Total daily energy expenditure and elevated water turnover in a small-scale semi-nomadic pastoralist society from Northern Kenya.

BACKGROUND: Pastoralists live in challenging environments, which may be accompanied by unique activity, energy, and water requirements. AIM: Few studies have examined whether the demands of pastoralism contribute to differences in total energy expenditure (TEE) and water turnover (WT) compared to other lifestyles. SUBJECTS AND METHODS: Accelerometer-derived physical activity, doubly labelled water-derived TEE and WT, and anthropometric data were collected for 34 semi-nomadic Daasanach adults from three northern Kenyan communities with different levels of pastoralist activity. Daasanach TEEs and WTs were compared to those of other small-scale and industrialised populations. RESULTS: When modelled as a function of fat-free-mass, fat-mass, age, and sex, TEE did not differ between Daasanach communities. Daasanach TEE (1564-4172 kcal/day) was not significantly correlated with activity and 91% of TEEs were within the range expected for individuals from comparison populations. Mean WT did not differ between Daasanach communities; Daasanach absolute (7.54 litres/day men; 7.46 litres/day women), mass-adjusted, and TEE-adjusted WT was higher than most populations worldwide. CONCLUSIONS: The similar mass-adjusted TEE of Daasanach and industrialised populations supports the hypothesis that habitual TEE is constrained, with physically demanding lifestyles necessitating trade-offs in energy allocation. Elevated WT in the absence of elevated TEE likely reflects a demanding active lifestyle in a hot, arid climate.

Ad libitum dehydration is associated with poorer performance on a sustained attention task but not other measures of cognitive performance among middle-to-older aged community-dwelling adults: A short-term longitudinal study.

OBJECTIVE: Hydration status and water intake are critical to physiological health. Despite a popular narrative that dehydration impairs cognitive performance, results are mixed in the literature. Therefore, we tested how hydration status was associated with cognitive performance in an ad libitum state over the course of 3 months. METHODS: Data come from a short-term longitudinal study among middle-to-older aged US adults (n = 78) measured three times (207 observations). All participants were scheduled for 8:00 a.m. visits for the baseline, two-week, and 3-month examinations where they completed surveys, neuropsychological tests to measure cognitive performance, anthropometrics, and a blood draw for biomarker analysis. Serum osmolality (Sosm) was measured as a biomarker of hydration status using osmometry. Four cognitive performance tasks were assessed, including inhibition, working memory, cognitive flexibility, and sustained attention. RESULTS: Panel random effects linear regressions demonstrate that there was an inverse association between dehydration and sustained attention, whereas there were no significant relationships between dehydration and inhibition, working memory, and cognitive flexibility. Adults who were dehydrated (defined as Sosm >300 mOsm/kg) performed substantially worse (B = 0.65 z-score; SE = 0.28; p = .020) on the sustained attention task than those who were not dehydrated adjusting for time fixed effects, age, body mass index, sex, and educational attainment. CONCLUSION: This short-term longitudinal study found that dehydration was only associated with poorer performance on a cognitive performance task that required sustained attention. Maintaining adequate hydration may be increasingly important for middle-to-older aged adults to ensure proper cognitive function, particularly as water needs increase in future climatic scenarios.

Effects of a 1-hour per night week-long sleep extension in college students on cardiometabolic parameters, hydration status, and physical activity: A pilot study.

OBJECTIVES: Short sleep duration is associated with poor physical health in college students. Few studies examine the effects of sleep extension on physical health in this population, who are susceptible to sleep loss. We examined health effects of a 1-week, 1-hour nightly sleep extension in college students. METHODS: Twelve healthy undergraduate college students (83% female; age 20.2 ± 1.5years) completed a study consisting of sleeping typically for 1week ("Habitual"), then extending sleep by ≥1 hour/night during the second week ("Extension"). Sleep and physical activity actigraphy were collected throughout. Following each week, participants completed cardiometabolic assessments including a meal response and provided a urine sample for markers of hydration. RESULTS: In Extension compared to Habitual, average sleep duration increased (mean change±SEM, +42.6 ± 15.1 minutes; p = .005), while subjective sleepiness (-1.8 ± 0.8 units; p = .040), systolic blood pressure (-6.6 ± 2.8 mmHg; p = .037), postprandial glucose area under the curve (-26.5 ± 10.2 mg/dL × h; p = .025) and time to baseline (-83.0 ± 46.4 minutes; p = .031) after the meal response, sedentary time (-44.3 ± 15.7 minutes; p = .018), and percentage of wake in moderate-to-vigorous activity (-0.89% ± 0.35%; p = .030) decreased. Participants who increased average sleep duration by ≥20 minutes (n = 9) were better hydrated according to urine osmolality (-187.0 ± 68.4 mOsm/kg; p = .026) and specific gravity (-0.01 ± 0.002 g/mL; p = .012) and had reduced odds of dehydration according to urine osmolality (≥800 mOsm/kg; -67%; OR=0.03; p = .035). CONCLUSIONS: This pilot study's findings suggest that sleep extension may improve cardiometabolic functioning and hydration, and alter sedentary behavior and physical activity, in college students. Sleep extension may be employed to improve multiple aspects of health in this sleep-deprived population.

The effects of lifestyle change on indicators of cardiometabolic health in semi-nomadic pastoralists.

Background and objectives: Non-communicable disease risk and the epidemic of cardiometabolic diseases continue to grow across the expanding industrialized world. Probing the relationships between evolved human physiology and modern socioecological conditions is central to understanding this health crisis. Therefore, we investigated the relationships between increased market access, shifting subsistence patterns and cardiometabolic health indicators within Daasanach semi-nomadic pastoralists who vary in their engagement in traditional lifestyle and emerging market behaviors. Methodology: We conducted cross-sectional socioecological, demographic and lifestyle stressor surveys along with health, biomarker and nutrition examinations among 225 (51.6% female) Daasanach adults in 2019-2020. We used linear mixed-effects models to test how differing levels of engagement in market integration and traditional subsistence activities related to blood pressure (BP), body composition and blood chemistry. Results: We found that systolic and diastolic BP, as well as the probability of having high BP (hypertension), were negatively associated with distance to market, a proxy for market integration. Additionally, body composition varied significantly by socioeconomic status (SES), with significant positive associations between BMI and body fat and higher SES among adults. Conclusions and implications: While evidence for evolutionary mismatch and health variation have been found across a number of populations affected by an urban/rural divide, these results demonstrate the effects of market integration and sedentarization on cardiometabolic health associated with the early stages of lifestyle changes. Our findings provide evidence for the changes in health when small-scale populations begin the processes of sedentarization and market integration that result from myriad market pressures.

Ex vivo LPS-stimulated cytokine production is associated with hydration status in community-dwelling middle-to-older-aged adults.

PURPOSE: Suboptimal hydration has been linked to a variety of adverse health outcomes. Few studies have examined the impact of hydration status on immune function, a plausible physiological mechanism underlying these associations. Therefore, we tested how variation in hydration status was associated with circulating pro-inflammatory cytokine levels and ex vivo lipopolysaccharide (LPS)-stimulated pro-inflammatory cytokine production. METHODS: Blood samples were obtained from a community sample of healthy middle-to-older-aged adults (N = 72). These samples were used to assess serum osmolality, a biomarker of hydration status, and markers of immune function including circulating pro-inflammatory cytokines and stimulated pro-inflammatory cytokine production after 4 and 24 h of incubation with LPS. Multiple linear regressions were used to test the association between serum osmolality (as a continuous variable) and markers of immune function at baseline and after 4 and 24 h adjusting for age, sex, and BMI. These models were re-estimated with serum osmolality dichotomized at the cut-off for dehydration (> 300 mOsm/kg). RESULTS: While not significantly associated with circulating cytokines (B = - 0.03, p = 0.09), serum osmolality was negatively associated with both 4 h (B = - 0.05, p = 0.048) and 24 h (B = - 0.05, p = 0.03) stimulated cytokine production when controlling for age, sex, and BMI. Similarly, dehydration was associated with significantly lower cytokine production at both 4 h (B = - 0.54, p = 0.02) and 24 h (B = - 0.51, p = 0.02) compared to adequate hydration. CONCLUSION: These findings suggest that dehydration may be associated with suppressed immune function in generally healthy middle-to-older aged community-dwelling adults. Further longitudinal research is needed to more clearly define the role of hydration in immune function.

Tap Water Avoidance Is Associated with Lower Food Security in the United States: Evidence from NHANES 2005-2018.

BACKGROUND: Food insecurity has profound nutritional and public health consequences. Water insecurity may exacerbate food insecurity, yet little is known about the association between water and food insecurity in the United States or other high-income countries. OBJECTIVE: This study aimed to estimate how tap water avoidance, a proxy of water insecurity, covaries with food insecurity; examine how the probability of food insecurity changed by tap water avoidance between 2005 and 2018; and test how the association between tap water avoidance and food insecurity differed across income and housing statuses. DESIGN: This was a secondary analysis of the cross-sectional 2005-2018 National Health and Nutrition Examination Survey. PARTICIPANTS/SETTING: Participants were 31,390 US adults 20 years and older. MAIN OUTCOME MEASURES: The main outcome was food insecurity, using the US Food Security Survey Module. STATISTICAL ANALYSES: Adjusted logistic regression models estimated how tap water avoidance was associated with the odds of food insecurity. Predicted probabilities of food insecurity over time and by income and housing status were plotted using marginal standardization. RESULTS: Adults who avoided tap water had 21% higher odds (95% CI 1.09 to 1.34) of food insecurity compared with those who drank tap water. The probability of any food insecurity doubled between 2005-2006 and 2017-2018 and was consistently higher for tap water avoiders. Food insecurity decreased across both tap water drinkers and avoiders as income increased, but was higher among tap water avoiders at all income levels. Likewise, food insecurity was higher among renters than among homeowners but was higher among tap water avoiders in both housing groups. CONCLUSIONS: Tap water avoidance is positively associated with food insecurity in the United States, and both insecurities have increased over time. Efforts to mitigate food insecurity should simultaneously address water insecurity issues, including tap water availability and quality, as these may be a modifiable contributors to food insecurity.

When the flood passes, does health return? A short panel examining water and food insecurity, nutrition, and disease after an extreme flood in lowland Bolivia.

OBJECTIVES: Flooding is the most frequent extreme-weather disaster and disproportionately burdens marginalized populations. This article examines how food and water insecurity, blood pressure (BP), nutritional status, and diarrheal and respiratory illnesses changed during the 2 months following a historic flood in lowland Bolivia. METHODS: Drawing on longitudinal data from Tsimane' forager-horticulturalist (n = 118 household heads; n = 129 children) directly after a historic 2014 flood and ~2 months later, we use fixed effects linear regression and random effects logistic regression models to test changes in the markers of well-being and health over the recovery process. RESULTS: Results demonstrated that water insecurity scores decreased significantly 2 month's postflood, while food insecurity scores remained high. Adults' systolic and diastolic BP significantly declined 2 months after the flood's conclusion. Adults experienced losses in measures of adiposity (BMI, sum of four skinfolds, waist circumference). Children gained weight and BMI-for-age Z-scores indicating buffering of children by adults from food stress that mainly occurred in the community closer to the main market town with greater access to food aid. Odds of diarrhea showed a nonsignificant decline, while cough increased significantly for both children and adults 2 months postflood. CONCLUSIONS: Water insecurity and BP improved during the recovery process, while high levels of food insecurity persisted, and nutritional stress and respiratory illness worsened. Not all indicators of well-being and health recover at the same rate after historic flooding events. Planning for multiphase recovery is critical to improve health of marginalized populations after flooding.

Extreme climatic events and human biology and health: A primer and opportunities for future research.

Extreme climatic events are increasing in frequency, leading to hotter temperatures, flooding, droughts, severe storms, and rising oceans. This special issue brings together a collection of seven articles that describe the impacts of extreme climatic events on a diverse set of human biology and health outcomes. The first two articles cover extreme temperatures extending from extreme heat to cold and changes in winter weather and the respective implications for adverse health events, human environmental limits, well-being, and human adaptability. Next, two articles cover the effects of exposures to extreme storms through an examination of hurricanes and cyclones on stress and birth outcomes. The following two articles describe the effects of extreme flooding events on livelihoods, nutrition, water and food insecurity, diarrheal and respiratory health, and stress. The last article examines the effects of drought on diet and food insecurity. Following a brief review of each extreme climatic event and articles covered in this special issue, I discuss future research opportunities-highlighting domains of climate change and specific research questions that are ripe for biological anthropologists to investigate. I close with a description of interdisciplinary methods to assess climate exposures and human biology outcomes to aid the investigation of the defining question of our time - how climate change will affect human biology and health. Ultimately, climate change is a water, food, and health problem. Human biologists offer a unique perspective for a combination of theoretical, methodological, and applied reasons and thus are in a prime position to contribute to this critical research agenda.

Early childhood growth in Daasanach pastoralists of Northern Kenya: Distinct patterns of faltering in linear growth and weight gain.

OBJECTIVES: Investigations of early childhood growth among small-scale populations are essential for understanding human life history variation and enhancing the ability to serve such communities through global public health initiatives. This study characterizes early childhood growth trajectories and identifies differences in growth patterns relative to international references among Daasanach semi-nomadic pastoralist children living in a hot, arid region of northern Kenya. METHODS: A large sample of height and weight measures were collected from children (N = 1756; total observations = 4508; age = 0-5 years) between 2018 and 2020. Daasanach growth was compared to international reference standards and Daasanach-specific centile growth curves and pseudo-velocity models were generated using generalized additive models for location scale and size. RESULTS: Compared to World Health Organization (WHO) reference, relatively few Daasanach children were stunted (14.3%), while a large proportion were underweight (38.5%) and wasted (53.6%). Additionally, Daasanach children had a distinctive pattern of growth, marked by an increase in linear growth velocity after 24 months of age and relatively high linear growth velocity throughout the rest of early childhood. CONCLUSIONS: These results identify a unique pattern of early childhood growth faltering among children in a small-scale population and may reflect a thermoregulatory adaptation to their hot, arid environment. As linear growth and weight gain remain important indicators of health, the results of this study provide insight into growth velocity variations. This study has important implications for global public health efforts to identify and address sources of early growth faltering and undernutrition in small-scale populations.

Water Sharing Is a Distressing Form of Reciprocity: Shame, Upset, Anger, and Conflict Over Water in Twenty Cross-Cultural Sites.

Anthropological theories of reciprocity suggest it enhances prestige, social solidarity, and material security. Yet, some ethnographic cases suggest that water sharing-a form of reciprocity newly gaining scholarly attention-might work in the opposite way, increasing conflict and emotional distress. Using cross-cultural survey data from twenty global sites (n=4,267), we test how household water reciprocity (giving and receiving) is associated with negative emotional and social outcomes. Participation in water sharing as both givers and receivers is consistently associated with greater odds of reporting shame, upset, and conflict over water. Water sharing experiences in a large, diverse sample confirm a lack of alignment with predictions of classic reciprocity theories. Recent ethnographic research on reciprocity in contexts of deepening contemporary poverty will allow development of ethnographically informed theories to better explain negative experiences tied to water reciprocity.

Teorías antropológicas de reciprocidad sugieren que ésta mejora el prestigio, la solidaridad social y la seguridad material. Sin embargo, algunos casos etnográficos sugieren que compartir el agua ­una forma de reciprocidad que esta ganando atención académica recientemente­ puede funcionar de forma opuesta, incrementando el conflicto y la angustia emocional. Utilizando información de una encuesta intercultural de veinte sitios globales (n=4,267), evaluamos cómo la reciprocidad de agua en hogares (dar y recibir) esta asociada con resultados emocionales y sociales negativos. La participación en el compartir de agua como dadores y recibidores esta asociada consistentemente con mayores probabilidades de reportar culpa, malestar y conflicto sobre el agua. Las experiencias de compartir agua en una muestra amplia y diversa confirman una falta de alineación con las predicciones de las teorías clásicas de reciprocidad. Investigación etnográfica reciente sobre reciprocidad en contextos de profundización de la pobreza contemporánea permitirá el desarrollo de teorías informadas etnográficamente para explicar mejor las experiencias negativas ligadas a la reciprocidad del agua.

Using Water Intake Dietary Recall Data to Provide a Window into US Water Insecurity.

BACKGROUND: In the United States, problems with the provision of safe, affordable water have resulted in an increasing number of adults who avoid their tap water, which could indicate underlying water insecurity. Dietary recalls provide critical nutritional surveillance data, yet have been underexplored as a water insecurity monitoring tool. OBJECTIVES: This article aims to demonstrate how water intake variables from dietary recall data relate to and predict a key water insecurity proxy, that is, tap water avoidance. METHODS: Using 2005-2018 NHANES data from 32,329 adults, I examine distributions and trends of mean intakes of total, plain (sum of tap and bottled water), tap, and bottled water, and percentage consuming no tap and exclusive bottled water. Second, I use multiple linear and logistic regressions to test how tap water avoidance relates to plain water intake and sugar-sweetened beverage (SSB) consumption. Next, I use receiver operating characteristics (ROC) curves to test the predictive accuracy of no plain water, no tap, and exclusive bottled water intake, and varying percentages of plain water consumed from tap water compared with tap water avoidance. RESULTS: Trends indicate increasing plain water intake between 2005 and 2018, driven by increasing bottled water intake. In 2017-18, 51.4% of adults did not drink tap water on a given day, whereas 35.8% exclusively consumed bottled water. Adults who avoided their tap water consumed less tap and plain water, and significantly more bottled water and SSBs on a given day. No tap intake and categories of tap water intake produced 77% and 78% areas under the ROC curve in predicting tap water avoidance. CONCLUSIONS: This study demonstrates that water intake variables from dietary recalls can be used to accurately predict tap water avoidance and provide a window into water insecurity. Growing reliance on bottled water could indicate increasing concerns about tap water.

High sugar intake from sugar-sweetened beverages is associated with prevalence of untreated decay in US adults: NHANES 2013-2016.

OBJECTIVES: To assess the association between sugar from sugar-sweetened beverages (SSBs) and untreated decay in permanent teeth and calculate the cost burden of sugar from SSBs on untreated decay in US adults. METHODS: Cross-sectional data from the 2013-2014 and 2015-2016 cycles of the National Health and Nutrition Examination Survey (NHANES) were analysed in 2020 (n = 9001 adults aged ≥20). Multivariable analyses assessed sugar intake from SSB consumption with the presence of untreated decay in permanent teeth and number of untreated decayed teeth. Population attributable risk was used to estimate the cost burden arising from SSBs on untreated decay in US adults. RESULTS: One fourth (25.1%) of US adults had untreated dental decay, and higher prevalence was observed among those with low income, low education and race/ethnicity of non-Hispanic Black. Overall, 53% of adults reported no intake of SSBs. For the remaining 47%, the median 24-h intake was 46.8 g of sugar from SSBs. The adjusted prevalence ratio (PR) for untreated decay was 1.3 (95% confidence interval [CI] 1.1-1.5) for consumption of 46.8 g or more of sugar from SSBs compared to those reporting no sugar from SSBs. Number of untreated decayed teeth increased with sugar intake from SSBs from lowest to highest tertile: 0.1, (p = .35); 0.4, (p = .006); and 0.6, (p < .001). The cost burden of untreated decay attributable to SSBs in US adults is estimated conservatively at $1.6 billion USD. CONCLUSIONS: Community level interventions directed at sugar from SSBs are justified to address disparities in the burden of untreated dental decay.

Cross-cultural variation in thirst perception in hot-humid and hot-arid environments: Evidence from two small-scale populations.

OBJECTIVES: Thirst is an evolved central homeostatic feedback system that helps regulate body water for survival. Little research has examined how early development and exposure to extreme environments and water availability affect thirst perception, particularly outside Western settings. Therefore, we compared two indicators of perceived thirst (current thirst and pleasantness of drinking water) using visual scales among Tsimane' forager-horticulturalists in the hot-humid Bolivian Amazon and Daasanach agro-pastoralists in hot-arid Northern Kenya. METHODS: We examined how these measures of perceived thirst were associated with hydration status (urine specific gravity), ambient temperatures, birth season, age, and population-specific characteristics for 607 adults (n = 378 Tsimane', n = 229 Daasanach) aged 18+ using multi-level mixed-effect regressions. RESULTS: Tsimane' had higher perceived thirst than Daasanach. Across populations, hydration status was unrelated to both measures of thirst. There was a significant interaction between birth season and temperature on pleasantness of drinking water, driven by Kenya data. Daasanach born in the wet season (in utero during less water availability) had blunted pleasantness of drinking water at higher temperatures compared to those born in the dry season (in utero during greater water availability). CONCLUSIONS: Our findings suggest hydration status is not a reliable predictor of thirst perceptions in extreme-hot environments with ad libitum drinking. Rather, our findings, which require additional confirmation, point to the importance of water availability during gestation in affecting thirst sensitivity to heat and water feedback mechanisms, particularly in arid environments. Thirst regulation will be increasingly important to understand given climate change driven exposures to extreme heat and water insecurity.

Examining recent trends in the racial disparity gap in tap water consumption: NHANES 2011-2018.

OBJECTIVE: As tap water distrust has grown in the USA with greater levels among Black and Hispanic households, we aimed to examine recent trends in not drinking tap water including the period covering the US Flint Water Crisis and racial/ethnic disparities in these trends. DESIGN: Cross-sectional analysis. We used log-binomial regressions and marginal predicted probabilities to examine US nationally representative trends in tap and bottled water consumption overall and by race/ethnicity. SETTING: The National Health and Nutrition Examination Survey data, 2011-2018. PARTICIPANTS: Nationally representative sample of 9439 children aged 2-19 years and 17 268 adults. RESULTS: Among US children and adults, respectively, in 2017-2018 there was a 63 % (adjusted prevalence ratio (PR): 1·63, 95 % CI (1·25, 2·12), P < 0·001)) and 40 % (PR: 1·40, 95 % CI (1·16, 1·69), P = 0·001)) higher prevalence of not drinking tap water compared to 2013-2014 (pre-Flint Water Crisis). For Black children and adults, the probability of not drinking tap water increased significantly from 18·1 % (95 % CI (13·4, 22·8)) and 24·6 % (95 % CI (20·7, 28·4)) in 2013-2014 to 29·3 % (95 % CI (23·5, 35·1)) and 34·5 % (95 % CI (29·4, 39·6)) in 2017-2018. Among Hispanic children and adults, not drinking tap water increased significantly from 24·5 % (95 % CI (19·4, 29·6)) and 27·1 % (95 % CI (23·0, 31·2)) in 2013-2014 to 39·7 % (95 % CI (32·7, 46·8)) and 38·1 % (95 % CI (33·0, 43·1)) in 2017-2018. No significant increases were observed among Asian or White persons between 2013-2014 and 2017-2018. Similar trends were found in bottled water consumption. CONCLUSIONS: This study found persistent disparities in the tap water consumption gap from 2011 to 2018. Black and Hispanics' probability of not drinking tap water increased following the Flint Water Crisis.

Variation in urine osmolality throughout pregnancy: a longitudinal, randomized-control trial among women with overweight and obesity.

PURPOSE: Water needs increase during pregnancy, and proper hydration is critical for maternal and fetal health. This study characterized weekly hydration status changes throughout pregnancy and examined change in response to a randomized, behavioral intervention. An exploratory analysis tested how underhydration during pregnancy was associated with birth outcomes. METHODS: The Healthy Mom Zone Study is a longitudinal, randomized-control trial intervention aiming to regulate gestational weight gain (GWG) in pregnant women with overweight/obesity (n = 27). Fourteen women received standard of care; 13 women additionally received weekly guidance on nutrition, physical activity, water intake, and health-promoting behaviors. Hydration status was measured weekly via overnight urine osmolality (Uosm) from ~ 8-36 weeks gestation; underhydration was dichotomized (Uosm ≥ 500 mOsm/kg). Gestational age- and sex-standardized birth weight and length z scores and percentiles were calculated. We used mixed-effect and linear regression models to test covariate-adjusted relationships. RESULTS: No differences existed in Uosm or other characteristics between control and intervention women at baseline. Significant interactions (p = 0.01) between intervention and week of pregnancy on Uosm indicated intervention women maintained lower Uosm, whereas control women had a significant quadratic (inverse-U) relationship and greater Uosm in the second and early third trimesters. Results were consistent across robustness and sensitivity checks. Exploratory analyses suggest underhydration was associated with birth weight, but not length, in opposite ways in the second vs. third trimester. CONCLUSION: A multi-component behavioral intervention helped women with overweight/obesity maintain better hydration throughout pregnancy. Future studies should confirm birth outcome results as they have important implications for early life nutrition. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03945266; registered May 10, 2019 retrospectively.

The embodiment of water insecurity: Injuries and chronic stress in lowland Bolivia.

Water is critical to health and wellbeing. Studies have theorized that problems with water can become embodied, yet few studies have quantified this. Therefore, we first sought to understand the lowland Bolivian water environment of Tsimane' forager-horticulturalists. We assessed the water environment holistically, using objective measures of water quality and water services (Joint Monitoring Programme's drinking water services ladder) and subjective measures, including perceived water safety and water insecurity experiences [Household Water Insecurity Experiences Scale (HWISE)]. We tested how water service levels, perceived water safety, and water fetching frequency were associated with HWISE scores using Tobit regression models among 270 households. We then tested if and how water becomes embodied via self-reported water-related injury and a chronic stress biomarker, hair cortisol concentration (HCC). Results demonstrated that, compared with households using surface water, households with basic water services had HWISE scores 1.59-pts lower (SE = 0.29; P < 0.001). Ingestion of water perceived to be "bad" and more daily water-fetching trips were associated with higher HWISE scores. Twenty percent of households reported prior water-related injuries, with women most commonly injured. In logistic regressions, each point higher HWISE score was associated with 28% (95%CI:1.16-1.41; P < 0.001) higher odds of injury. Basic water services compared to surface water was associated with 48% lower odds (OR = 0.52; 95%CI:0.33-0.82; P = 0.005) of injury. Finally, using linear regressions among 332 adults, HWISE scores were not associated with HCC. Past water-related injury was associated with higher HCC (Beta = 0.31; SE = 0.09; P = 0.029) among women, but not men. Relying on unimproved water services compared to surface was associated with 46.2% higher HCC for women (Beta=0.38; SE=0.14; P=0.048) and 55.3% higher HCC for men (Beta=0.44; SE=0.15; P=0.044), respectively. Overall, our findings demonstrate that water insecurity can become embodied through water-related injuries and elevated HCC. Improving water service levels through an equity lens may help ameliorate water insecurity and its accompanying negative health effects.

Evaluating Differences in Whole Blood, Serum, and Urine Screening Tests for Zika Virus, Puerto Rico, USA, 2016.

We evaluated nucleic acid amplification testing (NAAT) for Zika virus on whole-blood specimens compared with NAAT on serum and urine specimens among asymptomatic pregnant women during the 2015-2016 Puerto Rico Zika outbreak. Using NAAT, more infections were detected in serum and urine than in whole blood specimens.

Household Food Insecurity, Hair Cortisol, and Adiposity Among Tsimane' Hunter-Forager-Horticulturalists in Bolivia.

OBJECTIVES: This study examined how household food insecurity (HFI) and chronic stress relate to adiposity among Tsimane' hunter-forager-horticulturalists in remote Bolivia with limited access to energy-dense processed foods that promote weight gain among industrialized populations. METHODS: Retrospective cross-sectional data on HFI (via the Household Food Insecurity Access Scale [HFIAS]), hair cortisol concentration (HCC), adiposity (BMI, body fat percentage [%BF]), and sociodemographics were collected from 171 men, 164 women, and 167 children. Linear mixed-effects models tested linear, quadratic, joint, and interactive relationships between adiposity measures and both the HFIAS score and HCC. RESULTS: Among children, each 3-point HFIAS score increase was associated with a 0.44-point higher %BF (SE = 0.22, P = 0.04). However, each 20% increase in HCC was associated with a -0.29-point difference in %BF (SE = 0.12, P = 0.01). Among men, a slight curvilinear relationship emerged between HFIAS and BMI. HFIAS and HCC were unrelated to adiposity measures among women. HCC did not modify relationships between HFIAS and adiposity in any subgroup. CONCLUSIONS: These findings from a remote, small-scale population suggest that positive associations between HFI and adiposity are not isolated to contexts of industrialized food environments and heavy reliance on processed foods. However, these dynamics and the role of stress appear to differ by sex and age group.

Household water insecurity will complicate the ongoing COVID-19 response: Evidence from 29 sites in 23 low- and middle-income countries.

In March 2020, the World Health Organization (WHO) issued a set of public guidelines for Coronavirus Disease 2019 (COVID-19) prevention measures that highlighted handwashing, physical distancing, and household cleaning. These health behaviors are severely compromised in parts of the world that lack secure water supplies, particularly in low- and middle-income countries (LMICs). We used empirical data gathered in 2017-2018 from 8,297 households in 29 sites across 23 LMICs to address the potential implications of water insecurity for COVID-19 prevention and response. These data demonstrate how household water insecurity presents many pathways for limiting personal and environmental hygiene, impeding physical distancing and exacerbating existing social and health vulnerabilities that can lead to more severe COVID-19 outcomes. In the four weeks prior to survey implementation, 45.9% of households in our sample either were unable to wash their hands or reported borrowing water from others, which may undermine hygiene and physical distancing. Further, 70.9% of households experienced one or more water-related problems that potentially undermine COVID-19 control strategies or disease treatment, including insufficient water for bathing, laundering, or taking medication; drinking unsafe water; going to sleep thirsty; or having little-to-no drinking water. These findings help identify where water provision is most relevant to managing COVID-19 spread and outcomes.