A longitudinal study of household water, sanitation, and hygiene characteristics and environmental enteropathy markers in children less than 24 months in Iquitos, Peru

Funding Information: Financial support: The MAL-ED is carried out as a collaborative project supported by the Bill & Melinda Gates Foundation, the Foundation for the National Institutes of Health, and the National Institutes of Health, Fogarty International Center. While conducting this work, Natalie Exum was supported by The NSF IGERT Grant 1069213, The Osprey Foundation of Maryland Grant 1602030014, the Johns Hopkins Water Institute, Johns Hopkins Fisher Center Discovery Program Grant 010 KOS2015, The Kazuyoshi Kawata fund in Sanitary Engineering and Science, and the Dr. C. W. Kruse Memorial Fund Scholarship. Publisher Copyright: © 2018 by The American Society of Tropical Medicine and Hygiene.Peer reviewedPublisher PD

Productividad primaria y biomasa fitoplanctónica de la laguna Quistococha, Iquitos-Perú 1999

En la laguna de Quistococha, se estudió la productividad primaria y la biomasa fitoplanctónica junto con los parámetros físicos y químicos desde el mes de julio a diciembre de 1,999 (época de vaciante). Se determinaron tres estaciones de muestreo y en cada uno de ellos tres estratos de la columna de agua. El método de los frascos claros y oscuros fue para la productividad primaria y la colecta de una muestra de agua por estrato a través de una red de plancton y luego filtrado por un filtro de membrana de 0.47u para la biomasa fitoplantónica. La productividad primaria y la Biomasa variaron significativamente entre las estaciones de muestreo durante todo el periodo de estudio, donde el rango de productividad fue de 0.129 y 0.3766 gCm-3h-t. Tanto la productividad primaria y la Biomasa fueron consistentemente altos en la estación de muestreo Nro. 2 (centro de la laguna). Y básicamente en el estrato de superficie. La Laguna Quistococha es un ambiente relativamente pobre en nutrientes pero presenta buenas condiciones de transparencia que variaron entre 0.92 y 160 cm, lo que nos indica que hay poco material en suspensión. La productividad primaria y la biomasa presentaron correlación significativa con la concentración de oxígeno, esto es consistente ya que la productividad suele presentar una buena relación con la cantidad de oxigeno que se genera en el proceso de la fotosíntesis. La Laguna Quistococha presenta un metabolismo autotrófico, donde los parámetros físicos y químicos registran pequeñas oscilaciones por lo que se considera que este es un ambiente acuático bastante estable en cuanto a su funcionalidad limnológica.Tesi

Multiple entries and exits and other complex human patterns of insecticide-treated net use: a possible contributor to residual malaria transmission?

Abstract Background Increased insecticide-treated net (ITN) use over the last decade has contributed to dramatic declines in malaria transmission and mortality, yet residual transmission persists even where ITN coverage exceeds 80%. This article presents observational data suggesting that complex human net use patterns, including multiple entries to and exits from ITNs by multiple occupants throughout the night, might be a contributing factor. Methods The study included dusk-to-dawn observations of bed net use in 60 households in the Peruvian Amazon. Observers recorded number of net occupants and the time and number of times each occupant entered and exited each net. The study team then tabulated time of first entry, total times each net was lifted, and, where possible, minutes spent outside by each occupant. Results The sample included 446 individuals and 171 observed sleeping spaces with nets. Household size ranged from 2 to 24 occupants; occupants per net ranged from 1 to 5. Nets were lifted a mean 6.1 times per night (SD 4.35, range 1–22). Observers captured substantial detail about time of and reasons for net entry and exit as well as length of time and activities undertaken outside. Conclusions These findings suggest that the ITN use patterns observed in this study may contribute to residual transmission. As a result, respondents to net use surveys may truthfully report that they slept under a net the previous night but may not have received the anticipated protection. More research is warranted to explore the impact of this phenomenon. Concurrent entomological data would help assess the magnitude of the effect

Social connectedness is associated with food security among peri-urban Peruvian Amazonian communities

Background: Food insecurity is a major global public health issue. Social capital has been identified as central to maintaining food security across a wide range of low- and middle-income country contexts, but few studies have examined this relationship through sociocentric network analysis. Objective: We investigated relationships between household- and community-level social connectedness, household food security, and household income; and tested the hypothesis that social connectedness modified the relationship between income and food security. Methods: A cross-sectional census with an embedded questionnaire to capture social relationships was conducted among eleven peri-urban communities. Community connectedness was related to study outcomes of food security and per-capita income through regression models. Results: Of 1520 households identified, 1383 were interviewed (91.0%) and 1272 (83.9%) provided complete data. Households in the youngest communities had the most total contacts, and the highest proportion of contacts outside of the community. Household income was also associated with more outside-community contacts (0.05 more contacts per standard deviation increase in income, p<0.001). Less food secure households reported more contacts nearby (0.24 increase in household food insecurity access scale (HFIAS) for each additional contact, p<0.001). After adjusting for household-level socioeconomic status, membership in an older, larger, and better-connected community, with a greater proportion of residents engaged in rural livelihood strategies, was associated with greater food security (-0.92 decrease in HFIAS for each one-unit increase in community mean degree, p=0.008). There was no evidence that social connectedness modified the relationship between income and food security such that lower-income households benefited more from community membership than higher-income households. Conclusions: Although households reported networks that spanned rural villages and urban centers, contacts within the community, with whom food was regularly shared, were most important to maintaining food security. Interventions that build within-community connectedness in peri-urban settings may increase food security