe anemia secondary to severe blood loss or malaria on an emergency basis. In many areas with high prevalence of transfusion-transmissible agents, blood safety measures are insufficient. Pathogen reduction technology applied to WB might considerably improve blood safety. Methods: Whole blood from 40 different donors were treated with riboflavin and UV light (pathogen reduction technology) in order to inactivate malaria parasite replication. The extent of parasite inactivation was determined using quantitative polymerase chain reaction methods and was correlated to studies evaluating the replication of malaria parasites in culture. Products were also stored for 21 days at +4°C and monitored for cell quality throughout storage. Results: Plasmodium amplicon was present in 21 samples (>100 copies/mL), doubtful in four (10–100 genome equivalents [gEq]/mL), and negative in 15 U. The majority of asymptomatic parasitemic donors carried low parasite levels, with only six donors above 5,000 copies/mL (15%). After treatment with riboflavin and UV light, these six samples demonstrated a 0.5 to 1.2 log reduction in quantitative polymerase chain reaction amplification. This correlated to equal to or greater than 6.4 log reductions in infectivity. In treated WB units, cell quality parameters remained stable; however, plasma hemoglobin increased to 0.15 g/dL. All markers behaved similarly to published data for stored, untreated WB. Conclusions: Pathogen reduction technology treatment can inactivate malaria parasites in WB while maintaining adequate blood quality during posttreatment cold storage for 21 days.

Transfusion-transmitted malaria: donor prevalence of parasitaemia and a survey of healthcare workers knowledge and practices in a district hospital in Ghana

Background

Transfusion-transmitted malaria (TTM) is a risk of transfusion that has not been well described in malaria endemic regions. The risk of the recipient getting malaria is related to the prevalence of malaria in the blood donors. There is however little information on the prevalence of malaria among donors in Akatsi district of Ghana. Further, the knowledge and practices of healthcare workers to TTM is unknown. The study was undertaken to determine the prevalence of malaria parasite infection among blood donors and to evaluate the knowledge and practices of healthcare workers to TTM in the Akatsi district of Ghana.

Methods

The study was conducted at Akatsi South District Hospital between May and August 2014. To screen for Plasmodium falciparum, 5 µl of capillary blood was obtained by finger prick from 200 participants (100 donors and 100 healthy controls). Plasmodium falciparum screening was done using CareStart™ Malaria Antigen kit. To obtain information regarding TTM knowledge and practices, questionnaires were completed by 100 health workers including nurses, doctors and laboratory staff.

Results

The prevalence of P. falciparum was the same (10 %) in both donors and controls. All those who were malaria RDT positive were aged 15–25 years. Out of the 100 healthcare workers (31 males and 69 females) surveyed, 45 % of respondents (45/100) had never heard of transfusion-transmitted malaria. Almost all respondents (91 %) had not attended any lecture/seminar/workshop on blood transfusion in the past 12 months. There were 44 respondents (44 %) who wrongly said malaria was being screened for prior to transfusion in their hospital. However, 98.2 % (54/55) of those who had heard about TTM rightly stated that TTM can be prevented.

Conclusion

The prevalence of P. falciparum parasitaemia is 10 % in healthy blood donors in the Akatsi district and represents a risk for TTM though the extent of this risk is unclear. Knowledge about TTM in healthcare workers in the district is low. Continuous education and in-service training may be a means to improve TTM knowledge and preventive practices by the health workers in the district.

Assessing ABO/Rh Blood Group Frequency and Association with Asymptomatic Malaria among Blood Donors Attending Arba Minch Blood Bank, South Ethiopia

Background. Determination of the various ABO/Rh blood group distributions and their association with malaria infection has paramount importance in the context of transfusion medicine and malaria control. Methods. Facility based cross-sectional study was conducted from February to June, 2015, to assess ABO/Rh blood groups distribution and their association with asymptomatic malaria. A structured questionnaire was used to collect data. Blood grouping was done using monoclonal antibodies. Thin and thick blood films were examined for Plasmodium parasites. Data were analyzed using SPSS version 20.0. Results. A total of 416 blood donors participated with median age of 22 ± 0.29 (median ± standard error of the mean). Distribution of ABO phenotypes, in decreasing order, was O (175, 42.1%), A (136, 32.7%), B (87, 20.9%), and AB (18, 4.3%). Most of them were Rh+ (386, 92.8%). The overall malaria prevalence was 4.1% (17/416). ABO blood group is significantly associated with malaria infection (P = 0.022). High rate of parasitemia was seen in blood group O donors (6.899, P = 0.003) compared to those with other ABO blood groups. Conclusion. Blood groups O and AB phenotypes are the most and the least ABO blood groups, respectively. There is significant association between ABO blood group and asymptomatic malaria parasitemia.

Malaria and blood transfusion: major issues of blood safety in malaria-endemic countries and strategies for mitigating the risk of Plasmodium parasites

Malaria inflicts humankind over centuries, and it remains as a major threat to both clinical medicine and public health worldwide. Though hemotherapy is a life-sustaining modality, it continues to be a possible source of disease transmission. Hence, hemovigilance is a matter of grave concern in the malaria-prone third-world countries. In order to pursue an effective research on hemovigilance, a comprehensive search has been conducted by using the premier academic-scientific databases, WHO documents, and English-language search engines. One hundred two appropriate articles were chosen for data extraction, with a particular reference to emerging pathogens transmitted through blood transfusion, specifically malaria. Blood donation screening is done through microscopic examination and immunological assays to improve the safety of blood products by detection major blood-borne pathogens, viz., HIV, HBV, HCV, syphilis, and malarial parasites. Transfusion therapy significantly dwindles the preventable morbidity and mortality attributed to various illnesses and diseases, particularly AIDS, tuberculosis, and malaria. Examination of thick and thin blood smears are performed to detect positivity and to identify the Plasmodium species, respectively. However, all of these existing diagnostic tools have their own limitations in terms of sensitivity, specificity, cost-effectiveness, and lack of resources and skilled personnel. Globally, despite the mandate need of screening blood and its components according to the blood-establishment protocols, it is seldom practiced in the low-income/poverty-stricken settings. In addition, each and every single phase of transfusion chain carries sizable inherent risks from donors to recipients. Interestingly, opportunities also lie ahead to enhance the safety of blood-supply chain and patients. It can be achieved through sustainable blood-management strategies like (1) appropriate usage of precise diagnostic tools/techniques, (2) promoting hemovigilance system, and (3) adopting novel processes of inactivation technology. Furthermore, selection of the zero-risk donors could pave the way to build a transmissible malaria-free world in the near future.

The use of rapid diagnostic tests for transfusion infectious screening in Africa: a literature review

Infectious risk associated with blood transfusion remains a major public health challenge in Africa, where prevalence rates of the major transfusion-transmissible infections (ie, hepatitis B, hepatitis C, human immunodeficiency virus, and syphilis) are among the highest in the world. Resource-limited blood services often operate with minimal predonation screening safeguards, prompting exclusive reliance on laboratory testing to mitigate infectious risk. Transfusion screening with rapid diagnostic tests (RDTs) has been adopted in areas that lack the capacity to support the routine use of more sophisticated technologies. However, uncertainty surrounding the performance of some RDTs in the field has spurred debate regarding their application to blood donation screening. Our review of the literature identified 17 studies that evaluated RDTs for the infectious screening of blood donors in Africa. The review highlights the variable performance of available RDTs and the importance of their use in a quality-assured manner. Deficiencies in performance observed with some RDTs underscore the need to validate test kits prior to use under field conditions with locally acquired samples. Suboptimal sensitivities of some available tests, specifically hepatitis B virus rapid assays, question their suitability in single-test algorithms, particularly in high-prevalence regions. Although RDTs have limitations, many of which can be addressed through improved training and quality systems, they are frequently the only viable option for infectious screening in resource-poor African countries. Therefore, additional studies and specific guidelines regarding the use of RDTs in the context of blood safety are needed.

Evaluation of a novel magneto-optical method for the detection of malaria parasites

Improving the efficiency of malaria diagnosis is one of the main goals of current malaria research. We have recently developed a magneto-optical (MO) method which allows high-sensitivity detection of malaria pigment (hemozoin crystals) in blood via the magnetically induced rotational motion of the hemozoin crystals. Here, we evaluate this MO technique for the detection of Plasmodium falciparum in infected erythrocytes using in-vitro parasite cultures covering the entire intraerythrocytic life cycle. Our novel method detected parasite densities as low as ∼ 40 parasites per microliter of blood (0.0008% parasitemia) at the ring stage and less than 10 parasites/µL (0.0002% parasitemia) in the case of the later stages. These limits of detection, corresponding to approximately 20 pg/µL of hemozoin produced by the parasites, exceed that of rapid diagnostic tests and compete with the threshold achievable by light microscopic observation of blood smears. The MO diagnosis requires no special training of the operator or specific reagents for parasite detection, except for an inexpensive lysis solution to release intracellular hemozoin. The devices can be designed to a portable format for clinical and in-field tests. Besides testing its diagnostic performance, we also applied the MO technique to investigate the change in hemozoin concentration during parasite maturation. Our preliminary data indicate that this method may offer an efficient tool to determine the amount of hemozoin produced by the different parasite stages in synchronized cultures. Hence, it could eventually be used for testing the susceptibility of parasites to antimalarial drugs.

Plasmodium genome in blood donors at risk for malaria after several years of residence in Italy

BACKGROUND

At present, the main risk of transfusion-transmitted malaria (TTM) in nonendemic countries is chronic, asymptomatic immigrants from malaria-endemic areas. Semi-immune donors may carry undetected parasitemia. This study examines Plasmodium infection in at-risk blood donors in Northern Italy.

STUDY DESIGN AND METHODS

Plasma samples from 97 candidate donors and 80 controls were tested for malarial antibodies using a commercial enzyme immunoassay. The conserved 18S rRNA and the mitochondrial genes of Plasmodium were amplified to detect and quantify parasite genomes (copies/mL). Plasmodium species were identified with a species-specific nested polymerase chain reaction. Parasitemic samples were further tested by amplification of polymorphic repetitive regions in MSP-1 Block 2, MSP-2 Block 3, and glutamate-rich protein (GLURP) confirmed by sequencing.

RESULTS

Three of 83 seropositive (3.6%) and one of 14 seronegative at-risk candidate donors carried Plasmodium genome (4 × 10(3) -8.5 × 10(4) copies/mL): two P. falciparum, one P. malariae (seronegative sample), and one coinfection with P. malariae and P. ovale. Alleles of MSP-1 (MAD20 and K1), MSP-2 (3D7 and FC27), and GLURP were amplified from Sample 261. In Sample 282 only one allele in MSP-2 (FC27) and GLURP was amplified. No alleles were detected in Samples 283 and 331.

CONCLUSIONS

Immigrants from endemic countries might carry infectious Plasmodium after 2 to 5 years of continuous residence in Italy. Serologic screening may miss donors carrying P. malariae. Permanent exclusion or screening for both antibodies and genome are needed to prevent TTM.

What is the best strategy for the prevention of transfusion-transmitted malaria in sub-Saharan African countries where malaria is endemic?

The transmission of malaria by blood transfusion was one of the first recorded incidents of transfusion-transmitted infections (TTIs). Although the World Health Organization (WHO) recommends that blood for transfusion should be screened for TTIs, malaria screening is not performed in most malaria-endemic countries in sub-Saharan Africa (SSA). The transfusion of infected red blood cells may lead to severe post-transfusion clinical manifestations of malaria, which could be rapidly fatal. Ensuring that blood supply in endemic countries is free from malaria is highly problematical, as most of the donors may potentially harbour low levels of malaria parasites. Pre-transfusion screening within endemic settings has been identified as a cost-effective option for prevention of transfusion-transmitted malaria (TTM). But currently, there is no screening method that is practical, affordable and suitably sensitive for use by blood banks in SSA. Even if this method was available, rejection of malaria-positive donors would considerably jeopardize the blood supply and increase morbidity and mortality, especially among pregnant women and children who top the scale of blood transfusion users in SSA. In this context, the systematic prophylaxis of recipients with anti-malarials could constitute a good alternative, as it prevents any deferral of donor units as well as the occurrence of TTM. With the on-going programme, namely the Affordable Medicine Facility - Malaria, there is an increase in the availability of low-priced artemisinin-based combination therapy that can be used for systematic prophylaxis. It appears nonetheless an urgent need to conduct cost-benefit studies in order to evaluate each of the TTM preventive methods. This approach could permit the design and implementation of an evidence-based measure of TTM prevention in SSA, advocating thereby its widespread use in the region.

Malaysian child infected with Plasmodium vivax via blood transfusion: a case report

Malaria may be a serious complication of blood transfusion due to the asymptomatic persistence of parasites in some donors. This case report highlights the transfusion-transmitted malaria of Plasmodium vivax in a child diagnosed with germ cell tumour. This child had received blood transfusion from three donors and a week later started developing malaria like symptoms. Nested PCR and sequencing confirmed that one of the three donors was infected with P. vivax and this was transmitted to the 12-year-old child. To the best of the authors’ knowledge, this is the first reported transfusion-transmitted malaria case in Malaysia.