Monitoring In Resource-limited Settings Research Articles

Validation of a Handheld 6-Lead Device for QT Interval Monitoring in Resource-Limited Settings

Validation of a Handheld 6-Lead Device for QT Interval Monitoring in Resource-Limited Settings

A smartphone-based diagnostic analyzer for point-of-care milk somatic cell counting

BackgroundMastitis, a pervasive and detrimental disease in dairy farming, poses a significant challenge to the global dairy industry. Monitoring the milk somatic cell count (SCC) is vital for assessing the incidence of mastitis and the quality of raw cow's milk. However, existing SCC detection methods typically require large-scale instruments and specialized operators, limiting their application in resource-constrained settings such as dairy farms and small-scale labs. To address these limitations, this study introduces a novel, smartphone-based, on-site SCC testing method that leverages smartphone capabilities for milk somatic cell identification and enumeration, offering a portable and user-friendly testing platform. ResultsThe central findings of our study demonstrate the effectiveness of the proposed method for counting milk somatic cells. Its on-site applicability, facilitated by the microfluidic chip, optical system, and smartphone integration, heralds a paradigm shift in point-of-care testing (POCT) for dairy farms and smaller laboratories. This approach bypasses complex processing and presents a user-friendly solution for real-time SCC monitoring in resource-limited settings. This device boasts several unique features: small size, low cost (<$1,000 total manufacturing cost and <$1 per test), and high accuracy. Remarkably, it delivers test results within just 2 min. Actual-sample testing confirmed its consistency with results from the commercial Bentley FTS/FCM cytometer, affirming the reliability of the proposed method. Overall, these results underscore the potential for transformative change in dairy farm management and laboratory testing practices. SignificanceIn summary, this study concludes that the proposed smartphone-based method significantly contributes to the accessibility and ease of SCC testing in resource-limited environments. By fostering the use of POCT technology in food safety control, particularly in the dairy industry, this innovative approach has the potential to revolutionize the monitoring and management of mastitis, ultimately benefiting the global dairy sector.

Performance of Galectin-9 for Identification of HIV Viremia in Adults Receiving Antiretroviral Therapy in a Resource-Limited Setting.

Targeted viral load (VL) testing has been proposed for antiretroviral treatment (ART) monitoring in resource-limited settings. In this study, we have investigated the performance of the host biomarker galectin-9 (Gal-9), alone and in combination with interferon-γ-inducible protein 10 (IP-10), in identifying individuals at increased likelihood of viremia during ART. Cohort of HIV-positive adults receiving ART at Ethiopian health centers. We included participants with detectable viremia (VL ≥150 copies/mL) 12 months after starting ART and sex-matched nonviremic controls. Performance to identify individuals with VL ≥1000 copies/mL was determined for Gal-9 and the Gal-9/IP-10 combination, respectively, using receiver operating characteristic (ROC) analysis. Among 191 participants (50.3% women), 46 (24.1%) had VL ≥1000 copies/mL, 23 (12.0%) had 150-999 copies/mL, and 122 (63.9%) had <150 copies/mL. Gal-9 and VL were positively correlated (r s = 0.451, P < 0.001). Sensitivity and specificity for Gal-9 to identify individuals with VL ≥1000 copies/mL were 91.3% (95% CI: 79.2-97.6) and 54.5% (95% CI: 46.0-62.8), respectively. The area under the ROC curve for Gal-9 was 0.810 (95% CI: 0.745-0.875), which was similar to that of the combination of Gal-9 and IP-10 [0.849 (95% CI: 0.792-0.905)]. Assuming 10% prevalence of VL ≥1000 copies/mL, using Gal-9 for targeted VL testing instead of universal VL testing would reduce the number of VL tests from 10 to 5 to identify 1 viremic individual, with misclassification of 1 in 10 viremic individuals. Gal-9 is a potential screening marker for targeted VL monitoring in ART recipients. Further studies are needed to determine optimal threshold levels.

Low-level of HIV-1 Seroreversion among People on Successful Antiretroviral Therapy in Cameroon: Implications for Clinical Monitoring in Resource-limited Settings

Background: Initiating early HIV treatment results to sustained viral suppression, reduced viral reservoirs and prompt immune reconstitution that may lead to HIV seronegativity (seroreversion). Seroreversion can be misinterpreted, leading to inappropriate clinical considerations. We thus sought to determine the HIV seroreversion among antiretroviral therapy (ART)-experienced Cameroonians. Method: A laboratory-based cross-sectional study was conducted among ART-experienced individuals with undetectable plasma viral load (less than 40 copies/mL) in 2019 at the Chantal BIYA International Reference Centre in Yaounde-Cameroon. On all blood samples, HIV antibody testing was performed using two rapid diagnostic tests (RDTs), followed by enzyme-linked immunosorbent assay. On non-reactive samples, proviral DNA was tested on on dried blood spots (DBS) specimens. Results: Of the 546 participants on ART (median ART duration : 5 years) and all experiencing a successful ART (VL&lt;40 copies/ml), only 01% (5/546) had shown HIV negative results. Of these five non-reactive cases, only one case (0.18%) was non-reactive to HIV RDTs but reactive to ELISA, and four cases (0.72%) were non-reactive to both RDTs and ELISA. These four samples were also negative for HIV proviral DNA, indicating potential absence of infection or an optimal control of viral replication. Conclusion: Seroreversion of HIV-1 infection is possible but may occur rarely among HIV-infected Cameroonians who are on successful ART. The few cases of HIV negativity on serology and DBS-PCR (proviral DNA) underscores the need for deeper HIV proviral DNA testing (on PBMC) to guide either continuous ART, detect possible functional cure, or events of HIV misdiagnosis in an era of declining prevalence.

Electroencephalogram in the intensive care unit: a focused look at acute brain injury.

Over the past decades, electroencephalography (EEG) has become a widely applied and highly sophisticated brain monitoring tool in a variety of intensive care unit (ICU) settings. The most common indication for EEG monitoring currently is the management of refractory status epilepticus. In addition, a number of studies have associated frequent seizures, including nonconvulsive status epilepticus (NCSE), with worsening secondary brain injury and with worse outcomes. With the widespread utilization of EEG (spot and continuous EEG), rhythmic and periodic patterns that do not fulfill strict seizure criteria have been identified, epidemiologically quantified, and linked to pathophysiological events across a wide spectrum of critical and acute illnesses, including acute brain injury. Increasingly, EEG is not just qualitatively described, but also quantitatively analyzed together with other modalities to generate innovative measurements with possible clinical relevance. In this review, we discuss the current knowledge and emerging applications of EEG in the ICU, including seizure detection, ischemia monitoring, detection of cortical spreading depolarizations, assessment of consciousness and prognostication. We also review some technical aspects and challenges of using EEG in the ICU including the logistics of setting up ICU EEG monitoring in resource-limited settings.

Validation of automated malaria parasite diagnostic machines based on first principle: A pre-requisite for acceptable results and treatment monitoring in resource limited settings

Background: Following the very recent introduction of automated malaria parasite diagnostic machines; the need to validate these high technology machines based on the first principle protocol in malaria parasite density determination for acceptable results and treatment monitoring cannot be over-emphasized. The aim of this review is to update Medical Laboratory Scientists, Medical Laboratory Technicians, and researchers alike on the first principle in the diagnosis of malaria using Giemsa stained thick and thin blood films and to build their capacity on how to validate any automated malaria parasite diagnostic machine. Methods: The first principle protocol in malaria parasite density determination was used. With 8 µL of blood spread within 18 mm diameter of circle (thick film), the volume of blood in one thick film field (0.002 µL) is obtained; which when multiplied by a factor (500) gives 1 µL. The number of parasites seen per 100 thick film fields or average number per each thick film field multiplied by 500 gives the number of parasites / µL of blood. Results: Malaria parasites counts of 5 – 50 parasites (1+), 50 – 500 parasites (2+), 500 – 5000 parasites (3+), and (4+) &gt; 5000 parasites / µL of blood, and with the results obtained from the automated machine which when entered into a 2 x 2 table reveal the performance evaluation of automated machine. Conclusion: With several results obtained, any automated malaria diagnostic machine can be validated for its ability to detect disease (sensitivity, specificity, positive and negative predictive values). Commencement of the use of automated malaria parasites diagnostic machines in parasitology laboratory should not lead to discontinuity in the use of thick and thin blood films in malaria diagnosis as it remains the gold standard in resource limited settings.

Multi-reagents dispensing centrifugal microfluidics for point-of-care testing

Point-of-care testing (POCT) has shown great advantages for public health monitoring in resource-limited settings. However, developing of POCT tools with automated and accurate quantitative dispensing of multiple reagents and samples is challenging. Here, we demonstrate a novel multi-reagents dispensing centrifugal microfluidics (MDCM) that allows rapid and automated dispensing of multiple reagents and samples with high throughput and accuracy. The MDCM was designed with multiple aliquoting units with the hydrophobic valve at different radial positions. All reagents and samples were loaded simultaneously, dispensed in parallel by centrifugation at low speed, and then introduced into the reaction chamber sequentially by centrifugation at high speed. Two MDCM chips are demonstrated, including a uniform concentration generator and a gradient concentration generator. The concentration coefficient of variation (CV) among the independent reaction chambers was lower than 0.56%, and the theoretical quantitative concentration gradient was strongly correlated with the actual concentration gradient (R2 = 0.9938). We have successfully applied the MDCM to loop-mediated isothermal amplification (LAMP)-based nucleic acid detection for multiple infectious pathogens and antimicrobial susceptibility testing (AST) for kanamycin sulfate against E. coli. To further extend the applications, the MDCM has also been applied to bicinchoninic acid (BCA) protein assays with online calibration, reducing the detection time from 2 h to 10 min with a twenty-fold reduction in reagent consumption. These results indicated that the MDCM is a high potential platform for POCT.

Prediction-driven pooled testing methods: Application to HIV treatment monitoring in Rakai, Uganda.

Chronic medical conditions often necessitate regular testing for proper treatment. Regular testing of all afflicted individuals may not be feasible due to limited resources, as is true with HIV monitoring in resource-limited settings. Pooled testing methods have been developed in order to allow regular testing for all while reducing resource burden. However, the most commonly used methods do not make use of covariate information predictive of treatment failure, which could improve performance. We propose and evaluate four prediction-driven pooled testing methods that incorporate covariate information to improve pooled testing performance. We then compare these methods in the HIV treatment management setting to current methods with respect to testing efficiency, sensitivity, and number of testing rounds using simulated data and data collected in Rakai, Uganda. Results show that the prediction-driven methods increase efficiency by up to 20% compared with current methods while maintaining equivalent sensitivity and reducing number of testing rounds by up to 70%. When predictions were incorrect, the performance of prediction-based matrix methods remained robust. The best performing method using our motivating data from Rakai was a prediction-driven hybrid method, maintaining sensitivity over 96% and efficiency over 75% in likely scenarios. If these methods perform similarly in the field, they may contribute to improving mortality and reducing transmission in resource-limited settings. Although we evaluate our proposed pooling methods in the HIV treatment setting, they can be applied to any setting that necessitates testing of a quantitative biomarker for a threshold-based decision.

Chemiluminescent Protease Probe for Rapid, Sensitive, and Inexpensive Detection of Live Mycobacterium tuberculosis.

Tuberculosis (TB) is a top-ten cause of death worldwide. Successful treatment is often limited by insufficient diagnostic capabilities, especially at the point of care in low-resource settings. The ideal diagnostic must be fast, be cheap, and require minimal clinical resources while providing high sensitivity, selectivity, and the ability to differentiate live from dead bacteria. We describe here the development of a fast, luminescent, and affordable sensor of Hip1 (FLASH) for detecting and monitoring drug susceptibility of Mycobacterium tuberculosis (Mtb). FLASH is a selective chemiluminescent substrate for the Mtb protease Hip1 that, when processed, produces visible light that can be measured with a high signal-to-noise ratio using inexpensive sensors. FLASH is sensitive to fmol of recombinant Hip1 enzyme in vitro and can detect as few as thousands of Mtb cells in culture or in human sputum samples within minutes. The probe is highly selective for Mtb compared to other nontuberculous mycobacteria and can distinguish live from dead cells. Importantly, FLASH can be used to measure antibiotic killing of Mtb in culture with greatly accelerated timelines compared to traditional protocols. Overall, FLASH has the potential to enhance both TB diagnostics and drug resistance monitoring in resource-limited settings.

How to monitor cardiovascular function in critical illness in resource-limited settings.

Purpose of reviewHemodynamic monitoring is an essential component in the care for critically ill patients. A range of tools are available and new approaches have been developed. This review summarizes their availability, affordability and feasibility for hospital settings in resource-limited settings.Recent findingsEvidence for the performance of specific hemodynamic monitoring tools or strategies in low-income and middle-income countries (LMICs) is limited. Repeated physical examination and basic observations remain a cornerstone for patient monitoring and have a high sensitivity for detecting organ hypoperfusion, but with a low specificity. Additional feasible approaches for hemodynamic monitoring in LMICs include: for tissue perfusion monitoring: urine output, skin mottling score, capillary refill time, skin temperature gradients, and blood lactate measurements; for cardiovascular monitoring: echocardiography and noninvasive or minimally invasive cardiac output measurements; and for fluid status monitoring: inferior vena cava distensibility index, mini-fluid challenge test, passive leg raising test, end-expiratory occlusion test and lung ultrasound. Tools with currently limited applicability in LMICs include microcirculatory monitoring devices and pulmonary artery catheterization, because of costs and limited added value. Especially ultrasound is a promising and affordable monitoring device for LMICs, and is increasingly available.SummaryA set of basic tools and approaches is available for adequate hemodynamic monitoring in resource-limited settings. Future research should focus on the development and trialing of robust and context-appropriate monitoring technologies.

Multifunctional hybrid soret nanoarchitectures for mobile phone-based picomolar Cu2+ ion sensing and dye degradation applications

The ability of nanoscale materials to trap electromagnetic field beyond the diffraction limit is seldom studied using multifunctional nanohybrids. To this end, we demonstrate a thermo-migratively assembled Soret nanoassembly that enable unique metal-metal, metal-graphene and metal-dielectric resonances. In contrast to the well-explored standalone plasmonic and dielectric platforms, the Soret colloids possess salient nanogaps that exhibit delocalized Bragg and localized Mie plasmon resonances with effective EM field confinement. Accordingly, the Soret colloids of silver metal with plasmonic NPs: platinum (AgPtSC), 2D material: graphene oxide (AgGOSC) and dielectric NPs: TiC (AgTiCSC), TiN (AgTiNSC) and TiCN (AgTiCNSC) comprehensively have been utilized to achieve >600-fold fluorescence enhancements. The ability to tailor the highly directional and p-polarized emission enhancements using these well-characterized multifunctional sorets has been experimentally demonstrated on surface plasmon-coupled emission (SPCE) platform. The mobile phone-based detection of environmentally relevant Cu 2+ ions in drinking water using AgPtSC presents low-cost, rapid, simple, sensitive and reliable sensing strategy for Cu 2+ ion monitoring in resource-limited settings. Further, dye-degradation of xenobiotic pollutants for environmental remediation presents multifarious applications with these nano-architectures. This study opens a new window to explore synergy of nanomaterials constituting elements from different parts of periodic table to accomplish essential properties for desired applications. The hybrid multifunctional soret colloids assisting metal-metal, metal-dielectric and metal-π-plasmon resonances are most suitable candidates for plasmonic as well as xenobiotic dye degradation applications. Mobile phone-based surface plasmon-coupled emission platform was utilized for sensing Cu 2+ ions at picomolar concentration. • An adiabatic cooling based synthesis of hybrid multifunctional soret nanoassembly. • Utility of synergistic metal-metal, metal-dielectric and metal-π-plasmon resonances. • Multifold hot-spots from localized and delocalized plasmons of nanohybrids in SPCE. • Enhanced 600-fold polarized SPCE for mobile phone-based picomolar Cu 2+ ion sensing. • Xenobiotic degradation using π-plasmon and electron relay in hybrid silver sorets.

Performance Comparison of Xpert HIV-1 Viral Load Assay and Roche Taqman and Abbott M2000 RT in Bamako, Mali.

Routine monitoring of HIV-1 Viral Load (VL) is important in patients on Antiretroviral Therapy (ART) management. Access to HIV VL remains a challenge in resource-limited settings, especially in rural areas. Universal access to VL requires more simplified and less restrictive alternatives to current conventional VL methods. The objective of this study was to evaluate the performance of the new rapid (2-hour turnaround time) Xpert HIV-1VL technique compared to Roche TaqMan and Abbott RT m2000 for HIV-1 RNA quantification in HIV- infected patients. We conducted a cross-sectional study in patients seen for routine VL monitoring between August and November 2018 in a HIV care site in Bamako. The performance of the Xpert HIV-1 VL assay was evaluated against the Roche TaqMan assay and Abbott m2000 RT assay. Performance, utility and reliability/reproducibility were verified using accuracy, sensitivity, specificity, positive and negative predictive values, Diagnostic Odds Ratio (DOR), Kappa coefficient, Pearson correlation coefficient, and Bland-Altman analysis. The Xpert assay compared well with the two current referral assays (Roche TaqMan and Abbott m2000 RT assays). Compared to Roche TaqMan assay the sensitivity was 93.10%, specificity (97.01%) and accuracy (95.20%), the correlation coefficient of Pearson (r) was 0.98 (p <0.01). Bland-Altman analysis showed a mean difference of 0.18 log10 cp/mL; (Standard Deviation) SD=0.33. Compared to the Abbott m2000 RT, the sensitivity, the specificity and the accuracy were respectively 93.44%; 92% and 92.65%. The Xpert HIV-1 VL assay showed a good correlation with a correlation coefficient of Pearson, r=0.99 (p <0.001). The overall mean difference in the HIV-1 VL values obtained by Xpert HIV-1 VL and Abbott m2000 RT assays was 0.08 log10 cp/mL; SD=0.30. Xpert HIV-1 VL showed a good performance compared to Roche TaqMan and Abbott m2000 RT. With the rapid test results (less than 2 h) and ease of testing individual specimens, the Xpert HIV-1 VL assay could be an effective alternative for HIV VL monitoring in resource-limited settings.

2504. Laboratory Evaluation of HIV-1 Viral Load Pooling with Marker-Assisted Deconvolution

BackgroundCost still limits HIV-1 viral load (VL) routine monitoring in resource limited settings (RLS), preventing early detection of virologic failure (VF). Pooled VL testing reduces cost over individual testing (IND). We previously showed in simulation, that additional cost benefits over previously-used pooling deconvolution algorithms can be achieved by using low-cost, routinely-collected clinical markers to determine the order for VL testing in deconvolution (termed marker-assisted minipool plus algorithm; mMPA). This algorithm has not been assessed in-vitro.Methods150 samples from 99 Ghanaian adults with HIV on first-line therapy (VF 17%; CD4-VL correlation −0.35) were used to construct 30, 5-sample pools: n = 10 with 0, n = 5 with 1, and n = 15 with 2 individuals with VF. VL testing was with Abbott M2000. Accuracy, number of tests and rounds of testing to deconvolute pools were estimated using four strategies: (1) IND; (2) Minipooling (MP); (3) Minipooling with algorithm (MPA); and (4) mMPA.ResultsCompared with IND, MP and MPA, mMPA reduced total number of tests per pool needed to ascertain VF: MP average 4.3 (95% confidence interval (CI) 3.5–5.2, p> 0.05), MPA 3.0 (95% CI 2.4–3.5, P < 0.001), and mMPA 2.5 (CI 2.0–3.0, P < 0.001). Compared with MP and MPA, mMPA further reduced VL tests by 42% (1.9 tests/pool, CI 1.3–2.4, P < 0.001) and 17% (0.5, CI 0.2–0.8, p = 0.004); and required fewer testing rounds than MPA by 17% (P < 0.01), thus producing results quicker. IND and MP had 100% sensitivity and specificity. MPA and mMPA had similar sensitivity of 96.1% (MPA CI 90.7–100%; mMPA CI 88.0–100.0%) and specificity of 99.5% and 99.2% (98.5–100.0% for MPA and 97.5–100.0% for mMPA). Specifically, 3/150 samples were misclassified with MPA and mMPA: one suppression as VF, and two VF as suppressed.ConclusionLaboratory evaluation confirms that deconvolution using mMPA with CD4 or other routinely-collected clinical information as low-cost biomarkers reduces the number of VL assays required to identify VF in a setting with a low prevalence of VF. Implementation of pooled VL testing using mMPA for deconvolution may increase the availability of VL monitoring in RLS. Work is ongoing to reduce complexity and misclassification, required prior to widespread implementation.Disclosures All authors: No reported disclosures.

Smartphone photography as a possible method of post-validation trachoma surveillance in resource-limited settings.

Validation of trachoma elimination requires monitoring after discontinuation of trachoma program activities, though such evaluations are not commonly done. Conjunctival examinations and smartphone photography were performed on a random sample of pre-school children from 15 villages in a region of Burkina Faso thought to have eliminated trachoma. No clinically active trachoma was detected by in-field or photographic evaluation. Smartphone images demonstrated high agreement with field grading (>99% concordance). Trachoma appears to have been eliminated from this area of Burkina Faso. Smartphone cameras may be a useful aid for monitoring in resource-limited settings.

Automatic Detection of General Anesthetic-States using ECG-Derived Autonomic Nervous System Features.

Electroencephalogram (EEG)-based prediction systems are used to target anesthetic-states in patients undergoing procedures with general anesthesia (GA). These systems are not widely employed in resource-limited settings because they are cost-prohibitive. Although anesthetic-drugs induce highly-structured, oscillatory neural dynamics that make EEG-based systems a principled approach for anesthetic-state monitoring, anesthetic-drugs also significantly modulate the autonomic nervous system (ANS). Because ANS dynamics can be inferred from electrocardiogram (ECG) features such as heart rate variability, it may be possible to develop an ECG-based system to infer anesthetic-states as a low-cost and practical alternative to EEG-based anesthetic-state prediction systems. In this work, we demonstrate that an ECG-based system using ANS features can be used to discriminate between non-GA and GA states in sevoflurane, with a GA F1 score of 0.834, [95% CI, 0.776, 0.892], and in sevoflurane-plus-ketamine, with a GA F1 score of 0.880 [0.815, 0.954]. With further refinement, ECG-based anesthetic-state systems could be developed as a fully automated system for anesthetic-state monitoring in resource-limited settings.

Safety monitoring of treatment in bipolar disorder in a tertiary care setting in Sri Lanka and recommendations for improved monitoring in resource limited settings

BackgroundSafety monitoring of medicines is essential during therapy for bipolar disorder (BD). We determined the extent of safety monitoring performed according to the International Society for Bipolar Disorders (ISBD) guidelines in patients with BD attending the main tertiary care psychiatry clinics in Sri Lanka to give realistic recommendations for safety monitoring in resource limited settings.MethodsPatients diagnosed with BD on mood stabilizer medications for more than 1 year were recruited. Data were collected retrospectively from clinic and patient held records and compared with the standards of care recommended by ISBD guidelines for safety monitoring of medicines.ResultsOut of 256 patients diagnosed with BD, 164 (64.1%) were on lithium. Only 75 (45.7%) had serum lithium measurements done in the past 6 months and 96 (58.5%) had concentrations recorded at least once in the past year. Blood urea or creatinine was measured in the last 6 months only in 30 (18.3%). Serum electrolytes and thyroid-stimulating hormone (TSH) concentrations were measured in the last year only in 34 (20.7%) and 30 (18.3%) respectively. Calcium concentrations were not recorded in any patient. None of the patients on sodium valproate (n = 119) or carbamazepine (n = 6) had blood levels recorded to establish therapeutic concentrations. Atypical antipsychotics were prescribed for 151 (59%), but only 13 (8.6%) had lipid profiles and only 31 (20.5%) had blood glucose concentration measured annually. Comorbidities experienced by patients influenced monitoring more than the medicines used. Patients with diabetes, hypothyroidism and hypercholesterolemia were more likely to get monitored for fasting blood glucose and (p < 0.001), TSH (p < 0.001) and lipid profiles (p < 0.001). Lithium therapy was associated with TSH monitoring (p < 0.05). Therapy with atypical antipsychotics was not associated with fasting blood glucose or lipid profile monitoring (p > 0.05). A limitation of the study is that although some tests were performed, the results may not have been recorded.ConclusionsSafety monitoring in BD was suboptimal compared to the ISBD guidelines. ISBD standards are difficult to achieve in resource limited settings due to a multitude of reasons. Realistic monitoring benchmarks and recommendations are proposed for methods to improve monitoring in resource limited settings based on our experience.

Measuring Adherence to Antiretroviral Therapy via Hair Concentrations in India.

Objective adherence measures are of increasing interest in antiretroviral treatment (ART) monitoring. Hair ART levels predict virologic suppression, and hair is easy to collect and store. No previous study has examined hair levels in an India-based cohort or laboratory. Small hair samples were collected from HIV-positive participants on either efavirenz (EFV)-based or nevirapine (NVP)-based ART in a South India-based study. Hair samples were split and analyzed for EFV or NVP in the University of California, San Francisco -based Hair Analytical Laboratory and the analytic laboratory of the Division of Nutrition at St. John's Research Institute, Bangalore, India, using liquid chromatography/tandem mass spectrometry. Agreement (using Bland-Altman methods) and rank correlation between the 2 laboratories' hair levels were calculated. Rank correlation between self-reported adherence (SRA) over the previous month using a visual analog scale and hair ART levels was calculated. Among 75 participants (38 on NVP; 37 on EFV), the correlation between NVP levels generated by the 2 laboratories was 0.66 (P < 0.0001) and between EFV levels was 0.87 (P < 0.0001). Measurements from St. John's Research Institute were usually within 20% of those from the University of California, San Francisco Hair Analytical Laboratory. SRA was essentially uncorrelated with hair antiretroviral levels for either drug (all correlations < 0.04). Hair levels showed variability in adherence although SRA was >85% in all participants. Hair ART levels measured by both an India-based laboratory and the standard U.S.-based laboratory showed generally high agreement and correlation, demonstrating local capacity. As in many other cohorts, hair ART levels and SRA were not well-correlated, likely indicating limitations in self-report and the need for objective adherence monitoring in resource-limited settings.

Colorimetric Bisphenol-A Detection With a Portable Smartphone-Based Spectrometer

Water quality monitoring in resource-limited settings without access to a sophisticated laboratory requires the development of low cost and portable instrumentation. Herein, we propose a newly designed handheld reflection-based smartphone sensing platform to detect Bisphenol-A (BPA), a well-known endocrine disruptor agent abundantly used in plastic industry. An experimental investigation relying on color change due to the formation of quinone-type complex was conducted with samples from two different water sources: distilled and commercial drinking water. This colorimetric measurement device was used to determine BPA in distilled water in alkaline environments. The successful combination of colorimetric assay and spectrometer facilitates limit of detection in the low ppm levels, 0.29 ppm for smartphone and 0.23 ppm for commercial spectrometer, with a sensitivity of 0.1/ppm.

Plasma Levels of Rifampin Correlate with the Tuberculosis Drug Activity Assay.

The plasma tuberculosis drug activity (TDA) assay may be an alternative tool for therapeutic drug monitoring in resource-limited settings. In tuberculosis (TB) patients (n = 30), TDA and plasma levels of first-line drugs were analyzed 2 h postdose, 2 weeks after treatment initiation. Patients with plasma levels of rifampin lower than 8 mg/liter had a significantly lower median TDA (1.40 versus 1.68, P = 0.0013). TDA may be used to identify TB patients with suboptimal rifampin levels during TB treatment.

A competitive lateral flow assay for the detection of tenofovir

Proper management of an HIV infection requires that a patient be at least 80–95% adherent to a prescribed drug regimen to avoid poor health outcomes and the development of drug-resistant HIV strains. Clinicians generally monitor adherence habits indirectly through patient self-reporting, pill counting, and electronic drug monitoring. While direct measurement of patient samples like urine for monitoring drug levels is possible, it requires specialized equipment and training that is not readily available in resource-limited settings where the need is greatest. In this work we report the development of an antibody that binds to tenofovir (TFV), a key small molecule drug for both the treatment and prevention of HIV, and a competitive lateral flow assay that uses that antibody to monitor urine samples for the presence of the drug. TFV was conjugated to an immunogenic protein and injected into rabbits to raise polyclonal antibodies sensitive to the drug. The antibodies were verified for TFV-sensitivity by immunoprecipitation and HPLC. A gold nanoparticle-based competitive assay was developed to detect the presence of TFV in urine samples with a sensitivity of 1 μg mL−1. This TFV assay could be deployed as a point-of-care device for adherence monitoring in resource-limited settings as a low-cost, accurate, and speedy alternative to current methods to better inform changes in treatment.