Measuring Environmental Exposure to Enteric Pathogens in Low-Income Settings: Review and Recommendations of an Interdisciplinary Working Group.

Infections with enteric pathogens impose a heavy disease burden, especially among young children in low-income countries. Recent findings from randomized controlled trials of water, sanitation, and hygiene interventions have raised questions about current methods for assessing environmental exposure to enteric pathogens. Approaches for estimating sources and doses of exposure suffer from a number of shortcomings, including reliance on imperfect indicators of fecal contamination instead of actual pathogens and estimating exposure indirectly from imprecise measurements of pathogens in the environment and human interaction therewith. These shortcomings limit the potential for effective surveillance of exposures, identification of important sources and modes of transmission, and evaluation of the effectiveness of interventions. In this review, we summarize current and emerging approaches used to characterize enteric pathogen hazards in different environmental media as well as human interaction with those media (external measures of exposure), and review methods that measure human infection with enteric pathogens as a proxy for past exposure (internal measures of exposure). We draw from lessons learned in other areas of environmental health to highlight how external and internal measures of exposure can be used to more comprehensively assess exposure. We conclude by recommending strategies for advancing enteric pathogen exposure assessments.

Oxytocin quality: evidence to support updated global recommendations on oxytocin for postpartum hemorrhage.

BACKGROUND: The use of quality injectable oxytocin effectively prevents and treats postpartum hemorrhage, the leading cause of maternal death worldwide. In low- and middle-income countries (LMICs), characteristics of oxytocin-specifically its heat sensitivity-challenge efforts to ensure its quality throughout the health supply chain. In 2019, WHO, UNFPA and UNICEF released a joint-statement to clarify and recommend that oxytocin should be kept in the cold chain (between 2 and 8 °C) during transportation and storage; however, confusion among stakeholders in LMICs persists. OBJECTIVES AND METHODS: To further support recommendations in the WHO/UNFPA/UNICEF joint-statement, this paper reviews results of oxytocin quality testing in LMICs, evaluates product stability considerations for its management and considers quality risks for oxytocin injection throughout the health supply chain. This paper concludes with a set of recommended actions to address the challenges in maintaining quality for a heat sensitive pharmaceutical product. RESULTS: Due to the heat sensitivity of oxytocin, its quality may be degraded at numerous points along the health supply chain including: At the point of manufacture, due to poor quality active pharmaceutical ingredients; lack of sterile manufacturing environments; or low-quality manufacturing processesDuring storage and distribution, due to lack of temperature control in the supply chain, including cold chain at the end user health facilitySafeguarding the quality of oxytocin falls under the purview of national medicines regulatory authorities; however, regulators in LMICs may not adhere to good regulatory practices. CONCLUSIONS: Storing oxytocin from 2 to 8 °C throughout the supply chain is important for maintaining its quality. While short temperature excursions may not harm product quality, the cumulative heat exposure is generally not tracked and leads to degradation. National and sub-national policies must prioritize procurement of quality oxytocin and require its appropriate storage and management.

Maximizing the benefits of improved cookstoves: moving from acquisition to correct and consistent use.

The adoption of clean cooking technologies goes beyond mere product acquisition and requires attention to issues of cooking traditions, user engagement, gender dynamics, culture, and religion to effect correct and consistent use.

Integration of water, sanitation, and hygiene for the prevention and control of neglected tropical diseases: a rationale for inter-sectoral collaboration.

Improvements of water, sanitation, and hygiene (WASH) infrastructure and appropriate health-seeking behavior are necessary for achieving sustained control, elimination, or eradication of many neglected tropical diseases (NTDs). Indeed, the global strategies to fight NTDs include provision of WASH, but few programs have specific WASH targets and approaches. Collaboration between disease control programs and stakeholders in WASH is a critical next step. A group of stakeholders from the NTD control, child health, and WASH sectors convened in late 2012 to discuss opportunities for, and barriers to, collaboration. The group agreed on a common vision, namely "Disease-free communities that have adequate and equitable access to water and sanitation, and that practice good hygiene." Four key areas of collaboration were identified, including (i) advocacy, policy, and communication; (ii) capacity building and training; (iii) mapping, data collection, and monitoring; and (iv) research. We discuss strategic opportunities and ways forward for enhanced collaboration between the WASH and the NTD sectors.

Photoaptamer arrays applied to multiplexed proteomic analysis.

Multiplexed photoaptamer-based arrays that allow for the simultaneous measurement of multiple proteins of interest in serum samples are described. Since photoaptamers covalently bind to their target analytes before fluorescent signal detection, the arrays can be vigorously washed to remove background proteins, providing the potential for superior signal-to-noise ratios and lower limits of quantification in biological matrices. Data are presented here for a 17-plex photoaptamer array exhibiting limits of detection below 10 fM for several analytes including interleukin-16, vascular endothelial growth factor, and endostatin and able to measure proteins in 10% serum samples. The assays are simple, scalable, and reproducible. Affinity of the capture reagent is shown to be directly correlated to the limit of detection for the analyte on the array.

Processing of photoaptamer microarrays.

Photoaptamers are single-stranded nucleic acids selected for their high affinity to specific proteins of interest. Photoaptamer microarrays capture and quantify proteins from complex samples using a unique protocol that leverages both high-affinity capture with covalent retention of analytes. The initial capture of proteins from solution is similar to the well-known antibody capture, but the "secondary binding event" affected by photoaptamers is a covalent crosslink between the photoaptamer capture agent and the protein analyte. The nature of this specific covalent reaction allows a unique microarray processing that is described in detail in this chapter.

Dimensionality is the issue: use of photoaptamers in protein microarrays.

The development of high-density arrays for proteomics has become a goal of SomaLogic, many other companies, and a wide variety of academic entities. Unfortunately, the word proteomics has come to mean virtually everything. We define proteomics as being derived from arrays of analyte-specific reagents (ASRs) used to measure (something about) proteins. As the density of the ASRs on a chip increases toward the number of proteins in an organism, the concept of proteomics moves toward comprehensive proteomics. At issue then, is what constitutes an ASR, and what differences between them lead toward more or less biological information from a high-density panel of ASRs.