Comparative field performance and adherence to test results of four malaria rapid diagnostic tests among febrile patients more than five years of age in Blantyre, Malawi

Diagnostic accuracy of DPP Fever Panel II Asia tests for tropical fever diagnosis

BACKGROUND

Fever is the most frequent symptom in patients seeking care in South and Southeast Asia. The introduction of rapid diagnostic tests (RDTs) for malaria continues to drive patient management and care. Malaria-negative cases are commonly treated with antibiotics without confirmation of bacteraemia. Conventional laboratory tests for differential diagnosis require skilled staff and appropriate access to healthcare facilities. In addition, introducing single-disease RDTs instead of conventional laboratory tests remains costly. To overcome some of the delivery challenges of multiple separate tests, a multiplexed RDT with the capacity to diagnose a diverse range of tropical fevers would be a cost-effective solution. In this study, a multiplex lateral flow immunoassay (DPP Fever Panel II Assay) that can detect serum immunoglobulin M (IgM) and specific microbial antigens of common fever agents in Asia (Orientia tsutsugamushi, Rickettsia typhi, Leptospira spp., Burkholderia pseudomallei, Dengue virus, Chikungunya virus, and Zika virus), was evaluated.

METHODOLOGY/PRINCIPAL FINDINGS

Whole blood (WB) and serum samples from 300 patients with undefined febrile illness (UFI) recruited in Vientiane, Laos PDR were tested using the DPP Fever Panel II, which consists of an Antibody panel and Antigen panel. To compare reader performance, results were recorded using two DPP readers, DPP Micro Reader (Micro Reader 1) and DPP Micro Reader Next Generation (Micro Reader 2). WB and serum samples were run on the same fever panel and read on both micro readers in order to compare results. ROC analysis and equal variance analysis were performed to inform the diagnostic validity of the test compared against the respective reference standards of each fever agent (S1 Table). Overall better AUC values were observed in whole blood results. No significant difference in AUC performance was observed when comparing whole blood and serum sample testing, except for when testing for R. typhi IgM (p = 0.04), Leptospira IgM (p = 0.02), and Dengue IgG (p = 0.03). Linear regression depicted R2 values had ~70% agreement across WB and serum samples, except when testing for leptospirosis and Zika, where the R2 values were 0.37 and 0.47, respectively. No significant difference was observed between the performance of Micro Reader 1 and Micro Reader 2, except when testing for the following pathogens: Zika IgM, Zika IgG, and B pseudomallei CPS Ag.

CONCLUSIONS/SIGNIFICANCE

These results demonstrate that the diagnostic accuracy of the DPP Fever Panel II is comparable to that of commonly used RDTs. The optimal cut-off would depend on the use of the test and the desired sensitivity and specificity. Further studies are required to authenticate the use of these cut-offs in other endemic regions. This multiplex RDT offers diagnostic benefits in areas with limited access to healthcare and has the potential to improve field testing capacities. This could improve tropical fever management and reduce the public health burden in endemic low-resource areas.

Sensitivity and specificity of DPP® Fever Panel II Asia in the diagnosis of malaria, dengue and melioidosis

Introduction. Rapid diagnostic tests (RDTs) that can facilitate the diagnosis of a panel of tropical infectious diseases are critically needed. DPP® Fever Panel II Asia is a multiplex lateral flow immunoassay comprising antigen and IgM panels for the diagnosis of pathogens that commonly cause febrile illness in Southeast Asia.Hypothesis/Gap Statement. Accuracy of DPP® Fever Panel II Asia has not been evaluated in clinical studies.Aim. To evaluate the sensitivity and specificity of DPP® Fever Panel II Asia for malaria, dengue and melioidosis.Methodology. We conducted a cohort-based case-control study. Both cases and controls were derived from a prospective observational study of patients presenting with community-acquired infections and sepsis in northeast Thailand (Ubon sepsis). We included 143 and 98 patients diagnosed with malaria or dengue based on a positive PCR assay and 177 patients with melioidosis based on a culture positive for Burkholderia pseudomallei. Controls included 200 patients who were blood culture-positive for Staphylococcus aureus, Escherichia coli or Klebsiella pneumoniae, and cases of the other diseases. Serum samples collected from all patients within 24 h of admission were stored and tested using the DPP® Fever Panel II Asia antigen and IgM multiplex assays. We selected cutoff values for each individual assay corresponding to a specificity of ≥95 %. When assessing diagnostic tests in combination, results were considered positive if either individual test was positive.Results. Within the DPP® Fever Panel II Asia antigen assay, a combination of pLDH and HRPII for malaria had a sensitivity of 91 % and a specificity of 97 %. The combination of dengue NS1 antigen and dengue antibody tests had a sensitivity of 61 % and a specificity of 91 %. The B. pseudomallei CPS antigen test had a sensitivity of 27 % and a specificity of 97 %. An odds ratio of 2.34 (95 % CI 1.16-4.72, P=0.02) was observed for the association between CPS positivity and mortality among melioidosis patients.Conclusion. The performance of the DPP® Fever Panel II Asia for diagnosis of malaria was high and that for dengue and melioidosis was relatively limited. For all three diseases, performance was comparable to that of other established RDTs. The potential operational advantages of a multiplex and quantitative point-of-care assay are substantial and warrant further investigation.

Analysis of nucleic acids extracted from rapid diagnostic tests reveals a significant proportion of false positive test results associated with recent malaria treatment

BACKGROUND

Surveillance programmes often use malaria rapid diagnostic tests (RDTs) to determine the proportion of the population carrying parasites in their peripheral blood to assess the malaria transmission intensity. Despite an increasing number of reports on false-negative and false-positive RDT results, there is a lack of systematic quality control activities for RDTs deployed in malaria surveillance programmes.

METHODS

The diagnostic performance of field-deployed RDTs used for malaria surveys was assessed by retrospective molecular analysis of the blood retained on the tests.

RESULTS

Of the 2865 RDTs that were collected in 2018 on Bioko Island and analysed in this study, 4.7% had a false-negative result. These false-negative RDTs were associated with low parasite density infections. In 16.6% of analysed samples, masked pfhrp2 and pfhrp3 gene deletions were identified, in which at least one Plasmodium falciparum strain carried a gene deletion. Among all positive RDTs analysed, 28.4% were tested negative by qPCR and therefore considered to be false-positive. Analysing the questionnaire data collected from the participants, this high proportion of false-positive RDTs could be explained by P. falciparum histidine rich protein 2 (PfHRP2) antigen persistence after recent malaria treatment.

CONCLUSION

Malaria surveillance depending solely on RDTs needs well-integrated quality control procedures to assess the extent and impact of reduced sensitivity and specificity of RDTs on malaria control programmes.

Overdiagnosis of Malaria Illness in an Endemic Setting: A Facility-Based Surveillance Study in Malawi

In endemic settings where asymptomatic malaria infections are common, malaria infection can complicate fever diagnosis. Factors influencing fever misdiagnosis, including accuracy of malaria rapid diagnostic tests (mRDTs) and the malaria-attributable fraction of fevers (MAF), require further investigation. We conducted facility-based surveillance in Malawi, from January 2012 through December 2013 in settings of high perennial (Chikhwawa), high seasonal (Thoylo), and moderate seasonal (Ndirande) malaria transmission. Consecutive patients presenting to outpatient departments were screened; those with suspected malaria illness were tested by mRDT or routine thick-smear microscopy. Test positivity rates (TPRs), positive predictive value (PPVs) of mRDTs, and MAFs were calculated by site, age, and season. Of 41,471 patients, 10,052 (24.2%) tested positive for malaria. The TPR was significantly greater in Chikhwawa (29.9%; 95% CI, 28.6-30.0) compared with Thyolo (13.2%; 95% CI, 12.5-13.7) and Ndirande (13.1%; 95% CI, 12.2-14.4). The overall PPV was 77.8% (95% CI, 76.8-78.7); it was lowest among infants (69.9%; 95% CI, 65.5-74.2) and highest among school-age children (81.9%; 95% CI, 80.3-83.4). Malaria infection accounted for about 50% of fevers in children younger than 5 years old with microscopy-confirmed Plasmodium falciparum infection, and less than 20% of such fevers in school-age children. Outpatient settings in Malawi had a high burden of malaria illness, but also possible overdiagnosis of malaria illness. Interventions to reduce malaria transmission and rapid testing for other common febrile illness may improve diagnostic clarity among outpatients in malaria endemic settings.

Diagnosis of clinical malaria in endemic settings

INTRODUCTION

Malaria continues to be a major global health problem, with over 228 million cases and 405,000 deaths estimated to occur annually. Rapid and accurate diagnosis of malaria is essential to decrease the burden and impact of this disease, particularly in children. We aimed to review the main available techniques for the diagnosis of clinical malaria in endemic settings and explore possible future options to improve its rapid recognition.

AREAS COVERED

literature relevant to malaria diagnosis was identified through electronic searches in Pubmed, with no language or date restrictions and limited to humans.

EXPERT OPINION

Light microscopy is still considered the gold standard method for malaria diagnosis and continues to be at the frontline of malaria diagnosis. However, technologies as rapid diagnostic tests, mainly those who detect histidine-rich protein-2, offer an accurate, rapid and affordable alternative for malaria diagnosis in endemic areas. They are now the technique most extended in endemic areas for parasitological confirmation. In these settings, PCR-based assays are usually restricted to research and they are not currently helpful in the management of clinical malaria. Other technologies, such as isothermal methods could be an interesting and alternative approach to PCR in the future.

Malaria Test, Treat and Track policy implementation in Angola: a retrospective study to assess the progress achieved after 4 years of programme implementation

Background

Malaria is one of the main causes of death in Angola, particularly among children under 5 years of age. An essential means to improve the situation is with strong malaria case management; this includes diagnosing suspected patients with a confirmatory test, either with a rapid diagnostic test (RDT) or microscopy, prompt and correct treatment with artemisinin-based combination therapy (ACT), and proper case registration (track). In 2011, the United States President’s Malaria Initiative (PMI) launched a country-wide programme to improve malaria case management through the provision of regular training and supervision at different levels of health care provision. An evaluation of malaria testing, treatment and registration practices in eight provinces, and at health facilities of various capacities, across Angola was conducted to assess progress of the national programme implementation.

Methods

A retrospective assessment analysed data collected during supervision visits to health facilities conducted between 2012 and 2016 in 8 provinces in Angola. The supervision tool used data collected for malaria knowledge, testing, treatment and case registration practices among health workers as well as health facilities stock outs from different levels of health care delivery. Contingency tables with Pearson chi-squared (χ²) tests were used to identify factors associated with “knowledge”, “test”, “treat” and “track.” Multivariable logistic regression models were used to assess factors associated with the defined outcomes.

Results

A total of 7156 supervisions were conducted between September 2012 and July 2016. The overall knowledge, testing, treatment and tracking practices among health care workers (HCWs) increased significantly from 2013 to 2016. Health care workers in 2016 were 3.3 times (95% CI: 2.7–3.9) as likely to have a higher knowledge about malaria case management as in 2013 (p < 0.01), 7.4 (95% CI: 6.1–9.0) times as likely to test more suspected cases (p < 0.01), 10.9 (95% CI: 8.6–13.6) times as likely to treat more confirmed cases (p < 0.01) and 3.7 (95% CI: 3.2–4.4) times as likely to report more accurately in the same period (p < 0.01).

Discussion

Improvements demonstrated in knowledge about malaria case management, testing with RDT and treatment with artemisinin-based combinations among HCWs is likely associated with malaria case management trainings and supportive supervisions. Gaps in testing and treatment practices are associated with RDT and ACT medicines stock outs in health facilities. Tracking of malaria cases still poses a major challenge, despite training and supervision. Hospitals consistently performed better compared to other health facilities against all parameters assessed; likely due to a better profile of HCWs.

Conclusion

Significant progress in malaria case management in eight provinces Angola was achieved in the period of 2013–2016. Continued training and supportive supervision is essential to sustain gains and close existing gaps in malaria case management and reporting in Angola.

Comparative performance of four malaria rapid diagnostic tests, Vikia Malaria Pf/Pan, Meriline-Meriscreen Pf/Pv/Pan, Right Sign Malaria Pf/Pan, and Right Sign Malaria Pf, among febrile patients in Gabon

INTRODUCTION:

Rapid diagnostic tests (RDTs) are selected based on their performances. Here, we compared the diagnostic performance of different malaria RDTs.

METHODS:

Febrile patients were tested for malaria using Vikia Malaria Pf/Pan, Meriline-Meriscreen Pf/Pv/Pan, Right Sign Malaria Pf/Pan, and Right Sign Malaria Pf RDTs at Melen Regional Hospital in Gabon.

RESULTS:

In total, 120 of 274 tested children (43.8%) had malaria. The sensitivity was > 95% for all RDTs, while the specificity was > 85% for two tests. One test generated invalid tests (8%).

CONCLUSIONS:

Based on their performances, all tests except one may be recommended for malaria diagnosis.

Effect of pre-consultation testing on clinicians' adherence to malaria test results and waiting time among children under 5 years in the Northern Zone of Volta Region of Ghana

BACKGROUND

The Ministry of Health, Ghana, in accordance with global policy, recommends that all suspected malaria cases be confirmed parasitologically before treatment. Not all clinicians, however, base their treatment on test results. Patients also spend a lot of time at health facilities waiting to consult a clinician before being asked to go for testing and to see a clinician with test results. The purpose of the study was to determine if testing all children aged 6 to 59 months with fever reporting at an outpatients department (OPD) for malaria before consultation with a clinician (pre-consultation testing) will influence clinicians to adhere to test results and also reduce the time spent by such patients.

METHODS

A quasi-experimental study design was used involving two randomly selected government-owned hospitals in the Northern Volta, Ghana. In each hospital, 439 children were recruited between November 2018 and January 2019. The intervention hospital implemented pre-consultation testing. In the comparator arm, standard practices, which involved patients seeing the clinician before he/she decides whether to send the patient for testing or not, were maintained.

RESULTS

Out of 878 children screened the overall prevalence of malaria was 31.9% by malaria rapid diagnostic test (RDT) and 26.7% by microscopy. Clinicians in the intervention arm adhered more to the malaria test results than those in the comparator arm (93.2 vs. 84.3%; p < 0.001). The proportion of children who tested negative but were still diagnosed with malaria was significantly lower in the intervention arm compared to the comparator arm (8.4 vs. 21.2%: p < 0.001). Clinicians and mothers/caregivers in both arms preferred pre-consulting testing. Six out of every 10 mothers/caregivers in the comparator arm viewed the waiting time as 'too long'' compared to 4 out of every 10 mothers in the intervention arm. On average, patient waiting time was significantly lower in the intervention arm (2.61 h) than in the comparator arm (3.42 h).

CONCLUSION

Pre-consultation testing significantly improves clinicians' adherence to malaria test results, shortens patients' waiting time and leads to overall patient satisfaction. There is a need to establish RDT corners at OPDs of health facilities to implement pre-consultation testing.

Multilevel Analysis of Factors Associated with Treatment-Seeking Behaviors among Caregivers with Febrile Children in Malawi

Early diagnosis and treatment of childhood fever, an important sign of potentially serious infections such as malaria, is essential for controlling disease progression, and ultimately, preventing deaths. This study examined individual- and community-level factors associated with treatment-seeking behaviors and promptness in these behaviors among caregivers of febrile under-five children in Malawi. The 2015-2016 Malawi Demographic Health Survey was used to analyze a nationally representative sample of 4,133 under-five children who had fever within 2 weeks before the survey. A multilevel logistic regression model was used to examine the association between individual- and community-level factors and treatment-seeking behaviors. Approximately 67.3% of the caregivers reported seeking treatment for their febrile child, whereas only 46.3% reported promptly seeking treatment. Children from communities with moderate and high percentages of educated caregivers were more likely to be taken for treatment (adjusted odds ratio [aOR] = 1.26, 95% CI = 1.01-1.58 and aOR = 1.31, 95% CI = 1.02-1.70, respectively) than those from communities with a low percentage of educated caregivers. Children from communities with moderate and high percentages of caregivers complaining about the distance to a health facility were less likely to be taken for treatment (aOR = 0.74, 95% CI = 0.58-0.96 and aOR = 0.67, 95% CI = 0.51-0.88, respectively). At the individual level, having a cough in the last 2 weeks, region, religion, and having better health behaviors in other health dimensions were associated with fever treatment-seeking behaviors among Malawian caregivers. Programs aimed at improving treatment-seeking behaviors should consider these factors and the regional variations observed in this study.

Effect of Supportive Supervision on Performance of Malaria Rapid Diagnostic Tests in Sub-Saharan Africa

Rapid diagnostic tests (RDTs) are one of the primary tools used for parasitological confirmation of suspected cases of malaria. To ensure accurate results, health-care workers (HCWs) must conduct the RDT test correctly. Trained supervisors visited 3,603 facilities to assess RDT testing performance and conduct outreach training and supportive supervision activities in eight African countries between 2015 and 2017, using a 12-point checklist to determine if key steps were being performed. The proportion of HCWs performing each step correctly improved between 1.1 and 21.0 percentage points between the first and third visits. Health-care worker scores were averaged to calculate facility scores, which were found to be high: the average score across all facilities was 85% during the first visit and increased to 91% during the third visit. A regression analysis of these facility scores estimated that, holding key facility factors equal, facility performance improved by 5.3 percentage points from the first to the second visit (P < 0.001), but performance improved only by 0.6 percentage points (P = 0.10) between the second and third visits. Factors strongly associated with higher scores included the presence of a laboratory worker at the facility and the presence of at least one staff member with previous formal training in malaria RDTs. Findings confirm that a comprehensive quality assurance system of training and supportive supervision consistently, and often significantly, improves RDT performance.

A comparison of thick-film microscopy, rapid diagnostic test, and polymerase chain reaction for accurate diagnosis of Plasmodium falciparum malaria

Background

Accurate diagnosis of malaria is important for effective disease management and control. In Cameroon, presumptive clinical diagnosis, thick-film microscopy (TFM), and rapid diagnostic tests (RDT) are commonly used to diagnose cases of Plasmodium falciparum malaria. However, these methods lack sensitivity to detect low parasitaemia. Polymerase chain reaction (PCR), on the other hand, enhances the detection of sub-microscopic parasitaemia making it a much-needed tool for epidemiological surveys, mass screening, and the assessment of interventions for malaria elimination. Therefore, this study sought to determine the frequency of cases missed by traditional methods that are detected by PCR.

Methods

Blood samples, collected from 551 febrile Cameroonian patients between February 2014 and February 2015, were tested for P. falciparum by microscopy, RDT and PCR. The hospital records of participants were reviewed to obtain data on the clinical diagnosis made by the health care worker.

Results

The prevalence of malaria by microscopy, RDT and PCR was 31%, 45%, and 54%, respectively. However, of the 92% of participants diagnosed as having clinical cases of malaria by the health care worker, 38% were malaria-negative by PCR. PCR detected 23% and 12% more malaria infections than microscopy and RDT, respectively. A total of 128 (23%) individuals had sub-microscopic infections in the study population. The sensitivity of microscopy, RDT, and clinical diagnosis was 57%, 78% and 100%; the specificity was 99%, 94%, and 17%; the positive predictive values were 99%, 94%, and 59%; the negative predictive values were 66%, 78%, and 100%, respectively. Thus, 41% of the participants clinically diagnosed as having malaria had fever caused by other pathogens.

Conclusions

Malaria diagnostic methods, such as TFM and RDT missed 12–23% of malaria cases detected by PCR. Therefore, traditional diagnostic approaches (TFM, RDT and clinical diagnosis) are not adequate when accurate epidemiological data are needed for monitoring malaria control and elimination interventions.

Practice of antimalarial prescription to patients with negative rapid test results and associated factors among health workers in Oyo State, Nigeria

Introduction

Contrary to World Health Organizations recommendations, health workers (HWs) still prescribe antimalarials to malaria rapid diagnostic test (mRDT)-negative patients, thus increasing overuse and the risk of parasite resistance to the antimalarials. The reasons for this are not clear. We identified factors associated with antimalarial prescription to mRDT-negative patients.

Methods

We conducted a cross-sectional study among 423 HWs. Data on socio-demographic characteristics, training, supervision experience and fever management practices were collected. We tested associations between independent variables and prescription of antimalarials to mRDT-negative patients using Chi square and logistic regression at p < 0.05.

Results

The HWs were mostly community health workers (58.6%), with mean age of 41.0 (±8.8) years and 13.6 (± 9.0) years of professional practice. Females were 322 (76.1%) and 368 (87%) were married. Of the 423 HWs interviewed, 329 (77.8%) received training on mRDT use, 329 (80.6%) received supervision and 129 (30.5%) had good knowledge of causes of fever. Overall, 110 (26.0%) of the HWs prescribed antimalarials to mRDT-negative patients. A higher proportion of non-trained vs trained HWs [Adjusted Odds Ratio (aOR) = 4.9; 95% Confidence Interval (CI) (2.5-8.3)], and HWs having poor knowledge vs HWs having good knowledge of causes of fever [aOR = 1.9; 95% CI (1.0-3.5)], prescribed antimalarials to mRDT-negative patients.

Conclusion

HWs' lack of training on mRDT use and poor knowledge of causes of fever were associated with prescription of antimalarials to mRDT-negative patients. We recommend training on management of fever and mRDT use to reduce such inappropriate antimalarial prescriptions.

Diagnostic tools for tackling febrile illness and enhancing patient management

Most patients with acute infectious diseases develop fever, which is frequently a reason to visit health facilities in resource-limited settings. The symptomatic overlap between febrile diseases impedes their diagnosis on clinical grounds. Therefore, the World Health Organization promotes an integrated management of febrile illness. Along this line, we present an overview of endemic and epidemic etiologies of fever and state-of-the-art diagnostic tools used in the field. It becomes evident that there is an urgent need for the development of novel technologies to fulfill end-users' requirements. This need can be met with point-of-care and near-patient diagnostic platforms, as well as e-Health clinical algorithms, which co-assess test results with key clinical elements and biosensors, assisting clinicians in patient triage and management, thus enhancing disease surveillance and outbreak alerts. This review gives an overview of diagnostic technologies featuring a platform based approach: (i) assay (nucleic acid amplification technologies are examined); (ii) cartridge (microfluidic technologies are presented); (iii) instrument (various detection technologies are discussed); and at the end proposes a way that such technologies can be interfaced with electronic clinical decision-making algorithms towards a broad and complete diagnostic ecosystem.

Can malaria rapid diagnostic tests by drug sellers under field conditions classify children 5 years old or less with or without Plasmodium falciparum malaria? Comparison with nested PCR analysis

Background

Malaria rapid diagnostic tests (RDTs) available as dipsticks or strips, are simple to perform, easily interpretable and do not require electricity nor infrastructural investment. Correct interpretation of and compliance with the RDT results is a challenge to drug sellers. Thus, drug seller interpretation of RDT strips was compared with laboratory scientist re-reading, and PCR analysis of Plasmodium DNA extracted from RDT nitrocellulose strips and fast transient analysis (FTA) cards. Malaria RDT cassettes were also assessed as a potential source of Plasmodium DNA.

Methods

A total of 212 children aged between 2 and 60 months, 199 of whom had complete records at two study drug shops in south western Uganda participated in the study. Duplicate 5 μL samples of capillary blood were picked from the 212 children, dispensed onto the sample well of the CareStart™ Pf-HRP2 RDT cassette and a FTA, Whatman™ 3MM filter paper in parallel. The RDT strip was interpreted by the drug seller within 15–20 min, visually re-read centrally by laboratory scientist and from it; Plasmodium DNA was recovered and detected by PCR, and compared with FTA recovered P. falciparum DNA PCR detection.

Results

Malaria positive samples were 62/199 (31.2%, 95% CI 24.9, 38.3) by drug seller interpretation of RDT strip, 59/212 (27.8%, 95% CI 22.2, 34.3) by laboratory scientist, 55/212 (25.9%, 95% CI 20.0, 32.6) by RDT nitrocellulose strip PCR and 64/212 (30.2%, 95% CI 24.4, 37.7). The overall agreement between the drug seller interpretation and laboratory scientist re-reading of the RDT strip was 93.0% with kappa value of 0.84 (95% CI 0.75, 0.92). The drug seller compliance with the reported RDT results was 92.5%. The performance of the three diagnostic strategies compared with FTA-PCR as the gold standard had sensitivity between 76.6 and 86.9%, specificity above 90%, positive predictive values ranging from 79.0 to 89.8% and negative predictive values above 90%.

Conclusion

Drug sellers can use RDTs in field conditions and achieve acceptable accuracy for malaria diagnosis, and they comply with the RDT results. Plasmodium DNA can be recovered from RDT nitrocellulose strips even in the context of drug shops. Future malaria surveillance and diagnostic quality control studies with RDT cassette as a source of Plasmodium DNA are recommended.

Electronic supplementary material

The online version of this article (10.1186/s12936-018-2508-x) contains supplementary material, which is available to authorized users.

Compliance With Malaria Rapid Diagnostic Testing by Community Health Workers in 3 Malaria-Endemic Countries of Sub-Saharan Africa: An Observational Study

Background. The World Health Organization recommends that all malaria management be based on parasitological identification. We monitored performance of trained community health workers (CHWs) in adhering to this recommendation to restrict artemisinin-based combination therapies (ACTs) to positive rapid diagnostic test (RDT)–confirmed cases in children in 3 malaria-endemic sub-Saharan African countries.

Methods. In 33 villages in Burkina Faso, 45 villages in Nigeria, and 84 villages in Uganda, 265 CHWs were trained over a minimum of 3 days to diagnose malaria using RDTs (prepare, read, record results, and inform the patient about results) and treat RDT-confirmed uncomplicated malaria cases with ACTs. In Nigeria, CHWs were also taught to obtain a thick blood smear. Spent RDT kits and prepared blood slides were collected and interpreted independently in Burkina Faso and Nigeria to confirm CHWs' diagnoses. Interviews were held with 12 of 17 CHWs who prescribed ACTs for patients with RDT-negative test results, and with 16 of 29 caregivers to determine factors related to noncompliance.

Results. Of 12 656 patients treated with ACTs in the participating countries (5365 in Burkina Faso, 1648 in Nigeria, and 5643 in Uganda), 29 patients (8 from Burkina Faso, 17 from Nigeria, 4 from Uganda) were RDT negative. The small number of RDT-negative ACT-treated cases limits statistical analysis. Only a few CHWs were involved, and they were more likely to be traders rather than farmers (odds ratio [OR], 6.15; 95% confidence interval [CI], 2.09–18.07; P = .0004). RDT-negative children who were treated with ACTs had a significantly higher probability of residing in a village other than that of the CHW (OR, 3.85; 95% CI, 1.59–9.30; P = .0018). Parental pressure was identified in interviews with parents.

Conclusions. Noncompliance with results of RDT tests is relatively rare when CHWs are trained and well supervised.

Clinical Trials Registration. ISRCTN13858170.

Evaluation of Diagnostic Accuracy of Rapid Diagnostic Test for Malaria Diagnosis among Febrile Children in Calabar, Nigeria

Background

The WHO recommends that all cases of suspected malaria should undergo parasitological test. Currently, the parasitological test comprises the rapid diagnostic test (RDT) or the microscopy. The performance of RDT in relation to microscopy is yet to be fully comprehended.

Objectives

This study evaluated the diagnostic accuracy of RDT as against the diagnosis provided by microscopy in detecting malaria parasites among febrile under-5 children.

Design

The study was a cross-sectional hospital-based design.

Materials and Methods

Capillary blood samples were collected from 167 children who came to the hospital with a history of fever over a period of 6 months. The Paracheck-Pf RDT kit was used and its performance was compared with the gold standard, microscopy using thick film.

Results

The prevalence of malaria infection was 41.9%. On comparing RDT with microscopy (microscopy assumed to be 100% sensitive and specific), RDT had a sensitivity of 51.4% and a specificity of 73.2%. The false-positive rate was 26.8% whereas the false-negative rate was 48.6%. The positive predictive value was 58.1% whereas the negative predictive value (NPV) was 67.6%. The RDT also had a positive likelihood ratio (LR) of 1.92 and a negative LR of 0.67. The RDT test accuracy was 64.1%.

Conclusion

Malaria prevalence among febrile children was found to be high. The findings also suggest that inconsistencies in the performance of RDT kits may arise from many extraneous factors, and as such, they should not be used as a stand-alone test kit except a prior batch/lot validation test was carried on them.

The Impact of Introducing Malaria Rapid Diagnostic Tests on Fever Case Management: A Synthesis of Ten Studies from the ACT Consortium

Since 2010, the World Health Organization has been recommending that all suspected cases of malaria be confirmed with parasite-based diagnosis before treatment. These guidelines represent a paradigm shift away from presumptive antimalarial treatment of fever. Malaria rapid diagnostic tests (mRDTs) are central to implementing this policy, intended to target artemisinin-based combination therapies (ACT) to patients with confirmed malaria and to improve management of patients with nonmalarial fevers. The ACT Consortium conducted ten linked studies, eight in sub-Saharan Africa and two in Afghanistan, to evaluate the impact of mRDT introduction on case management across settings that vary in malaria endemicity and healthcare provider type. This synthesis includes 562,368 outpatient encounters (study size range 2,400-432,513). mRDTs were associated with significantly lower ACT prescription (range 8-69% versus 20-100%). Prescribing did not always adhere to malaria test results; in several settings, ACTs were prescribed to more than 30% of test-negative patients or to fewer than 80% of test-positive patients. Either an antimalarial or an antibiotic was prescribed for more than 75% of patients across most settings; lower antimalarial prescription for malaria test-negative patients was partly offset by higher antibiotic prescription. Symptomatic management with antipyretics alone was prescribed for fewer than 25% of patients across all scenarios. In community health worker and private retailer settings, mRDTs increased referral of patients to other providers. This synthesis provides an overview of shifts in case management that may be expected with mRDT introduction and highlights areas of focus to improve design and implementation of future case management programs.

Accuracy of a Plasmodium falciparum specific histidine-rich protein 2 rapid diagnostic test in the context of the presence of non-malaria fevers, prior anti-malarial use and seasonal malaria transmission

Background

It remains challenging to distinguish malaria from other fever causing infections, as a positive rapid diagnostic test does not always signify a true active malaria infection. This study was designed to determine the influence of other causes of fever, prior anti-malarial treatment, and a possible seasonality of the performance of a PfHRP2 RDT for the diagnosis of malaria in children under-5 years of age living in a malaria endemic area.

Methods

A prospective etiology study was conducted in 2015 among febrile children under 5 years of age in Burkina Faso. In order to assess the influence of other febrile illnesses, prior treatment and seasonality on the performance of a PfHRP2 RDT in diagnosing malaria, the RDT results were compared with the gold standard (expert microscopic diagnosis of Plasmodium falciparum) and test results were analysed by assuming that prior anti-malarial use and bacterial/viral infection status would have been known prior to testing. To assess bacterial and viral infection status blood, urine and stool samples were analysed.

Results

In total 683 blood samples were analysed with microscopy and RDT-PfHRP2. Plasmodium falciparum malaria was diagnosed in 49.8% (340/683) by microscopy compared to 69.5% (475/683) by RDT-PfHRP2. The RDT-PfHRP2 reported 29.7% (141/475) false positive results and 1.8% (6/340) false negative cases. The RDT-PfHRP2 had a high sensitivity (98.2%) and negative predictive value (97.1%), but a low specificity (58.9%) and positive predictive value (70.3%). Almost 50% of the alternative cause of fever were diagnosed by laboratory testing in the RDT false positive malaria group.

Conclusions

The use of a malaria RDT-PfHRP2 in a malaria endemic area may cause misdiagnosis of the actual cause of fever due to false positive test results. The development of a practical diagnostic tool to screen for other causes of fever in malaria endemic areas is required to save lives.

Clinical outcomes among febrile children aged 2 to 59 months with negative malaria rapid diagnostic test results in Mchinji District, Malawi

BACKGROUND

Malawi malaria treatment guidelines recommend a definitive diagnosis, using a malaria rapid diagnostic test (mRDT), for all patients with fever or history of fever. Improving the management and outcomes of febrile children with negative mRDT results should be a priority.

METHODS

Through a prospective cohort study designed to investigate clinical outcomes of children treated at the community level, we followed, for 7 days, children aged 2 to 59 months, who had negative mRDT results and were treated with antipyretic medication. Clinical outcomes were assessed on days 3 and 7 post-recruitment.

RESULTS

The median age of recruited children was 19 months. Of the 285 children enrolled, 139 (48.8%) were females. Of the children for whom data were available for analysis, 95/236 (40.3%) had fever (temperature ≥ 37.5°C) at enrolment, and almost half of the sick children (125/268; 46.6%) had symptoms of upper respiratory tract infection. Most sick children (89.6%; 95% confidence interval, CI = 84.2 to 93.3) recovered, while 10.4% (95% CI: 6.7 to 15.8) were still sick by day 7 of follow-up. There were no deaths reported during the 7 days of follow-up. Being afebrile at enrolment (odds ratio, OR = 2.5; 95% CI = 1.1 to 6.0; P = 0.027) and sleeping under an insecticide-treated net (ITN) (OR = 2.7; 95% CI = 1.2 to 6.2; P = 0.011) were associated with recovery by day 7. In multivariable analysis, sleeping under an ITN the previous night was the only factor associated with recovery by day 7. Microscopy did not detect any malaria parasites in the blood of recruited children, at recruitment or on day 7.

CONCLUSIONS

In this community-level study, the majority of febrile children with negative mRDT results recovered within 7 days of health worker consultation for a febrile illness, having only taken antipyretics.

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

BACKGROUND

The World Health Organization recommends parasitological confirmation of malaria prior to treatment. Malaria rapid diagnostic tests (RDTs) represent one diagnostic method that is used in a variety of contexts to overcome limitations of other diagnostic techniques. Malaria RDTs increase the availability and feasibility of accurate diagnosis and may result in improved quality of care. Though RDTs are used in a variety of contexts, no studies have compared how well or effectively RDTs are used across these contexts. This review assesses the diagnostic use of RDTs in four different contexts: health facilities, the community, drug shops and schools.

METHODS

A comprehensive search of the Pubmed database was conducted to evaluate RDT execution, test accuracy, or adherence to test results in sub-Saharan Africa. Original RDT and Plasmodium falciparum focused studies conducted in formal health care facilities, drug shops, schools, or by CHWs between the year 2000 and December 2016 were included. Studies were excluded if they were conducted exclusively in a research laboratory setting, where staff from the study team conducted RDTs, or in settings outside of sub-Saharan Africa.

RESULTS

The literature search identified 757 reports. A total of 52 studies were included in the analysis. Overall, RDTs were performed safely and effectively by community health workers provided they receive proper training. Analogous information was largely absent for formal health care workers. Tests were generally accurate across contexts, except for in drug shops where lower specificities were observed. Adherence to RDT results was higher among drug shop vendors and community health workers, while adherence was more variable among formal health care workers, most notably with negative test results.

CONCLUSIONS

Malaria RDTs are generally used well, though compliance with test results is variable - especially in the formal health care sector. If low adherence rates are extrapolated, thousands of patients may be incorrectly diagnosed and receive inappropriate treatment resulting in a low quality of care and unnecessary drug use. Multidisciplinary research should continue to explore determinants of good RDT use, and seek to better understand how to support and sustain the correct use of this diagnostic tool.

The correlation between malaria RDT (Paracheck pf.®) faint test bands and microscopy in the diagnosis of malaria in Malawi

Background

Faint test bands of Paracheck Pf.® are interpreted as malaria positive according to world health organization (WHO) guideline. However if there are conspicuous number of faint test bands, a performance of Paracheck Pf.® could be influenced depending on whether interpreting faint test bands as malaria positive or negative. Finding out the frequency and accurate interpretation of faint test bands are important to prevent the overdiagnosis and drug resistance.

Methods

A cross-sectional, descriptive study was conducted to find out the frequency of faint test bands and evaluate the performance of Paracheck Pf.® by sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of diagnosis of Paracheck Pf.® using microscopy as the gold standard. 388 suspected patients with malaria in Malawi were recruited in this study. Malaria rapid diagnostic tests (RDTs) and microscopy were used and patients’ information which includes age, sex, body temperature and signs or symptoms of malaria were recorded.

Results

Among all patients involved in the study, 29.1% (113/388) were found malaria positive by RDT. Overall 5.4% (21/388) of all Paracheck Pf.® tests resulted in a “faint test band” and 85.7% (18/21) corresponded with malaria negative by microscopy. Faint test bands which corresponded with malaria positive by microscopy were lower parasite density and there are no patients who showed definitive symptom of malaria, such as fever. When Paracheck Pf.® “faint test bands” were classified as positive, accuracy of diagnosis was 76.5% (95% CI 72%–80.7%) as compared to 80.4% (95% CI 76.1%–84.2%) when Paracheck Pf.® “faint test bands” were classified as negative.

Conclusions

This study shows that frequency of faint test bands is 5.4% in all malaria RDTs. The accuracy of diagnosis was improved when faint test bands were interpreted as malaria negative. However information and data obtained in this study may not be enough and more intensive research including a frequency and property of faint test bands is needed for significant interpretation of faint test bands.

[Rapid diagnostic test for malaria]

The rapid diagnostic tests (RDTs) whose main interest lies in their implementation without special equipment by unskilled personnel have grown significantly over the past fifteen years to diagnose malaria. They rely on the detection of specific Plasmodium proteins, PfHRP2, pLDH and aldolase. If the detection of PfHRP2 has very good sensitivity for the diagnosis of Plasmodium falciparum malaria, the detection of pLDH or aldolase is less efficient for other species, leaving its place to the reference microscopic diagnosis. RDT could not generally be used to monitor therapeutic efficacy because they can remain positive after clinical and parasitological cure. Furthermore, the development of the use of these tests has highlighted the need for quality assurance programs to monitor their production as their use.

Multicenter Pivotal Clinical Trial of Urine Malaria Test for Rapid Diagnosis of Plasmodium falciparum Malaria

The need to expand malaria diagnosis capabilities alongside policy requirements for mandatory testing before treatment motivates exploration of noninvasive rapid diagnostic tests (RDTs). We report the outcome of the first cross-sectional, single-blind clinical performance evaluation of a urine malaria test (UMT) for diagnosis of Plasmodium falciparum malaria in febrile patients. Matched urine and finger-prick blood samples from participants ≥2 years of age with fever (axillary temperature of ≥37.5°C) or with a history of fever in the preceding 48 h were tested with UMT and microscopy (as the gold standard). BinaxNOW (Pf and Pan versions) blood RDTs were done to assess relative performance. Urinalysis and rheumatoid factor (RF) tests were conducted to evaluate possible interference. Diagnostic performance characteristics were computed at 95% confidence intervals (CIs). Of 1,800 participants screened, 1,691 were enrolled; of these 566 (34%) were febrile, and 1,125 (66%) were afebrile. Among enrolled participants, 341 (20%) tested positive by microscopy, 419 (25%) were positive by UMT, 676 (40%) were positive by BinaxNOW Pf, and 368 (22%) were positive by BinaxNow Pan. UMT sensitivity among febrile patients (for whom the test was indicated) was 85%, and specificity was 84%. Among febrile children ≤5 years of age, UMT sensitivity was 93%, and specificity was 83%. The area under the receiver-operator characteristic curve (AUC) of UMT (0.84) was not significantly different from that of BinaxNOW Pf (0.86) or of BinaxNOW Pan (0.87), indicating that the tests do not differ in overall performance. Gender, seasons, and RF did not impact UMT performance. Leukocytes, hematuria, and urobilinogen concentrations in urine were associated with lower UMT specificities. UMT performance was comparable to that of the BinaxNOW Pf/Pan tests, making UMT a promising tool to expand malaria testing in public and private health care settings where there are challenges to blood-based malaria diagnosis testing.

Field evaluation of diagnostic performance of malaria rapid diagnostic tests in western Kenya

BACKGROUND

Malaria continues to be a major burden in the endemic regions of Kenya. Health outcomes associated with case management are dependent on the use of appropriate diagnostic methods. Rapid diagnostic tests (RDTs) have provided an important tool to help implement the WHO recommended parasite-based diagnosis in regions where expert microscopy is not available. One of the questions that must be answered when implementing RDTs is whether these tests are useful in a specific endemic region, as well as the most appropriate RDT to use. Data on the sensitivity and specificity of RDT test kits is important information to help guide test selection by national malaria control programmes.

METHODS

This study evaluated the diagnostic performance of RDTs including First Response (FR), CareStart (CS), SD Bioline (SD), and Binax Now (BN). The performance of these malaria kits was compared to microscopy, the gold standard, for the detection of malaria parasites. The malaria RDTs were also compared to PCR which is a more sensitive reference test. Five-hundred participants were included in the study through community screening (50 %) and testing suspected malaria cases referred from health facilities.

RESULTS

Of the 500 participants recruited, 33 % were malaria positive by microscopy while 51.2 % were positive by PCR. Compared to microscopy, the sensitivity of eight RDTs to detect malaria parasites was 90.3-94.8 %, the specificity was 73.3-79.3 %, the positive predictive value was 62.2-68.8 %, and the negative predictive value was 94.3-96.8 %. Compared to PCR, the sensitivity of the RDTs to detect malaria parasites was 71.1-75.4 %, the specificity was 80.3-84.4 %, the positive predictive value was 80.3-83.3 %, and the negative predictive value was 73.7-76.1 %. The RDTs had a moderate measure of agreement with both microscopy (>80.1 %) and PCR (>77.6 %) with a κ > 0.6.

CONCLUSION

The performance of the evaluated RDTs using field samples was moderate; hence they can significantly improve the quality of malaria case management in endemic regions in Kenya by ensuring appropriate treatment of malaria positive individuals and avoiding indiscriminate use of anti-malarial drugs for parasite negative patients.

Feasibility and implementation of community-based malaria case management with integrated vector control in the Democratic Republic of Congo

Background

Malaria prevalence in the Mulumbu Health Area in Lualaba Province, Democratic Republic of the Congo has remained high (>70 %) despite repeated vector control (indoor residual spray) and mass insecticide-treated bed net coverage. Therefore, a pilot study was implemented to attack the parasite directly and demonstrate the feasibility and acceptability of community case management of malaria (CCMm) using trained community health workers (CHWs).

Methods

A 13 month prospective evaluation of CCMm was undertaken in 14 rural villages. Focus group discussions and structured interviews were conducted in pre- and post-intervention periods to assess community acceptability of CCMm. Weekly data collected by CHWs assessed program impact over time, matched with malaria school-based prevalence surveys (MSPS) in the Mulumbu Health Area (CCMm study arm) compared to a comparison (non-CCMm) arm in the Mpala Health Area approximately 25 km apart.

Results

Overall population perception of the CCMm was highly positive. 6619 community contacts were managed by CHWs from which 1433 (21.6 %) were malaria positive by rapid detection tests during the 10 month intervention. Among the malaria infected, 94.7 % (1358) were recorded as ‘uncomplicated’ infections with 99.7 % provided full course of treatment. CHWs referred 278 (4.2 %) patients deemed ‘complicated’ to a designated primary health center for advanced care. While pre-intervention MSPS data revealed significantly higher (p = 0.0135) malaria in the CCMm area compared to the non-CCMm area, at post-intervention there was no statistical difference (p = 0.562) between the two areas. Notably, for the first time, no malaria-related deaths were recorded in the 14 CCMm intervention villages during observation.

Conclusion

Community case management of malaria was shown to be an effective and promising strategy for prompt and effective management of malaria. It was well accepted by the community and showed evidence of a reduction in malaria morbidity and mortality. Further refinement of CCMm implementation, cost implications and sustainability is advised before expanding the programme.

Appropriate targeting of artemisinin-based combination therapy by community health workers using malaria rapid diagnostic tests: findings from randomized trials in two contrasting areas of high and low malaria transmission in south-western Uganda

Objective

To compare the impact of malaria rapid diagnostic tests (mRDTs), used by community health workers (CHWs), on the proportion of children <5 years of age receiving appropriately targeted treatment with artemisinin‐based combination therapy (ACT), vs. presumptive treatment.

Methods

Cluster‐randomized trials were conducted in two contrasting areas of moderate‐to‐high and low malaria transmission in rural Uganda. Each trial examined the effectiveness of mRDTs in the management of malaria and targeting of ACTs by CHWs comparing two diagnostic approaches: (i) presumptive clinical diagnosis of malaria [control arm] and (ii) confirmatory diagnosis with mRDTs followed by ACT treatment for positive patients [intervention arm], with village as the unit of randomisation. Treatment decisions by CHWs were validated by microscopy on a reference blood slide collected at the time of consultation, to compare the proportion of children <5 years receiving appropriately targeted ACT treatment, defined as patients with microscopically‐confirmed presence of parasites in a peripheral blood smear receiving artemether‐lumefantrine or rectal artesunate, and patients with no malaria parasites not given ACT.

Results

In the moderate‐to‐high transmission area, ACT treatment was appropriately targeted in 79.3% (520/656) of children seen by CHWs using mRDTs to diagnose malaria, vs. 30.8% (215/699) of children seen by CHWs using presumptive diagnosis (P < 0.001). In the low transmission area, 90.1% (363/403) children seen by CHWs using mRDTs received appropriately targeted ACT treatment vs. 7.8% (64/817) seen by CHWs using presumptive diagnosis (P < 0.001). Low mRDT sensitivity in children with low‐density parasitaemia (<200 parasites/μl) was identified as a potential concern.

Conclusion

When equipped with mRDTs, ACT treatments delivered by CHWs are more accurately targeted to children with malaria parasites. mRDT use could play an important role in reducing overdiagnosis of malaria and improving fever case management within iCCM, in both moderate‐to‐high and low transmission areas. Nonetheless, missed treatments due to the low sensitivity of current mRDTs in patients with low parasite density are a concern. For community‐based treatment in areas of low transmission and/or non‐immune populations, presumptive treatment of all fevers as malaria may be advisable, until more sensitive diagnostic assays, suitable for routine use by CHWs in remote settings, become available.

Adherence to national guidelines for the diagnosis and management of severe malaria: a nationwide, cross-sectional survey in Malawi, 2012

Background

Severe malaria has a case fatality rate of 10-20 %; however, few studies have addressed the quality of severe malaria case management. This study evaluated the diagnostic and treatment practices of malaria patients admitted to inpatient health facilities (HF) in Malawi.

Methods

In July–August 2012, a nationwide, cross-sectional survey of severe malaria management was conducted in 36 HFs selected with equal probability from all eligible public sector HFs in Malawi. Patient records from all admissions during October 2011 and April 2012 (low and high season, respectively) were screened for an admission diagnosis of malaria or prescription of any anti-malarial. Eligible records were stratified by age (< 5 or ≥ 5 years). A maximum of eight records was randomly selected within each age and month stratum. Severe malaria was defined by admission diagnosis or documentation of at least one sign or symptom of severe malaria. Treatment with intravenous (IV) quinine or artesunate was considered correct. Patients without documentation of severe malaria were analysed as uncomplicated malaria patients; treatment with an artemisinin-based combination therapy (ACT) or oral quinine based on malaria test results was considered correct. All analyses accounted for HF level clustering and sampling weights.

Results

The analysis included 906 records from 35 HFs. Among these, 42 % (95 % confidence interval [CI] 35–49) had a severe malaria admission diagnosis and 50 % (95 % CI 44–57) had at least one severe malaria sign or symptom documented. Severe malaria patients defined by admission diagnosis (93, 95 % CI 86–99) were more likely to be treated correctly compared to patients defined by a severe sign (82, 95 % CI 75–89) (p < 0.0001). Among uncomplicated malaria patients, 26 % (95 % CI 18–35) were correctly treated and 53 % (95 % CI 42–64) were adequately treated with IV quinine alone or in combination with an ACT or oral quinine.

Conclusions

A majority of patients diagnosed with severe malaria received the recommended IV therapy in accordance with national treatment guidelines. However, the inconsistencies between diagnosis of severe malaria and documentation of severe signs and symptoms highlight the need to improve healthcare worker recognition and documentation of severe signs and symptoms.

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-016-1423-2) contains supplementary material, which is available to authorized users.

Feasibility, acceptability and impact of integrating malaria rapid diagnostic tests and pre-referral rectal artesunate into the integrated community case management programme. A pilot study in Mchinji district, Malawi

Background

The World Health Organization recommends that persons of all ages suspected of malaria should receive a parasitological confirmation of malaria by use of malaria rapid diagnostic test (RDT) at community level, and that rectal artesunate should be used as a pre-referral treatment for severe malaria to rapidly reduce parasitaemia. This paper reports on findings from a pilot study that assessed the feasibility, acceptability and effects of integrating RDTs and pre-referral rectal artesunate into the integrated Community Case Management programme in Malawi.

Methods

This study used mixed methods to collect information for this survey. Pre- and post-intervention, cross-sectional, household surveys were carried out. A review of integrated community case management reports, including supervision checklists was conducted. Quantitative data were collected in tablets running on open data kit software, and then data were transferred to STATA version 12 for analysis. For key indicators, proportions were calculated at 95 % confidence intervals. Qualitative data were recorded onto digital recorders, translated into English and transcribed for analysis.

Results

Out of 86 observed RDT performances, a total of 83 (97 %) were performed correctly with a proper disposal of sharps and biohazard wastes. Only two (2 %) febrile children who had an RDT negative result were treated with artemether–lumefantrine, contrary to malaria treatment guidelines. Utilization of community health workers (CHWs) as a first source of care increased from (33.9 %) (95 % CI; 25.5–42.3) at baseline to (89.7 %) (95 % CI; 83.5–95.5) at end line in the intervention villages. There was a corresponding decrease in the proportion of caregivers that first sought care from informal sources from 12.9 % (95 % CI; 6.9–18.9) to 1.9 % (95 % CI; 0.9–4.4) in the intervention villages. Acceptability of the use of RDTs and pre-referral rectal artesunate at the community level was relatively high.

Conclusion

Integration of RDTs and pre-referral rectal at artesunate community level is both feasible and acceptable. The strategy has the potential to increase and improve utilization of child health services at community level. However, this depends on the CHWs’ skills and their availability in remote areas.

Health workers' compliance to rapid diagnostic tests (RDTs) to guide malaria treatment: a systematic review and meta-analysis

Background

The World Health Organization recommends malaria to be confirmed by either microscopy or a rapid diagnostic test (RDT) before treatment. The correct use of RDTs in resource-limited settings facilitates basing treatment onto a confirmed diagnosis; contributes to speeding up considering a correct alternative diagnosis, and prevents overprescription of anti-malarial drugs, reduces costs and avoids unnecessary exposure to adverse drug effects. This review aims to evaluate health workers’ compliance to RDT results and factors contributing to compliance.

Methods

A PROSPERO-registered systematic review was conducted to evaluate health workers’ compliance to RDTs in sub-Saharan Africa, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies published up to November 2015 were searched without language restrictions in Medline/Ovid, Embase, Cochrane Central Register of Controlled Trials, Web of Science, LILACS, Biosis Previews and the African Index Medicus. The primary outcome was health workers treating patients according to the RDT results obtained.

Results

The literature search identified 474 reports; 14 studies were eligible and included in the quantitative analysis. From the meta-analysis, health workers’ overall compliance in terms of initiating treatment or not in accordance with the respective RDT results was 83 % (95 % CI 80–86 %). Compliance to positive and negative results was 97 % (95 % CI 94–99 %) and 78 % (95 % CI 66–89 %), respectively. Community health workers had higher compliance rates to negative test results than clinicians. Patient expectations, work experience, scepticism of results, health workers’ cadres and perceived effectiveness of the test, influenced compliance.

Conclusions

With regard to published data, compliance to RDT appears to be generally fair in sub-Saharan Africa; compliance to negative results will need to improve to prevent mismanagement of patients and overprescribing of anti-malarial drugs. Improving diagnostic capacity for other febrile illnesses and developing local evidence-based guidelines may help improve compliance and management of negative RDT results.

Trial registration: CRD42015016151 (PROSPERO)

Electronic supplementary material

The online version of this article (doi:10.1186/s12936-016-1218-5) contains supplementary material, which is available to authorized users.

Field evaluation of a PfHRP-2/pLDH rapid diagnostic test and light microscopy for diagnosis and screening of falciparum malaria during the peak seasonal transmission in an endemic area in Yemen

BACKGROUND

Malaria is a public health threat in Yemen, with 149,451 cases being reported in 2013. Of these, Plasmodium falciparum represents 99%. Prompt diagnosis by light microscopy (LM) and rapid diagnostic tests (RTDs) is a key element in the national strategy of malaria control. The heterogeneous epidemiology of malaria in the country necessitates the field evaluation of the current diagnostic strategies, especially RDTs. Thus, the present study aimed to evaluate LM and an RDT, combining both P. falciparum histidine-rich protein-2 (PfHRP-2) and Plasmodium lactate dehydrogenase (pLDH), for falciparum malaria diagnosis and survey in a malaria-endemic area during the transmission season against nested polymerase chain reaction (PCR) as the reference method.

METHODS

A household-based, cross-sectional malaria survey was conducted in Mawza District, a malaria-endemic area in Taiz governorate. A total of 488 participants were screened using LM and PfHRP-2/pLDH RDT. Positive samples (160) and randomly selected negative samples (52) by both RDT and LM were further analysed using 18S rRNA-based nested PCR.

RESULTS

The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the RDT were 96.0% (95% confidence interval (CI): 90.9-98.3), 56.0% (95% CI: 44.7-66.8), 76.3% (95% CI: 69.0-82.3), and 90.4% (95% CI: 78.8-96.8), respectively. On the other hand, LM showed sensitivity of 37.6% (95% CI: 29.6-46.3), specificity of 97.6% (95% CI: 91.7-99.7), PPV of 95.9% (95% CI: 86.3-98.9), and NPV of 51.3% (95% CI: 43.2-59.2). The sensitivity of LM dropped to 8.5% for detecting asymptomatic malaria. Malaria prevalence was 32.8% (32.1 and 37.5% for ≥10 and <10 years, respectively) with the RDT compared with 10.7% (10.8 and 9.4% for age groups of ≥10 and <10 years, respectively) with LM. Among asymptomatic malaria individuals, LM and RDT-based prevalence rates were 1.6 and 25.6%, respectively. However, rates of 88.2 and 94.1% of infection with P. falciparum were found among patients who reported fever in the 48 h prior to the survey by LM and PfHRP-2/pLDH RDT, respectively.

CONCLUSIONS

The PfHRP-2/pLDH RDT shows high sensitivity for the survey of falciparum malaria even for asymptomatic malaria cases. Although the RDT had high sensitivity, its high false-positivity rate limits its utility as a single diagnostic tool for clinical diagnosis of malaria. On the other hand, low sensitivity of LM indicates that a high proportion of malaria cases is missed, underestimating the true prevalence of malaria in the community. Higher NPV of PfHRP-2/pLDH RDT than LM can give a straightforward exclusion of malaria among febrile patients, helping to avoid unnecessary presumptive treatments.

Why do health workers give anti-malarials to patients with negative rapid test results? A qualitative study at rural health facilities in western Uganda

BACKGROUND

The large-scale introduction of malaria rapid diagnostic tests (RDTs) promises to improve management of fever patients and the rational use of valuable anti-malarials. However, evidence on the impact of RDT introduction on the overprescription of anti-malarials has been mixed. This study explored determinants of provider decision-making to prescribe anti-malarials following a negative RDT result.

METHODS

A qualitative study was conducted in a rural district in mid-western Uganda in 2011, ten months after RDT introduction. Prescriptions for all patients with negative RDT results were first audited from outpatient registers for a two month period at all facilities using RDTs (n = 30). Facilities were then ranked according to overall prescribing performance, defined as the proportion of patients with a negative RDT result prescribed any anti-malarial. Positive and negative deviant facilities were sampled for qualitative investigation; positive deviants (n = 5) were defined ex post facto as <0.75% and negative deviants (n = 7) as >5%. All prescribing clinicians were targeted for qualitative observation and in-depth interview; 55 fever cases were observed and 22 providers interviewed. Thematic analysis followed the 'framework' approach.

RESULTS

8344 RDT-negative patients were recorded at the 30 facilities (prescription audit); 339 (4.06%) were prescribed an anti-malarial. Of the 55 observed patients, 38 tested negative; one of these was prescribed an anti-malarial. Treatment decision-making was influenced by providers' clinical beliefs, capacity constraints, and perception of patient demands. Although providers generally trusted the accuracy of RDTs, anti-malarial prescription was driven by perceptions of treatment failure or undetectable malaria in patients who had already taken artemisinin-based combination therapy prior to facility arrival. Patient assessment and other diagnostic practices were minimal and providers demonstrated limited ability to identify alternative causes of fever. Provider perceptions of patient expectations sometimes appeared to influence treatment decisions.

CONCLUSIONS

The study found high provider adherence to RDT results, but that providers believed in certain clinical exceptions and felt they lacked alternative options. Guidance on how the RDT works and testing following partial treatment, better methods for assisting providers in diagnostic decision-making, and a context-appropriate provider behaviour change intervention package are needed.

Prescription practices for malaria in Mozambique: poor adherence to the national protocols for malaria treatment in 22 public health facilities

Background

Current World Health Organization and national protocols recommend the ‘test and treat’ strategy for the management of uncomplicated malaria, to reduce over prescription of artemisinin-based combination treatment (ACT). Therefore, adherence to these protocols varies in different sub-Saharan African countries and no information is available for Mozambique. This study was conducted with the aim to evaluate the prescription practices of ACT in Mozambique.

Methods

Retrospective audit of medical records corresponding to the period between July and December 2011 was conducted in 22 health units across 11 provinces in Mozambique. Two health units were selected per province according to availability of laboratory data (performing microscopy and rapid diagnostics testing-RDT or RDT only) and geographic setting (rural versus urban). At each facility, demographic data, laboratory results (blood smear or RDT), and prescription of ACT were all collected from the existing records.

Results

Between July and December 2011, a total of 61,730 cases were tested for malaria, of which 42.7 % (26,369/61,730) were positive. A total of 35.361 patients were malaria negative, and ACT was prescribed to 72.0 % (25.448/35.361) of them. Prescription of ACT to malaria negative patients was higher in the central region of the country as compared to the northern and southern (81.1 % in the central region versus 72.4 and 63.7 % in the northern and southern, respectively, p = 0.000) and in urban settings (88.7 % in rural versus 58.0 % in urban settings, p = 0.000). Stock out of RDT was observed in six (27.3 %) of the health facilities. When no RDT was available, patients were empirically treated with ACT.

Conclusion

Findings from this study demonstrate that health care worker’s adherence to the new guidelines for malaria treatment is poor in Mozambique and prescription of ACT to malaria negative patients remains very high. Enhanced training and supervision activities, community education and external quality assurance might lead to significant improvements in the clinician’s adherence to the new guideline for malaria treatment in Mozambique.

Integrated community case management of fever in children under five using rapid diagnostic tests and respiratory rate counting: a multi-country cluster randomized trial

Evidence on the impact of using diagnostic tests in community case management of febrile children is limited. This effectiveness trial conducted in Burkina Faso, Ghana, and Uganda, compared a diagnostic and treatment package for malaria and pneumonia with presumptive treatment with anti-malarial drugs; artemisinin combination therapy (ACT). We enrolled 4,216 febrile children between 4 and 59 months of age in 2009–2010. Compliance with the malaria rapid diagnostic test (RDT) results was high in the intervention arm across the three countries, with only 4.9% (17 of 344) of RDT-negative children prescribed an ACT. Antibiotic overuse was more common: 0.9% (4 of 446) in Uganda, 38.5% (114 of 296) in Burkina Faso, and 44.6% (197 of 442) in Ghana. Fever clearance was high in both intervention and control arms at both Day 3 (97.8% versus 96.9%, P = 0.17) and Day 7 (99.2% versus 98.8%, P = 0.17). The use of diagnostic tests limits overuse of ACTs. Its impact on antibiotic overuse and on fever clearance is uncertain.

Impact of community management of fever (using antimalarials with or without antibiotics) on childhood mortality: a cluster-randomized controlled trial in Ghana

Malaria and pneumonia are leading causes of childhood mortality. Home Management of fever as Malaria (HMM) enables presumptive treatment with antimalarial drugs but excludes pneumonia. We aimed to evaluate the impact of adding an antibiotic, amoxicillin (AMX) to an antimalarial, artesunate amodiaquine (AAQ+AMX) for treating fever among children 2–59 months of age within the HMM strategy on all-cause mortality. In a stepped-wedge cluster-randomized, open trial, children 2–59 months of age with fever treated with AAQ or AAQ+AMX within HMM were compared with standard care. Mortality reduced significantly by 30% (rate ratio [RR] = 0.70, 95% confidence interval [CI] = 0.53– 0.92, P = 0.011) in AAQ clusters and by 44% (RR = 0.56, 95% CI = 0.41–0.76, P = 0.011) in AAQ+AMX clusters compared with control clusters. The 21% mortality reduction between AAQ and AAQ+AMX (RR = 0.79, 95% CI = 0.56 –1.12, P = 0.195) was however not statistically significant. Community fever management with antimalarials significantly reduces under-five mortality. Given the lower mortality trend, adding an antibiotic is more beneficial.

Qualitative assessment of rural health workers' management of malaria in sick children

Background

Febrile illnesses are common causes of morbidity and mortality among under-five children in sub-Saharan Africa. The recommended strategy for effective case management of uncomplicated malaria is parasitological confirmation prior to use of artemisinin-based combination therapy (ACT). There is a lack of qualitative information explaining factors, which influence malaria case management practices among health workers. This study explores the perceptions of health managers and health care providers on the case management of uncomplicated malaria among under-fives in selected primary health care (PHC) facilities of two Local Government Areas (LGAs), Katcha and Gbako, as part of baselines for capacity-building interventions planned in Niger State, Nigeria.

Methods

Interviewees included state- and LGA-level health programme managers, and frontline health workers purposively selected to cover a range of cadres involved in case management of sick children. Issues explored were history taking, diagnosis, appropriate diagnosis of malaria, prescription for malaria, referrals and adherence to referral. Data coding was carried out with Nvivo qualitative software (version 8) and content analysed.

Results

History taking was often not carried out appropriately by the health workers. Treatment of malaria was not based on parasite-based diagnosis. Most of the health workers reported that they prescribed ACTs for treating presumed uncomplicated malaria. Care givers' preferences, poor transportation systems and lack of financial resources led to poor adherence to referral advice. Absence of health workers from their duty post hindered effective service delivery. Prescription of ACTs as a first line of treatment for uncomplicated malaria without a parasite-based diagnosis was the standard case management practice.

Conclusion

Parasite-based diagnosis for malaria will invariably lead to better treatment for non-malaria fever cases among the studied age group. Continuous capacity building aimed at improving adherence to current recommendations on parasite-based diagnosis and good clinical practice would be required to support the paradigm shift to parasite-based diagnosis of malaria.

The role of point-of-care tests in antibiotic stewardship for urinary tract infections in a resource-limited setting on the Thailand-Myanmar border

Objective

Published literature from resource‐limited settings is infrequent, although urinary tract infections (UTI) are a common cause of outpatient presentation and antibiotic use. Point‐of‐care test (POCT) interpretation relates to antibiotic use and antibiotic resistance. We aimed to assess the diagnostic accuracy of POCT and their role in UTI antibiotic stewardship.

Methods

One‐year retrospective analysis in three clinics on the Thailand–Myanmar border of non‐pregnant adults presenting with urinary symptoms. POCT (urine dipstick and microscopy) were compared to culture with significant growth classified as pure growth of a single organism >10⁵ CFU/ml.

Results

In 247 patients, 82.6% female, the most common symptoms were dysuria (81.2%), suprapubic pain (67.8%) and urinary frequency (53.7%). After excluding contaminated samples, UTI was diagnosed in 52.4% (97/185); 71.1% (69/97) had a significant growth on culture, and >80% of these were Escherichia coli (20.9% produced extended‐spectrum β‐lactamase (ESBL)). Positive urine dipstick (leucocyte esterase ≥1 and/or nitrate positive) compared against positive microscopy (white blood cell >10/HPF, bacteria ≥1/HPF, epithelial cells <5/HPF) had a higher sensitivity (99% vs. 57%) but a lower specificity (47% vs. 89%), respectively. Combined POCT resulted in the best sensitivity (98%) and specificity (81%). Nearly one in ten patients received an antimicrobial to which the organism was not fully sensitive.

Conclusion

One rapid, cost‐effective POCT was too inaccurate to be used alone by healthcare workers, impeding antibiotic stewardship in a high ESBL setting. Appropriate prescribing is improved with concurrent use and concordant results of urine dipstick and microscopy.

Effect of diagnostic testing on medicines used by febrile children less than five years in 12 malaria-endemic African countries: a mixed-methods study

BACKGROUND

In 2010, WHO revised guidelines to recommend testing all suspected malaria cases prior to treatment. Yet, evidence to assess programmes is largely derived from limited facility settings in a limited number of countries. National surveys from 12 sub-Saharan African countries were used to examine the effect of diagnostic testing on medicines used by febrile children under five years at the population level, including stratification by malaria risk, transmission season, source of care, symptoms, and age.

METHODS

Data were compiled from 12 Demographic and Health Surveys in 2010-2012 that reported fever prevalence, diagnostic test and medicine use, and socio-economic covariates (n=16,323 febrile under-fives taken to care). Mixed-effects logistic regression models quantified the influence of diagnostic testing on three outcomes (artemisinin combination therapy (ACT), any anti-malarial or any antibiotic use) after adjusting for data clustering and confounding covariates. For each outcome, interactions between diagnostic testing and the following covariates were separately tested: malaria risk, season, source of care, symptoms, and age. A multiple case study design was used to understand varying results across selected countries and sub-national groups, which drew on programme documents, published research and expert consultations. A descriptive typology of plausible explanations for quantitative results was derived from a cross-case synthesis.

RESULTS

Significant variability was found in the effect of diagnostic testing on ACT use across countries (e.g., Uganda OR: 0.84, 95% CI: 0.66-1.06; Mozambique OR: 3.54, 95% CI: 2.33-5.39). Four main themes emerged to explain results: available diagnostics and medicines; quality of care; care-seeking behaviour; and, malaria epidemiology.

CONCLUSIONS

Significant country variation was found in the effect of diagnostic testing on paediatric fever treatment at the population level, and qualitative results suggest the impact of diagnostic scale-up on treatment practices may not be straightforward in routine conditions given contextual factors (e.g., access to care, treatment-seeking behaviour or supply stock-outs). Despite limitations, quantitative results could help identify countries (e.g., Mozambique) or issues (e.g., malaria risk) where facility-based research or programme attention may be warranted. The mixed-methods approach triangulates different evidence to potentially provide a standard framework to assess routine programmes across countries or over time to fill critical evidence gaps.

Rapid diagnostic tests for diagnosing uncomplicated non-falciparum or Plasmodium vivax malaria in endemic countries

BACKGROUND

In settings where both Plasmodium vivax and Plasmodium falciparum infection cause malaria, rapid diagnostic tests (RDTs) need to distinguish which species is causing the patients' symptoms, as different treatments are required. Older RDTs incorporated two test lines to distinguish malaria due to P. falciparum, from malaria due to any other Plasmodium species (non-falciparum). These RDTs can be classified according to which antibodies they use: Type 2 RDTs use HRP-2 (for P. falciparum) and aldolase (all species); Type 3 RDTs use HRP-2 (for P. falciparum) and pLDH (all species); Type 4 use pLDH (fromP. falciparum) and pLDH (all species).More recently, RDTs have been developed to distinguish P. vivax parasitaemia by utilizing a pLDH antibody specific to P. vivax.

OBJECTIVES

To assess the diagnostic accuracy of RDTs for detecting non-falciparum or P. vivax parasitaemia in people living in malaria-endemic areas who present to ambulatory healthcare facilities with symptoms suggestive of malaria, and to identify which types and brands of commercial test best detect non-falciparum and P. vivax malaria.

SEARCH METHODS

We undertook a comprehensive search of the following databases up to 31 December 2013: Cochrane Infectious Diseases Group Specialized Register; MEDLINE; EMBASE; MEDION; Science Citation Index; Web of Knowledge; African Index Medicus; LILACS; and IndMED.

SELECTION CRITERIA

Studies comparing RDTs with a reference standard (microscopy or polymerase chain reaction) in blood samples from a random or consecutive series of patients attending ambulatory health facilities with symptoms suggestive of malaria in non-falciparum endemic areas.

DATA COLLECTION AND ANALYSIS

For each study, two review authors independently extracted a standard set of data using a tailored data extraction form. We grouped comparisons by type of RDT (defined by the combinations of antibodies used), and combined in meta-analysis where appropriate. Average sensitivities and specificities are presented alongside 95% confidence intervals (95% CI).

MAIN RESULTS

We included 47 studies enrolling 22,862 participants. Patient characteristics, sampling methods and reference standard methods were poorly reported in most studies. RDTs detecting 'non-falciparum' parasitaemiaEleven studies evaluated Type 2 tests compared with microscopy, 25 evaluated Type 3 tests, and 11 evaluated Type 4 tests. In meta-analyses, average sensitivities and specificities were 78% (95% CI 73% to 82%) and 99% (95% CI 97% to 99%) for Type 2 tests, 78% (95% CI 69% to 84%) and 99% (95% CI 98% to 99%) for Type 3 tests, and 89% (95% CI 79% to 95%) and 98% (95% CI 97% to 99%) for Type 4 tests, respectively. Type 4 tests were more sensitive than both Type 2 (P = 0.01) and Type 3 tests (P = 0.03).Five studies compared Type 3 tests with PCR; in meta-analysis, the average sensitivity and specificity were 81% (95% CI 72% to 88%) and 99% (95% CI 97% to 99%) respectively. RDTs detecting P.vivax parasitaemiaEight studies compared pLDH tests to microscopy; the average sensitivity and specificity were 95% (95% CI 86% to 99%) and 99% (95% CI 99% to 100%), respectively.

AUTHORS' CONCLUSIONS

RDTs designed to detect P. vivax specifically, whether alone or as part of a mixed infection, appear to be more accurate than older tests designed to distinguish P. falciparum malaria from non-falciparum malaria. Compared to microscopy, these tests fail to detect around 5% ofP. vivax cases. This Cochrane Review, in combination with other published information about in vitro test performance and stability in the field, can assist policy-makers to choose between the available RDTs.

Performance and clinical usefulness of the Optimal-IT® test in the treatment of confirmed malaria cases in rural areas in Côte d'Ivoire

Background

In Africa, malaria care is mostly based on clinical presumption and the general application of antimalarial treatment to all febrile episodes over several years. Treatment limited to confirmed cases might curb the practice of equating fever with malaria, antimalarial drug abuse and the extension of Plasmodium resistance, provided that powerful and reliable rapid diagnostic tests are used. This study aimed at determining the performances of the Optimal-IT® test in the strategy for the exclusive treatment of uncomplicated malaria in rural areas.

Materials and Methods

A prospective study conducted in the forest region of San Pedro, Côte d'Ivoire, included patients exhibiting clinical signs of uncomplicated malaria who gave their consent and benefited from thick blood film (TBF), blood smear (BS) and Optimal-IT® (pLDH-based) test. Rapid diagnostic test (RDT) results were taken into consideration to decide on malaria treatment and then compared with TBF/BS results (reference) to assess the performances and clinical usefulness of the RDT.

Results

The mean age of the 384 patients included (209 men, 175 women) was 28 years and the mean temperature was 38.1°C. TBF/BS and Optimal-IT® were concordant in 92% of patients but discordant in 10 false negative (3%) and 19 false-positive patients (5%). The average parasite density of P. falciparum was 25,600 trophozoites/μl. The performances calculated were: sensitivity=95%, specificity=91%, positive predictive value=90%, negative predictive value=95%, positive likelihood ratio=10, negative likelihood ratio=0.06 and diagnostic odds ratio=166, indicating that Optimal-IT® is a powerful and credible diagnostic tool. The 193 RDT-positive patients treated were healed, despite three recurrence cases at day (D) D17, D25 and D27, respectively. RDT-negative patients received various treatments (antibiotics, paracetamol), but two patients among them presented with a bout of malaria on D7. None of the previously untreated patients returned with severe malaria.

Conclusions

The Optimal-IT® test, which is already used in the field, showed good performances to effectively detect patients with and without malaria. It is therefore adapted to the malaria treatment strategy limited to confirmed cases.

A reliable and rapid method for molecular detection of malarial parasites using microwave irradiation and loop mediated isothermal amplification

Background

Improved living conditions together with appropriate diagnosis can reduce avoidable malarial deaths substantially. Microscopy remains the gold standard in the diagnosis of malaria. However, rapid molecular diagnostic tests (RmDT) are becoming increasingly important and will, most likely, be the diagnostic techniques of choice in the next years.

Methods

In this study, a rapid and reliable nucleic acid extraction procedure from human blood and malarial parasites using microwave irradiation as a promising platform is described. In addition, a tailored loop mediated isothermal amplification (LAMP) methodology that utilizes hydroxynaphthol blue (HNB) and Bst 2.0 DNA polymerases in molecular detection of malarial parasites is described.

Results

Following microwave irradiation for DNA isolation, conventional PCR assays were able to detect up to five malaria parasites/μl. The LAMP methodology described here was capable to detect as low as one Plasmodium falciparum parasite/μl after DNA extraction by microwave irradiation. A turnover time of 45 minutes from nucleic acid extraction to final visual read-out was achieved.

Conclusions

The described procedure offers a cheap, simple and fast method of molecular detection of malaria parasites. This test can easily be performed in basic laboratories. The methodology has been validated as a proof of concept and has specifically be developed for use at low-resource settings. Such RmDTs may aid health providers to make timely therapeutic interventions in malaria endemic regions.

High-resolution melting analysis reveals low Plasmodium parasitaemia infections among microscopically negative febrile patients in western Kenya

Background

Microscopy and rapid diagnostic tests (RDTs) are common tools for diagnosing malaria, but are deficient in detecting low Plasmodium parasitaemia. A novel molecular diagnostic tool (nPCR-HRM) that combines the sensitivity and specificity of nested PCR (nPCR) and direct PCR-high resolution melting analysis (dPCR-HRM) was developed. To evaluate patterns of anti-malarial drug administration when no parasites are detected, nPCR-HRM was employed to screen blood samples for low parasitaemia from febrile patients without microscopically detectable Plasmodium infections in a rural malaria-endemic setting.

Methods

Blood samples (n = 197) were collected in two islands of Lake Victoria, Kenya, from febrile patients without Plasmodium detectable by microscopy or RDTs. 18S rRNA gene sequences were amplified from extracted DNA by nPCR-HRM, nPCR, and dPCR-HRM to detect and differentiate Plasmodium parasites. The limits of detection (LoD) were compared using serial dilutions of the WHO International Standard for P. falciparum DNA. Data on administration of anti-malarials were collected to estimate prescription of anti-malarial drugs to patients with and without low parasitaemia Plasmodium infections.

Results

The coupled nPCR-HRM assay detected Plasmodium parasites with greater sensitivity (LoD = 236 parasites/mL) than either nPCR (LoD = 4,700 parasites/mL) or dPCR-HRM (LoD = 1,490 parasites/mL). Moreover, nPCR-HRM detected and differentiated low-parasitaemia infections in significantly greater proportions of patients than did either nPCR or dPCR-HRM (p-value <0.001). Among these low-parasitaemia infections, 67.7% of patients were treated with anti-malarials, whereas 81.5% of patients not infected with Plasmodium parasites were treated with anti-malarials.

Conclusions

The enhanced sensitivity of nPCR-HRM demonstrates limitations of differential febrile illness diagnostics in rural malaria endemic settings that confound epidemiological estimates of malaria, and lead to inadvertent misadministration of anti-malarial drugs. This is the first study that employs low-parasitaemia Plasmodium diagnostics to quantify the prescription of anti-malarial drugs to both non-malaria febrile patients and patients with low-parasitaemia Plasmodium infections. nPCR-HRM enhances low-parasitaemia malaria diagnosis and can potentially surmount the deficiencies of microscopy and RDT-based results in determining low-parasitaemia Plasmodium infection rates for evaluating malaria elimination efforts. The findings highlight the need for improved differential diagnostics of febrile illness in remote malaria endemic regions.

Community health workers and stand-alone or integrated case management of malaria: a systematic literature review

A systematic literature review was conducted to assess the effectiveness of strategies to improve community case management (CCM) of malaria. Forty-three studies were included; most (38) reported indicators of community health worker (CHW) performance, 14 reported on malaria CCM integrated with other child health interventions, 16 reported on health system capacity, and 13 reported on referral. The CHWs are able to provide good quality malaria care, including performing procedures such as rapid diagnostic tests. Appropriate training, clear guidelines, and regular supportive supervision are important facilitating factors. Crucial to sustainable success of CHW programs is strengthening health system capacity to support commodity supply, supervision, and appropriate treatment of referred cases. The little evidence available on referral from community to health facility level suggests that this is an area that needs priority attention. The studies of integrated CCM suggest that additional tasks do not reduce the quality of malaria CCM provided sufficient training and supervision is maintained.

Success or failure of critical steps in community case management of malaria with rapid diagnostic tests: a systematic review

BACKGROUND

Malaria still causes high morbidity and mortality around the world, mainly in sub-Saharan Africa. Community case management of malaria (CCMm) by community health workers (CHWs) is one of the strategies to combat the disease by increasing access to malaria treatment. Currently, the World Health Organization recommends to treat only confirmed malaria cases, rather than to give presumptive treatment.

OBJECTIVES

This systematic review aims to provide a comprehensive overview of the success or failure of critical steps in CCMm with rapid diagnostic tests (RDTs).

METHODS

The databases of Medline, Embase, the Cochrane Library, the library of the 'Malaria in Pregnancy' consortium, and Web of Science were used to find studies on CCMm with RDTs in SSA. Studies were selected according to inclusion and exclusion criteria, subsequently risk of bias was assessed and data extracted.

RESULTS

27 articles were included. CHWs were able to correctly perform RDTs, although specificity levels were variable. CHWs showed high adherence to test results, but in some studies a substantial group of RDT negatives received treatment. High risk of bias was found for morbidity and mortality studies, therefore, effects on morbidity and mortality could not be estimated. Uptake and acceptance by the community was high, however negative-tested patients did not always follow up referral advice. Drug or RDT stock-outs and limited information on CHW motivation are bottlenecks for sustainable implementation. RDT-based CCMm was found to be cost effective for the correct treatment of malaria in areas with low to medium malaria prevalence, but study designs were not optimal.

DISCUSSION

Trained CHWs can deliver high quality care for malaria using RDTs. However, lower RDT specificity could lead to missed diagnoses of non-malarial causes of fever. Other threats for CCMm are non-adherence to negative test results and low referral completion. Integrated CCM may solve some of these issues. Unfortunately, morbidity and mortality are not adequately investigated. More information is needed about influencing sociocultural aspects, CHW motivation and stock supply.

CONCLUSION

CCMm is generally well executed by CHWs, but there are several barriers for its success. Integrated CCM may overcome some of these barriers.

Diagnosing acute and prevalent HIV-1 infection in young African adults seeking care for fever: a systematic review and audit of current practice

Fever is a common complaint in HIV-1 infected adults and may be a presenting sign of acute HIV-1 infection (AHI). We investigated the extent to which HIV-1 infection was considered in the diagnostic evaluation of febrile adults in sub-Saharan Africa (SSA) through a systematic review of published literature and guidelines in the period 2003–2014. We also performed a detailed audit of current practice for the evaluation of febrile young adults in coastal Kenya. Our review identified 43 studies investigating the aetiology of fever in adult outpatients in SSA. While the guidelines identified recommend testing for HIV-1 infection, none mentioned AHI. In our audit of current practice at nine health facilities, only 189 out of 1173 (16.1%) patients, aged 18–29 years, were tested for HIV-1. In a detailed record review, only 2 out of 39 (5.1%) young adults seeking care for fever were tested for HIV-1, and the possibility of AHI was not mentioned. Available literature on adult outpatients presenting with fever is heavily focused on diagnosing malaria and guidelines are poorly defined in terms of evaluating aetiologies other than malaria. Current practice in coastal Kenya shows poor uptake of provider-initiated HIV-1 testing and AHI is not currently considered in the differential diagnosis.

External quality assurance of malaria nucleic acid testing for clinical trials and eradication surveillance

Nucleic acid testing (NAT) for malaria parasites is an increasingly recommended diagnostic endpoint in clinical trials of vaccine and drug candidates and is also important in surveillance of malaria control and elimination efforts. A variety of reported NAT assays have been described, yet no formal external quality assurance (EQA) program provides validation for the assays in use. Here, we report results of an EQA exercise for malaria NAT assays. Among five centers conducting controlled human malaria infection trials, all centers achieved 100% specificity and demonstrated limits of detection consistent with each laboratory's pre-stated expectations. Quantitative bias of reported results compared to expected results was generally <0.5 log₁₀ parasites/mL except for one laboratory where the EQA effort identified likely reasons for a general quantitative shift. The within-laboratory variation for all assays was low at <10% coefficient of variation across a range of parasite densities. Based on this study, we propose to create a Molecular Malaria Quality Assessment program that fulfills the need for EQA of malaria NAT assays worldwide.

Rapid diagnostic tests for malaria and health workers' adherence to test results at health facilities in Zambia

Background

In Zambia, there has been a large scaling up of interventions to control malaria in recent years including the deployment of rapid diagnostic tests (RDTs) to improve malaria surveillance data as well as guide malaria treatment in health facilities. The practical challenge is the impact of RDT results on subsequent management of patients. This study explored the role of RDTs in malaria diagnosis and the health workers’ adherence to test results.

Methods

An observational prospective study was carried out at health centres in four districts, namely Chibombo, Chingola, Chipata, and Choma. Children under the age of five years with history of fever were recruited and the clinicians’ use of RDT results was observed to establish whether prescriptions were issued prior to the availability of parasitological results or after, and whether RDT results influenced their prescriptions.

Results

Of the 2, 393 recruited children, 2, 264 had both RDT and microscopic results. Two in three (68.6%) children were treated with anti-malarials despite negative RDT results and almost half (46.2%) of these were prescribed Coartem^®. Only 465 (19.4%) of the 2,393 children were prescribed drugs before receiving laboratory results. A total of 76.5% children were prescribed drugs after laboratory results. Children with RDT positive results were 2.66 (95% CI (2.00, 3.55)) times more likely to be prescribed anti-malarial drugs. Children who presented with fever at admission (although history of fever or presence of fever at admission was an entry criterion) were 42% less likely to be prescribed an anti-malarial drug compared to children who had no fever (AOR = 0.58; 95% CI (0.52, 0.65)). It was noted that proportions of children who were RDT- and microscopy-positive significantly declined over the years from 2005 to 2008.

Conclusions

RDTs may contribute to treatment of febrile illness by confirming malaria cases from non-malaria cases in children under the age of five. However, the adherence of the health workers to prescribing anti-malarials to only RDT-positive cases at health facility level will still require to be explored further as their role is crucial in more precise reporting of malaria cases in this era towards malaria elimination as the target.

Rapid diagnostic tests versus clinical diagnosis for managing people with fever in malaria endemic settings

BACKGROUND

In 2010, the World Health Organization recommended that all patients with suspected malaria are tested for malaria before treatment. In rural African settings light microscopy is often unavailable. Diagnosis has relied on detecting fever, and most people were given antimalarial drugs presumptively. Rapid diagnostic tests (RDTs) provide a point-of-care test that may improve management, particularly of people for whom the RDT excludes the diagnosis of malaria.

OBJECTIVES

To evaluate whether introducing RDTs into algorithms for diagnosing and treating people with fever improves health outcomes, reduces antimalarial prescribing, and is safe, compared to algorithms using clinical diagnosis.

SEARCH METHODS

We searched the Cochrane Infectious Disease Group Specialized Register; CENTRAL (The Cochrane Library); MEDLINE; EMBASE; CINAHL; LILACS; and the metaRegister of Controlled Trials for eligible trials up to 10 January 2014. We contacted researchers in the field and reviewed the reference lists of all included trials to identify any additional trials.

SELECTION CRITERIA

Individual or cluster randomized trials (RCTs) comparing RDT-supported algorithms and algorithms using clinical diagnosis alone for diagnosing and treating people with fever living in malaria-endemic settings.

DATA COLLECTION AND ANALYSIS

Two authors independently applied the inclusion criteria and extracted data. We combined data from individually and cluster RCTs using the generic inverse variance method. We presented all outcomes as risk ratios (RR) with 95% confidence intervals (CIs), and assessed the quality of evidence using the GRADE approach.

MAIN RESULTS

We included seven trials, enrolling 17,505 people with fever or reported history of fever in this review; two individually randomized trials and five cluster randomized trials. All trials were conducted in rural African settings.In most trials the health workers diagnosing and treating malaria were nurses or clinical officers with less than one week of training in RDT supported diagnosis. Health worker prescribing adherence to RDT results was highly variable: the number of participants with a negative RDT result who received antimalarials ranged from 0% to 81%.Overall, RDT supported diagnosis had little or no effect on the number of participants remaining unwell at four to seven days after treatment (6990 participants, five trials, low quality evidence); but using RDTs reduced prescribing of antimalarials by up to three-quarters (17,287 participants, seven trials, moderate quality evidence). As would be expected, the reduction in antimalarial prescriptions was highest where health workers adherence to the RDT result was high, and where the true prevalence of malaria was lower.Using RDTs to support diagnosis did not have a consistent effect on the prescription of antibiotics, with some trials showing higher antibiotic prescribing and some showing lower prescribing in the RDT group (13,573 participants, five trials, very low quality evidence).One trial reported malaria microscopy on all enrolled patients in an area of moderate endemicity, so we could compare the number of patients in the RDT and clinical diagnosis groups that actually had microscopy confirmed malaria infection but did not receive antimalarials. No difference was detected between the two diagnostic strategies (1280 participants, one trial, low quality evidence).

AUTHORS' CONCLUSIONS

Algorithms incorporating RDTs can substantially reduce antimalarial prescribing if health workers adhere to the test results. Introducing RDTs has not been shown to improve health outcomes for patients, but adherence to the test result does not seem to result in worse clinical outcomes than presumptive treatment.Concentrating on improving the care of RDT negative patients could improve health outcomes in febrile children.

Performance of Paracheck™-Pf, SD Bioline malaria Ag-Pf and SD Bioline malaria Ag-Pf/pan for diagnosis of falciparum malaria in the Central African Republic

Background

Rapid diagnostic tests (RDTs) are the current complement to microscopy for ensuring prompt malaria treatment. We determined the performance of three candidate RDTs (Paracheck™-Pf, SD Bioline malaria Ag-Pf and SD Bioline malaria Ag-Pf/pan) for rapid diagnosis of malaria in the Central African Republic.

Methods

Blood samples from consecutive febrile patients who attended for laboratory analysis of malaria at the three main health centres of Bangui were screened by microscopy and the RDTs. Two reference standards were used to assess the performance of the RDTs: microscopy and, a combination of microscopy plus nested PCR for slides reported as negative, on the assumption that negative results by microscopy were due to sub-patent parasitaemia.

Results

We analysed 436 samples. Using the combined reference standard of microscopy + PCR, the sensitivity of Paracheck™-Pf was 85.7% (95% CI, 80.8–89.8%), that of SD Bioline Ag-Pf was 85.4% (95% CI, 80.5–90.7%), and that of SD Bioline Ag-Pf/pan was 88.2% (95% CI, 83.2–92.0%). The tests performed less well in cases of low parasitaemia; however, the sensitivity was > 95% at > 500 parasites/μl.

Conclusions

Overall, SD Bioline malaria Ag-Pf and SD Bioline malaria Ag-Pf/pan performed slightly better than Paracheck™-Pf. Use of RDTs with reinforced microscopy practice and laboratory quality assurance should improve malaria treatment in the Central African Republic.

Patient-, health worker-, and health facility-level determinants of correct malaria case management at publicly funded health facilities in Malawi: results from a nationally representative health facility survey

Background

Prompt and effective case management is needed to reduce malaria morbidity and mortality. However, malaria diagnosis and treatment is a multistep process that remains problematic in many settings, resulting in missed opportunities for effective treatment as well as overtreatment of patients without malaria.

Methods

Prior to the widespread roll-out of malaria rapid diagnostic tests (RDTs) in late 2011, a national, cross-sectional, complex-sample, health facility survey was conducted in Malawi to assess patient-, health worker-, and health facility-level factors associated with malaria case management quality using multivariate Poisson regression models.

Results

Among the 2,019 patients surveyed, 34% had confirmed malaria defined as presence of fever and parasitaemia on a reference blood smear. Sixty-seven per cent of patients with confirmed malaria were correctly prescribed the first-line anti-malarial, with most cases of incorrect treatment due to missed diagnosis; 31% of patients without confirmed malaria were overtreated with an anti-malarial. More than one-quarter of patients were not assessed for fever or history of fever by health workers. The most important determinants of correct malaria case management were patient-level clinical symptoms, such as spontaneous complaint of fever to health workers, which increased both correct treatment and overtreatment by 72 and 210%, respectively (p < 0.0001). Complaint of cough was associated with a 27% decreased likelihood of correct malaria treatment (p = 0.001). Lower-level cadres of health workers were more likely to prescribe anti-malarials for patients, increasing the likelihood of both correct treatment and overtreatment, but no other health worker or health facility-level factors were significantly associated with case management quality.

Conclusions

Introduction of RDTs holds potential to improve malaria case management in Malawi, but health workers must systematically assess all patients for fever, and then test and treat accordingly, otherwise, malaria control programmes might miss an opportunity to dramatically improve malaria case management, despite better diagnostic tools.