Testing In Resource-limited Settings Research Articles

M13mp18 nanoscaffold-based strip sensor for detecting influenza A virus (H1N1)

We report the development of an amplification-free nucleic acid assay using lateral flow test strips. M13mp18 nanoscaffold signal amplification permitted the visual detection of H1N1 RNA in 20 min. M13mp18 nanoscaffold supported a set of backbone, variable, detection, and modified oligonucleotides. A bridging-type FAM probe/H1N1 RNA/M13mp18 was used in the lateral flow test strip format. The bridging-type complexes were captured on the test zone. The lower limit of detection of specific H1N1 RNA was 1 pM. The method directly detected H1N1 RNA without amplification, eliminating the risk of amplicon contamination and lessening the chance of false positives. This biosensor has potential value for field testing in resource-limited settings and monitoring viral loads in recovering patients. The amplification-free lateral flow detection of RNA provides an alternative between amplification-based RNA assays and protein antigen assays for facilitating the rapid identification of H1N1 virus during point-of-care testing.

A rapid and simple modified nitrate reductase assay for testing first and second-line antituberculosis drug susceptibilities in Mycobacterium tuberculosis isolates

In this study, we developed a modified NRA (MONRA) to determine the first and second-line drug susceptibilities of 5 reference ATCC strains and 42 clinical M. tuberculosis isolates. Unlike conventional NRA, which is often performed in solid media or 7H9 broth, the MONRA is performed in a different medium, AYC.2.1 broth, using lyophilized antibiotic tubes to determine drug susceptibility. The MONRA results were compared with BACTEC MGIT 960 method as the reference method for first-line drugs and conventional NRA performed in 7H9 broth for second-line drugs. The agreement between the MONRA and the reference method was determined as 97.62, 100, 97.62, and 100 % for streptomycin, isoniazid, rifampicin, and ethambutol, respectively. When the results were compared with convantional NRA, the agreement was determined as 100 % for all second-line antibiotics including levofloxacin, ofloxacin, and kanamycin. MONRA has the potential to eliminate challenges in implementing drug susceptibility testing in resource-limited settings.

Lab-on-a-chip paper-based electrochemically assisted solid-phase microextraction and ion selective sensor for determination of naproxen in biological fluid samples

BackgroundThe integration of paper-based analytical devices with lab-on-a-chip technology has opened up new possibilities for miniaturized, rapid, low cost and portable diagnostic testing in resource limited settings. This work introduces an integrated lab-on-a-chip platform coupling paper-based analytical devices (LOC-PADs) for dual usage: electrochemically controlled solid-phase microextraction (EC-SPME) and determination of naproxen (NAP) by potentiometric ion-selective electrode (ISE) in biological samples. ResultsConductive papers were successfully fabricated by a chemical procedure. Thereupon, a conducting molecularly imprinted polymer (CMIP) film based on PPy and an anionic model drug (NAP) as a template were applied to the conductive paper substrate via electrochemical methods. A microfluidic chip device was employed to assess the analytical performance of the fabricated paper-based CMIP. The designed chip is divided into two parts with a microfluidic channel between them. The first chamber is an extraction zone for EC-SPME of NAP by using the CMIP paper as a selective sorbent. The second chamber is the detection zone and consists of a paper-based NAP ion selective sensor for potentiometric detection of drug. The analytical process was investigated and optimized for each chamber. Remarkable selectivity towards NAP was achieved in the concentration range from 4.0 × 10−7 to 1.0 × 10−2 mol L−1 with determination coefficient (R2 = 0.99) and the limit of detection (LOD) was 2.0 × 10−7 mol L−1. Anionic Nernstian compliance was gained −58.5 ± 0.5 mV decade−1, and response time in the detection step was 7s for ISE. Satisfactory spiking recovery values within the acceptable range of 90–110 % with RSDs ≤7 % were achieved for the analysis of real samples with fully portable LOC device. SignificanceThe LOC-PADs were favorably used for selective extraction and determination of NAP in serum and saliva samples, respectively. EC-SPME caused sample clean-up, reduced or eliminated different interferences and enhanced selective response of ISE as detection zone of device. Integration of EC-SPME and ISE in a single chip enabled easy and fast determination of trace amounts of NAP in limited real sample volumes, and fully portable advantages.

Availability of point-of-care HBV tests in resource-limited settings

Availability of point-of-care HBV tests in resource-limited settings

The Impact of GeneXpert Cerebrospinal Fluid Testing on Tuberculous Meningitis Diagnosis in Routine Care in Botswana

Abstract Background Tuberculous meningitis (TBM) disproportionately impacts high–HIV prevalence, resource-limited settings where diagnosis is challenging. The GeneXpert platform has utility in TBM diagnosis, but uptake remains limited. In Botswana, before the introduction of GeneXpert, tuberculosis (TB) testing was only available through mycobacterial culture at the National TB Reference Laboratory. Data describing routine use of Xpert MTB/RIF for cerebrospinal fluid (CSF) testing in resource-limited settings are scarce. Methods Electronic records for patients with CSF tested in government facilities in Botswana between 2016 and 2022 were obtained from a central online repository as part of ongoing national meningitis surveillance. Samples were excluded from 1 site where Xpert MTB/RIF is performed universally. The proportion receiving TB-specific investigation on CSF and the number positive for Mycobacterium tuberculosis following increased Xpert MTB/RIF capacity were determined. Results The proportion of CSF samples receiving TB-specific investigation increased from 4.5% (58/1288) in 2016 to 29.0% (201/693) in 2022, primarily due to increased analysis with Xpert MTB/RIF from 0.9% (11/1288) to 23.2% (161/693). There was an overall decline in the annual number of CSF samples analyzed, but the proportion with microbiologically confirmed TBM increased from 0.4% to 1.2%. The proportion of samples tested for TB that were collected from health care facilities >100 km from the National TB Reference Laboratory increased with Xpert MTB/RIF rollout from 65.9% (87/132) to 78.0% (494/633). Conclusions In Botswana, access to TB culture is challenging in remote populations; more accessible near-patient testing using Xpert MTB/RIF increased the number of patients receiving TB-specific testing on CSF and the number of confirmed TBM cases.

Simplified Electrochemical Approach for End-Point Yet Quantitative Detection of Nucleic Acids in Resource-Limited Settings.

Nucleic acid detection plays a crucial role in various aspects of health care, necessitating accessible and reliable quantification methods, especially in resource-limited settings. This work presents a simplified electrochemical approach for end-point yet quantitative nucleic acid detection. By elevating the concentration of redox species and choosing potential as the signals, we achieved enhanced signal robustness, even in the presence of interfering substances. Leveraging this robustness, we accurately measured pH-induced redox potential changes in methylene blue solution for end-point nucleic acid detection after loop-mediated isothermal amplification (LAMP). Our method demonstrated quantitative detection of the SARS-CoV-2 N gene and human ATCB gene and successful discrimination of the human BRAF V600E mutation, comparable in sensitivity to commercial kits. The developed user-friendly electrochemical method offers a simplified and reliable approach for end-point yet quantitative detection of nucleic acids, potentially expanding the benefits of nucleic acid testing in resource-limited settings.

Predictive models as a clinical decision support tool for genetic cancer risk assessment among Mexican patients at risk of hereditary colorectal cancer.

10617 Background: Hereditary cancer syndromes, including Lynch syndrome (LS) with an increased risk of colorectal cancer (CRC), have prompted the development of clinical criteria and predictive models (PM) to identify at-risk individuals. However, these criteria have been validated with limited representation from the Latino population. Several factors may influence CRC penetrance, potentially leading to variations in PM performance across populations. Given that CRC ranks as the third most prevalent cancer worldwide, the increasing incidence of early-onset disease highlights the need for expanding Genetic Cancer Risk Assessment (GCRA) services. Methods: This prospective study included Mexican patients who were diagnosed with CRC and met NCCN criteria for GCRA. Participants were enrolled at two referral centers in Mexico, the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran, Mexico City and at the Hospital Zambrano Hellion TecSalud, Nuevo Leon. Participants' carrier risk was estimated using the PREMM5 model. Amsterdam II and revised Bethesda criteria, immunohistochemistry (IHC) for DNA mismatch repair (MMR) proteins in tumor tissue and multigene panel testing results were reviewed. For this analysis, only pathogenic and likely pathogenic (P/LP) variants in probands were reported. Results: From April 2016 to October 2023, 194 patients were included, with a median age at diagnosis of 45.0 (range 17-82) years, and 49.5% were women. P/LP variants were identified in 37.6% (n=73). 27.5% (n=50) were carriers of P/LP variants associated with LS (29 MLH1, 13 MSH2, 6 MSH6, and 2 PMS2). 11.8% (n=23) were carriers of P/LP variants in other genes (7 APC, 4 ATM, 3 CHEK2, 2 BRCA1, 2 TP53, 2 STK11, 1 PALB2, 1 BRIP1, and 1 MUTYH). Overall, carriers of PVs were diagnosed with CRC at a younger age than non-carriers (42 vs 46 years, p=0.034). The Amsterdam II criteria proved to be accurate (Sen 55%, Spe 91%, PPV 0.69, NPV 0.85), while the Bethesda criteria (Sen 98%, Spe 18%, PPV 0.29, NPV 0.96) and IHC for MMR proteins (Sen 94%, Spe 67%, PPV 0.61, NPV 0.95) were found to be highly sensitive. The area under the ROC curve for PREMM5 was 0.82 with a mean score 28.5 (2.1 – 50) in patients with LS and 6.0 (0.9 – 50) in non-carriers. Carriers of PVs had a higher rate of multiple primary malignancies than non-carriers (41.0% vs 19.0%, p=0.0014), and self-reported family history of CRC (65.7% vs 24.8%, p<0.001). Conclusions: Our results showed the PREMM5 model and IHC for MMR proteins effectively prioritized patients eligible for germline genetic testing in resource-limited settings. The performance of PREMM5 in this Mexican cohort was similar to that reported in the validation study of this model in other populations. Considering the spectrum of identified P/LP variants, the multigene panel test should be used in the comprehensive evaluation of Mexican patients with CRC.

Performance evaluation of loop-mediated isothermal amplification, polymerase chain reaction and real-time polymerase chain reaction methods to detect Neisseria gonorrhoeae among symptomatic patients from India.

Background: Neisseria gonorrhoeae is one of the most important causative organisms in causing sexually transmitted infections. The clinical presentation of gonorrhoea mimics the symptoms of other sexually transmitted infections, and a proper diagnosis of the same is therefore crucial in patient management. The current study intended to compare different in-house molecular methods: that is, conventional PCR, real-time PCR, and LAMP assay for detection of N. gonorrhoeae. Methods: A total of 163 samples were collected from 145 patients who presented with urethral and vaginal discharge. Collected samples were processed for culture on GC agar base, and three different molecular diagnostic tests (conventional PCR, real-time PCR, and LAMP assay) were performed simultaneously on all the samples. Results: Culture of N. gonorrhoeae was positive in 17 out of 21 (80.9%) swab samples. With culture as the gold standard method, conventional and real-time PCR had a sensitivity of 94.1%, whereas the sensitivity of the LAMP assay was found to be 88.2%. All three methods had a specificity of 100%. In addition to swab samples, evaluation of urine samples by different molecular methods yielded a good concordance with a kappa value of 0.85 by conventional PCR and real-time PCR showing a perfect level of agreement, while the LAMP assay was found to have a substantial level of agreement. Conclusion: LAMP assay had a comparable diagnostic accuracy to other molecular methods for the detection of N. gonorrhoeae and can be used as a point-of-care test in resource-limited settings.

Performance of two SARS-CoV-2 rapid antigen detection tests in resource limited settings, the case of Mali.

While real-time reverse transcription PCR (RT-PCR) is the recommended laboratory method to diagnose severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection, its use in resource limited settings can be difficult to maintain due to high testing demand and shortage of reagents. The aim of this study was to evaluate the performances of Realy Tech™ and Standard Q™ in comparison to RT-PCR in a relatively low COVID-19 prevalence setting, Mali. We conducted a cross-sectional study between January and April 2021 in Bamako and Kati regions to evaluate both rapid tests during a large SARS-CoV-2 prevalence study in Mali. Of the 390 samples tested, the sensitivity and specificity of Realy Tech™ and Standard Q™ were 57.1% (95%CI: 44.1-69.2), 95.8% (95%CI: 93.1-97.5); 61.9% (95%CI: 46.8-75.0), and 94.1% (95%CI: 89.5-96.8) respectively. Using RT-PCR, the global prevalence of SARS-CoV-2 was 14.4% (56/390). In both rapid antigen tests, the performance was better when used in suspected patients compared to positive patients under treatment. Moreover, higher viral loads equivalent to Ct < 25 were associated with better detection rates. While waiting for more complete data, these preliminary studies suggest that Realy Tech™ and Standard Q™ should not be used alone for COVID-19 diagnosis in Mali.

Utility of a Novel Clinical Scoring System and its Association with Procalcitonin in Patients of Acute Heart Failure with Respiratory Infections: A Limited Resource Perspective

Abstract Background: Heart failure (HF) is a global health burden that is usually simple to diagnose, but concomitant respiratory infections are difficult to distinguish clinically. Inflammatory markers can be used to differentiate between the two conditions, especially procalcitonin (PCT), one of the most specific markers for bacterial infections. PCT-guided antibiotic treatment has shown good results and could help in decreasing the indiscriminate prescription of antibiotics in HF patients. Methodology: A prospective observational study was carried out in a tertiary care hospital in Western India. Three hundred HF patients were separated into either high- or low-PCT level groups. A novel clinical score for clinically suspecting superimposed respiratory infection in acute HF patients was devised and its association with PCT level was measured. Results: 62.87 years was the average age of the study population with a male preponderance. While breathlessness was the presenting complaint in all 300 patients, the presence of fever and edema was significantly associated with raised PCT. A higher total leukocyte count and neutrophil count were seen in patients with high PCT. A higher incidence of consolidation, pulmonary edema, and pulmonary hypertension was noted in those with high PCT. A significant association was found between the clinical scoring system and the PCT level. Conclusion: The novel clinical scoring system has a satisfactory sensitivity, specificity, positive predictive value, and negative predictive value in diagnosing superimposed respiratory infections in acute HF patients. It can aid in the judicious use of the PCT test in resource-limited settings.

Boosting Electrochemiluminescence Immunoassay Sensitivity via Co-Pt Nanoparticles within a Ti3C2 MXene-Modified Single Electrode Electrochemical System on Raspberry Pi.

Point-of-care testing plays a crucial role in diagnostics within resource-poor areas, necessitating the utilization of portable and user-friendly devices. The adaptation of biosensors for point-of-care applications requires careful considerations, such as miniaturization, cost-effectiveness, and streamlined sample processing. In recent years, the electrochemiluminescence (ECL) immunoassay has gained significant attention due to its visual detection capabilities and ability to facilitate high-throughput analysis. However, the development of a practical and cost-effective ECL device remains a challenging task. This study presents the development of an integrated MXene-modified single-electrode electrochemical system (SEES) for visual and high-throughput ECL immunoassays incorporating a Raspberry Pi system. The SEES was designed by affixing a plastic sticker with multiple perforations onto a single carbon ink screen-printed electrode, which operates based on a resistance-induced potential difference. Leveraging the excellent adsorption and bioaffinity properties of the carbon ink screen-printed electrode, effective immobilization of antibodies was achieved. Furthermore, the incorporation of Co-Pt nanoparticles enhanced the ECL intensity and electron transfer kinetics, enabling the sensitive detection of SARS-CoV-2. The developed system comprised 18 individual reaction cells, allowing for simultaneous analysis while maintaining sample isolation. Impressively, the system achieved a remarkable minimum virus detection limit of 10-14 g mL-1, accompanied by a high R2 value of 0.9798. These findings highlight the promising potential of our developed system for efficient point-of-care testing in resource-limited settings.

Impact of storage time in dried blood samples (DBS) and dried plasma samples (DPS) for point-of-care hepatitis C virus (HCV) RNA quantification and HCV core antigen detection.

The scale-up of hepatitis C virus (HCV) diagnosis and treatment requires affordable and simple tools to improve access to care, especially in low- and middle-income settings with limited infrastructure or high-risk populations. Dried blood and plasma samples (DBS and DPS) are useful alternative for hepatitis C detection in settings lacking adequate infrastructure. We evaluated the performance of DBS and DPS vs plasma in a point-of-care HCV RNA quantitative assay (Xpert HCV Viral Load-Cepheid), and compared HCV core antigen (HCVcAg) detection by the Architect HCV core antigen assay (Abbott) in DBS vs serum. The dried samples were stored at room temperature for different storage times to reproduce the time from sampling to testing in settings with centralized diagnosis or when testing mobile populations. HCV RNA quantification in DBS and DPS presented 100% sensitivity and specificity and a high correlation for up to 3 months of storage. HCV viremia showed a mean decrease of 0.5 log10 IU/mL (DBS) and 0.3 log10 IU/mL (DPS) for storage times up to 1 month. Architect HCVcAg detection presented high sensitivity/specificity (96%/100%) in DBS tested immediately after sampling, decreasing to 86% sensitivity after 7 days of storage. However, sensitivity increased when an optimized cut-off was applied for each storage time. We conclude that DBS and DPS are suitable samples for HCV RNA detection and quantification, being DPS more reliable for shorter storage times. DBS can be also used for HCVcAg qualitative detection and the sensitivity can be increased when adjusting the cut-off values. IMPORTANCE Hepatitis C infection remains a global burden despite the effectiveness of antivirals. In the WHO roadmap to accomplish HCV elimination by 2030, HCV diagnosis is one of the main targets. However, identifying patients in resource-limited settings and high-risk populations with limited access to healthcare remains a challenge and requires innovative approaches that allow decentralized testing. The significance of our research is in verifying the good performance of dried samples for HCV diagnosis using two different diagnostics assays and considering the effect of room temperature storage in this sample format. We confirmed dried samples are an interesting alternative for HCV screening and reflex testing in resource-limited settings or high-risk populations.

Detection of acute dengue virus infection, with and without concurrent malaria infection, in a cohort of febrile children in Kenya, 2014-2019, by clinicians or machine learning algorithms.

Poor access to diagnostic testing in resource limited settings restricts surveillance for emerging infections, such as dengue virus (DENV), to clinician suspicion, based on history and exam observations alone. We investigated the ability of machine learning to detect DENV based solely on data available at the clinic visit. We extracted symptom and physical exam data from 6,208 pediatric febrile illness visits to Kenyan public health clinics from 2014-2019 and created a dataset with 113 clinical features. Malaria testing was available at the clinic site. DENV testing was performed afterwards. We randomly sampled 70% of the dataset to develop DENV and malaria prediction models using boosted logistic regression, decision trees and random forests, support vector machines, naïve Bayes, and neural networks with 10-fold cross validation, tuned to maximize accuracy. 30% of the dataset was reserved to validate the models. 485 subjects (7.8%) had DENV, and 3,145 subjects (50.7%) had malaria. 220 (3.5%) subjects had co-infection with both DENV and malaria. In the validation dataset, clinician accuracy for diagnosis of malaria was high (82% accuracy, 85% sensitivity, 80% specificity). Accuracy of the models for predicting malaria diagnosis ranged from 53-69% (35-94% sensitivity, 11-80% specificity). In contrast, clinicians detected only 21 of 145 cases of DENV (80% accuracy, 14% sensitivity, 85% specificity). Of the six models, only logistic regression identified any DENV case (8 cases, 91% accuracy, 5.5% sensitivity, 98% specificity). Without diagnostic testing, interpretation of clinical findings by humans or machines cannot detect DENV at 8% prevalence. Access to point-of-care diagnostic tests must be prioritized to address global inequities in emerging infections surveillance.

The risk of sexual transmission of HIV in individuals with low-level HIV viraemia: a systematic review

The risk of sexual transmission of HIV from individuals with low-level HIV viraemia receiving antiretroviral therapy (ART) has important public health implications, especially in resource-limited settings that use alternatives to plasma-based viral load testing. This Article summarises the evidence related to sexual transmission of HIV at varying HIV viral load levels to inform messaging for people living with HIV, their partners, their health-care providers, and the wider public. We conducted a systematic review and searched PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Embase, Conference Proceedings Citation Index-Science, and WHO Global Index Medicus, for work published from Jan 1, 2010 to Nov 17, 2022. Studies were included if they pertained to sexual transmission between serodiscordant couples at various levels of viraemia, the science behind undetectable=untransmittable, or the public health impact of low-level viraemia. Studies were excluded if they did not specify viral load thresholds or a definition for low-level viraemia or did not provide quantitative viral load information for transmission outcomes. Reviews, non-research letters, commentaries, and editorials were excluded. Risk of bias was evaluated using the ROBINS-I framework. Data were extracted and summarised with a focus on HIV sexual transmission at varying HIV viral loads. 244 studies were identified and eight were included in the analysis, comprising 7762 serodiscordant couples across 25 countries. The certainty of evidence was moderate; the risk of bias was low. Three studies showed no HIV transmission when the partner living with HIV had a viral load less than 200 copies per mL. Across the remaining four prospective studies, there were 323 transmission events; none were in patients considered stably suppressed on ART. Among all studies there were two cases of transmission when the index patient's (ie, patient with previously diagnosed HIV infection) most recent viral load was less than 1000 copies per mL. However, interpretation of both cases was complicated by long intervals (ie, 50 days and 53 days) between the transmission date and the most recent index viral load result. There is almost zero risk of sexual transmission of HIV with viral loads of less than 1000 copies per mL. These data provide a powerful opportunity to destigmatise HIV and promote adherence to ART through dissemination of this positive public health message. These findings can also promote access to viral load testing in resource-limited settings for all people living with HIV by facilitating uptake of alternative sample types and technologies. Bill & Melinda Gates Foundation.

Descriptive spectrum of thiamine deficiency in pregnancy: Apotentially preventable condition.

Pregnancy, a nutritionally demanding situation in terms of macro- and micronutrient supply owing to heightened maternal, placental, and fetal needs, significantly affects thiamine reserves. Thiamine deficiency during pregnancy and the postpartum period, presenting with varied manifestations and outcomes, is a relatively common condition in our population. The study aimed to understand the various manifestations and outcomes of acute thiamine deficiency in pregnant and postpartum women, emphasizing the significance of early recognition and thiamine therapy to prevent serious complications during pregnancy and after childbirth. This prospective study conducted in a tertiary care center in North India enrolled consecutive pregnant and postpartum women presenting with clinical features consistent with thiamine deficiency disorders, such as thiamine deficiency-related neuropathy, high-output heart failure, heart failure with reduced ejection fraction, Wernicke's encephalopathy, gastric beriberi, and thiamine-responsive acute pulmonary hypertension. In addition to capturing medical history including drug intake, dietary consumption, and comorbidities, women underwent brief relevant clinical examinations and laboratory assessments, including whole-blood thiamine levels. Response to intravenous thiamine supplementation was also monitored. Data of 31 women (12 pregnant, 19 postpartum) with a diagnosis of acute thiamine deficiency and a mean age of 28.88 ± 2.69 years were analyzed. The mean thiamine level was 1.28 ± 0.44 μg/dL with mean blood lactate of 3.46 ± 3.33. The most common presentation was gastric beriberi (n = 10), followed by paraparesis (n = 6), high-output heart failure (n = 6), acute pulmonary hypertension, heart failure with reduced ejection fraction (n = 3 each), and an acute confusional state (n = 2). All patients responded to thiamine challenge. In the context of borderline thiamine status, particularly in our population with endemic thiamine deficiency and heightened demand for thiamine during pregnancy and the peripartum period, the deficiency can have varied and serious manifestations of dry and wet beriberi. Early recognition of the clinical features and thiamine therapy can be life-saving. There is a need for validated clinical criteria owing to the non-availability of thiamine testing in resource-limited settings.

Comparison of methods to engage diverse stakeholder populations in prioritizing PrEP implementation strategies for testing in resource-limited settings: a cross-sectional study

BackgroundThere is a lack of consensus about how to prioritize potential implementation strategies for HIV pre-exposure prophylaxis (PrEP) delivery. We compared several prioritization methods for their agreement and pragmatism in practice in a resource-limited setting.MethodsWe engaged diverse stakeholders with clinical PrEP delivery and PrEP decision-making experience across 55 facilities in Kenya to prioritize 16 PrEP delivery strategies. We compared four strategy prioritization methods: (1) “past experience surveys” with experienced practitioners reflecting on implementation experience (N = 182); (2 and 3) “pre- and post-small-group ranking” surveys before and after group discussion (N = 44 and 40); (4) “go-zone” quadrant plots of perceived effectiveness vs feasibility. Kendall’s correlation analysis was used to compare strategy prioritization using the four methods. Additionally, participants were requested to group strategies into three bundles with up to four strategies/bundle by phone and online survey.ResultsThe strategy ranking correlation was strongest between the pre- and post-small-group rankings (Tau: 0.648; p < 0.001). There was moderate correlation between go-zone plots and post-small-group rankings (Tau: 0.363; p = 0.079) and between past-experience surveys and post-small-group rankings (Tau: 0.385; p = 0.062). For strategy bundling, participants primarily chose bundles of strategies in the order in which they were listed, reflecting option ordering bias. Neither the phone nor online approach was effective in selecting strategy bundles. Participants agreed that the strategy ranking activities conducted during the workshop were useful in prioritizing a final set of strategies.ConclusionsBoth experienced and inexperienced stakeholder participants’ strategy rankings tended to prioritize strategies perceived as feasible. Small group discussions focused on feasibility and effectiveness revealed moderately different priorities than individual rankings. The strategy bundling approach, though less time- and resource-intensive, was not effective. Future research should further compare the relative effectiveness and pragmatism of methodologies to prioritize implementation strategies.

Near point-of-care HIV viral load testing: Cascade after high viral load in suburban Yangon, Myanmar.

HIV viral load (VL) testing in resource-limited settings is often centralised, limiting access. In Myanmar, we assessed outcomes according to VL access and the VL cascade (case management after a first high VL result) before and after near point-of-care (POC) VL was introduced. Routine programme data from people living with HIV (PLHIV) on antiretroviral therapy (ART) were used. We assessed the odds of getting a VL test done by year. Attrition and mortality two years after ART initiation were compared between three groups of PLHIV with different access to VL testing using Kaplan-Meier analysis. We compared VL cascades in those with a first VL result before and after near POC VL testing became available. With logistic regression, predictors of confirmed virological failure after a first high VL in the POC era were explored. Among 4291 PLHIV who started ART between July 2009 and June 2018, 794 (18.5%) became eligible for VL testing when it was not available, 2388 (55.7%) when centralised laboratory-based VL testing was available, and 1109 (25.8%) when near POC VL testing was available. Between 2010 and 2019, the odds of getting a VL test among those eligible increased with each year (OR: 5.21 [95% CI: 4.95-5.48]). Attrition and mortality were not different in the three groups. When comparing PLHIV with a first VL result before and after implementation of the near POC VL testing, in the latter, more had a first VL test (92% versus 15%, p<0.001), less had a first high VL result (5% versus 14%, p<0.001), and more had confirmed virological failure (67% versus 47%, p = 0.013). Having a first VL ≥5000 copies/mL after near POC implementation was associated with confirmed virological failure (adjusted OR: 2.61 [95% CI: 1.02-6.65]). Near POC VL testing enabled rapid increase of VL coverage and a well-managed VL cascade in Myanmar.

The use of colorimetric loop-mediated isothermal amplification assay for naked-eye detection of bean common mosaic virus

Bean common mosaic virus (BCMV), one of the most prevalent viral diseases of common beans, has been intensively studied since its initial identification. In this paper, a one-step colorimetric reverse-transcription loop-mediated isothermal amplification (RT-LAMP) method was performed by designing oligonucleotide primers to amplify the gene encoding the coat protein of BCMV. Positive LAMP reactions were observed with the naked eye using WarmStart 2 × Master Mix from NEB, changing from pink to yellowish if the test is positive. The sensitivity of this method was similar to that of conventional PCR. The method was tested on common bean and another virus, bean common mosaic necrosis virus (BCMNV), and it was shown to specifically detect BCMV and not produce false positive from other RNAs. The RT-LAMP test was quite reliable for the diagnosis of BCMV from infected samples, and the precise, sensitive. The cost analysis showed that the development of a less expensive and efficient RT-LAMP assay for BCMV detection is an important step in expanding testing capacity and improving access to accurate testing in resource-limited settings. The test can be utilized in laboratory and in the field for the diagnosis and monitoring of BCMV, and is the first reported use of RT-LAMP for BCMV detection.

Improving awareness, diagnosis and management of invasive fungal infections in Ghana: establishment of the Ghana Medical Mycology Society.

Invasive fungal infections (IFIs) and medical mycology receive little attention in Ghana. However, the present evolution of biomarker assays for IFIs, offers an opportunity for an increased access to fungal laboratory testing in resource-limited settings, and probably make a case for availability of essential antifungal agents. Using surveys and personal communications, the state of medical mycology and IFI in Ghana were highlighted. Inadequate awareness and insufficient access to fungal diagnostics and therapeutics were identified as the key challenges, the establishment of the Ghana Medical Mycology Society was discussed, and recommendations were made to improve the status quo.

The performance of using dried blood spot specimens for HIV-1 viral load testing: A systematic review and meta-analysis.

BackgroundAccurate routine HIV viral load testing is essential for assessing the efficacy of antiretroviral treatment (ART) regimens and the emergence of drug resistance. While the use of plasma specimens is the standard for viral load testing, its use is restricted by the limited ambient temperature stability of viral load biomarkers in whole blood and plasma during storage and transportation and the limited cold chain available between many health care facilities in resource-limited settings. Alternative specimen types and technologies, such as dried blood spots, may address these issues and increase access to viral load testing; however, their technical performance is unclear. To address this, we conducted a meta-analysis comparing viral load results from paired dried blood spot and plasma specimens analyzed with commonly used viral load testing technologies.Methods and findingsStandard databases, conferences, and gray literature were searched in 2013 and 2018. Nearly all studies identified (60) were conducted between 2007 and 2018. Data from 40 of the 60 studies were included in the meta-analysis, which accounted for a total of 10,871 paired dried blood spot:plasma data points. We used random effects models to determine the bias, accuracy, precision, and misclassification for each viral load technology and to account for between-study variation. Dried blood spot specimens produced consistently higher mean viral loads across all technologies when compared to plasma specimens. However, when used to identify treatment failure, each technology compared best to plasma at a threshold of 1,000 copies/ml, the present World Health Organization recommended treatment failure threshold. Some heterogeneity existed between technologies; however, 5 technologies had a sensitivity greater than 95%. Furthermore, 5 technologies had a specificity greater than 85% yet 2 technologies had a specificity less than 60% using a treatment failure threshold of 1,000 copies/ml. The study’s main limitation was the direct applicability of findings as nearly all studies to date used dried blood spot samples prepared in laboratories using precision pipetting that resulted in consistent input volumes.ConclusionsThis analysis provides evidence to support the implementation and scale-up of dried blood spot specimens for viral load testing using the same 1,000 copies/ml treatment failure threshold as used with plasma specimens. This may support improved access to viral load testing in resource-limited settings lacking the required infrastructure and cold chain storage for testing with plasma specimens.