Malaria Diagnostics Research Articles

Comparative evaluation of diagnostic approaches for malaria

Introduction : microscopy is the backbone of traditional malaria diagnostics. However, availability of technical assistants on military deployments who are well experienced with malaria microscopy is scarce. Therefore, molecular diagnostic procedures are desirable which are widely independent from the skills of the investigator. Methods : in-house and commercial PCRs systems and various nucleic acid extraction procedures were compared. Results : there was no relevant difference in the performance of a well-established in-house PCR approach in comparison with a commercial PCR kit for the detection of malaria. Automated nucleic acid extraction from blood samples proved to be as reliable as manual column-based nucleic acid extraction. Conclusion : the results demonstrate the basic suitability of molecular diagnostic approaches for the detection of malaria with a high degree of automation for the deployment setting. Potential future optimization may include modern approaches like loop-mediated amplification (LAMP), which is currently under investigation at our department.

International survey to identify diagnostic needs to support malaria elimination: guiding the development of combination highly sensitive rapid diagnostic tests

BackgroundIn malaria elimination settings, the very low levels of transmission now being attained present challenges that demand new strategies to identify and treat low-density infections in both symptomatic and asymptomatic populations. Accordingly, passive case detection activities need to be supplemented by active case detection (ACD) strategies with more sensitive diagnostic tools. Malaria rapid diagnostic tests (RDTs) have provided low- and middle-income countries with unprecedented access to malaria diagnostics. Nevertheless, conventional RDTs miss a potentially important proportion of sub-microscopic infections. Therefore, new combination highly sensitive (HS-)RDTs, able to detect low parasite densities and identify all infected individuals, could support countries implementing ACD strategies for radical cure to accelerate malaria elimination. To address this need, an on-line survey was conducted to gather information from malaria control programme representatives to guide the development of next-generation RDTs.ResultsMost of respondents confirmed that ACD was a common activity in their programmes (56/75; 75%). Although microscopy was the preferred method in case management and reactive case detection, RDTs were the primary diagnostic tests used in proactive case detection (31/75; 41%). In terms of preferences for species detection in a new combination HS-RDT, data was not one-directional. Survey respondents slightly preferred the Pf/Pv/Pan combination (42%; 21/50), while Pf/Pan was more popular among end-users. Survey respondents also valued a low-cost (< $1.00 USD), lightweight and portable test, able to detect asymptomatic infections and differentiate species, as well as provide immediate results that could be interpreted with the naked eye. In addition, respondents were open to new tests and even to replace the existing ones for ACD (63%; 47/75).ConclusionsThis survey provided valuable information on the use and current limitations of ACD, on the primary product characteristics for a next-generation combination HS-RDT to support ACD and radical cure, and on the potential adoption of such a test, if available, to support malaria elimination.

Factors associated with malaria microscopy diagnostic performance following a pilot quality-assurance programme in health facilities in malaria low-transmission areas of Kenya, 2014

BackgroundMalaria accounts for ~21% of outpatient visits annually in Kenya; prompt and accurate malaria diagnosis is critical to ensure proper treatment. In 2013, formal malaria microscopy refresher training for microscopists and a pilot quality-assurance (QA) programme for malaria diagnostics were independently implemented to improve malaria microscopy diagnosis in malaria low-transmission areas of Kenya. A study was conducted to identify factors associated with malaria microscopy performance in the same areas.MethodsFrom March to April 2014, a cross-sectional survey was conducted in 42 public health facilities; 21 were QA-pilot facilities. In each facility, 18 malaria thick blood slides archived during January–February 2014 were selected by simple random sampling. Each malaria slide was re-examined by two expert microscopists masked to health-facility results. Expert results were used as the reference for microscopy performance measures. Logistic regression with specific random effects modelling was performed to identify factors associated with accurate malaria microscopy diagnosis.ResultsOf 756 malaria slides collected, 204 (27%) were read as positive by health-facility microscopists and 103 (14%) as positive by experts. Overall, 93% of slide results from QA-pilot facilities were concordant with expert reference compared to 77% in non-QA pilot facilities (p < 0.001). Recently trained microscopists in QA-pilot facilities performed better on microscopy performance measures with 97% sensitivity and 100% specificity compared to those in non-QA pilot facilities (69% sensitivity; 93% specificity; p < 0.01). The overall inter-reader agreement between QA-pilot facilities and experts was κ = 0.80 (95% CI 0.74–0.88) compared to κ = 0.35 (95% CI 0.24–0.46) between non-QA pilot facilities and experts (p < 0.001). In adjusted multivariable logistic regression analysis, recent microscopy refresher training (prevalence ratio [PR] = 13.8; 95% CI 4.6–41.4), ≥5 years of work experience (PR = 3.8; 95% CI 1.5–9.9), and pilot QA programme participation (PR = 4.3; 95% CI 1.0–11.0) were significantly associated with accurate malaria diagnosis.ConclusionsMicroscopists who had recently completed refresher training and worked in a QA-pilot facility performed the best overall. The QA programme and formal microscopy refresher training should be systematically implemented together to improve parasitological diagnosis of malaria by microscopy in Kenya.

Malaria vivax in Bukovyna: the clinical case of uncontrolled self-treatment

Materials and methods. There were used clinical, general laboratory, parasitological (microscopy of a smear and thick drop of blood), instrumental, epidemiological research methods. The descriptive analysis of the medical documentation (outpatient and stationary card of a patient) was realized, clinical-epidemiological data of a patient were analyzed. Results of research and their discussion. At the admission of a patient of the infectious stationary of MCI “Regional clinical hospital of Chernyvtsi city” it was elucidated that he has been suffering from malaria attacks (ague-fever-perspiration) since 2013 after staying in Venezuela. He has the distinctly expressed positive epidemiological anamnesis, connected with a contract work. In the presented clinical case the patient was aware as to the malaria symptoms, because worked as a ship doctor. The uncontrolled self-treatment at the absence of the “gold standard” of laboratory diagnostics of malaria led to the long parasite-spreading in the liver tissue as “dormant forms”.Conclusions. 1. At the positive epidemic anamnesis all cases of fever of unexplained genesis must be diagnosed for the most socially important tropic disease of 21 century in the world scale – malaria.2. It is obligatory to establish the type of a malaria plasmodium by the repeated parasitoscopy of blood by the methods of thin smear, stained according to Gimza-Romanovsky and thick drop taking into account the predicted sensitivity to anti-malaria chemopreparations.3. The attentive attitude of family doctors of the first link of family medicine to malaria allows to avoid complicated forms and remote relapses of this inoculable infection, caused by different types of plasmodia

Malaria epidemiology in low-endemicity areas of the northern coast of Ecuador: high prevalence of asymptomatic infections

BackgroundThe recent scale-up in malaria control measures in Latin America has resulted in a significant decrease in the number of reported cases in several countries including Ecuador, where it presented a low malaria incidence in recent years (558 reported cases in 2015) with occasional outbreaks of both Plasmodium falciparum and Plasmodium vivax in the coastal and Amazonian regions. This success in malaria control in recent years has led Ecuador to transition its malaria policy from control to elimination.ResultsThis study evaluated the general knowledge, attitude and practices (KAP) about malaria, as well as its prevalence in four communities of an endemic area in northwest Ecuador. A total of 258 interviews to assess KAP in the community indicated that most people in the study area have a basic knowledge about the disease but did not use to contribute to its control. Six hundred and forty-eight blood samples were collected and analysed by thick blood smear and real-time PCR. In addition, the distribution of the infections was mapped in the study communities. Although, no parasites were found by microscopy, by PCR the total malaria prevalence was 7.5% (6.9% P. vivax and 0.6% P. falciparum), much higher than expected and comparable to that reported in endemic areas of neighbouring countries with higher malaria transmission. Serology using ELISA and immunofluorescence indicated 27% respondents for P. vivax and 22% respondents for P. falciparum.ConclusionsResults suggest that despite a great malaria reduction in Ecuador, transition from control to elimination would demand further improvement in malaria diagnostics, including active case detection to identify and treat parasite asymptomatic carriers, as well as community participation in its elimination.

Development of an Immunosensor for PfHRP 2 as a Biomarker for Malaria Detection

Plasmodium falciparum histidine-rich protein 2 (PfHRP 2) was selected in this work as the biomarker for the detection and diagnosis of malaria. An enzyme-linked immunosorbent assay (ELISA) was first developed to evaluate the immunoreagent’s suitability for the sensor’s development. A gold-based sensor with an integrated counter and an Ag/AgCl reference electrode was first selected and characterised and then used to develop the immunosensor for PfHRP 2, which enables a low cost, easy to use, and sensitive biosensor for malaria diagnosis. The sensor was applied to immobilise the anti-PfHRP 2 monoclonal antibody as the capture receptor. A sandwich ELISA assay format was constructed using horseradish peroxidase (HRP) as the enzyme label, and the electrochemical signal was generated using a 3, 3′, 5, 5′tetramethyl-benzidine dihydrochloride (TMB)/H2O2 system. The performance of the assay and the sensor were optimised and characterised, achieving a PfHRP 2 limit of detection (LOD) of 2.14 ng·mL−1 in buffer samples and 2.95 ng∙mL−1 in 100% spiked serum samples. The assay signal was then amplified using gold nanoparticles conjugated detection antibody-enzyme and a detection limit of 36 pg∙mL−1 was achieved in buffer samples and 40 pg∙mL−1 in serum samples. This sensor format is ideal for malaria detection and on-site analysis as a point-of-care device (POC) in resource-limited settings where the implementation of malaria diagnostics is essential in control and elimination efforts.

Comparative Analysis of Malaria Diagnostic Tests and Prevalence of Malaria Infection among Blood Donors at General Hospital, Hadejia, Jigawa State, Nigeria

Blood for transfusion is not routinely tested for malaria in Nigeria despite the recommendation by World Health Organization (WHO) that all donated blood should be tested for malaria where appropriate and possible and that there should be quality assured testing for transfusion- transmissible infection. A hospital based cross sectional descriptive study was carried out to screen for malaria parasites using microscopy and rapid diagnostic tests among consented blood donors at General Hospital, Hadejia, Jigawa State, Nigeria. Four hundred, 400 blood samples were collected from apparently healthy blood donors (398 Males, 2 Females) who presented with no overt signs and symptoms of malaria and routinely screened free of Hepatitis B Virus, Hepatitis C Virus, Syphilis, HIV I and II Virus. The samples were screened for malaria parasites using CareStartTm Malaria HRP2 One Step Rapid Diagnostic Test (RDT) and Microscopy, and blood group determined using ABO blood grouping system. Out of the 400 samples screened 107 (26.7%) were found to be positive using Microscopy with a density of +++ trophozoite in 1 (0.2%) blood donor, ++ in 2 (0.5%) blood donors, and + in 104 (26%) blood donors with an overall prevalence of 26.7%. Fourteen (3.5%) blood donors were positive by RDT with 3 false positive RDT. High positivity rate was found among blood donors with blood group O+ (48.1%), majority were farmers and from the age group 18 – 25 years with the highest prevalent rate of 46.2% and 39.3% respectively. The most preventive measures taken were the use of insecticide treated bed-nets. Most of the blood donors (49.8%) have primary level of education (western). Blood film was found to be highly sensitive than RDT with a positivity rate of 26.7% and 3.5% respectively. These were however statistically significantly different (P&lt;0.05).

Malaria in Children: Diagnostic Tools in Resource-Limited Settings

AbstractMalaria contributes to a major reason for the cause of fatality and serious health problems among children mainly in various parts of tropical Africa and Asia. The extraction of DNA plays a vital role in the diagnosis of this life-threatening parasite Plasmodium. Difficulties with existing extraction methods of DNA are increasing with time including detection limits, time duration, sensitivity, availability of chemicals, and cost. Consequently, there is now renewed interest in finding of novel methods for DNA extraction of Plasmodium. However, the extraction of DNA by using microwave irradiation is found to be most convenient and suitable due to its low-cost and usage of common chemical reagents especially for the children in poor resource settings. In addition, the low cost, noninvasive malaria diagnostics tests are needed to carry out particularly for children to avoid accidental infections which may happen due to drawing blood.

Evaluation of a laboratory quality assurance pilot programme for malaria diagnostics in low-transmission areas of Kenya, 2013

BackgroundOne objective of the Kenya National Malaria Strategy 2009–2017 is scaling access to prompt diagnosis and effective treatment. In 2013, a quality assurance (QA) pilot was implemented to improve accuracy of malaria diagnostics at selected health facilities in low-transmission counties of Kenya. Trends in malaria diagnostic and QA indicator performance during the pilot are described.MethodsFrom June to December 2013, 28 QA officers provided on-the-job training and mentoring for malaria microscopy, malaria rapid diagnostic tests and laboratory QA/quality control (QC) practices over four 1-day visits at 83 health facilities. QA officers observed and recorded laboratory conditions and practices and cross-checked blood slides for malaria parasite presence, and a portion of cross-checked slides were confirmed by reference laboratories.ResultsEighty (96%) facilities completed the pilot. Among 315 personnel at pilot initiation, 13% (n = 40) reported malaria diagnostics training within the previous 12 months. Slide positivity ranged from 3 to 7%. Compared to the reference laboratory, microscopy sensitivity ranged from 53 to 96% and positive predictive value from 39 to 53% for facility staff and from 60 to 96% and 52 to 80%, respectively, for QA officers. Compared to reference, specificity ranged from 88 to 98% and negative predictive value from 98 to 99% for health-facility personnel and from 93 to 99% and 99%, respectively, for QA officers. The kappa value ranged from 0.48–0.66 for facility staff and 0.57–0.84 for QA officers compared to reference. The only significant test performance improvement observed for facility staff was for specificity from 88% (95% CI 85–90%) to 98% (95% CI 97–99%). QA/QC practices, including use of positive-control slides, internal and external slide cross-checking and recording of QA/QC activities, all increased significantly across the pilot (p < 0.001). Reference material availability also increased significantly; availability of six microscopy job aids and seven microscopy standard operating procedures increased by a mean of 32 percentage points (p < 0.001) and 38 percentage points (p < 0.001), respectively.ConclusionsSignificant gains were observed in malaria QA/QC practices over the pilot. However, these advances did not translate into improved accuracy of malaria diagnostic performance perhaps because of the limited duration of the QA pilot implementation.

Testing times: trends in availability, price, and market share of malaria diagnostics in the public and private healthcare sector across eight sub-Saharan African countries from 2009 to 2015

BackgroundThe World Health Organization guidelines have recommended that all cases of suspected malaria should receive a confirmatory test with microscopy or a malaria rapid diagnostic test (RDT), however evidence from sub-Saharan Africa (SSA) illustrates that only one-third of children under five with a recent fever received a test. The aim of this study was to evaluate availability, price and market share of microscopy and RDT from 2009/11 to 2014/15 in 8 SSA countries, to better understand barriers to improving access to malaria confirmatory testing in the public and private health sectors.ResultsRepeated national cross-sectional quantitative surveys were conducted among a sample of outlets stocking anti-malarial medicines and/or diagnostics. In total, 169,655 outlets were screened. Availability of malaria blood testing among all screened public health facilities increased significantly between the first survey wave in 2009/11 and the most recent in 2014/15 in Benin (36.2, 85.4%, p < 0.001), Kenya (53.8, 93.0%, p < 0.001), mainland Tanzania (46.9, 89.9%, p < 0.001), Nigeria (28.5, 86.2%, p < 0.001), Katanga, the Democratic Republic of the Congo (DRC) (76.0, 88.2%, p < 0.05), and Uganda (38.9, 95.6%, p < 0.001). These findings were attributed to an increase in availability of RDTs. Diagnostic availability remained high in Kinshasa (the DRC) (87.6, 97.6%) and Zambia (87.9, 91.6%). Testing availability in public health facilities significantly decreased in Madagascar (88.1, 73.1%, p < 0.01). In the most recent survey round, the majority of malaria testing was performed in the public sector in Zambia (90.9%), Benin (90.3%), Madagascar (84.5%), Katanga (74.3%), mainland Tanzania (73.5%), Uganda (71.8%), Nigeria (68.4%), Kenya (53.2%) and Kinshasa (51.9%). In the anti-malarial stocking private sector, significant increases in availability of diagnostic tests among private for-profit facilities were observed between the first and final survey rounds in Kinshasa (82.1, 94.0%, p < 0.05), Nigeria (37.0, 66.0%, p < 0.05), Kenya (52.8, 74.3%, p < 0.001), mainland Tanzania (66.8, 93.5%, p < 0.01), Uganda (47.1, 70.1%, p < 0.001), and Madagascar (14.5, 45.0%, p < 0.01). Blood testing availability remained low over time among anti-malarial stocking private health facilities in Benin (33.1, 20.7%), and high over time in Zambia (94.4, 87.5%), with evidence of falls in availability in Katanga (72.7, 55.6%, p < 0.05). Availability among anti-malarial stocking pharmacies and drug stores—which are the most common source of anti-malarial medicines—was rare in all settings, and highest in Uganda in 2015 (21.5%). Median private sector price of RDT for a child was equal to the price of pre-packaged quality-assured artemisinin-based combination therapy (QAACT) treatment for a two-year old child in some countries, and 1.5–2.5 times higher in others. Median private sector QAACT price for an adult varied from having parity with an RDT for an adult to being up to 2 times more expensive. The exception was in both Kinshasa and Katanga, where the median price of QAACT was less expensive than RDTs.ConclusionsSignificant strides have been made in the availability of testing, mainly through the widespread distribution of RDT, and especially in public health facilities. Significant barriers to universal coverage of diagnostic testing can be attributed to very low availability in the private sector, particularly among pharmacies and drug stores, which are responsible for most anti-malarial distribution. Where tests are available, price may serve as a barrier to uptake, particularly for young children. Several initiatives that have introduced RDT into the private sector can be modified and expanded as a means to close this gap in malaria testing availability and promote universal diagnosis.

Rapid concentration and elution of malarial antigen histidine-rich protein II using solid phase Zn(II) resin in a simple flow-through pipette tip format.

Rapid diagnostic tests (RDTs) designed to function at the point of care are becoming more prevalent in malaria diagnostics because of their low cost and simplicity. While many of these tests function effectively with high parasite density samples, their poor sensitivity can often lead to misdiagnosis when parasitemia falls below 100 parasites/μl. In this study, a flow-through pipette-based column was explored as a cost-effective means to capture and elute more Plasmodium falciparum histidine-rich protein II (HRPII) antigen, concentrating the biomarker available in large-volume lysed whole blood samples into volumes compatible with Plasmodium falciparum-specific RDTs. A systematic investigation of immobilized metal affinity chromatography divalent metal species and solid phase supports established the optimal design parameters necessary to create a flow-through column incorporated into a standard pipette tip. The bidirectional flow inherent to this format maximizes mixing efficiency so that in less than 5 min of sample processing, the test band signal intensity was increased up to a factor of twelve from HRPII concentrations as low as 25 pM. In addition, the limit of detection per sample was decreased by a factor of five when compared to the RDT manufacturer's suggested protocol. Both the development process and commercial viability of this application are explored, serving as a potential model for future applications.

The malaria testing and treatment landscape in Benin

BackgroundSince 2004, artemisinin-based combination therapy (ACT) has been the first-line treatment for uncomplicated malaria in Benin. In 2016, a medicine outlet survey was implemented to investigate the availability, price, and market share of anti-malarial treatment and malaria diagnostics. Results provide a timely and important benchmark to measure future interventions aimed at increasing access to quality malaria case management services.MethodsBetween July 5th to August 6th 2016, a cross sectional, nationally-representative malaria outlet survey was conducted in Benin. A census of all public and private outlets with potential to distribute malaria testing and/or treatment was implemented among 30 clusters (arrondissements). Outlets were eligible for inclusion in the study if they met at least one of three study criteria: (1) one or more anti-malarials reportedly in stock on the day of the survey; (2) one or more anti-malarials reportedly in stock within the 3 months preceding the survey; and/or (3) provided malaria blood testing. An audit was completed for all anti-malarials, malaria rapid diagnostic tests (RDT) and microscopy.Results7260 outlets with the potential to sell or distribute anti-malarials were included in the census and 2966 were eligible and interviewed. A total of 17,669 anti-malarial and 494 RDT products were audited. Quality-assured ACT was available in 95.0% of all screened public health facilities and 59.4% of community health workers (CHW), and availability of malaria blood testing was 94.7 and 68.4% respectively. Sulfadoxine–pyrimethamine (SP) was available in 73.9% of public health facilities and not found among CHWs. Among private-sector outlets stocking at least one anti-malarial, non-artemisinin therapies were most commonly available (94.0% of outlets) as compared to quality-assured ACT (36.1%). 31.3% of the ACTs were marked with a “green leaf” logo, suggesting leakage of a co-paid ACT into Benin’s unsubsidized ACT market from another country. 78.5% of the anti-malarials distributed were through the private sector, typically through general retailers (47.6% of all anti-malarial distribution). ACT comprised 44% of the private anti-malarial market share. Private-sector price of quality-assured ACT ($1.35) was three times more expensive than SP ($0.42) or chloroquine ($0.41). Non-artemisinin therapies were cited as the most effective treatment for uncomplicated malaria among general retailers and itinerant drug vendors.ConclusionsThe ACTwatch data has shown the importance of the private sector in terms of access to malaria treatment for the majority of the population in Benin. These findings highlight the need for increased engagement with the private sector to improve malaria case management and an immediate need for a national ACT subsidy.

The malaria testing and treatment landscape in the southern Lao People\u2019s Democratic Republic (PDR)

BackgroundIn the context of national and regional goals to eliminate malaria by 2030, the Center for Malaria Parasitology and Entomology in the Lao PDR is implementing strategies to ensure all malaria cases are detected and appropriately treated with first-line artemisinin combination therapy, artemether–lumefantrine (AL). Timely and relevant evidence to inform policies and strategies is needed to ensure the most effective and efficient use of resources, and to accelerate progress towards elimination goals. A 2015 outlet survey conducted in five provinces of the southern Lao PDR was the first of its kind to study the total market for malaria treatments and diagnostics. The sub-national outlet survey was designed to describe the market and to assess public and private sector readiness and performance for malaria case management. Additionally, key indicators were estimated among private outlets within districts with and without a Public Private Mix (PPM) programme.ResultsOver half of anti-malarial stockists were public sector (65.1%). In the private sector, pharmacies most commonly stocked anti-malarials, although anti-malarials were also found in private health facilities, drug stores, general retailers, and itinerant drug vendors. Nearly all anti-malarial stocking public health facilities had AL (99.5%) and 90.8% had confirmatory testing. Fewer than half of anti-malarial stocking private outlets stocked AL (40.8%) and malaria testing (43.5%). Chloroquine has not been a first-line treatment for Plasmodium falciparum malaria since 2005 and Plasmodium vivax since 2011 yet private sector availability was 77.6% and chloroquine accounted for 62.2% of the total anti-malarial market share. AL and confirmatory testing availability were higher in private outlets in PPM (68.1, 72.6%) versus non-PPM districts (2.5, 12.1%). Chloroquine was available in 63.6% of PPM and 96.7% of non-PPM-district outlets, and was the most commonly distributed anti-malarial among private outlets in both PPM (61.7%) and non-PPM districts (99.1%).ConclusionsPublic sector outlets in the southern Lao PDR are typically equipped to test and appropriately treat malaria. There is need to address widespread private sector availability and distribution of chloroquine. The PPM programme has improved private provider readiness to manage malaria according to national guidelines. However, supporting interventions to address provider and consumer behaviours are needed to further drive uptake.

The malaria testing and treatment landscape in mainland Tanzania, 2016

BackgroundUnderstanding the key characteristics of malaria testing and treatment is essential to the control of a disease that continues to pose a major risk of morbidity and mortality in mainland Tanzania, with evidence of a resurgence of the disease in recent years. The introduction of artemisinin combination therapy (ACT) as the first-line treatment for malaria, alongside policies to promote rational case management following testing, highlights the need for evidence of anti-malarial and testing markets in the country. The results of the most recent mainland Tanzania ACTwatch outlet survey are presented here, including data on the availability, market share and price of anti-malarials and malaria diagnosis in 2016.MethodsA nationally-representative malaria outlet survey was conducted between 18th May and 2nd July, 2016. A census of public and private outlets with potential to distribute malaria testing and/or treatment was conducted among a representative sample of administrative units. An audit was completed for all anti-malarials, malaria rapid (RDT) diagnostic tests and microscopy.ResultsA total of 5867 outlets were included in the nationally representative survey, across both public and private sectors. In the public sector, availability of malaria testing was 92.3% and quality-assured (QA) ACT was 89.1% among all screened outlets. Sulfadoxine–pyrimethamine (SP) was stocked by 51.8% of the public sector and injectable artesunate was found in 71.4% of all screened public health facilities. Among anti-malarial private-sector stockists, availability of testing was 15.7, and 65.1% had QA ACT available. The public sector accounted for 83.4% of the total market share for malaria diagnostics. The private sector accounted for 63.9% of the total anti-malarial market, and anti-malarials were most commonly distributed through accredited drug dispensing outlets (ADDOs) (39.0%), duka la dawa baridi (DLDBs) (13.3%) and pharmacies (6.7%). QA ACT comprised 33.1% of the national market share (12.2% public sector and 20.9% private sector). SP accounted for 53.3% of the total market for anti-malarials across both private and public sectors (31.3 and 22.0% of the total market, respectively). The median price per adult equivalent treatment dose (AETD) of QA ACT in the private sector was $1.40, almost 1.5 times more expensive than the median price per AETD of SP ($1.05). In the private sector, 79.3% of providers perceived ACT to be the most effective treatment for uncomplicated malaria for adults and 88.4% perceived this for children.ConclusionsWhile public sector preparedness for appropriate malaria testing and case management is showing encouraging signs, QA ACT availability and market share in the private sector continues to be sub-optimal for most outlet types. Furthermore, it is concerning that SP continues to predominate in the anti-malarial market. The reasons for this remain unclear, but are likely to be in part related to price, availability and provider knowledge or preferences. Continued efforts to implement government policy around malaria diagnosis and case management should be encouraged.

Update on Malaria Diagnostics and Test Utilization.

Malaria is a potentially life-threatening disease requiring rapid diagnosis and treatment. Although microscopic examination of thick and thin blood films remains the gold standard for laboratory diagnosis, rapid antigen tests and nucleic acid amplification methods may also play a useful role in detection of acute infection. This review discusses the advantages and disadvantages of the commonly used diagnostic methods and provides important practice points for optimal malaria test utilization.

Enhancing the sensing specificity of a MoS2 nanosheet-based FRET aptasensor using a surface blocking strategy.

Aptamer-based biosensing, which uses short, single-stranded nucleic acid segments to bind to a target, can be advantageous over antibody-based diagnostics due to the ease of synthesis and high stability of aptamers. However, the development of most aptamer-based sensors (aptasensors) is still in its initial stages and many factors affecting their performance have not been studied in great detail. Here, we enhance the sensing specificity of a fluorescence resonance energy transfer (FRET)-based MoS2 nanosheet aptasensor in detecting the malarial biomarker Plasmodium lactate dehydrogenase (pLDH). In this sensing scheme, the presence of target is signaled by an increase in fluorescence when fluorescently-labeled aptamers bind to pLDH and release from a quenching material. Interestingly, unlike most of the reported literature on aptasensors, we observe that non-target proteins also cause a considerable increase in the detected fluorescence. This may be due to the nonspecific adsorption of proteins onto the fluorescence quencher, leading to the displacement of aptamers from the quencher surface. To reduce this nonspecific association and to enhance the sensor specificity, we propose the application of a surface blocking agent to the quenching material. Importantly, we demonstrate that the sensing specificity of the MoS2 nanosheet-based aptasensor towards target pLDH biomolecules can be significantly enhanced through surface passivation, thus contributing to the development of highly selective and robust point-of-care malaria diagnostics.

Current Status of Standard Diagnostics and Treatment for Malaria, Tuberculosis, and Hepatitis in Myanmar

Current Status of Standard Diagnostics and Treatment for Malaria, Tuberculosis, and Hepatitis in Myanmar

Advances in Molecular Diagnosis of Malaria.

Malaria is a mosquito-borne disease caused by five species of Plasmodium parasites. Accurate diagnosis of malaria plays an essential part in malaria control. With traditional diagnostic methodologies, malaria control programs have achieved remarkable success during the past decade, and are now heading toward malaria elimination in many areas. This new situation, however, calls for novel diagnostics with improved sensitivity, throughput, and reduced cost for active screening of malaria parasites, as all transfected individuals have to be identified in order to block transmission. In this chapter, we provide a brief introduction of malaria, the requirement of diagnostic advances in the age of malaria elimination, and a comprehensive overview of the currently available molecular malaria diagnostics, ranging from well-known tests to platforms in early stages of evaluation. We also discussed several practical issues for the application of molecular tests in malaria identification.

Impact of Improving Community-Based Access to Malaria Diagnosis and Treatment on Household Costs.

Background. Community health workers (CHWs) were trained in Burkina Faso, Nigeria, and Uganda to diagnose febrile children using malaria rapid diagnostic tests, and treat positive malaria cases with artemisinin-based combination therapy (ACT) and those who could not take oral medicines with rectal artesunate. We quantified the impact of this intervention on private household costs for childhood febrile illness.Methods. Households with recent febrile illness in a young child in previous 2 weeks were selected randomly before and during the intervention and data obtained on household costs for the illness episode. Household costs included consultation fees, registration costs, user fees, diagnosis, bed, drugs, food, and transport costs. Private household costs per episode before and during the intervention were compared. The intervention's impact on household costs per episode was calculated and projected to districtwide impacts on household costs.Results. Use of CHWs increased from 35% of illness episodes before the intervention to 50% during the intervention (P < .0001), and total household costs per episode decreased significantly in each country: from US Dollars (USD) $4.36 to USD $1.54 in Burkina Faso, from USD $3.90 to USD $2.04 in Nigeria, and from USD $4.46 to USD $1.42 in Uganda (all P < .0001). There was no difference in the time used by the child's caregiver to care for a sick child (59% before intervention vs 51% during intervention spent ≤2 days). Using the most recent population figures for each study district, we estimate that the intervention could save households a total of USD $29 965, USD $254 268, and USD $303 467, respectively, in the study districts in Burkina Faso, Nigeria, and Uganda.Conclusions. Improving access to malaria diagnostics and treatments in malaria-endemic areas substantially reduces private household costs. The key challenge is to develop and strengthen community human resources to deliver the intervention, and ensure adequate supplies of commodities and supervision. We demonstrate feasibility and benefit to populations living in difficult circumstances.Clinical Trials Registration. ISRCTN13858170.

Optimized Detection of Plasmodium falciparum Topoisomerase I Enzyme Activity in a Complex Biological Sample by the Use of Molecular Beacons.

The so-called Rolling Circle Amplification allows for amplification of circular DNA structures in a manner that can be detected in real-time using nucleotide-based molecular beacons that unfold upon recognition of the DNA product, which is being produced during the amplification process. The unfolding of the molecular beacons results in a fluorescence increase as the Rolling Circle Amplification proceeds. This can be measured in a fluorometer. In the current study, we have investigated the possibility of using two different molecular beacons to detect two distinct Rolling Circle Amplification reactions proceeding simultaneously and in the same reaction tube by measurement of fluorescence over time. We demonstrate the application of this fluorometric readout method, for automated and specific detection of the activity of the type IB topoisomerase from the malaria parasite Plasmodium falciparum in the presence of human cell extract containing the related topoisomerase I from humans. The obtained results point towards a future use of the presented assay setup for malaria diagnostics or drug screening purposes. In longer terms the method may be applied more broadly for real-time sensing of various Rolling Circle Amplification reactions.