Contribution of P. falciparum parasites with Pfhrp 2 gene deletions to false negative PfHRP 2 based malaria RDT results in Ghana: A nationwide study of symptomatic malaria patients

High prevalence of asymptomatic and subpatent Plasmodium falciparum infections but no histidine-rich protein 2 gene deletion in Bouaké, Côte d'Ivoire

This study aimed to estimate the prevalence of asymptomatic and subpatent P. falciparum infections in the city of Bouaké, Central Côte d'Ivoire, to compare the performance of three tests, and to investigate potential P. falciparum histidine-rich protein 2 (pfhrp2) gene deletions. A cross-sectional survey was conducted in nine neighborhoods in Bouaké in 2016. Matched light microscopy (LM), rapid diagnostic test (RDT), and quantitative PCR (qPCR) data were used to determine the prevalence of P. falciparum infection and compare the performance of the three diagnostic tests. Pfhrp2/3 deletions were genotyped by digital PCR. Among 2313 individuals, 97.2% were asymptomatic and 2.8% were symptomatic. P. falciparum prevalence among symptomatic individuals was 25.8%, 30.3%, and 40.9% by LM, RDT, and varATS qPCR, respectively, and among asymptomatic individuals, it was 10.3%, 12.5%, and 34.9%. Asymptomatic infections comprised 96.4% of all malaria infections, with 58.2% detectable only by varATS qPCR. Although the prevalence of asymptomatic P. falciparum infections was higher in school-age children (5-14 years: 42.0%) compared to < 5 years (17.3%) and ≥ 15 years (35.9%), subpatent infections were more likely in ≥ 15 years (70.4%) than in < 5 years (39.7%) and school-age children (41.2%). LM and RDTs were reliable only at parasite densities > 10,000 parasites/µL. Individuals who were positive according to all three tests had significantly greater parasite density (856.8 parasites/µL; 95% CI 707.3-1,038) than did those who were positive by varATS qPCR only (13.7 parasites/µL; 95% CI 11.4-16.3) (p < 0.0001). No pfhrp2 deletions were observed. The high prevalence of asymptomatic and subpatent infections highlights the need for targeted strategies to reduce malaria in urban Côte d'Ivoire.

Malaria diagnosis challenges and pfhrp2 and pfhrp3 gene deletions using pregnant women as sentinel population in Nanoro region, Burkina Faso

Malaria in pregnancy causes adverse consequences and prompt and accurate diagnosis is essential for case management. In malaria endemic countries, diagnosis is mainly based on rapid diagnostic tests (RDT) and microscopy. However, increasing reports of false negatives caused by low parasitemia and pfhrp2/3 deletions raise concerns about HRP2-based RDT usefulness. This study aimed to assess RDT and microscopy performance and to describe pfhrp2/3 deletions in a cohort of 418 pregnant women in Burkina Faso. Malaria was diagnosed using RDT and microscopy and blood samples were collected during antenatal care visits. Diagnostic results were compared to PCR as gold standard. Pfhrp2 and pfhrp3 deletions were characterized for patients with confirmed P. falciparum infection. RDT had better sensitivity (76%) but lower specificity (83%) than microscopy (sensitivity = 57%; specificity = 98%). Low parasitemia (<150 parasites/µL), especially in multigravidae, was the principal factor causing false negatives by both methods. Moreover, pfhrp2 deletion frequency among overall false negatives by RDT was 21.43%. Higher frequency of deletions was found among all samples, independently of RDT result, for example around 2% of samples had double deletions meaning that the majority of deletions had no effect on RDT testing. Finally, it was found higher pfhrp2 deletion in women with lower uterine height during the first trimester. Wider and National surveillance study of deletions is recommended among pregnant women and in Burkina Faso.

Lingering challenges in malaria elimination efforts in sub-Saharan Africa: Insights and potential solutions

Introduction

Between 2000 and 2015, significant gains were recorded in reducing the global burden of malaria due to enhanced global collaboration and increased funding. However, progress has stagnated post-2015, and the COVID-19 pandemic seems to have reversed some of these gains, necessitating a critical reevaluation of interventions. This paper aims to analyze the setbacks and offer recommendations for advancement in malaria control and prevention in sub-Saharan Africa.

Methods

We conducted searches on Google Scholar, PubMed, and relevant organization websites to identify relevant studies on malaria control and prevention and associated challenges in sub-Saharan Africa from 2015 to the present. Additionally, studies on individual sub-Saharan African countries were reviewed to ensure comprehensiveness. Data from selected studies were extracted and analyzed using a narrative synthesis approach to offer a concise overview of the evidence.

Findings

We observe that the halt in progress of malaria control in sub-Saharan Africa has deep roots in socioeconomic, political, and environmental factors. These challenges are exacerbated by the population explosion in the region, low coverage of interventions due to funding deficits and incessant crises, and the degradation of the efficacy of existing malaria commodities.

Conclusion

Sub-Saharan Africa is at a crossroads in its fight against malaria. Promising new frontiers such as malaria vaccines, preventive monoclonal antibodies, new-generation insecticide-treated nets, and potentially artificial intelligence-driven technologies offer hope in advancing malaria control and prevention in the region. Through commitment and collaboration, leveraging these opportunities can help surmount challenges and ultimately eliminate malaria in sub-Saharan Africa.

Plasmodium falciparum pfhrp2 and pfhrp3 gene deletions among patients enrolled at 100 health facilities throughout Tanzania: February to July 2021

Plasmodium falciparum with the histidine rich protein 2 gene (pfhrp2) deleted from its genome can escape diagnosis by HRP2-based rapid diagnostic tests (HRP2-RDTs). The World Health Organization (WHO) recommends switching to a non-HRP2 RDT for P. falciparum clinical case diagnosis when pfhrp2 deletion prevalence causes ≥ 5% of RDTs to return false negative results. Tanzania is a country of heterogenous P. falciparum transmission, with some regions approaching elimination and others at varying levels of control. In concordance with the current recommended WHO pfhrp2 deletion surveillance strategy, 100 health facilities encompassing 10 regions of Tanzania enrolled malaria-suspected patients between February and July 2021. Of 7863 persons of all ages enrolled and providing RDT result and blood sample, 3777 (48.0%) were positive by the national RDT testing for Plasmodium lactate dehydrogenase (pLDH) and/or HRP2. A second RDT testing specifically for the P. falciparum LDH (Pf-pLDH) antigen found 95 persons (2.5% of all RDT positives) were positive, though negative by the national RDT for HRP2, and were selected for pfhrp2 and pfhrp3 (pfhrp2/3) genotyping. Multiplex antigen detection by laboratory bead assay found 135/7847 (1.7%) of all blood samples positive for Plasmodium antigens but very low or no HRP2, and these were selected for genotyping as well. Of the samples selected for genotyping based on RDT or laboratory multiplex result, 158 were P. falciparum DNA positive, and 140 had sufficient DNA to be genotyped for pfhrp2/3. Most of these (125/140) were found to be pfhrp2+/pfhrp3+, with smaller numbers deleted for only pfhrp2 (n = 9) or only pfhrp3 (n = 6). No dual pfhrp2/3 deleted parasites were observed. This survey found that parasites with these gene deletions are rare in Tanzania, and estimated that 0.24% (95% confidence interval: 0.08% to 0.39%) of false-negative HRP2-RDTs for symptomatic persons were due to pfhrp2 deletions in this 2021 Tanzania survey. These data provide evidence for HRP2-based diagnostics as currently accurate for P. falciparum diagnosis in Tanzania.

Welcome to the next generation of Malaria Rapid Diagnostic Tests: Comparative Analysis of NxTek Eliminate Malaria P.f, Biocredit Malaria Ag Pf, and SD Bioline Malaria Ag Pf for Plasmodium falciparum Diagnosis in Ghana

Background

Accurate diagnosis and timely treatment are crucial in combating malaria.

Methods

We evaluated the diagnostic performance of three Rapid Diagnostic Tests (RDTs) in diagnosing febrile patients, namely: Abbott NxTek Eliminate Malaria Ag Pf (detecting HRP2), Rapigen Biocredit Malaria Ag Pf (detecting HRP2 and LDH on separate bands), and SD Bioline Malaria Ag Pf (detecting HRP2). Results were compared to qPCR.

Results

Among 449 clinical patients, 45.7% (205/449) tested positive by qPCR for P. falciparum with a mean parasite density of 12.5parasites/μL. The sensitivity of the Biocredit RDT was 52.2% (107/205), NxTek RDT was 49.3% (101/205), and Bioline RDT was 40.5% (83/205). When samples with parasite densities lower than 20 parasites/uL were excluded (n=116), a sensitivity of 88.8% (79/89, NxTek), 89.9% (80/89, Biocredit), and 78.7% (70/89, Bioline) was obtained. All three RDTs demonstrated specificity above 95%. The limits of detection was 84 parasites/μL (NxTek), 56 parasites/μL (Biocredit, considering either HRP2 or LDH), and 331 parasites/μL (Bioline). None of the three qPCR-confirmed P. falciparum positive samples, identified solely through the LDH target, carried hrp2/3 deletions.

Conclusion

The Biocredit and NxTek RDTs demonstrated comparable diagnostic efficacies and both RDTs performed better than Bioline RDT.

Housing modification for malaria control: impact of a "lethal house lure" intervention on malaria infection prevalence in a cluster randomised control trial in Côte d'Ivoire

BACKGROUND

In recent years, the downward trajectory of malaria transmission has slowed and, in some places, reversed. New tools are needed to further reduce malaria transmission. One approach that has received recent attention is a novel house-based intervention comprising window screening (S) and general house repairs to make the house more mosquito proof, together with EaveTubes (ET) that provide an innovative way of targeting mosquitoes with insecticides as they search for human hosts at night. The combined approach of Screening + EaveTubes (SET) essentially turns the house into a 'lure and kill' device.

METHODS

This study evaluated the impact of SET on malaria infection prevalence in Côte d'Ivoire and compares the result in the primary outcome, malaria case incidence. Malaria infection prevalence was measured in a cross-sectional survey in 40 villages, as part of a cluster-randomised trial evaluating the impact of SET on malaria case incidence.

RESULTS

Infection prevalence, measured by rapid diagnostic test (RDT), was 50.4% and 36.7% in the control arm and intervention arm, respectively, corresponding to an odds ratio of 0.57 (0.45-0.71), p < 0.0001). There was moderate agreement between RDT and microscopy results, with a reduction in odds of infection of 36% recorded when infection was measured by microscopy. Prevalence measured by RDT correlated strongly with incidence at a cluster level.

CONCLUSIONS

In addition to reducing malaria case incidence, house screening and EaveTubes substantially reduced malaria infection prevalence 18 months after installation. Infection prevalence may be a good metric to use for evaluating malaria interventions in areas of similar transmission levels to this setting.

TRIAL REGISTRATION

ISRCTN18145556, registered 1 February 2017.

Low Prevalence of Plasmodium falciparum Histidine-Rich Protein 2 and 3 Gene Deletions—A Multiregional Study in Central and West Africa

Plasmodium falciparum parasites carrying deletions of histidine-rich protein 2 and 3 genes, pfhrp2 and pfhrp3, respectively, are likely to escape detection via HRP2-based rapid diagnostic tests (RDTs) and, consequently, treatment, posing a major risk to both the health of the infected individual and malaria control efforts. This study assessed the frequency of pfhrp2- and pfhrp3-deleted strains at four different study sites in Central Africa (number of samples analyzed: Gabon N = 534 and the Republic of Congo N = 917) and West Africa (number of samples analyzed: Nigeria N = 466 and Benin N = 120) using a highly sensitive multiplex qPCR. We found low prevalences for pfhrp2 (1%, 0%, 0.03% and 0) and pfhrp3 single deletions (0%, 0%, 0.03% and 0%) at all study sites (Gabon, the Republic of Congo, Nigeria and Benin, respectively). Double-deleted P. falciparum were only found in Nigeria in 1.6% of all internally controlled samples. The results of this pilot investigation do not point towards a high risk for false-negative RDT results due to pfhrp2/pfhrp3 deletions in Central and West African regions. However, as this scenario can change rapidly, continuous monitoring is essential to ensure that RDTs remain a suitable tool for the malaria diagnostic strategy.

Accuracy of diagnosis among clinical malaria patients: comparing microscopy, RDT and a highly sensitive quantitative PCR looking at the implications for submicroscopic infections

BACKGROUND

The World Health Organization recommends parasitological confirmation of all suspected malaria cases by microscopy or rapid diagnostic tests (RDTs) before treatment. These conventional tools are widely used for point-of-care diagnosis in spite of their poor sensitivity at low parasite density. Previous studies in Ghana have compared microscopy and RDT using standard 18S rRNA PCR as reference with varying outcomes. However, how these conventional tools compare with ultrasensitive varATS qPCR has not been studied. This study, therefore, sought to investigate the clinical performance of microscopy and RDT assuming highly sensitive varATS qPCR as gold standard.

METHODS

1040 suspected malaria patients were recruited from two primary health care centers in the Ashanti Region of Ghana and tested for malaria by microscopy, RDT, and varATS qPCR. The sensitivity, specificity, and predictive values were assessed using varATS qPCR as gold standard.

RESULTS

Parasite prevalence was 17.5%, 24.5%, and 42.1% by microscopy, RDT, and varATS qPCR respectively. Using varATS qPCR as the standard, RDT was more sensitive (55.7% vs 39.3%), equally specific (98.2% vs 98.3%), and reported higher positive (95.7% vs 94.5%) and negative predictive values (75.3% vs 69.0%) than microscopy. Consequently, RDT recorded better diagnostic agreement (kappa = 0.571) with varATS qPCR than microscopy (kappa = 0.409) for clinical detection of malaria.

CONCLUSIONS

RDT outperformed microscopy for the diagnosis of Plasmodium falciparum malaria in the study. However, both tests missed over 40% of infections that were detected by varATS qPCR. Novel tools are needed to ensure prompt diagnosis of all clinical malaria cases.

Genetic deletions and high diversity of Plasmodium falciparum histidine-rich proteins 2 and 3 genes in parasite populations in Ghana

Rapid diagnostic tests (RDTs) are used to diagnose malaria in Ghana and other malaria endemic countries. Plasmodium falciparum histidine-rich protein 2 (PFHRP2) based RDTs are widely used, however the occurrence of deletions of the pfhrp2 gene in some parasites have resulted in false negative test results. Monoclonal antibodies of PFHRP2 cross reacts with PFHRP3 because they share structural similarities and this complements the detection of the parasites by RDT. These two genes were investigated in Ghanaian P. falciparum parasite population to detect deletions and the polymorphisms in exon 2 of the pfhrp2 and pfhrp3 genes. Parasite isolates (2,540) from children ≤ 12 years with uncomplicated malaria from 2015 to 2020 transmission seasons were used. Both genes were amplified using nested PCR and negative results indicated the presence of the deletion of genes. Amplified genes were sequenced for the detection of the amino acid repeats. Deletions were observed in 30.7% (780/2,540) and 17.2% (438/2,540) of the samples for pfhrp2 and pfhrp3 respectively with increasing trends over the three time periods (χ2 -10.305, p = 0.001). A total of 1,632 amplicons were sequenced for each gene, analysis was done on 1,124 and 1,307 good quality sequences for pfhrp2 and pfhrp3 respectively. Pfhrp2 repeat polymorphisms were dominantly of types 2 (AHHAHHAAD) and 7 (AHHAAD) with large numbers of variants. A novel variant of type 14 (AHHANHATD) was seen for pfhrp2. For the pfhrp3 repeat types, 16 (AHHAAN), 17 (AHHDG) and 18 (AHHDD) were the dominant types observed. Variants of type 16 (AHHAAH) and (AHHASH) were also dominant. Repeat types 1, 2, 3, 4, 5, 6, 7, 8, 11, 13, 15, 16, and 19 were observed be shared by both genes. The haplotype diversity of both genes ranged between 0.872 and 1 indicating high diversity of the polymorphisms in the isolates. The implication of the findings of the frequencies of the pfhrp2 and pfhrp3 deletions as well as the variants of the main epitopes of the monoclonal antibodies for the RDT (types 2 and 7) in our isolates is an indication of decreased sensitivity of the RDTs in diagnosing malaria infections in Ghana.

Utilization of 18s ribosomal RNA LAMP for detecting Plasmodium falciparum in microscopy and rapid diagnostic test negative patients

In this study, Plasmodium falciparum was detected in patients that were declared negative for malaria microscopy and rapid diagnostic test kit (mRDT), using Plasmodium 18s rRNA loop-mediated isothermal amplification (LAMP) technique. The main aim of this study was to assess the usefulness of LAMP assay for detecting pre-clinical malaria, when microscopy and mRDT were less sensitive. DNA was obtained from 100 μL of whole blood using the boil and spin method. Subsequently, the Plasmodium 18s rRNA LAMP assay was performed to amplify the specific Plasmodium 18s rRNA gene. Microscopy and mRDT negative samples [697/2223 (31.2%)] were used for this study. Compared to frequencies obtained for the other demographic variables, most of the patients were < 6 years (37.7%), females (59.0%), peri-urban dwellers (39.0%) and patients that sought outpatient department services (39.3%). Overall, the prevalence of Plasmodium 18s rRNA was 17.5%. when stratified by study variables, Plasmodium 18s rRNA LAMP positivity was higher in patients over 30 years [58/122 (54.2%)], males [69/122 (56.5%)], rural dwellers [69/122 (56.5%)] and patients that sought OPD services [68/122 (55.7%)]. The risk of being infected with Plasmodium when routine tests were negative was higher in 15-30-year group (OR = 3.03, 95% CI: 1.6-5.8, p = 0.0007), patients > 30 years (OR = 15.2, 95% CI: 8.3-27.7, p<0.001), males (OR = 2.1, 95% CI: 1.4-3.2, p = 0.0002) and rural dwellers (OR = 2.2, 95% CI:1.4-3.6, p = 0.0009). However, risk was lower in post-natal children (OR = 0.3, 95% CI: 0.18-0.51, p<0.001). Majority (81.5%) of the infected patients presented with headache, herpes labialis, diarrhea and vomiting. We demonstrated the lack of sensitivities of microscopy and mRDT for one-time diagnosis of malaria. Therefore, it is essential to utilize a sensitive technique such as Plasmodium 18s rRNA LAMP to increase the detection rate of Plasmodium infection.

Nationwide Surveillance of Pfhrp2 Exon 2 Diversity in Plasmodium falciparum Circulating in Symptomatic Malaria Patients Living in Ghana

Reports of increasing false-negative HRP2-based rapid diagnostic test results across Africa require constant monitoring of factors associated with these false-negative outcomes, as failure of this diagnostic tool will have severe consequences on malaria treatment and control programs. This study characterized the extent of genetic diversity in the Plasmodium falciparum histidine-rich protein 2 (Pfhrp2) gene in P. falciparum isolates from symptomatic malaria patients across the regions of Ghana. Exon 2 of Pfhrp2 was amplified from gDNA using polymerase chain reaction. All Pfhrp2-negative samples were subjected to Pf18S rRNA and Pfmsp2 gene amplifications. The amplified Pfhrp2 exon 2 fragments from clonal samples were sent for commercial Sanger sequencing. The type and number of PfHRP2 repeats, classified based on repeat types previously reported, were estimated from the sequence data and compared among geographical regions. About 81% (2,333/2,890) of the original microscopy positive DBS were available and used in this study. The Pfhrp2 exon 2 amplification was successful in 98.5% (2,297/2,333) of the tested samples, with band size ranging from 400 bp to 1,050 bp. A total of 13 out of the 24 previously reported repeat types were identified among the samples, with three samples lacking both type 2 and type 7 repeat motifs. This study suggested that the genetic diversity of Pfhrp2 exon 2 identified in P. falciparum circulating in symptomatic malaria patients in Ghana is unlikely to influence the sensitivity and specificity of HRP2 RDT-based diagnosis.

Detecting asymptomatic carriage of Plasmodium falciparum in southern Ghana: utility of molecular and serological diagnostic tools

Background

Asymptomatic malaria infections can serve as potential reservoirs for malaria transmission. The density of parasites contained in these infections range from microscopic to submicroscopic densities, making the accurate detection of asymptomatic parasite carriage highly dependent on the sensitivity of the tools used for the diagnosis. This study sought to evaluate the sensitivities of a variety of molecular and serological diagnostic tools at determining the prevalence of asymptomatic Plasmodium falciparum parasite infections in two communities with varying malaria parasite prevalence.

Methods

Whole blood was collected from 194 afebrile participants aged between 6 and 70 years old living in a high (Obom) and a low (Asutsuare) malaria transmission setting of Ghana. Thick and thin blood smears, HRP2 based malaria rapid diagnostic test (RDT) and filter paper dried blood spots (DBS) were prepared from each blood sample. Genomic DNA was extracted from the remaining blood and used in Plasmodium specific photo-induced electron transfer polymerase chain reaction (PET-PCR) and Nested PCR, whilst the HRP2 antigen content of the DBS was estimated using a bead immunoassay. A comparison of malaria parasite prevalence as determined by each method was performed.

Results

Parasite prevalence in the high transmission site of Obom was estimated at 71.4%, 61.9%, 60%, 37.8% and 19.1% by Nested PCR, the HRP2 bead assay, PET-PCR, HRP2-RDT and microscopy respectively. Parasite prevalence in the low transmission site of Asutsuare was estimated at 50.1%, 11.2%, 5.6%, 0% and 2.2% by Nested PCR, the HRP2 bead assay, PET-PCR, RDT and microscopy, respectively. The diagnostic performance of Nested PCR, PET-PCR and the HRP2 bead assay was similar in Obom but in Asutsuare, Nested PCR had a significantly higher sensitivity than PET-PCR and the HRP2 bead assay, which had similar sensitivity.

Conclusions

Nested PCR exhibited the highest sensitivity by identifying the highest prevalence of asymptomatic P. falciparum in both the high and low parasite prevalence settings. However, parasite prevalence estimated by the HRP2 bead assay and PET-PCR had the highest level of inter-rater agreement relative to all the other tools tested and have the advantage of requiring fewer processing steps relative to Nested PCR and producing quantitative results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04078-w.

Nationwide molecular surveillance of three Plasmodium species harboured by symptomatic malaria patients living in Ghana

BACKGROUND

Clinical presentations of malaria in Ghana are primarily caused by infections containing microscopic densities of Plasmodium falciparum, with a minor contribution from Plasmodium malariae and Plasmodium ovale. However, infections containing submicroscopic parasite densities can result in clinical disease. In this study, we used PCR to determine the prevalence of three human malaria parasite species harboured by suspected malaria patients attending healthcare facilities across the country.

METHODS

Archived dried blood spots on filter paper that had been prepared from whole blood collected from 5260 patients with suspected malaria attending healthcare facilities across the country in 2018 were used as experimental material. Plasmodium species-specific PCR was performed on DNA extracted from the dried blood spots. Demographic data and microscopy data for the subset of samples tested were available from the original study on these specimens.

RESULTS

The overall frequency of P. falciparum, P. malariae and P. ovale detected by PCR was 74.9, 1.4 and 0.9%, respectively. Of the suspected symptomatic P. falciparum malaria cases, 33.5% contained submicroscopic densities of parasites. For all regions, molecular diagnosis of P. falciparum, P. malariae and P. ovale was significantly higher than diagnosis using microscopy: up to 98.7% (75/76) of P. malariae and 97.8% (45/46) of P. ovale infections detected by PCR were missed by microscopy.

CONCLUSION

Plasmodium malariae and P. ovale contributed to clinical malaria infections, with children aged between 5 and 15 years harbouring a higher frequency of P. falciparum and P. ovale, whilst P. malariae was more predominant in individuals aged between 10 and 20 years. More sensitive point-of-care tools are needed to detect the presence of low-density (submicroscopic) Plasmodium infections, which may be responsible for symptomatic infections.

Genotypic glucose-6-phosphate dehydrogenase (G6PD) deficiency protects against Plasmodium falciparum infection in individuals living in Ghana

INTRODUCTION

The global effort to eradicate malaria requires a drastic measure to terminate relapse from hypnozoites as well as transmission via gametocytes in malaria-endemic areas. Primaquine has been recommended for the treatment of P. falciparum gametocytes and P. vivax hypnozoites, however, its implementation is challenged by the high prevalence of G6PD deficient (G6PDd) genotypes in malaria endemic countries. The objective of this study was to profile G6PDd genotypic variants and correlate them with malaria prevalence in Ghana.

METHODS

A cross-sectional survey of G6PDd genotypic variants was conducted amongst suspected malaria patients attending health care facilities across the entire country. Malaria was diagnosed using microscopy whilst G6PD deficiency was determined using restriction fragment length polymorphisms at position 376 and 202 of the G6PD gene. The results were analysed using GraphPad prism.

RESULTS

A total of 6108 subjects were enrolled in the study with females representing 65.59% of the population. The overall prevalence of malaria was 36.31%, with malaria prevalence among G6PDd genotypic variants were 0.07% for A-A- homozygous deficient females, 1.31% and 3.03% for AA- and BA- heterozygous deficient females respectively and 2.03% for A- hemizygous deficient males. The odd ratio (OR) for detecting P. falciparum malaria infection in the A-A- genotypic variant was 0.0784 (95% CI: 0.0265-0.2319, p<0.0001). Also, P. malariae and P. ovale parasites frequently were observed in G6PD B variants relative to G6PD A- variants.

CONCLUSION

G6PDd genotypic variants, A-A-, AA- and A- protect against P. falciparum, P. ovale and P. malariae infection in Ghana.