Use of malaria RDTs in various health contexts across sub-Saharan Africa: a systematic review

Diagnostic role of Sysmex hematology analyzer in the detection of malaria: A systematic review and meta-analysis

BACKGROUND

Malaria control depends primarily on rapid and accurate diagnosis followed by successful treatment. Light microscopy is still used as a gold standard method for the diagnosis of malaria. The Sysmex hematology analyzer is a novel method for malaria detection. Therefore, the aim of this review was to investigate the diagnostic accuracy of the Sysmex hematology analyzer for malaria diagnosis.

METHODS

Electronic databases like PubMed, PubMed Central, Science Direct databases, Google Scholar, and Scopus were used to find relevant articles from April to June 14, 2023. The studies' methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. Using Review Manager 5.4.1, the estimates of sensitivity and specificity, as well as their 95% confidence intervals, were shown in forest plots. Midas software in Stata 14.0 was utilized to calculate the summary estimates of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. Heterogeneity was assessed by using I2 statistics. In addition, publication bias was assessed using a funnel plot and Deeks' test. Sub-group and meta- regression analysis were also performed.

RESULTS

A total of 15 studies were assessed for diagnostic accuracy. The sensitivity and specificity of Sysmex hematology analyzer for studies ranged from 46% to 100% and 81% to 100%, respectively. The summary estimate of sensitivity and specificity of Sysmex hematology analyzer were 95% (95% CI: 85%-99%) and 99% (95% CI: 97%-100%), respectively. It had excellent diagnostic accuracy. There were significant heterogeneity among the studies included in this meta-analysis. The summary estimate of sensitivity and specificity of Sysmex hematology analyzer using polymerase chain reaction as the gold standard was 97.6% (95% CI: 83.2, 99.7) and 99.4% (98.5, 99.8), respectively.

CONCLUSION

In this review, Sysmex hematology analyzer had excellent diagnostic accuracy. Therefore, it could be used as an alternate diagnostic tool for malaria diagnosis in the hospital and health center.

TRIAL REGISTRATION

Systematic review registration PROSPERO (2023: CRD42023427713). https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023427713.

Receipt of antimalarials among children aged 6-59 months in Nigeria from 2010 to 2021

BACKGROUND

Nigeria has the highest malaria burden globally, and anti-malarials have been commonly used to treat malaria without parasitological confirmation. In 2012, Nigeria implemented rapid diagnostic tests (RDTs) to reduce the use of anti-malarials for those without malaria and to increase the use of artemisinin-based combination therapy (ACT) for malaria treatment. This study examined changes in anti-malarial receipt among children aged 6-59 months during a 12-year period of increasing RDT availability.

METHODS

A cross-sectional analysis was conducted using the Nigeria Malaria Indicator Survey (NMIS) data from 2010 (before RDT implementation in 2012), 2015, and 2021. The analysis assessed trends in prevalence of malaria by survey RDT result, and fever and anti-malarial/ACT receipt in the 2 weeks prior to the survey. A multivariable logistic regression was used to account for the complex survey design and to examine factors associated with anti-malarial receipt, stratified by survey RDT result, a proxy for recent/current malaria infection.

RESULTS

In a nationally-representative, weighted sample of 22,802 children aged 6-59 months, fever prevalence remained stable over time, while confirmed malaria prevalence decreased from 51.2% in 2010 to 44.3% in 2015 and 38.5% in 2021 (trend test p < 0.0001). Anti-malarial use among these children decreased from 19% in 2010 to 10% in 2021 (trend test p < 0.0001), accompanied by an increase in ACT use (2% in 2010 to 8% in 2021; trend test p < 0.0001). Overall, among children who had experienced fever, 30.6% of survey RDT-positive and 36.1% of survey RDT-negative children had received anti-malarials. The proportion of anti-malarials obtained from the private sector increased from 61.8% in 2010 to 80.1% in 2021 for RDT-positive children; most of the anti-malarials received in 2021 were artemisinin-based combinations. Factors associated with anti-malarial receipt for both RDT-positive and RDT-negative children included geographic region, greater household wealth, higher maternal education, and older children.

CONCLUSION

From 2010 to 2021 in Nigeria, both malaria prevalence and anti-malarial treatments among children aged 6-59 months decreased, as RDT availability increased. Among children who had fever in the prior 2 weeks, anti-malarial receipt was similar between children with either positive or negative survey RDT results, indicative of persistent challenges in reducing inappropriate anti-malarials uptake.

Implementation of Glucose-6-Phosphate Dehydrogenase (G6PD) testing for Plasmodium vivax case management, a mixed method study from Cambodia

Plasmodium vivax remains a challenge for malaria elimination since it forms dormant liver stages (hypnozoites) that can reactivate after initial infection. 8-aminoquinolone drugs kill hypnozoites but can cause severe hemolysis in individuals with Glucose-6-Phosphate Dehydrogenase (G6PD) deficiency. The STANDARD G6PD test (Biosensor) is a novel point-of-care diagnostic capable of identifying G6PD deficiency prior to treatment. In 2021, Cambodia implemented the Biosensor to facilitate radical cure treatment for vivax malaria. To assess the Biosensor's implementation after its national rollout, a mixed-methods study was conducted in eight districts across three provinces in Cambodia. Interviews, focus group discussions, and observations explored stakeholders' experiences with G6PD testing and factors influencing its implementation. Quantitative data illustrative of test implementation were gathered from routine surveillance forms and key proportions derived. Qualitative data were analyzed thematically. The main challenge to implementing G6PD testing was that only 49.2% (437/888) of eligible patients reached health centers for G6PD testing following malaria diagnosis by community health workers. Factors influencing this included road conditions and long distances to the health center, compounded by the cost of seeking further care and patients' perceptions of vivax malaria and its treatment. 93.9% (790/841) of eligible vivax malaria patients who successfully completed referral (429/434) and directly presented to the health center (360/407) were G6PD tested. Key enabling factors included the test's acceptability among health workers and their understanding of the rationale for testing. Only 36.5% (443/1213) of eligible vivax episodes appropriately received primaquine. 70.5% (165/234) of female patients and all children under 20 kilograms never received primaquine. Our findings suggest that access to radical cure requires robust infrastructure and income security, which would likely improve referral rates to health centers enabling access. Bringing treatment closer to patients, through community health workers and nuanced community engagement, would improve access to curative treatment of vivax malaria.

Malaria in under-five children: prevalence and multi-factor analysis of high-risk African countries

BACKGROUND

Malaria remains a significant public health challenge in Sub-Saharan Africa (SSA), particularly affecting under-five (UN5) children. Despite global efforts to control the disease, its prevalence in high-risk African countries continues to be alarming, with records of substantial morbidity and mortality rates. Understanding the association of multiple childhood, maternal, and household factors with malaria prevalence, especially among vulnerable young populations, is crucial for effective intervention strategies.

OBJECTIVE

This study examines the prevalence of malaria among UN5 children in selected high-risk SSA countries and analyzes its association with various childhood, maternal, and household factors.

METHODS

Data from the Malaria Indicator Surveys (MIS) spanning from 2010 to 2023 were analyzed. A weighted sample of 35,624 UN5 children from seven countries in sub-Saharan Africa (SSA) known for high malaria prevalence was considered in the analyses. Descriptive statistics and modified Poisson regression analysis were used to assess the association of multiple factors with malaria prevalence. Stata version 15 software was used in analyzing the data and statistical significance was set at a 5% significance level.

RESULTS

The overall pooled prevalence of malaria among the studied population was 26.2%, with substantial country-specific variations observed. In terms of child factors, a child's age was significantly associated with malaria prevalence (APR = 1.010, 95% CI: 1.007-1.012). Children of mothers with higher education levels (APR for higher education = 0.586, 95% CI: 0.425-0.806) and Fansidar uptake during pregnancy (APR = 0.731, 95% CI: 0.666-0.802) were associated with lower malaria risk. Children from middle-wealth (APR = 0.783, 95% CI: 0.706-0.869) and rich (APR = 0.499, 95% CI: 0.426-0.584) households had considerably lower malaria prevalence compared to those from poor households. Additionally, rural residency was associated with a higher risk of malaria compared to urban residency (APR = 1.545, 95% CI: 1.255-1.903).

CONCLUSION

The study highlights a notable malaria prevalence among under-five (UN5) children in high-risk SSA countries, influenced significantly by factors such as maternal education, Fansidar uptake during pregnancy, socioeconomic status, and residency. These findings underscore the importance of targeted malaria prevention strategies that address these key determinants to effectively reduce the malaria burden in this vulnerable population.

Health workers' adherence to malaria case management protocols in Northern Sudan: a qualitative study

BACKGROUND

Nonadherence to national standards for malaria diagnosis and treatment has been reported in Sudan. In this study, qualitative research examined the clinical domains of nonadherence, factors influencing nonadherent practices and health workers' views on how to improve adherence.

METHODS

In September 2023, five Focus Group Discussions (FGDs) were undertaken with 104 health workers from 42 health facilities in Sudan's Northern State. The participants included medical assistants, doctors, nurses, laboratory personnel, pharmacists and public health officers. The FGDs followed a semi-structured guide reflecting the national malaria case management protocol. Qualitative thematic analysis was performed.

RESULTS

Nonadherent practices included disregarding parasitological test results, suboptimal paediatric artemether-lumefantrine (AL) dosing, lack of counselling, use of prohibited artemether injections for uncomplicated and severe malaria, artesunate dose approximations and suboptimal preparations, lack of AL follow on treatment for severe malaria; and rare use of primaquine for radical Plasmodium vivax treatment and dihydroartemisinin-piperaquine as the second-line treatment for uncomplicated malaria. Factors influencing nonadherence included stock-outs of anti-malarials and RDTs; staff shortages; lack of training, job aids and supervision; malpractice by specialists; distrust of malaria microscopy and RDTs; and patient pressure for diagnosis and treatment. Health workers recommended strengthening the supply chain; hiring personnel; providing in-service protocol training including specialists; establishing external quality assurance for malaria diagnosis; and providing onsite supportive supervision and public health campaigns.

CONCLUSIONS

This study revealed a broad spectrum of behavioural and systemic challenges in malaria management among frontline health workers in Northern Sudan, including nonadherence to protocols due to resource shortages, training gaps, a lack of supportive supervision and patient pressure. These insights, including health workers' views about improvements, will inform evidence-based interventions by Sudan's National Malaria Control Programme to improve health systems readiness and the quality of malaria case management.

Cloning, Expression, Purification, and Characterization of Lactate Dehydrogenase from Plasmodium knowlesi: A Zoonotic Malaria Parasite

Plasmodium knowlesi is the only Plasmodium that causes zoonotic disease among the Plasmodium that cause infection in humans. It is fatal due to its short asexual growth cycle within 24 h. Lactate dehydrogenase (LDH), an enzyme that catalyzes the final step of glycolysis, is a biomarker for diagnosing infection by Plasmodium spp. parasite. Therefore, this study aimed to efficiently produce the soluble form of P. knowlesi LDH (PkLDH) using a bacterial expression system for studying malaria caused by P. knowlesi. Recombinant pET-21a(+)-PkLDH plasmid was constructed by inserting the PkLDH gene into a pET-21a(+) expression vector. Subsequently, the recombinant plasmid was inserted into the protein-expressing Escherichia coli Rosetta(DE3) strain, and the optimal conditions for overexpression of the PkLDH protein were established using this strain. We obtained a yield of 52.0 mg/L PkLDH from the Rosetta(DE3) strain and confirmed an activity of 483.9 U/mg through experiments. This methodology for high-efficiency PkLDH production can be utilized for the development of diagnostic methods and drug candidates for distinguishing malaria caused by P. knowlesi.

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.

Challenges in Diagnosing and Treating Acutely Febrile Children with Suspected Malaria at Health Care Facilities in the Lake Mwanza Region of Tanzania

Acute febrile diseases transmitted by mosquitos are a diagnostic challenge for pediatricians working in sub-Saharan Africa. Misclassification due to the lack of rapid, reliable diagnostic tests leads to the overuse of antibiotics and antimalarials. Children presenting with acute fever and suspected of having malaria were examined at health care facilities in the Mwanza Region of Tanzania. The sensitivity and specificity of blood smear microscopy and malaria rapid diagnostic tests that targeted histidine-rich protein 2 and Plasmodium lactate dehydrogenase were compared with a multiplex reverse transcriptase-polymerase chain reaction (PCR)-ELISA. Six hundred ninety-eight children presented with acute fever and met the criteria for inclusion; 23% received antibiotics and 23% received antimalarials prior to admission. Subsequently, 20% were confirmed by PCR to have Plasmodium falciparum infection. Blood smear microscopy exhibited 33% sensitivity and 93% specificity. The malaria rapid test provided 87% sensitivity and 98% specificity in detecting acute malaria infections. Only 7% of malaria-negative children received antimalarials at Sengerema Designated District Hospital when treatment was guided by the results of rapid testing. In contrast, 75% of malaria-negative patients were treated with antimalarial drugs at health facilities that used blood smears as the standard diagnostic test. Misclassification and premedication of nonmalarial, febrile illnesses contribute to the emergence of antimalarial and antimicrobial resistance. The incorporation of malaria rapid diagnostic tests into the clinical routine translated into improved treatment and a significant reduction in antimalarial drug prescriptions.

Prevalence of Falciparum and non-Falciparum Malaria in the 2014-15 Rwanda Demographic Health Survey

Background

Malaria remains a major cause of morbidity in sub-Saharan Africa. Undetected asymptomatic falciparum malaria results in a large transmission reservoir and there is evidence of increasing non-falciparum malaria as malaria is controlled in Africa, both resulting in challenges for malaria control programs.

Methods

We performed quantitative real time PCR for 4 malaria species in 4,596 individuals from the 2014-2015 Rwanda Demographic Health Survey. Bivariate models were used to determine species-specific associations with risk factors.

Results

Asymptomatic falciparum malaria, P. ovale spp., and P. malariae infection had broad spatial distribution across Rwanda. P. vivax infection was rare. Overall infection prevalence was 23.6% (95%CI [21.7%, 26.0%]), with falciparum and non-falciparum at 17.6% [15.9%, 19.0%] and 8.3% [7.0%, 10.0%], respectively. Parasitemias tended to be low and mixed species infections were common, especially where malaria transmission was the highest. Falciparum infection was associated with socio-econiomic status, rural residence and low altitude. Few risk factors were associated with non-falciparum malaria.

Conclusions

Asymptomatic falciparum malaria and non-falciparum malaria are common and widely distributed across Rwanda. Continued molecular monitoring of Plasmodium spp. is needed to monitor these threats to malaria control in Africa.

Vivax malaria: a possible stumbling block for malaria elimination in India

Plasmodium vivax is geographically the most widely dispersed human malaria parasite species. It has shown resilience and a great deal of adaptability. Genomic studies suggest that P. vivax originated from Asia or Africa and moved to the rest of the world. Although P. vivax is evolutionarily an older species than Plasmodium falciparum, its biology, transmission, pathology, and control still require better elucidation. P. vivax poses problems for malaria elimination because of the ability of a single primary infection to produce multiple relapses over months and years. P. vivax malaria elimination program needs early diagnosis, and prompt and complete radical treatment, which is challenging, to simultaneously exterminate the circulating parasites and dormant hypnozoites lodged in the hepatocytes of the host liver. As prompt surveillance and effective treatments are rolled out, preventing primaquine toxicity in the patients having glucose-6-phosphate dehydrogenase (G6PD) deficiency should be a priority for the vivax elimination program. This review sheds light on the burden of P. vivax, changing epidemiological patterns, the hurdles in elimination efforts, and the essential tools needed not just in India but globally. These tools encompass innovative treatments for eliminating dormant parasites, coping with evolving drug resistance, and the development of potential vaccines against the parasite.

Improving Malaria Case Management and Referral Relationships at the Primary Care Level in Ghana: Evaluation of a Quality Assurance Internship

In Ghana, Community-based Health Planning and Services (CHPS) compounds managed by trained nurses and midwives called community health officers (CHOs) play a major role in malaria service delivery. With heavy administrative burdens and minimal training in providing patient care, particularly for febrile illnesses, including malaria, CHOs struggle to comply with the World Health Organization's test, treat, and track initiative guidelines and appropriate referral practices. A clinical training and mentorship program was implemented for CHOs to prevent and manage uncomplicated malaria and offer appropriate pre-referral treatment and referrals to district hospitals. Medical officers, pharmacists, midwives, health information officers, and medical laboratory scientists at 52 district referral hospitals were trained as mentors; CHOs from 520 poorly performing CHPS compounds underwent a 5-day internship at their assigned district referral hospital to improve knowledge and clinical skills for malaria case management. Three months later, mentors conducted post-training mentoring visits to assess knowledge and skill retention and provide ongoing on-the-job guidance. Significant percentage-point increases were observed immediately post-internship for history taking (+12.0, 95% confidence interval [CI]=8.3, 15.1; P<.001); fever assessment (+24.9, 95% CI=20.9, 29.3; P<.001); severe malaria assessment and referral (+32.0, 95% CI=28.2, 35.8; P<.001); and knowledge assessment (+15.8, 95% CI=10.0, 21.3; P<.001). Three months later, a third assessment revealed these gains were largely maintained. Analysis of national health management information system data showed statistically significant improvements in testing, treatment, and referral indicators at intervention CHPS compounds after the intervention that were not observed in comparison CHPS compounds. This training and mentorship approach offers a replicable model to build primary care provider competencies in malaria prevention and management and demonstrates how developing relationships between primary care and first-level referral facilities benefits both providers and clients. More methodologically rigorous studies are needed to measure the impact of this approach.

A community-based dynamic choice model for HIV prevention improves PrEP and PEP coverage in rural Uganda and Kenya: a cluster randomized trial

INTRODUCTION

Optimizing HIV prevention may require structured approaches for providing client-centred choices as well as community-based entry points and delivery. We evaluated the effect of a dynamic choice model for HIV prevention, delivered by community health workers (CHWs) with clinician support, on the use of biomedical prevention among persons at risk of HIV in rural East Africa.

METHODS

We conducted a cluster randomized trial among persons (≥15 years) with current or anticipated HIV risk in 16 villages in Uganda and Kenya (SEARCH; NCT04810650). The intervention was a client-centred HIV prevention model, including (1) structured client choice of product (pre-exposure prophylaxis [PrEP] or post-exposure prophylaxis [PEP]), service location (clinic or out-of-clinic) and HIV testing modality (self-test or rapid test), with the ability to switch over time; (2) a structured assessment of patient barriers and development of a personalized support plan; and (3) phone access to a clinician 24/7. The intervention was delivered by CHWs and supported by clinicians who oversaw PrEP and PEP initiation and monitoring. Participants in control villages were referred to local health facilities for HIV prevention services, delivered by Ministry of Health staff. The primary outcome was biomedical prevention coverage: a proportion of 48-week follow-up with self-reported PrEP or PEP use.

RESULTS

From May to July 2021, we enrolled 429 people (212 intervention; 217 control): 57% women and 35% aged 15-24 years. Among intervention participants, 58% chose PrEP and 58% chose PEP at least once over follow-up; self-testing increased from 52% (baseline) to 71% (week 48); ≥98% chose out-of-facility service delivery. Among 413 (96%) participants with the primary outcome ascertained, average biomedical prevention coverage was 28.0% in the intervention versus 0.5% in the control: a difference of 27.5% (95% CI: 23.0-31.9%, p<0.001). Impact was larger during periods of self-reported HIV risk: 36.6% coverage in intervention versus 0.9% in control, a difference of 35.7% (95% CI: 27.5-43.9, p<0.001). Intervention effects were seen across subgroups defined by sex, age group and alcohol use.

CONCLUSIONS

A client-centred dynamic choice HIV prevention intervention, including the option to switch between products and CHW-based delivery in the community, increased biomedical prevention coverage by 27.5%. However, substantial person-time at risk of HIV remained uncovered.

Assessing the histidine-rich protein 2/3 gene deletion in Plasmodium falciparum isolates from Burkina Faso

BACKGROUND

Dual hrp2/hrp3 genes deletions in P. falciparum isolates are increasingly reported in malaria-endemic countries and can produce false negative RDT results leading to inadequate case management. Data on the frequency of hrp2/hrp3 deleted parasites are rarely available and it has become necessary to investigate the issue in Burkina Faso.

METHODS

Plasmodium falciparum-positive dried blood spots were collected during a cross-sectional household survey of the malaria asymptomatic children from Orodara, Gaoua, and Banfora. Amplicons from the target regions (exon 2 of hrp2 and hrp3 genes) were generated using multiplexed nested PCR and sequenced according to Illumina's MiSeq protocol.

RESULTS

A total of 251 microscopically positive parasite isolates were sequenced to detect hrp2 and hrp3 gene deletions. The proportion of RDTs negative cases among microscopy positive slides was 12.7% (32/251). The highest prevalence of negative RDTs was found in Orodara 14.3% (5/35), followed by Gaoua 13.1%(24/183), and Banfora 9.1% (3/33). The study found that 95.6% of the parasite isolates were wild type hrp2/ hrp3 while 4.4% (11/251) had a single hrp2 deletion. Of the 11 hrp2 deletion samples, 2 samples were RDT negative (mean parasitaemia was 83 parasites/ μL) while 9 samples were RDT positive with a mean parasitaemia of 520 parasites /μL (CI95%: 192-1239). The highest frequency of hrp2 deletion 4/35 (11.4%) was found in Orodara, while it was similar in the other two sites (< 3.5%). No single deletion of the hrp3 or dual deletion hrp2/3 gene was detected in this study.

CONCLUSION

These results demonstrate that P. falciparum isolates lacking hrp2 genes are present in 4.4% of samples obtained from the asymptomatic children population in three sites in Burkina Faso. These parasites are circulating and causing malaria, but they are also still detectable by HRP2-based RTDs due to the presence of the intact pfhrp3 gene.

The feasibility of novel point-of-care diagnostics for febrile illnesses at health centres in Southeast Asia: a mixed-methods study

BACKGROUND

The decline of malaria in Southeast Asia means other causes of fever are increasingly relevant, but often undiagnosed. The objective of this study was to assess the feasibility of point-of-care tests to diagnose acute febrile illnesses in primary care settings.

METHODS

A mixed-methods study was conducted at nine rural health centres in western Cambodia. Workshops introduced health workers to the STANDARD(TM) Q Dengue Duo, STANDARD(TM) Q Malaria/CRP Duo and a multiplex biosensor detecting antibodies and/or antigens of eight pathogens. Sixteen structured observation checklists assessed users' performances and nine focus group discussions explored their opinions.

RESULTS

All three point-of-care tests were performed well under assessment, but sample collection was difficult for the dengue test. Respondents expressed that the diagnostics were useful and could be integrated into routine clinical care, but were not as convenient to perform as standard malaria rapid tests. Health workers recommended that the most valued point-of-care tests would directly inform clinical management (e.g. a decision to refer a patient or to provide/withhold antibiotics).

CONCLUSIONS

Deployment of new point-of-care tests to health centres could be feasible and acceptable if they are user-friendly, selected for locally circulating pathogens and are accompanied by disease-specific education and simple management algorithms.

Request for Antimalarial Medicines and Their Dispensing Without a Prescription in Community Pharmacies in Rwanda

Purpose

This study aimed to explore the request and dispensing of antimalarial medicines without a prescription in community pharmacies in Rwanda, as well as factors associated.

Methods

We employed an embedded mixed-methods design that involved a convenience sample of 235 licensed community pharmacists between February and April 2022. To simultaneously collect qualitative and quantitative data, we used a self-administered questionnaire containing a combination of close and open-ended questions. Bivariate and multivariate regression analyses were performed to examine the relationship between dispensing antimalarial medicines without a prescription and the selected independent variables. Statistical significance was set at p<0.05, and a 95% confidence interval was applied. The factors influencing the dispensing of antimalarial medicines without a prescription were analyzed using thematic content analysis as a qualitative analysis approach.

Results

Most respondents (88.5%) were asked to dispense antimalarial medicines by clients without a prescription. More than half of them (54%) agreed, but 34.5% refused; instead, they referred clients to malaria diagnostic testing facilities. Those who had rapid diagnostic tests for malaria in stock (OR=2.08, 95% CI:1.1-3.94), and thought that antimalarials were over-the-counter medicines (OR=7.03, 95% CI:2.01-24.5) were more likely to dispense antimalarial medicines without prescriptions. The primary reasons reported by community pharmacists for dispensing antimalarial medicines without prescriptions included their prior knowledge of malaria diagnosis, client pressure, and fear of losing clients. However, non-adherence to negative results obtained from formal health facilities and long queues at these institutions have also been cited as additional factors driving clients to seek antimalarial medicines without prescriptions.

Conclusion

Dispensing antimalarial medicines without prescriptions is a common practice in community pharmacies in Rwanda. The main factors contributing to this practice include lack of awareness regarding the classification of antimalarials as prescription medicines, the availability of malaria diagnostic tests, client pressure, and fear of losing clients.

The impact of anti-malarial markets on artemisinin resistance: perspectives from Burkina Faso

BACKGROUND

Widespread artemisinin resistance in Africa could be catastrophic when drawing parallels with the failure of chloroquine in the 1970s and 1980s. This article explores the role of anti-malarial market characteristics in the emergence and spread of arteminisin resistance in African countries, drawing on perspectives from Burkina Faso.

METHODS

Data were collected through in-depth interviews and focus group discussions. A representative sample of national policy makers, regulators, public and private sector wholesalers, retailers, clinicians, nurses, and community members were purposively sampled. Additional information was also sought via review of policy publications and grey literature on anti-malarial policies and deployment practices in Burkina Faso.

RESULTS

Thirty seven in-depth interviews and 6 focus group discussions were conducted. The study reveals that the current operational mode of anti-malarial drug markets in Burkina Faso promotes arteminisin resistance emergence and spread. The factors are mainly related to the artemisinin-based combination therapy (ACT) supply chain, to ACT quality, ACT prescription monitoring and to ACT access and misuse by patients.

CONCLUSION

Study findings highlight the urgent requirement to reform current characteristics of the anti-malarial drug market in order to delay the emergence and spread of artemisinin resistance in Burkina Faso. Four recommendations for public policy emerged during data analysis: (1) Address the suboptimal prescription of anti-malarial drugs, (2) Apply laws that prohibit the sale of anti-malarials without prescription, (3) Restrict the availability of street drugs, (4) Sensitize the population on the value of compliance regarding correct acquisition and intake of anti-malarials. Funding systems for anti-malarial drugs in terms of availability and accessibility must also be stabilized.

AIDMAN: An AI-based object detection system for malaria diagnosis from smartphone thin-blood-smear images

Malaria is a significant public health concern, with ∼95% of cases occurring in Africa, but accurate and timely diagnosis is problematic in remote and low-income areas. Here, we developed an artificial intelligence-based object detection system for malaria diagnosis (AIDMAN). In this system, the YOLOv5 model is used to detect cells in a thin blood smear. An attentional aligner model (AAM) is then applied for cellular classification that consists of multi-scale features, a local context aligner, and multi-scale attention. Finally, a convolutional neural network classifier is applied for diagnosis using blood-smear images, reducing interference caused by false positive cells. The results demonstrate that AIDMAN handles interference well, with a diagnostic accuracy of 98.62% for cells and 97% for blood-smear images. The prospective clinical validation accuracy of 98.44% is comparable to that of microscopists. AIDMAN shows clinically acceptable detection of malaria parasites and could aid malaria diagnosis, especially in areas lacking experienced parasitologists and equipment.

Point-of-care testing in private pharmacy and drug retail settings: a narrative review

BACKGROUND

Point-of-care testing (POCT) using rapid diagnostic tests for infectious disease can potentially guide appropriate use of antimicrobials, reduce antimicrobial resistance, and economise use of healthcare resources. POCT implementation in private retail settings such as pharmacies and drug shops could lessen the burden on public healthcare. We performed a narrative review on studies of POCTs in low- and middle-income countries (LMICs), and explored uptake, impact on treatment, and feasibility of implementation.

METHODS

We searched MEDLINE/PubMed for interventional studies on the implementation of POCT for infectious diseases performed by personnel in private retail settings. Data were extracted and analysed by two independent reviewers.

RESULTS

Of the 848 studies retrieved, 23 were included in the review. Studies were on malaria (19/23), malaria and pneumonia (3/23) or respiratory tract infection (1/23). Nine randomised controlled studies, four controlled, non-randomised studies, five uncontrolled interventions, one interventional pre-post study, one cross-over interventional study and three retrospective analyses of RCTs were included. Study quality was poor. Overall, studies showed that POCT can be implemented successfully, leading to improvements in appropriate treatment as measured by outcomes like adherence to treatment guidelines. Despite some concerns by health workers, customers and shop providers were welcoming of POCT implementation in private retail settings. Main themes that arose from the review included the need for well-structured training with post-training certification covering guidelines for test-negative patients, integrated waste management, community sensitization and demand generation activities, financial remuneration and pricing schemes for providers, and formal linkage to healthcare and support.

CONCLUSION

Our review found evidence that POCT can be implemented successfully in private retail settings in LMICs, but comprehensive protocols are needed. High-quality randomised studies are needed to understand POCTs for infectious diseases other than malaria.

Evaluation of a rapid diagnostic test for measles IgM detection; accuracy and the reliability of visual reading using sera from the measles surveillance programme in Brazil, 2015

Laboratory-based case confirmation is an integral part of measles surveillance programmes; however, logistical constraints can delay response. Use of RDTs during initial patient contact could enhance surveillance by real-time case confirmation and accelerating public health response. Here, we evaluate performance of a novel measles IgM RDT and assess accuracy of visual interpretation using a representative collection of 125 sera from the Brazilian measles surveillance programme. RDT results were interpreted visually by a panel of six independent observers, the consensus of three observers and by relative reflectance measurements using an ESEQuant Reader. Compared to the Siemens anti-measles IgM EIA, sensitivity and specificity of the RDT were 94.9% (74/78, 87.4-98.6%) and 95.7% (45/47, 85.5-99.5%) for consensus visual results, and 93.6% (73/78, 85.7-97.9%) and 95.7% (45/47, 85.5-99.5%), for ESEQuant measurement, respectively. Observer agreement, determined by comparison between individuals and visual consensus results, and between individuals and ESEQuant measurements, achieved average kappa scores of 0.97 and 0.93 respectively. The RDT has the sensitivity and specificity required of a field-based test for measles diagnosis, and high kappa scores indicate this can be accomplished accurately by visual interpretation alone. Detailed studies are needed to establish its role within the global measles control programme.

Plasmodium vivax Presenting With Septic Shock and Disseminated Intravascular Coagulation (DIC): A Case Report

Malaria has various causative agents that can have a spectrum of disease manifestations, some potentially fatal. Various species have been established as etiologies of malaria, though our understanding of the severity of various species is changing. We present a unique case of Plasmodium vivax malaria that resulted in severe disease, a magnitude rarely seen in previous literature. Our patient was a 35-year-old healthy woman who presented to the emergency department with abdominal pain, nausea, vomiting, and fever. Further workup revealed severe thrombocytopenia with prolonged prothrombin (PT) and partial thromboplastin time (PTT). An initial thick smear failed to detect any Plasmodium species, but a thin smear revealed P. vivax. The patient's hospital stay was complicated by septic shock requiring intensive care unit (ICU) admission. This unique case represents P. vivax as the causative agent of severe malaria even in healthy, immunocompetent patients.

Availability of malaria diagnostic tests, anti-malarial drugs, and the correctness of treatment: a systematic review and meta-analysis

BACKGROUND

Health facilities' availability of malaria diagnostic tests and anti-malarial drugs (AMDs), and the correctness of treatment are critical for the appropriate case management, and malaria surveillance programs. It is also reliable evidence for malaria elimination certification in low-transmission settings. This meta-analysis aimed to estimate summary proportions for the availability of malaria diagnostic tests, AMDs, and the correctness of treatment.

METHODS

The Web of Science, Scopus, Medline, Embase, and Malaria Journal were systematically searched up to 30th January 2023. The study searched any records reporting the availability of diagnostic tests and AMDs and the correctness of malaria treatment. Eligibility and risk of bias assessment of studies were conducted independently in a blinded way by two reviewers. For the pooling of studies, meta-analysis using random effects model were carried out to estimate summary proportions of the availability of diagnostic tests, AMDs, and correctness of malaria treatment.

RESULTS

A total of 18 studies, incorporating 7,429 health facilities, 9,745 health workers, 41,856 febrile patients, and 15,398 malaria patients, and no study in low malaria transmission areas, were identified. The pooled proportion of the availability of malaria diagnostic tests, and the first-line AMDs in health facilities was 76% (95% CI 67-84); and 83% (95% CI 79-87), respectively. A pooled meta-analysis using random effects indicates the overall proportion of the correctness of malaria treatment 62% (95% CI 54-69). The appropriate malaria treatment was improved over time from 2009 to 2023. In the sub-group analysis, the correctness of treatment proportion was 53% (95% CI 50-63) for non-physicians health workers and 69% (95% CI 55-84) for physicians.

CONCLUSION

Findings of this review indicated that the correctness of malaria treatment and the availability of AMDs and diagnostic tests need improving to progress the malaria elimination stage.

Leveraging innovation technologies to respond to malaria: a systematized literature review of emerging technologies

BACKGROUND

In 2019, an estimated 409,000 people died of malaria and most of them were young children in sub-Saharan Africa. In a bid to combat malaria epidemics, several technological innovations that have contributed significantly to malaria response have been developed across the world. This paper presents a systematized review and identifies key technological innovations that have been developed worldwide targeting different areas of the malaria response, which include surveillance, microplanning, prevention, diagnosis and management.

METHODS

A systematized literature review which involved a structured search of the malaria technological innovations followed by a quantitative and narrative description and synthesis of the innovations was carried out. The malaria technological innovations were electronically retrieved from scientific databases that include PubMed, Google Scholar, Scopus, IEEE and Science Direct. Additional innovations were found across grey sources such as the Google Play Store, Apple App Store and cooperate websites. This was done using keywords pertaining to different malaria response areas combined with the words "innovation or technology" in a search query. The search was conducted between July 2021 and December 2021. Drugs, vaccines, social programmes, and apps in non-English were excluded. The quality of technological innovations included was based on reported impact and an exclusion criterion set by the authors.

RESULTS

Out of over 1000 malaria innovations and programmes, only 650 key malaria technological innovations were considered for further review. There were web-based innovations (34%), mobile-based applications (28%), diagnostic tools and devices (25%), and drone-based technologies (13%.

DISCUSSION AND CONCLUSION

This study was undertaken to unveil impactful and contextually relevant malaria innovations that can be adapted in Africa. This was in response to the existing knowledge gap about the comprehensive technological landscape for malaria response. The paper provides information that countries and key malaria control stakeholders can leverage with regards to adopting some of these technologies as part of the malaria response in their respective countries. The paper has also highlighted key drivers including infrastructural requirements to foster development and scaling up of innovations. In order to stimulate development of innovations in Africa, countries should prioritize investment in infrastructure for information and communication technologies and also drone technologies. These should be accompanied by the right policies and incentive frameworks.

The effect of malaria on childhood anemia in a quasi-experimental study of 7,384 twins from 23 Sub-Saharan African countries

Background

Young children in Sub-Saharan Africa (SSA), particularly those from resource-limited settings, are heavily burdened by anemia and malaria. While malaria infected children frequently become anemic (hemoglobin < 110 g/L), anemia is a strongly multifactorial disease with many other risk factors than malaria. Due to the complex and often overlapping contributors to anemia, it remains challenging to isolate the true impact of malaria on population level hemoglobin concentrations.

Methods

We quantified the malaria-induced effect on hemoglobin levels in children under 5 years of age, leveraging data from 7,384 twins and other multiples, aged 6 to 59 months, from 57 nationally representative Demographic and Health Surveys (DHSs) from 23 SSA countries from 2006 to 2019. The quasi-experimental twin fixed-effect design let us minimize the impact of potential confounders that do not vary between twins.

Results

Our analyses of twins revealed a malaria-induced hemoglobin decrease in infected twins of 9 g/L (95% CI -10; -7, p<0.001). The relative risk of severe anemia was higher (RR = 3.01, 95% CI 1.79; 5.1, p<0.001) among malaria positive children, compared to malaria negative children. Conversely, malaria positive children are only half as likely to be non-anemic (RR = 0.51, 95% CI 0.43; 0.61, p<0.001).

Conclusion

Even after rigorous control for confounding through a twin fixed-effects study design, malaria substantially decreased hemoglobin levels among SSA twins, rendering them much more susceptible to severe anemia. This effect reflects the population-level effect of malaria on anemia.

How do malaria testing and treatment subsidies affect drug shop client expenditures? A cross-sectional analysis in Western Kenya

OBJECTIVES

To examine how drug shop clients' expenditures are affected by subsidies for malaria diagnostic testing and for malaria treatment, and also to examine how expenditures vary by clients' malaria test result and by the number of medications they purchased.

DESIGN

Secondary cross-sectional analysis of survey responses from a randomised controlled trial.

SETTING

The study was conducted in twelve private drug shops in Western Kenya.

PARTICIPANTS

We surveyed 836 clients who visited the drug shops between March 2018 and October 2019 for a malaria-like illness. This included children >1 year of age if they were physically present and accompanied by a parent or legal guardian.

INTERVENTIONS

Subsidies for malaria diagnostic testing and for malaria treatment (conditional on a positive malaria test result).

PRIMARY AND SECONDARY OUTCOME MEASURES

Expenditures at the drug shop in Kenya shillings (Ksh).

RESULTS

Clients who were randomised to a 50% subsidy for malaria rapid diagnostic tests (RDTs) spent approximately Ksh23 less than those who were randomised to no RDT subsidy (95% CI (-34.6 to -10.7), p=0.002), which corresponds approximately to the value of the subsidy (Ksh20). However, clients randomised to receive free treatment (artemisinin combination therapies (ACTs)) if they tested positive for malaria had similar spending levels as those randomised to a 67% ACT subsidy conditional on a positive test. Expenditures were also similar by test result, however, those who tested positive for malaria bought more medications than those who tested negative for malaria while spending approximately Ksh15 less per medication (95% CI (-34.7 to 3.6), p=0.102).

CONCLUSIONS

Our results suggest that subsidies for diagnostic health products may result in larger household savings than subsidies on curative health products. A better understanding of how people adjust their behaviours and expenditures in response to subsidies could improve the design and implementation of subsidies for health products.

TRIAL REGISTRATION NUMBER

NCT03810014.

Performance of antigen detection for HRP2-based malaria rapid diagnostic tests in community surveys: Tanzania, July-November 2017

BACKGROUND

Malaria rapid diagnostic tests (RDTs) based on the detection of the Plasmodium falciparum histidine-rich protein 2 (HRP2) antigen are widely used for detection of active infection with this parasite and are the only practical malaria diagnostic test in some endemic settings. External validation of RDT results from field surveys can confirm appropriate RDT performance.

METHODS

A community-based cross-sectional survey was conducted between July and November 2017 enrolling participants of all ages in households from 15 villages in four border regions of Tanzania: Geita, Kigoma, Mtwara and Ruvuma. All participants had an RDT performed in the field and provided a blood sample for later laboratory multiplex antigen detection of HRP2. In assessing the continuous HRP2 levels in participant blood versus RDT result, dose-response logistic regression provided quantitative estimates for HRP2 limit of detection (LOD).

RESULTS

From the 15 study villages, 6941 persons were enrolled that had a RDT at time of enrollment and provided a DBS for later laboratory antigen detection. RDT positive prevalence for the HRP2 band by village ranged from 20.0 to 43.6%, but the magnitude of this prevalence did not have an effect on the estimated LOD of RDTs utilized in different villages. Overall, HRP2 single-target tests had a lower LOD at the 95% probability of positive RDT (4.3 ng/mL; 95% CI 3.4-5.4) when compared to pLDH/HRP2 dual target tests (5.4 ng/mL; 4.5-6.3), though this difference was not significant. With the exception of one village, all other 14 villages (93.3%) showed RDT LOD estimates at 90% probability of positive RDT between 0.5 and 12.0 ng/mL.

CONCLUSIONS

Both HRP2-only and pLDH/HRP2 combo RDTs utilized in a 2017 Tanzania cross-sectional survey of border regions generally performed well, and reliably detected HRP2 antigen in the low ng/mL range. Though single target tests had lower levels of HRP2 detection, both tests were within similar ranges among the 15 villages. Comparison of quantitative HRP2 detection limits among study sites can help interpret RDT testing results when generating population prevalence estimates for malaria infection.

Advances and challenges in automated malaria diagnosis using digital microscopy imaging with artificial intelligence tools: A review

Malaria is an infectious disease caused by parasites of the genus Plasmodium spp. It is transmitted to humans by the bite of an infected female Anopheles mosquito. It is the most common disease in resource-poor settings, with 241 million malaria cases reported in 2020 according to the World Health Organization. Optical microscopy examination of blood smears is the gold standard technique for malaria diagnosis; however, it is a time-consuming method and a well-trained microscopist is needed to perform the microbiological diagnosis. New techniques based on digital imaging analysis by deep learning and artificial intelligence methods are a challenging alternative tool for the diagnosis of infectious diseases. In particular, systems based on Convolutional Neural Networks for image detection of the malaria parasites emulate the microscopy visualization of an expert. Microscope automation provides a fast and low-cost diagnosis, requiring less supervision. Smartphones are a suitable option for microscopic diagnosis, allowing image capture and software identification of parasites. In addition, image analysis techniques could be a fast and optimal solution for the diagnosis of malaria, tuberculosis, or Neglected Tropical Diseases in endemic areas with low resources. The implementation of automated diagnosis by using smartphone applications and new digital imaging technologies in low-income areas is a challenge to achieve. Moreover, automating the movement of the microscope slide and image autofocusing of the samples by hardware implementation would systemize the procedure. These new diagnostic tools would join the global effort to fight against pandemic malaria and other infectious and poverty-related diseases.

Achieving malaria testing and treatment targets for children under five in Mozambique: a cost-effectiveness analysis

Background

The entire population of Mozambique is at risk for malaria, which remains one of the leading causes of death. The 2017–2022 National Malaria Strategic Plan focuses on reducing malaria morbidity and mortality in high- and low-transmission areas. This study aimed to estimate the costs and health benefits of six variations of the World Health Organization’s “test-and-treat” strategy among children under five.

Methods

A decision tree model was developed that estimates the costs and health outcomes for children under five. Data on probabilities, costs, weights for disability-adjusted life years (DALYs), and quality-adjusted life years (QALYs) were based on peer-reviewed, grey literature, and primary data analysis of the 2018 Malaria Indicator Survey. Six scenarios were compared to the status quo and calculated the incremental cost-effectiveness ratio (ICER) in terms of cost per QALY gained, DALY averted, and life saved. Deterministic and probabilistic sensitivity analyses were conducted to understand the effect of parameter uncertainty on the findings.

Results

In the base case, reaching the target of 100% testing with rapid diagnostic tests (RDTs; Scenario 1) is more cost-effective than improving the testing rate alone by 10% (Scenario 2). Achieving a 100% (Scenario 3) or a 10% increase in treatment rate (Scenario 4) have ICERs that are lower than Scenarios 1 and 2. Both Scenarios 5 and 6, which represent combinations of Scenarios 1–4, have lower ICERs than their constituent strategies on their own, which suggests that improvements in treatment are more cost-effective than improvements in testing alone. These results held when DALYs averted or lives saved were used as health outcomes. Deterministic and probabilistic sensitivity analyses revealed that the cost-effectiveness of Scenarios 1–6 are subject sensitive to parameter uncertainty, though Scenarios 4 and 5 are the optimal choice when DALYs averted or QALYs gained were used as the measure of health outcomes across all cost-effectiveness thresholds.

Conclusions

Improving testing rates alone among children at risk for malaria has the potential to improve health but may not be the most efficient use of limited resources. Instead, small or large improvements in treatment, whether alone or in conjunction with improvements in testing, are the most cost-effective strategies for children under five in Mozambique.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04354-9.

Predicting Plasmodium falciparum infection status in blood using a multiplexed bead-based antigen detection assay and machine learning approaches

Background

Plasmodium blood-stage infections can be identified by assaying for protein products expressed by the parasites. While the binary result of an antigen test is sufficient for a clinical result, greater nuance can be gathered for malaria infection status based on quantitative and sensitive detection of Plasmodium antigens and machine learning analytical approaches.

Methods

Three independent malaria studies performed in Angola and Haiti enrolled persons at health facilities and collected a blood sample. Presence and parasite density of P. falciparum infection was determined by microscopy for a study in Angola in 2015 (n = 193), by qRT-PCR for a 2016 study in Angola (n = 208), and by qPCR for a 2012–2013 Haiti study (n = 425). All samples also had bead-based detection and quantification of three Plasmodium antigens: pAldolase, pLDH, and HRP2. Decision trees and principal component analysis (PCA) were conducted in attempt to categorize P. falciparum parasitemia density status based on continuous antigen concentrations.

Results

Conditional inference trees were trained using the known P. falciparum infection status and corresponding antigen concentrations, and PCR infection status was predicted with accuracies ranging from 73–96%, while level of parasite density was predicted with accuracies ranging from 59–72%. Multiple decision nodes were created for both pAldolase and HRP2 antigens. For all datasets, dichotomous infectious status was more accurately predicted when compared to categorization of different levels of parasite densities. PCA was able to account for a high level of variance (>80%), and distinct clustering was found in both dichotomous and categorical infection status.

Conclusions

This pilot study offers a proof-of-principle of the utility of machine learning approaches to assess P. falciparum infection status based on continuous concentrations of multiple Plasmodium antigens.

Adding rapid diagnostic tests to community-based programmes for treating malaria

BACKGROUND

The World Health Organization (WHO) recommends parasitological testing of all suspected malaria cases using malaria rapid diagnostic tests (mRDTs) or microscopy prior to treatment. Some governments have extended this responsibility to community health workers (CHWs) to reduce malaria morbidity and mortality through prompt and appropriate treatment. This is an update of a Cochrane Review first published in 2013.

OBJECTIVES

To evaluate community-based management strategies for treating malaria or fever that incorporate both a definitive diagnosis with an mRDT and appropriate antimalarial treatment.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, five other databases, and three trials registers up to 14 September 2021.

SELECTION CRITERIA

We included individually randomized trials and cluster-randomized controlled trials (cRCTs), controlled before-after studies, and controlled interrupted time series studies in people living in malaria-endemic areas, comparing programmes that train CHWs and drug shop vendors to perform mRDTs and provide appropriate treatment versus similar programmes that do not use mRDTs, and versus routine health facility care.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. For each dichotomous outcome, we extracted the number of participants with the event and the total number of participants in each group, unless studies presented results at a population level only. Primary outcomes were all-cause mortality, hospitalizations, and number of people receiving an antimalarial within 24 hours. Secondary outcomes were malaria-specific mortality, severe malaria, outcomes related to antimalarial treatments, antibiotic prescribing to people with a negative microscopy or polymerase chain reaction (PCR) result, parasitaemia, anaemia, and all adverse events.

MAIN RESULTS

We included eight studies from several African countries, Afghanistan, and Myanmar. Staff included CHWs and drug shop vendors.  Community use of malaria rapid diagnostic tests compared to clinical diagnosis Compared to clinical diagnosis, mRDT diagnosis results in reduced prescribing of antimalarials to people who are found to be malaria parasite-negative by microscopy or PCR testing (71 fewer per 100 people, 95% confidence interval (CI) 79 to 51 fewer; risk ratio (RR) 0.17, 95% CI 0.07 to 0.40; 3 cRCTs, 7877 participants; moderate-certainty evidence). This reduction may be greater among CHWs compared to drug shop vendors. People diagnosed by mRDT are more likely to receive appropriate treatment; that is, an antimalarial if they are microscopy- or PCR-positive and no antimalarial if they are microscopy- or PCR-negative (RR 3.04, 95% CI 2.46 to 3.74, 3 cRCTs, 9332 participants; high-certainty evidence). Three studies found that a small percentage of people with a negative mRDT result (as read by the CHW or drug shop vendors at the time of treatment) were nevertheless given an antimalarial: 38/1368 (2.8%), 44/724 (6.1%) and 124/950 (13.1%). Conversely, in two studies, a few mRDT-positive people did not receive an antimalarial (0.5% and 0.3%), and one small cross-over study found that 6/57 (10.5%) people classified as non-malaria in the clinical diagnosis arm received an antimalarial. Use of mRDTs probably increases antibiotic use compared to clinical diagnosis (13 more per 100 people, 95% CI 3 to 29 more; RR 2.02, 95% CI 1.21 to 3.37; 2 cRCTs, 5179 participants; moderate-certainty evidence). We were unable to demonstrate any effect on mortality. Community use of malaria rapid diagnostic tests compared to health facility care Results were insufficient to reach any conclusion.

AUTHORS' CONCLUSIONS

Use of mRDTs by CHWs and drug shop vendors compared to clinical diagnosis reduces prescribing of antimalarials to people without malaria. Deaths were uncommon in both groups. Antibiotic prescribing was higher in those with a negative mRDT than in those with a negative clinical diagnosis.

Experience and confidence in health technologies: evidence from malaria testing and treatment in Western Kenya

Background

Low adoption of effective health technologies increases illness morbidity and mortality worldwide. In the case of malaria, effective tools such as malaria rapid diagnostic tests (RDTs) and artemisinin-combination therapies (ACTs) are both under-used and used inappropriately. Individuals’ confidence in RDTs and ACTs likely affects the uptake of these tools.

Methods

In a cohort of 36 households (280 individuals) in Western Kenya observed for 30 months starting in June 2017, we examined if experience with RDTs and ACTs changes people’s beliefs about these technologies and how those beliefs affect treatment behavior. Household members requested a free RDT from the study team any time they suspected a malaria illness, and positive RDT results were treated with a free ACT. We conducted annual, monthly, and sick visit surveys to elicit beliefs about the accuracy of malaria RDT results and the effectiveness of ACTs. Beliefs were elicited on a 5-point Likert scale from “very unlikely” to “very likely.”

Results

Over the study period, the percentage of survey respondents that said a hypothetical negative RDT result was “very likely” to be correct increased from approximately 55% to 75%. Controlling for initial beliefs, people who had been tested at least once with an RDT in the past year had 3.6 times higher odds (95% CI [1 1.718 7.679], P = 0.001) of saying a negative RDT was “very likely” to be correct. Confidence in testing was associated with treatment behavior: those who believed a negative RDT was “very likely” to be correct had 1.78 times higher odds (95% CI [1.079 2.934], P = 0.024) of adhering to a negative RDT result (by not taking ACTs) than those who were less certain about the accuracy of negative RDTs. Adherence to a negative test also affected subsequent beliefs: controlling for prior beliefs, those who had adhered to their previous test result had approximately twice the odds (OR = 2.19, 95% CI [1.661 2.904], P < 0.001) of saying that a hypothetical negative RDT was “very likely” to be correct compared to those who had not adhered.

Conclusions

Our results suggest that greater experience with RDTs can not only increase people’s confidence in their accuracy but also improve adherence to the test result.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-14102-y.

Potential application of the haematology analyser XN-31 prototype for field malaria surveillance in Kenya

Background

Simple and accurate diagnosis is a key component of malaria control programmes. Microscopy is the current gold standard, however it requires extensive training and the results largely rely on the skill of the microscopists. Malaria rapid diagnostic tests (RDT) can be performed with minimal training and offer timely diagnosis, but results are not quantitative. Moreover, some Plasmodium falciparum parasites have evolved and can no longer be detected by existing RDT. Developed by the Sysmex Corporation, the XN-31 prototype (XN-31p) is an automated haematology analyser capable of detecting Plasmodium-infected erythrocytes and providing species differentiation and stage specific parasite counts in venous blood samples without any preparation in approximately one minute. However, factors such as stable electricity supply in a temperature-controlled room, cost of the instrument and its initial set-up, and need for proprietary reagents limit the utility of the XN-31p across rural settings. To overcome some of these limitations, a hub and spoke diagnosis model was designed, in which peripheral health facilities were linked to a central hospital where detection of Plasmodium infections by the XN-31p would take place. To explore the feasibility of this concept, the applicability of capillary blood samples with the XN-31p was evaluated with respect to the effect of sample storage time and temperature on the stability of results.

Methods

Paired capillary and venous blood samples were collected from 169 malaria-suspected outpatients in Homa Bay County Referral Hospital, Kenya. Malaria infections were diagnosed with the XN-31p, microscopy, RDT, and PCR. Capillary blood samples were remeasured on the XN-31p after 24 h of storage at either room (15–25 °C) or chilled temperatures (2–8 °C).

Results

Identical results in malaria diagnosis were observed between venous and capillary blood samples processed immediately after collection with the XN-31p. Relative to PCR, the sensitivity and specificity of the XN-31p with capillary blood samples were 0.857 and 1.000, respectively. Short-term storage of capillary blood samples at chilled temperatures had no adverse impact on parasitaemia and complete blood counts (CBC) measured by the XN-31p.

Conclusion

These results demonstrate the potential of the XN-31p to improve routine malaria diagnosis across remote settings using a hub and spoke model.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04259-7.

Clinical management and outcomes of acute febrile illness in children attending a tertiary hospital in southern Ethiopia

Background

The management of febrile illnesses is challenging in settings where diagnostic laboratory facilities are limited, and there are few published longitudinal data on children presenting with fever in such settings. We have previously conducted the first comprehensive study of infectious aetiologies of febrile children presenting to a tertiary care facility in Ethiopia. We now report on clinicians’ prescribing adherence with guidelines and outcomes of management in this cohort.

Methods

We consecutively enrolled febrile children aged 2 months and under 13 years, who were then managed by clinicians based on presentation and available laboratory and radiologic findings on day of enrolment. We prospectively collected outcome data on days 7 and 14, and retrospectively evaluated prescribing adherence with national clinical management guidelines.

Results

Of 433 children enrolled, the most common presenting syndromes were pneumonia and acute diarrhoea, diagnosed in 177 (40.9%) and 82 (18.9%), respectively. Antibacterial agents were prescribed to 360 (84.7%) of 425 children, including 36 (34.0%) of 106 children without an initial indication for antibacterials according to guidelines. Antimalarial drugs were prescribed to 47 (11.1%) of 425 children, including 30 (7.3%) of 411 children with negative malaria microscopy. Fever had resolved in 357 (89.7%) of 398 children assessed at day 7, and in-hospital death within 7 days occurred in 9 (5.9%) of 153 admitted patients. Among children with pneumonia, independent predictors of persisting fever or death by 7 days were young age and underweight for age. Antibacterial prescribing in the absence of a guideline-specified indication (overprescribing) was more likely among infants and those without tachypnea, while overprescribing antimalarials was associated with older age, anaemia, absence of cough, and higher fevers.

Conclusion

Our study underscores the need for improving diagnostic support to properly guide management decisions and enhance adherence by clinicians to treatment guidelines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07424-0.

Factors influencing health workers' compliance with outpatient malaria 'test and treat' guidelines during the plateauing performance phase in Kenya, 2014-2016

Background

Health workers’ compliance with outpatient malaria ‘test and treat’ guidelines has improved since 2010 but plateaued from 2014 at suboptimal levels in Kenya. This study examined the factors associated with high but suboptimal compliance levels at facilities with available malaria tests and drugs.

Methods

Data from four national, cross-sectional health facility surveys undertaken between 2014 and 2016 in Kenya were analysed. Association between 31 factors and compliance with malaria testing (survey range (SR): 65–69%) and no anti-malarial treatment for test negative patients (SR: 90–92%) were examined using multilevel logistic regression models.

Results

A total of 2,752 febrile patients seen by 594 health workers at 486 health facilities were analysed. Higher odds of malaria testing were associated with lake endemic (aOR = 12.12; 95% CI: 5.3–27.6), highland epidemic (aOR = 5.06; 95% CI: 2.7–9.5) and semi-arid seasonal (aOR = 2.07; 95% CI: 1.2–3.6) compared to low risk areas; faith-based (FBO)/ non-governmental organization (NGO)-owned compared to government-owned facilities (aOR = 5.80; 95% CI: 3.2–10.6); health workers’ perception of malaria endemicity as high-risk (aOR = 3.05; 95% CI: 1.8–5.2); supervision with feedback (aOR = 1.84; 95% CI: 1.2–2.9); access to guidelines (aOR = 1.96; 95% CI: 1.1–3.4); older patients compared to infants, higher temperature measurements and main complaints of fever, diarrhoea, headache, vomiting and chills. Lower odds of testing were associated with febrile patients having main complaints of a cough (aOR = 0.65; 95% CI: 0.5–0.9), a rash (aOR = 0.32; 95% CI: 0.2–0.7) or a running nose (aOR = 0.59; 95% CI: 0.4–0.9). Other factors associated with compliance with test negative results included the type of diagnostic test available at the facility, in-service training, health workers’ age, and correct knowledge of the targeted treatment policy.

Conclusions

To optimize outpatient malaria case-management, reduce testing compliance gaps and eliminate overtreatment of test negative patients, there is a need to focus on compliance within low malaria risk areas in addition to ensuring the universal and continuous availability of ‘test and treat’ commodities. Targeting of older and government health workers; dissemination of updated guidelines; and continuing with in-service training and supportive supervision with feedback is essential. Lastly, there is a need to improve health workers’ knowledge about malaria testing criteria considering their perceptions of endemicity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04093-x.

Analysis of malaria clinical-epidemiological predictors in individuals from Brazilian Amazon

This research aims to determine whether the combination of epidemiological and clinical features can predict malaria. Diagnostic investigation detected 22.3% of individuals with Plasmodium vivax (P. vivax) malaria, with significant predominance of the male gender. The malaria triad (fever, chills and headache) had a more expressive frequency (81.1%) in individuals with positive thick blood than those with negative thick blood smear (65.1%), although there was no statistical significance. Among the variables analysed as predictive for positive thick blood smear, it was observed that personal history of travel to an endemic malaria area and past malaria infection (PMI) were significantly associated with malaria, even in multiple logistic regression. Fever had the higher sensitivity (94.6%) and past malaria history had the greater specificity (68.2%), with accuracy of 23.5% and 67.5%, respectively. In combined analysis, fever with chills had the highest sensitivity (91.9%), but low accuracy (38.5%). High specificity (91.5%) was found in the association of malaria triad, PMI and history of travel to endemic malaria area (which along with anorexia, was higher 94.6%), with good accuracy (80.7%), suggesting that the screening of patients for performing thick blood smear can be based on these data. The epidemiological features and the malaria triad (fever, chills and headache) can be predictors for identification of malaria patients, concurring to precocious diagnosis and immediate treatment of individuals with malaria.

Determinants of malaria testing at health facilities: the case of Uganda

Background

The World Health Organization (WHO) recommends prompt malaria diagnosis with either microscopy or malaria rapid diagnostic tests (RDTs) and treatment with an effective anti-malarial, as key interventions to control malaria. However, in sub-Saharan Africa, malaria diagnosis is still often influenced by clinical symptoms, with patients and care providers often interpreting all fevers as malaria. The Ministry of Health in Uganda defines suspected malaria cases as those with a fever. A target of conducting testing for at least 75% of those suspected to have malaria was established by the National Malaria Reduction Strategic Plan 2014–2020.

Methods

This study investigated factors that affect malaria testing at health facilities in Uganda using data collected in March/April 2017 in a cross-sectional survey of health facilities from the 52 districts that are supported by the US President’s Malaria Initiative (PMI). The study assessed health facility capacity to provide quality malaria care and treatment. Data were collected from all 1085 public and private health facilities in the 52 districts. Factors assessed included supportive supervision, availability of malaria management guidelines, laboratory infrastructure, and training health workers in the use of malaria rapid diagnostic test (RDT). Survey data were matched with routinely collected health facility malaria data obtained from the district health information system Version-2 (DHIS2). Associations between testing at least 75% of suspect malaria cases with several factors were examined using multivariate logistic regression.

Results

Key malaria commodities were widely available; 92% and 85% of the health facilities reported availability of RDTs and artemether–lumefantrine, respectively. Overall, 933 (86%) of the facilities tested over 75% of patients suspected to have malaria. Predictors of meeting the testing target were: supervision in the last 6 months (OR: 1.72, 95% CI 1.04–2.85) and a health facility having at least one health worker trained in the use of RDTs (OR: 1.62, 95% CI 1.04–2.55).

Conclusion

The study findings underscore the need for malaria control programmes to provide regular supportive supervision to health facilities and train health workers in the use of RDTs.

Determinants of improvement trends in health workers' compliance with outpatient malaria case-management guidelines at health facilities with available "test and treat" commodities in Kenya

BACKGROUND

Health workers' compliance with outpatient malaria case-management guidelines has been improving in Africa. This study examined the factors associated with the improvements.

METHODS

Data from 11 national, cross-sectional health facility surveys undertaken from 2010-2016 were analysed. Association between 31 determinants and improvement trends in five outpatient compliance outcomes were examined using interactions between each determinant and time in multilevel logistic regression models and reported as an adjusted odds ratio of annual trends (T-aOR).

RESULTS

Among 9,173 febrile patients seen at 1,208 health facilities and by 1,538 health workers, a higher annual improvement trend in composite "test and treat" performance was associated with malaria endemicity-lake endemic (T-aOR = 1.67 annually; p<0.001) and highland epidemic (T-aOR = 1.35; p<0.001) zones compared to low-risk zone; with facilities stocking rapid diagnostic tests only (T-aOR = 1.49; p<0.001) compared to microscopy only services; with faith-based/non-governmental facilities compared to government-owned (T-aOR = 1.15; p = 0.036); with a daily caseload of >25 febrile patients (T-aOR = 1.46; p = 0.003); and with under-five children compared to older patients (T-aOR = 1.07; p = 0.013). Other factors associated with the improvement trends in the "test and treat" policy components and artemether-lumefantrine administration at the facility included the absence of previous RDT stock-outs, community health workers dispensing drugs, access to malaria case-management and Integrated Management of Childhood Illness (IMCI) guidelines, health workers' gender, correct health workers' knowledge about the targeted malaria treatment policy, and patients' main complaint of fever. The odds of compliance at the baseline were variable for some of the factors.

CONCLUSIONS

Targeting of low malaria risk areas, low caseload facilities, male and government health workers, continuous availability of RDTs, improving health workers' knowledge about the policy considering age and fever, and dissemination of guidelines might improve compliance with malaria guidelines. For prompt treatment and administration of the first artemether-lumefantrine dose at the facility, task-shifting duties to community health workers can be considered.

Evaluation of the combination of rapid diagnostic tests and microscopy for imported malaria surveillance in Anhui Province, China

BACKGROUND

In the Anhui Province, China, efforts to interrupt the local malaria transmission were successful, with no endemic cases reported since 2014. Contrastingly, imported malaria cases are still being reported, indicating a disease reintroduction risk after years of elimination. A good surveillance system is key for avoiding the risk, detecting imported cases and possible cases associated with local transmission early. Therefore, rapid diagnostic tests (RDTs) were combined with microscopy to strengthen malaria surveillance in the province. Herein, we aimed to evaluate the efficacy of this surveillance strategy.

METHODS

We conducted a retrospective study using malaria surveillance data from January 2016 to June 2020. Epidemiological characteristics and diagnostic information were analysed using descriptive and comparative statistics. The diagnostic performance of the combined toolbox (Wondfo RDTs plus microscopy) was evaluated based on its sensitivity, specificity, positive and negative predictive values, and Cohen's kappa coefficient, using real-time polymerase chain reaction as the gold standard.

RESULTS

The combined toolbox displayed a higher overall sensitivity for malaria cases than that of microscopy alone (93.74% vs 89.37%; p_adj <0.05), which could detect 94.65%, 88.16%, 95.00%, and 100.00% of Plasmodium falciparum, P. ovale, P. vivax, and P. malariae infections, respectively. In clinical practice, Wondfo RDTs ability to detect P. falciparum infections was better than that of microscopy (97.55% vs 89.67%, p_adj < 0.05). In contrast, microscopy displayed a higher specificity than that of Wondfo RDTs (81.82% vs 63.28%, p _adj <0.05). Moreover, the consistency between microscopy and the gold standard results was also better than that of RDTs (Kappa value:0.669 vs 0.596).

CONCLUSIONS

The combination of microscopy and RDTs is an effective strategy for malaria surveillance because it possibly detected more P. falciparum infections due to the introduction of RDTs. In contrast, microscopy is complementary to some limitations related to the use of RDTs in field practice. Thus, monitoring malaria cases in non-endemic areas may require employing more than one diagnostic tool in surveillance strategies. Moreover, further understanding of the advantages and disadvantages of different detection methods is necessary for applying optimum combinations in field settings.

Diagnostic Accuracy of CareStart™ Malaria HRP2 and SD Bioline Pf/PAN for Malaria in Febrile Outpatients in Varying Malaria Transmission Settings in Cameroon

Background: There was an increase in the number of malaria cases in Cameroon in 2018 that could reflect changes in provider practice, despite effective interventions. In this study, we assessed the diagnostic performance of two malaria rapid diagnostic tests (mRDTs) for diagnostic confirmation of suspected cases of malaria in public and private health facilities in two malaria transmission settings in Cameroon. Methods: We evaluated the diagnostic performance of CareStart pf and SD Bioline Pf/PAN mRDT and compared these parameters by RDT type and transmission setting. Nested PCR and blood film microscopy were used as references. The chi square test was used for independent sample comparisons, while the McNemar’s test was used to test for the dependence of categorical data in paired sample testing. A p < 0.05 was considered significant in all comparisons. The R (v.4.0.2) software was used for analyses. Results: A total of 1126 participants consented for the study in the four sites. The diagnostic accuracy of the CareStart Pf mRDT was 0.93.6% (0.911–0.961) in Yaoundé, 0.930% (0.90–0.960) in Ngounso, 0.84% (0.794–0.891) in St Vincent Catholic Hospital Dschang and 0.407 (0.345–0.468) in Dschang district hospital. For SD Bioline Pf/PAN the accuracy was 0.759 (0.738–0.846) for St Vincent Catholic Hospital Dschang and 0.426 (0.372–0.496) for the Dschang district hospital. The accuracy was slightly lower in each case but not statistically different when PCR was considered as the reference. The likelihood ratios of the positive and negative tests were high in the high transmission settings of Yaoundé (10.99 (6.24–19.35)) and Ngounso (14.40 (7.89–26.28)) compared to the low transmission settings of Dschang (0.71 (0.37–1.37)) and St Vincent Catholic hospital (7.37 (4.32−12.59)). There was a high degree of agreement between the tests in Yaoundé (Cohen’s Kappa: 0.85 ± 0.05 (0.7–0.95)) and Ngounso (Cohen’s Kappa: 0.86 ± 0.05 (0.74, 0.97)) and moderate agreement in St Vincent hospital Dschang (k: 0.58 ± 0.06 (0.44–0.71)) and poor agreement in the District Hospital Dschang (Cohen’s Kappa: −0.11 ± 0.05 (−0.21–0.01)). The diagnostic indicators of the SD Bioline Pf/PAN were slightly better than for CareStart Pf mRDT in St Vincent Catholic hospital Dschang, irrespective of the reference test. Conclusions: Publicly procured malaria rapid diagnostic tests in Cameroon have maintained high accuracy (91–94%) in the clinical diagnosis of malaria in high malaria transmission regions of Cameroon, although they failed to reach WHO standards. We observed an exception in the low transmission region of Dschang, West region, where the accuracy tended to be lower and variable between facilities located in this town. These results underscore the importance of the routine monitoring of the quality and performance of malaria RDTs in diverse settings in malaria endemic areas.

Usability of a point-of-care diagnostic to identify glucose-6-phosphate dehydrogenase deficiency: a multi-country assessment of test label comprehension and results interpretation

Background

Point-of-care glucose-6-phosphate dehydrogenase (G6PD) testing has the potential to make the use of radical treatment for vivax malaria safer and more effective. Widespread use of G6PD tests as part of malaria case management has been limited, in part due to due concerns regarding product usability, user training, and supervision. This study seeks to assess how well end users can understand the Standard™ G6PD Test (SD Biosensor, Suwon, South Korea) workflow, result output, and label after training. This will ultimately help inform test registration and introduction.

Methods

Potential G6PD test users who provide malaria case management at three sites in Brazil, Ethiopia, and India were trained on the use of the SD Biosensor Standard G6PD Test and assessed based on their ability to understand the test workflow and interpret results. The assessment was done through a questionnaire, designed to assess product usability against key technical product specifications and fulfill regulatory evidence requirements. Any participant who obtained 85% or above correct responses to the questionnaire was considered to adequately comprehend how to use and interpret the test.

Results

Forty-five participants, including malaria microscopists, laboratory staff, nurses, and community health workers took part in the study. Seventy-eight percent of all participants in the study (35/45) obtained passing scores on the assessment with minimal training. Responses to the multiple-choice questions indicate that most participants understood well the test intended use, safety claims, and warnings. The greatest source of error regarding the test was around the correct operating temperature. Most test results were also read and interpreted correctly, with the haemoglobin measurement being a more problematic output to interpret than the G6PD measurement.

Conclusions

These data results show how a standardized tool can be used to assess a user’s ability to run a point-of-care diagnostic and interpret results. When applied to the SD Biosensor Standard G6PD Test, this tool demonstrates that a range of users across multiple contexts can use the test and suggests improvements to the test instructions and training that can improve product usability, increase user comprehension, and ultimately contribute to more widespread effective use of point-of-care G6PD tests.

Trial registration: NCT04033640

Free Market Availability of Rapid Diagnostics Will Empower Communities To Control Malaria in India

Globally, malaria incidence has declined but further reductions in malaria are not evident in many countries. In addition to the public health approaches for tackling malaria, involvement of the private sector is vital because the private sector plays a central role in healthcare delivery to the masses. In India, malaria management is primarily provided through government programs, nonetheless, significant numbers of fever patients continue to seek healthcare in the private sector. The private sector in India is comprised of formal healthcare (qualified and approved), informal healthcare (unqualified, untrained), including traditional healers. Commercial channels for the procurement of quality-assured malaria diagnostics like rapid diagnostic tests via pharmacies or other approved outlets would empower Indian populations to self-detect malaria without delay. Easier access would minimize the diagnostic time gap, reduce costs to the patient, prevent inappropriate malaria treatment, and foster timely treatment of both malaria and non-malaria infections. Commercially available rapid diagnostic tests in the hands of the people could be an important tool in our fight against malaria.

Subsidise the test, the treatment or both? Results of an individually randomised controlled trial of the management of suspected malaria fevers in the retail sector in western Kenya

INTRODUCTION

In many malaria-endemic countries, the private retail sector is a major source of antimalarial drugs. However, the rarity of malaria diagnostic testing in the retail sector leads to overuse of the first-line class of antimalarial drugs known as artemisinin-combination therapies (ACTs). The goal of this study was to identify the combination of malaria rapid diagnostic test (RDT) and ACT subsidies that maximises the proportion of clients seeking care in a retail outlet that choose to purchase an RDT (RDT uptake) and use ACTs appropriately.

METHODS

842 clients seeking care in 12 select retail outlets in western Kenya were recruited and randomised into 4 arms of different combinations of ACT and RDT subsidies, with ACT subsidies conditional on a positive RDT. The outcomes were RDT uptake (primary) and appropriate and targeted ACT use (secondary). Participants' familiarity with RDTs and their confidence in test results were also evaluated.

RESULTS

RDT uptake was high (over 96%) across the study arms. Testing uptake was 1.025 times higher (98% CI 1.002 to 1.049) in the RDT subsidised arms than in the unsubsidised groups. Over 98% of clients were aware of malaria testing, but only 35% had a previous experience with RDTs. Nonetheless, confidence in the accuracy of RDTs was high. We found high levels of appropriate use and targeting of ACTs, with 86% of RDT positives taking an ACT, and 93.4% of RDT negatives not taking an ACT. The conditional ACT subsidy did not affect the RDT test purchasing behaviour (risk ratio: 0.994; 98% CI 0.979 to 1.009).

CONCLUSION

Test dependent ACT subsidies may contribute to ACT targeting. However, in this context, high confidence in the accuracy of RDTs and reliable supplies of RDTs and ACTs likely played a greater role in testing uptake and adherence to test results.

Considerations for quality assurance of multiplex malaria antigen detection assays with large sample sets

Multiplex assays for malaria antigen detection can gather data from large sample sets, but considerations for the consistency and quality assurance (QA) of mass testing lack evaluation. We present a QA framework for a study occurring November 2019 to March 2020 involving 504 assay plates detecting four Plasmodium antigens: pan-Plasmodium aldolase and lactate dehydrogenase (LDH), histidine-rich protein 2 (HRP2), P. vivax LDH (PvLDH). Controls on each plate included buffer blank, antigen negative blood, and 4-point positive dilution curve. The blank and negative blood provided consistently low signal for all targets except for pAldolase, which showed variability. Positive curve signals decreased throughout the 5-month study duration but retained a coefficient of variation (CV) of < 5%, with the exception of HRP2 in month 5 (CV of 11%). Regression fittings for inter-plate control signals provided mean and standard deviations (SDs), and of 504 assay plates, 6 (1.2%) violated the acceptable deviation limits and were repeated. For the 40,272 human blood samples assayed in this study, of 161,088 potential data points (each sample × 4 antigens), 160,641 (99.7%) successfully passed quality checks. The QA framework presented here can be utilized to ensure quality of laboratory antigen detection for large sample sets.

Community Health Workers Can Provide Psychosocial Support to the People During COVID-19 and Beyond in Low- and Middle- Income Countries

The COVID-19 pandemic has been the most challenging public health issue which not only affected the physical health of the global population but also aggravated the mental health conditions such as stress, anxiety, fear, depression and anger. While mental health services are seriously hampered amid this COVID-19 pandemic, health services, particularly those of Low- and Middle- Income Countries (LMICs) are looking for alternatives to provide psychosocial support to the people amid this COVID-19 and beyond. Community Health Workers (CHWs) are an integral part of the health systems in many LMICs and played significant roles such as health education, contact tracing, isolation and mobilization during past emergencies and amid COVID-19 in many LMICs. However, despite their potentials in providing psychosocial support to the people amid this COVID-19 pandemic, they have been underutilized in most health systems in LMICs. The CHWs can be effectively engaged to provide psychosocial support at the community level. Engaging them can also be cost-saving as they are already in place and may cost less compared to other health professionals. However, they need training and supervision and their safety and security needs to be protected during this COVID-19. While many LMICs have mental health policies but their enactment is limited due to the fragility of health systems and limited health care resources. CHWs can contribute in this regard and help to address the psychosocial vulnerabilities of affected population in LMICs during COVID-19 and beyond.

Plasmodium falciparum Histidine-Rich Protein 2 and 3 Gene Deletions in Strains from Nigeria, Sudan, and South Sudan

Deletion of histidine-rich protein genes pfhrp2/3 in Plasmodium falciparum causes infections to go undetected by HRP2-based malaria rapid diagnostic tests. We analyzed P. falciparum malaria cases imported to Australia (n = 210, collected 2010–2018) for their pfhrp2/3 status. We detected gene deletions in patients from 12 of 25 countries. We found >10% pfhrp2-deletion levels in those from Nigeria (13.3%, n = 30), Sudan (11.2%, n = 39), and South Sudan (17.7%, n = 17) and low levels of pfhrp3 deletion from Sudan (3.6%) and South Sudan (5.9%). No parasites with pfhrp2/3 double deletions were detected. Microsatellite typing of parasites from Nigeria, Sudan, and South Sudan revealed low relatedness among gene-deleted parasites, indicating independent emergences. The gene deletion proportions signify a risk of false-negative HRP2-RDT results. This study’s findings warrant surveillance to determine whether the prevalence of gene-deleted parasites justifies switching malaria rapid diagnostic tests in Nigeria, Sudan, and South Sudan.

Real-life implementation of a G6PD deficiency screening qualitative test into routine vivax malaria diagnostic units in the Brazilian Amazon (SAFEPRIM study)

Background

Glucose-6-phosphate dehydrogenase (G6PD) deficiency greatly hinders Plasmodium vivax malaria radical cure and further elimination due to 8-aminoquinolines-associated hemolysis. Although the deleterious health effects of primaquine in G6PD deficient individuals have been known for over 50 years, G6PD testing is not routinely performed before primaquine treatment in most P. vivax endemic areas.

Method/Principal findings

The qualitative CareStart G6PD screening test was implemented in 12 malaria treatment units (MTUs) in the municipality of Rio Preto da Eva, Western Brazilian Amazon, a malaria endemic area, between February 2019 and early January 2020. Training materials were developed and validated; evaluations were conducted on the effectiveness of training health care professionals (HCPs) to perform the test, the interpretation and reliability of routine testing performed by HCPs, and perceptions of HCPs and patients. Most HCPs were unaware of G6PD deficiency and primaquine-related adverse effects. Most of 110 HCPs trained (86/110, 78%) were able to correctly perform the G6PD test after a single 4-hour training session. The test performed by HCPs during implementation showed 100.0% (4/4) sensitivity and 68.1% (62/91) specificity in identifying G6PD deficient patients as compared to a point-of-care quantitative test (Standard G6PD).

Conclusions/Significance

G6PD screening using the qualitative CareStart G6PD test performed by HCPs in MTUs of an endemic area showed high sensitivity and concerning low specificity. The amount of false G6PD deficiency detected led to substantial loss of opportunities for radical cure.

Glucose 6-phosphate dehydrogenase deficiency (G6PDd) has greatly impacted the treatment of Plasmodium vivax malaria because of the red blood cell destruction in what is known as hemolysis. Primaquine, used to clear dormant liver parasites that cause relapses of the disease, is a well-known trigger that may lead to life-threatening complications in patients with this condition. Although there are several G6PDd diagnostic tests available to guide the decision of weekly or daily primaquine treatment, they are not yet routinely used: questions on how, when, where and who is going to perform the test remain unanswered. This study revealed that, although G6PDd was not previously known by most of the healthcare workers, they were able to perform the test after a single training session. The test performed well in the field, differentiating patients that cannot use daily primaquine from the others, but some expected limitations require further action to be taken into consideration. This research provides an important overall understanding that may aid policy makers in the process of recommending proven interventions, such as G6PDd screening, to implement them pragmatically.

First evidence of local circulation of Plasmodium ovale curtisi and reliability of a malaria rapid diagnostic test among symptomatic outpatients in Douala, Cameroon

The performances of a commonly used Plasmodium falciparum-detecting rapid diagnostic test (RDT) were determined in symptomatic individuals living in Cameroon. Discrepancies between RDT and light microscopy (LM) results were further investigated, with a focus on non-falciparum malaria (NFM) which are still largely understudied in sub-Saharan Africa (sSA) countries. In the present study, a total of 355 individuals aged 1-65 years were enrolled in the study. Their signs/symptoms and sociodemographic characteristics were documented. The RDT reliability was evaluated using LM as gold standard method. Polymerase chain reaction (PCR) of Plasmodium 18S gene was performed for samples with discordant results between LM and RDT (i.e., RDT-/LM+, and RDT+/LM-). The PCR amplicons of NFM species were sequenced and BLASTed. The prevalence of malaria infection by LM was 95.7% (95% CI: 93.1-97.4%). The sensitivity and specificity of RDT for P. falciparum detection was 94.0% and 66.7%, respectively. By PCR assay, P. ovale curtisi (PoC) was found in 5 of the 30 discordant samples, and on sequence analysis these isolates were found to be phylogenetically closer to sequences reported from China-Myanmar border and Malaysia. This is the first report on molecular characterization of P. ovale subspecies in Cameroon. The study also outlines the good diagnostic performances of the RDT for detection of P. falciparum. Though, the presence of PoC indicated the importance of having RDTs targeting the NFM species in malaria diagnosis and treatment, which is presently limited in the country.

Malaria micro-stratification using routine surveillance data in Western Kenya

BACKGROUND

There is an increasing need for finer spatial resolution data on malaria risk to provide micro-stratification to guide sub-national strategic plans. Here, spatial-statistical techniques are used to exploit routine data to depict sub-national heterogeneities in test positivity rate (TPR) for malaria among patients attending health facilities in Kenya.

METHODS

Routine data from health facilities (n = 1804) representing all ages over 24 months (2018-2019) were assembled across 8 counties (62 sub-counties) in Western Kenya. Statistical model-based approaches were used to quantify heterogeneities in TPR and uncertainty at fine spatial resolution adjusting for missingness, population distribution, spatial data structure, month, and type of health facility.

RESULTS

The overall monthly reporting rate was 78.7% (IQR 75.0-100.0) and public-based health facilities were more likely than private facilities to report ≥ 12 months (OR 5.7, 95% CI 4.3-7.5). There was marked heterogeneity in population-weighted TPR with sub-counties in the north of the lake-endemic region exhibiting the highest rates (exceedance probability > 70% with 90% certainty) where approximately 2.7 million (28.5%) people reside. At micro-level the lowest rates were in 14 sub-counties (exceedance probability < 30% with 90% certainty) where approximately 2.2 million (23.1%) people lived and indoor residual spraying had been conducted since 2017.

CONCLUSION

The value of routine health data on TPR can be enhanced when adjusting for underlying population and spatial structures of the data, highlighting small-scale heterogeneities in malaria risk often masked in broad national stratifications. Future research should aim at relating these heterogeneities in TPR with traditional community-level prevalence to improve tailoring malaria control activities at sub-national levels.

High value of rapid diagnostic tests to diagnose malaria within children: A systematic review and meta-analysis

Background

Children aged under five years accounted for 61% of all malaria deaths worldwide in 2017, and quicker differential diagnosis of malaria fever is vital for them. Rapid diagnostic tests (RDTs) are strips to detect

Plasmodium

specific antigens promptly and are helpful in resource-limited areas. Thus, our aim is to assess the diagnostic accuracy of RDTs for malaria in children against the gold standard.

Methods

MEDLINE, Web of Science, EMBASE, Cochrane Library, the China National Knowledge Infrastructure, Wanfang, and Sinomed databases were systematically searched on August 23, 2019. Studies that compared RDTs with microscopy or polymerase chain reaction in malaria diagnoses for children were eligible. Relevant data were extracted. The quality of studies was evaluated using the revised Quality Assessment of Diagnostic Accuracy Studies instrument. Meta-analyses were carried out to calculate the pooled estimates and 95% confidence intervals of sensitivity and specificity.

Results

51 articles were included. For diagnostic accuracy, the pooled estimates of the sensitivity and specificity of RDTs were 0.93 (95% confidence interval (CI) = 0.90, 0.95) and 0.93 (95% CI = 0.90, 0.96) respectively. Studies were highly heterogeneous, and subgroup analyses showed that the application of RDTs in high malaria transmission areas had higher sensitivity but lower specificity than those in low-to-moderate areas.

Conclusions

RDTs have high accuracy for malaria diagnosis in children, and this characteristic is more prominent in high transmission areas. As they also have the advantages of rapid-detection, are easy-to-use, and can be cost-effective, it is recommended that the wider usage of RDTs should be promoted, especially in resource-limited areas. Further research is required to assess their performance in WHO South-East Asia and Americas Region.

Field performance of ultrasensitive and conventional malaria rapid diagnostic tests in southern Mozambique

Background

An ultrasensitive malaria rapid diagnostic test (RDT) was recently developed for the improved detection of low-density Plasmodium falciparum infections. This study aimed to compare the diagnostic performance of the PfHRP2-based Abbott Malaria Ag P. falciparum ultrasensitive RDT (uRDT) to that of the conventional SD-Bioline Malaria Ag P. falciparum RDT (cRDT) when performed under field conditions.

Methods

Finger-prick blood samples were collected from adults and children in two cross-sectional surveys in May of 2017 in southern Mozambique. Using real-time quantitative PCR (RT-qPCR) as the reference method, the age-specific diagnostic performance indicators of the cRDT and uRDT were compared. The presence of histidine-rich protein 2 (HRP2) and Plasmodium lactate dehydrogenase (pLDH) antigens was evaluated in a subset from dried blood spots by a quantitative antigen assay. pfhrp2 and pfhrp3 gene deletions were assessed in samples positive by RT-qPCR and negative by both RDTs.

Results

Among the 4,396 participants with complete test results, the sensitivity of uRDTs (68.2; 95% CI 60.8 to 74.9) was marginally better than that of cRDTs (61.5; 95% CI 53.9 to 68.6) (p-value = 0.004), while the specificities were similar (uRDT: 99.0 [95% CI 98.6 to 99.2], cRDT: 99.2 [95% CI 98.9 to 99.4], p-value = 0.02). While the performance of both RDTs was lowest in ≥ 15-year-olds, driven by the higher prevalence of low parasite density infections in this group, the sensitivity of uRDTs was significantly higher in this age group (54.9, 95% CI 40.3 to 68.9) compared to the sensitivity of cRDTs (39.2, 95% CI 25.8 to 53.9) (p-value = 0.008). Both RDTs detected P. falciparum infections at similar geometric mean parasite densities (112.9  parasites/μL for uRDTs and 145.5 parasites/μL for cRDTs). The presence of HRP2 antigen was similar among false positive (FP) samples of both tests (80.5% among uRDT-FPs and 84.4% among cRDT-FPs). Only one false negative sample was detected with a partial pfhrp2 deletion.

Conclusion

This study showed that the uRDTs developed by Abbott do not substantially outperform SD-Bioline Pf malaria RDTs in the community and are still not comparable to molecular methods to detect P. falciparum infections in this study setting.