Resource-limited Situations Research Articles

Protein-templated gold nanoclusters sequestered within sol–gel thin films for the selective and ratiometric luminescence recognition of Hg2+

Sequestration of bovine serum albumin (BSA)-stabilized gold nanoclusters (AuNCs@BSA) prepared using microwave assistance within sol-gel-derived mesoporous silica films permits the selective and highly sensitive quenchometric detection of aqueous Hg(2+) (limit of detection = 600 pM) with luminescence signal arising from oxidized BSA allowing for an analytically robust and reliable ratiometric detection. Overall, this work highlights a number of important advances, including the highest luminescence quantum yield reported to date for a protein-templated luminescent noble metal nanocluster (13%) made possible using a microwave-mediated synthesis followed by cold incubation. We also demonstrate the clear advantage of exploiting the luminescence signal arising from oxidized BSA as an internal reference to generate selectivity of response to Hg(2+). A careful Stern-Volmer quenching analysis reveals the persistence of two unique quenching sites for AuNCs@BSA entrapped within a sol-gel-derived glass, a minor population of which is unquenchable. Finally, based on these AuNCs@BSA nanosensors, we advise a path forward for paper-based indicator strip detection of heavy metals in aqueous streams, the implementation of which can be performed using the unaided eye, making it a meaningful approach for routine screening and in resource-limited situations.

Severe hypertension in elapid envenomation

Snakebite is not an uncommon medical emergency in India; however, symptoms of autonomic dysfunction in snakebite are rare. The elapid snake envenomation is a frequent occurrence in India, and the krait bite is prevalent in the south Indian region. Here, we present three cases of snakebite with severe hypertension and requiring intravenous nitroglycerin (NTG). As the level of blood pressure (BP) decreased significantly following antisnake venom (ASV) injection in all three cases, it is likely that snake venom-induced dysautonomia might have contributed to severe hypertension in such patients. Clinical and therapeutic challenges of these cases are highlighted, so that practitioners coping with medical emergencies in resource-limited situations can consider snake (krait) bite in the differential diagnosis, and also manage effectively according to corroborative clinical evidences.

Post-flood measurement of fungal bio-aerosol in a resource-limited hospital: can the settle plate method be used?

The performance of the settle plate method (SPM) compared with the microbiological air sampler method (MAS) for post-flood fungal bio-aerosol (FB) measurement was evaluated in a Thai hospital. Compared with closed-ventilation units, open-ventilation units had significantly higher median FB level by SPM on days 3 and 5 of incubation (270 vs 90 colony-forming units (cfu)/m(3) and 420 vs 180cfu/m(3), respectively). Strong correlations between SPM and MAS results on day 3 (r=1.60, P<0.001) and day 5 (r=1.49, P=0.002) of incubation suggested the utility of SPM for post-flood FB measurement in open-ventilation units in resource-limited situations.

The role of therapeutic apheresis in the treatment of acute antibody‐mediated kidney rejection

Approximately 10% of renal transplant recipients experience acute antibody-mediated rejection (AMR) due to alloimmunization against human leukocyte antigen (HLA) molecules and other antigens. While therapeutic apheresis is included in most treatment protocols for acute kidney allograft rejection, these protocols have been derived mainly from single center experience rather than controlled trials. This concise review focuses on the role of therapeutic apheresis in AMR treatment. Two groups have recently reported treating acute AMR using drug-only strategies without therapeutic apheresis in particular situations, namely in clinically less severe cases or in resource-limited situations without testing for donor specific antibodies. A randomized controlled trial, designed to test the efficacy of immunoadsorption apheresis in AMR treatment, was terminated early and suggested a benefit of apheresis. An observational study suggested efficacy of plasmapheresis in acute AMR treatment, but all patients who received plasmapheresis also received rituximab. As new therapeutic modalities are becoming available, therapeutic apheresis continues to play a role in the treatment of acute kidney allograft rejection.

Dead or alive: animal sampling during Ebola hemorrhagic fever outbreaks in humans

There are currently no widely accepted animal surveillance guidelines for human Ebola hemorrhagic fever (EHF) outbreak investigations to identify potential sources of Ebolavirus (EBOV) spillover into humans and other animals. Animal field surveillance during and following an outbreak has several purposes, from helping identify the specific animal source of a human case to guiding control activities by describing the spatial and temporal distribution of wild circulating EBOV, informing public health efforts, and contributing to broader EHF research questions. Since 1976, researchers have sampled over 10,000 individual vertebrates from areas associated with human EHF outbreaks and tested for EBOV or antibodies. Using field surveillance data associated with EHF outbreaks, this review provides guidance on animal sampling for resource-limited outbreak situations, target species, and in some cases which diagnostics should be prioritized to rapidly assess the presence of EBOV in animal reservoirs. In brief, EBOV detection was 32.7% (18/55) for carcasses (animals found dead) and 0.2% (13/5309) for live captured animals. Our review indicates that for the purposes of identifying potential sources of transmission from animals to humans and isolating suspected virus in an animal in outbreak situations, (1) surveillance of free-ranging non-human primate mortality and morbidity should be a priority, (2) any wildlife morbidity or mortality events should be investigated and may hold the most promise for locating virus or viral genome sequences, (3) surveillance of some bat species is worthwhile to isolate and detect evidence of exposure, and (4) morbidity, mortality, and serology studies of domestic animals should prioritize dogs and pigs and include testing for virus and previous exposure.

Back to the future, current trends in breakthrough pain treatments

The importance of effectively managing breakthrough pain for patients on long term background analgesia has recently lead to the development of a range of new products aimed at filling this need. This review article looks at the reasons behind these developments and their implications for clinical practice in resource limited situations.

Optimal control for pandemic influenza: The role of limited antiviral treatment and isolation

The implementation of optimal control strategies involving antiviral treatment and/or isolation measures can reduce significantly the number of clinical cases of influenza. Pandemic-level control measures must be carefully assessed specially in resource-limited situations. A model for the transmission dynamics of influenza is used to evaluate the impact of isolation and/or antiviral drug delivery measures during an influenza pandemic. Five pre-selected control strategies involving antiviral treatment and isolation are tested under the “unlimited” resource assumption followed by an exploration of the impact of these “optimal” policies when resources are limited in the context of a 1918-type influenza pandemic scenario. The implementation of antiviral treatment at the start of a pandemic tends to reduce the magnitude of epidemic peaks, spreading the maximal impact of an outbreak over an extended window in time. Hence, the controls’ timing and intensity can reduce the pressures placed on the health care infrastructure by a pandemic reducing the stress put on the system during epidemic peaks. The role of isolation strategies is highlighted in this study particularly when access to antiviral resources is limited.

Development of a Reverse Transcription-Loop-Mediated Isothermal Amplification Assay for Detection of Pandemic (H1N1) 2009 Virus as a Novel Molecular Method for Diagnosis of Pandemic Influenza in Resource-Limited Settings

This paper reports on the development of a one-step, real-time reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay targeting the hemagglutinin (HA) gene for the rapid molecular-based detection of pandemic (H1N1) 2009 virus. The detection limit of the pandemic (H1N1) 2009 virus HA-specific RT-LAMP assay was same as that of the currently used real-time reverse transcription-PCR method. The assay detected the pandemic (H1N1) 2009 virus HA gene in 136 RNA samples extracted from nasopharyngeal swab specimens from Japanese and Vietnamese patients. No cross-reactive amplification with the RNA of other seasonal influenza viruses was observed, and the detection of specific viral genome targets in clinical specimens was achieved in less than 40 min. The sensitivity and specificity of the pandemic (H1N1) 2009 virus HA-specific RT-LAMP assay obtained in this study were 97.8% and 100%, respectively. Use of the (H1N1) 2009 virus HA-specific RT-LAMP assay will enable the faster and easier diagnosis of pandemic (H1N1) 2009 virus infection, especially in resource-limited situations in developing countries.

Diarrhoea and acute respiratory infections prevalence and risk factors among under-five children in Iraq in 2000

BackgroundDiarrhoea and acute respiratory conditions are common medical conditions among under-five children in resource-limited and conflict situations. The present study was conducted to estimate the prevalence and associated factors for acute respiratory conditions and diarrhoea among children under the age of five years in Iraq in 2000.MethodsData for the Iraqi Multiple Indicator Cluster Survey were obtained from UNICEF. We estimated the prevalence of acute respiratory conditions and diarrhoea. Assessment of the associations between these two medical conditions on one hand and socio-demographic and environmental variables on the other was done using logistic regression analysis. Weighted analysis was conducted to account for complex survey design.ResultsA total of 14,676 children under the age of 5 years were reported by their mothers in the study. Of these 50.4% were males. About half (53.9%) of the children had complete vaccination status. Overall, 21.3% of the children had diarrhoea, and 6.9% had acute respiratory infection (ARI) in the last two weeks. In multivariate analysis, diarrhoea was associated with age of child, area of residence, maternal education, source of water, toilet facility, disposal of children' stool and disposal of dirty water. Compared to children aged 48–59 months, children in the age groups 6–11 months and 12–23 months were 2.22 (95%CI [2.02, 2.44]) and 1.84 (95%CI [1.71, 2.00]) times more likely, respectively, to have diarrhoea. Children whose mothers had no formal education were 11% (AOR = 1.11, 95%CI [1.04, 1.18]) more likely to have diarrhoea compared to children with mothers who had attained secondary level of education. Compared to children who belonged to households with unprotected well or river as the main source of water, children who belonged to households with piped water were 32% (AOR = 1.32, 95%CI [1.17, 1.48]) more likely to have diarrhoea while those who belonged to households with protected well were 26% (AOR = 0.74, 95%CI [0.62, 0.89]) less likely to have diarrhoea. Age of child, toilet facility, wealth, and sex of child were significantly associated with ARI.ConclusionIn a study of under-five children in Iraq in 2000, we found that history of diarrhoea and ARI were negatively associated with lower socio-economic status, adequate disposal of children's stool and dirty water, but the results were inconsistent in terms of access to potable water and sanitation facilities possibly due to non-functioning of water and sewage plants after the war. Improvement in water quality and sanitation are vital in the reduction of diarrhoeal diseases.

Boosting Chinese Question Answering with Two Lightweight Methods

Question Answering (QA) research has been conducted in many languages. Nearly all the top performing systems use heavy methods that require sophisticated techniques, such as parsers or logic provers. However, such techniques are usually unavailable or unaffordable for under-resourced languages or in resource-limited situations. In this article, we describe how a top-performing Chinese QA system can be designed by using lightweight methods effectively. We propose two lightweight methods, namely the Sum of Co-occurrences of Question and Answer Terms (SCO-QAT) and Alignment-based Surface Patterns (ABSPs). SCO-QAT is a co-occurrence-based answer-ranking method that does not need extra knowledge, word-ignoring heuristic rules, or tools. It calculates co-occurrence scores based on the passage retrieval results. ABSPs are syntactic patterns trained from question-answer pairs with a multiple alignment algorithm. They are used to capture the relations between terms and then use the relations to filter answers. We attribute the success of the ABSPs and SCO-QAT methods to the effective use of local syntactic information and global co-occurrence information. By using SCO-QAT and ABSPs, we improved the RU-Accuracy of our testbed QA system, ASQA, from 0.445 to 0.535 on the NTCIR-5 dataset. It also achieved the top 0.5 RU-Accuracy on the NTCIR-6 dataset. The result shows that lightweight methods are not only cheaper to implement, but also have the potential to achieve state-of-the-art performances.

Approaches for Evaluating the Relevance of Multiroute Exposures in Establishing Guideline Values for Drinking Water Contaminants

In establishing the guideline values for chemical contaminants in drinking water, the contribution of inhalation and dermal routes associated with showering/bathing needs to be evaluated. The present article reviews the current approaches available for evaluating the importance of inhalation and dermal routes of exposure to drinking water contaminants (DWCs) and integrates them within a 2-tier approach. Accordingly, tier 1 would evaluate whether the dermal or inhalation route is likely to contribute to at least 10% of the dose received from ingestion of drinking water (i.e., 0.15 L-equivalent per day based on the daily water intake rate of 1.5 L/day typically used in Health Canada assessments). Based on the route-specific exposure parameters (i.e., area of skin exposed, effective skin permeability coefficient [Kp], and air to water concentration ratio during use conditions [Fair-water], breathing rate, duration of contact, and fraction absorbed), it was determined that for DWCs with Kp less than 0.024 cm/hr and Fair - water less than 0.0063, the dermal and inhalation routes during showering or bathing are unlikely to contribute significantly to the total dose. For DWCs with Kp value equal to or greater than 0.025 cm/hr, dermal notation is implied, and as such, tier 2 calculation of L-equivalent associated with dermal exposure needs to be performed. Similarly, for DWCs with Fair-water greater than 0.00063, inhalation notation is implied, and detailed evaluation of the L-equivalent associated with inhalation exposure (i.e., tier 2) is suggested. In general, data from human volunteer studies, observational measurements, and targeted modeling studies are useful for deriving L-equivalents, reflective of the magnitude of dose received via dermal and inhalation routes relative to the oral route. However, in resource-limited situations, these approaches can be integrated within a 2-tier approach for prioritizing and providing quantitative evaluations of the relevance of dermal and inhalation routes for developing exposure guidelines for DWCs.

Driver Support Functions under Resource-Limited Situations

What type of support should be given to an automobile driver when it is determined, via some monitoring method, that the driver's situation awareness may not be appropriate to a given traffic condition? With a driving simulator, the following three conditions were compared: (a) Warning type support in which an auditory warning is given to the driver to enhance situation awareness, (b) action type support in which an autonomous safety control action is executed to avoid an accident, and (c) the no-aid baseline condition. Although the both types of driver support are effective, the warning type support sometimes fail to assure safety, which suggests a limitation of the human locus of control assumption. Efficacy of the action type support can also be degraded due to a characteristic of human reasoning under uncertainty. This paper discusses viewpoints needed in the design of systems for supporting drivers in resource-limited situations.

Driver Support Functions Under Resource-Limited Situations

What type of support should be given to an automobile driver when it is determined, via some monitoring method, that the driver's situation awareness may not be appropriate to a given traffic condition? With a driving simulator, the following three conditions were compared: (a) Warning type support in which an auditory warning is given to the driver to enhance situation awareness, (b) action type support in which an autonomous safety control action is executed to avoid an accident, and (c) the no-aid baseline condition. Although the both types of driver support are effective, the warning type support sometimes fail to assure safety, which suggests a limitation of the human locus of control assumption. Efficacy of the action type support can also be degraded due to a characteristic of human reasoning under uncertainty. This paper discusses viewpoints needed in the design of systems for supporting drivers in resource-limited situations.

Agroforestry for Sustainability of Lower-Input Land-Use Systems

Agriculture and forestry are too often treated separately, yet these two sectors are often interwoven on the landscape and share many common goals. The age-old practice of growing crops and trees together was ignored or bypassed in the single-commodity paradigm of agricultural and forestry development. Thanks to 25 years of efforts, agroforestry the integration of multipurpose trees into farming systems-has now become a robust, science-based, integrated discipline. Agroforestry offers a unique set of opportunities for alleviating poverty and arresting land degradation, and providing ecosystem services in both low-income and industrialized nations. Improvement and exploitation of the large number of fruit trees and medicinal plants is but one of several promising opportunities for enhancing the food and nutritional security without causing the environmental hazards that are characteristic of input-intensive land-use systems. These agroforestry practices are particularly suitable for resource-limited conditions and lower-input situations, which cover an estimated 1.9 billion hectares of land and 800 million people in developing countries.

SMARThivDRmos: A complexity-free and Cost Effective Technology for Monitoring HIV Drug Resistance in Resource-Limited Situations

We design an HIV drug resistance monitoring system that is amenable to resource-poor and low expertise countries: SMARThivDRmos. Our system overcomes cost and complexity barriers, the two main factors that have so far limited access of HIV drug resistance monitoring to resource-poor and low expertise countries. We reduce complexity by transferring complex steps to computer execution, and we reduce cost by obviating sequencing requirement using DNA hybridization methods. We reduce both cost and complexity by importing template sequences for probe design, from freely accessible public HIV drug resistance databases using our SMARTsearch engine. We reduce complexity related to probe design in the DNA hybridization step by incorporating SMARTProbeMarker, a user-friendly version of a probe design algorithm, into the system. We reduce complexity related to HIV drug resistance interpretation, using web-based freely accessible public HIV drug resistance interpretation systems. We reduce cost by obviating sequencing requirement, using SMARThivDRmos DNA hybridization-based protocol for identifying HIV drug resistance mutations. Compared to previously developed HIV drug resistance monitoring systems that comports a sequencing step, SMARThivDRmos is a sequencing-free analysis system. SMARThivDRmos is a complexity-free and Cost effective alternative technology that is suitable for monitoring HIV drug resistance in resource-poor and low expertise countries.

Modified Dynabeads Method for Enumerating CD4+ T-Lymphocyte Count for Widespread Use in Resource-Limited Situations

The Dynabeads method showed the potential for enumerating CD4 T lymphocytes (CD4 count) in HIV-1-infected individuals. The large volume of Dynabeads required for 1 sample and complex procedure made the method expensive and not easy for use, however. To decrease the cost and simplify the procedure, we reduced the volume of the Dynabeads, added wash times, and skipped over the staining step so as to count the CD4 cells directly under an optical microscope. The CD4 count of 246 blood samples using our modified Dynabeads method (DynabeadsCD4) showed a significant correlation with that obtained by flow cytometry (FlowcytoCD4) (r = 0.91 [P < 0.0001]; slope = 1.03, intercept = -16). The sensitivity and specificity for a CD4 count less than 200 cells/microL were 79% and 94%, and for a CD4 count less than 350 cells/microL, the sensitivity and specificity were 95% and 88%, respectively. The positive and negative predictive values for a CD4 count less than 350 cells/microL were 97% and 83%, respectively. The systematic error was 8 cells/microL (95% confidence interval [CI]: 0.4-16). The cost of Dynabeads for 1 sample was less than $1.00; thus, the estimated cost per DynabeadsCD4 test is less than $3.00, including the cost of other disposable materials. Our modified method is simple, economic, and accurate enough to monitor antiretroviral therapy in resource-limited situations.

Practice points in utilizing local volunteers in community health projects.

Community volunteers are recruited for many health intervention projects. There are various motivations for the use of the volunteers and these include: the desire to reduce financial costs of projects/programmes; to encourage community ownership; ensure long-term sustainability of the health intervention; and to empower local communities through training offered the project. Health intervention measures working with community volunteers should not be implemented without due consideration of issues regarding mobilization and engagement, skills and motivation of the volunteers and their effectiveness and efficiency towards the attainment of the project goals. This paper discusses some tips that should be considered when community volunteers are used in resource-limited situations.