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Featured researches published by Clair Null.


BMJ Open | 2013

Cluster-randomised controlled trials of individual and combined water, sanitation, hygiene and nutritional interventions in rural Bangladesh and Kenya: the WASH Benefits study design and rationale.

Benjamin F. Arnold; Clair Null; Stephen P. Luby; Leanne Unicomb; Christine P. Stewart; Kathryn G. Dewey; Tahmeed Ahmed; Sania Ashraf; Garret Christensen; Thomas Clasen; Holly N. Dentz; Lia C. H. Fernald; Rashidul Haque; Alan Hubbard; Patricia Kariger; Elli Leontsini; Audrie Lin; Sammy M. Njenga; Amy J. Pickering; Pavani K. Ram; Fahmida Tofail; Peter J. Winch; John M. Colford

Introduction Enteric infections are common during the first years of life in low-income countries and contribute to growth faltering with long-term impairment of health and development. Water quality, sanitation, handwashing and nutritional interventions can independently reduce enteric infections and growth faltering. There is little evidence that directly compares the effects of these individual and combined interventions on diarrhoea and growth when delivered to infants and young children. The objective of the WASH Benefits study is to help fill this knowledge gap. Methods and analysis WASH Benefits includes two cluster-randomised trials to assess improvements in water quality, sanitation, handwashing and child nutrition—alone and in combination—to rural households with pregnant women in Kenya and Bangladesh. Geographically matched clusters (groups of household compounds in Bangladesh and villages in Kenya) will be randomised to one of six intervention arms or control. Intervention arms include water quality, sanitation, handwashing, nutrition, combined water+sanitation+handwashing (WSH) and WSH+nutrition. The studies will enrol newborn children (N=5760 in Bangladesh and N=8000 in Kenya) and measure outcomes at 12 and 24 months after intervention delivery. Primary outcomes include child length-for-age Z-scores and caregiver-reported diarrhoea. Secondary outcomes include stunting prevalence, markers of environmental enteropathy and child development scores (verbal, motor and personal/social). We will estimate unadjusted and adjusted intention-to-treat effects using semiparametric estimators and permutation tests. Ethics and dissemination Study protocols have been reviewed and approved by human subjects review boards at the University of California, Berkeley, Stanford University, the International Centre for Diarrheal Disease Research, Bangladesh, the Kenya Medical Research Institute, and Innovations for Poverty Action. Independent data safety monitoring boards in each country oversee the trials. This study is funded by a grant from the Bill & Melinda Gates Foundation to the University of California, Berkeley. Registration Trial registration identifiers (http://www.clinicaltrials.gov): NCT01590095 (Bangladesh), NCT01704105 (Kenya).


American Journal of Tropical Medicine and Hygiene | 2012

Evaluating the Sustained Health Impact of Household Chlorination of Drinking Water in Rural Haiti

Eric Harshfield; Daniele Lantagne; Anna Turbes; Clair Null

The Jolivert Safe Water for Families program has sold sodium hypochlorite solution (chlorine) and conducted household visits in rural Haiti since 2002. To assess the impact of the program on diarrheal disease, in 2010 we conducted a survey and water quality testing in 201 program participants and 425 control households selected at random. Fifty-six percent of participants (versus 10% of controls) had free chlorine residuals between 0.2 and 2.0 mg/L, indicating correct water treatment. Using intention-to-treat analysis, we found that significantly fewer children < 5 in participant households had an episode of diarrhea in the previous 48 hours (32% versus 52%; P < 0.001) with 59% reduced odds (odds ratio = 0.41, 95% confidence interval = 0.21–0.79). Treatment-on-treated estimates of the odds of diarrhea indicated larger program effects for participants who met more stringent verifications of participation. Diarrheal disease reduction in this long-term program was comparable with that seen in short-term randomized, controlled interventions, suggesting that household chlorination can be an effective long-term water treatment strategy.


Maternal and Child Nutrition | 2015

Dairy intensification, mothers and children: an exploration of infant and young child feeding practices among rural dairy farmers in Kenya

A. Wyatt; Kathryn M. Yount; Clair Null; Usha Ramakrishnan; Aimee Webb Girard

Agricultural strategies such as dairy intensification have potential to improve human nutrition through increased household food security. Increasing dairy productivity could also adversely affect infant and young child feeding (IYCF) practices because of increased maternal stress, demands on maternal time, and beliefs about the timing and appropriate types of complementary foods. Yet, few studies have looked rigorously at how interventions can affect young children (0-60 months). The study explores, within the context of rural dairy farming in Kenya, the relationship between level of household dairy production and selected IYCF practices using a mixed-methods approach. Six focus group discussions with women involved in dairy farming investigated their attitudes towards breastfeeding, introduction of complementary foods and child diets. Ninety-two households involved in three levels of dairy production with at least one child 0-60 months participated in a household survey. Quantitative results indicated that women from higher dairy producing households were more likely to introduce cows milk to infants before they reached 6 months than women from households not producing any dairy. Themes from the focus group discussions demonstrated that women were familiar with exclusive breastfeeding recommendations, but indicated a preference for mixed feeding of infants. Evidence from this study can inform nutrition education programmes targeted to farmers participating in dairy interventions in rural, low-income settings to minimise potential harm to the nutritional status of children.


Environment and Urbanization | 2015

Public toilets and their customers in low-income Accra, Ghana

Dorothy Peprah; Kelly K. Baker; Christine L. Moe; Katharine Robb; Nii Wellington; Habib Yakubu; Clair Null

Public pay-per-use toilets are the only alternative to open defecation for a significant number of people in many low-income, urban neighbourhoods where insecure tenure, space constraints, and/or cost make private sanitation facilities unfeasible. This study explores public toilet use, characteristics of public toilet customers and possible improvements to public toilet facilities in four neighbourhoods in Accra, Ghana, the country with the highest reliance on shared sanitation facilities globally. Reliance on public toilets ranged considerably depending on neighbourhood affluence, but even some people living in compounds with a private toilet used a public toilet. The vast majority of users were adults. Few public toilet customers could foresee owning a household toilet in the coming year, mostly because of lack of space, and they voiced desires for more and cleaner public toilets with better provision of handwashing facilities. Improved accessibility and management of public toilets, along with facilities more suitable for children, could reduce open defecation.


Journal of Nutrition | 2016

Vitamin B-12 concentrations in breast milk are low and are not associated with reported household hunger, recent animal-source food, or Vitamin B-12 intake in women in rural Kenya

Anne M Williams; Caroline J. Chantry; Sera L. Young; Beryl Achando; Lindsay H. Allen; Benjamin F. Arnold; John M. Colford; Holly N. Dentz; Daniela Hampel; Marion Kiprotich; Audrie Lin; Clair Null; Geoffrey M. Nyambane; Setti Shahab-Ferdows; Christine P. Stewart

BACKGROUND Breast milk vitamin B-12 concentration may be inadequate in regions in which animal-source food consumption is low or infrequent. Vitamin B-12 deficiency causes megaloblastic anemia and impairs growth and development in children. OBJECTIVE We measured vitamin B-12 in breast milk and examined its associations with household hunger, recent animal-source food consumption, and vitamin B-12 intake. METHODS In a cross-sectional substudy nested within a cluster-randomized trial assessing water, sanitation, hygiene, and nutrition interventions in Kenya, we sampled 286 women 1-6 mo postpartum. Mothers hand-expressed breast milk 1 min into a feeding after 90 min observed nonbreastfeeding. The Household Hunger Scale was used to measure hunger, food intake in the previous week was measured with the use of a food-frequency questionnaire (FFQ), and vitamin B-12 intake was estimated by using 24-h dietary recall. An animal-source food score was based on 10 items from the FFQ (range: 0-70). Breast milk vitamin B-12 concentration was measured with the use of a solid-phase competitive chemiluminescent enzyme immunoassay and was modeled with linear regression. Generalized estimating equations were used to account for correlated observations at the cluster level. RESULTS Median (IQR) vitamin B-12 intake was 1.5 μg/d (0.3, 9.7 μg/d), and 60% of women consumed <2.4 μg/d, the estimated average requirement during lactation. Median (IQR) breast milk vitamin B-12 concentration was 113 pmol/L (61, 199 pmol/L); 89% had concentrations <310 pmol/L, the estimated adequate concentration. Moderate or severe hunger prevalence was 27%; the animal-source food score ranged from 0 to 30 item-d/wk. Hunger and recent animal-source food and vitamin B-12 intake were not associated with breast milk vitamin B-12 concentrations. Maternal age was negatively associated with breast milk vitamin B-12 concentrations. CONCLUSION Most lactating Kenyan women consumed less than the estimated average requirement of vitamin B-12 and had low breast milk vitamin B-12 concentrations. We recommend interventions that improve vitamin B-12 intake in lactating Kenyan women to foster maternal health and child development. The main trial was registered at clinicaltrials.gov as NCT01704105.


American Journal of Tropical Medicine and Hygiene | 2016

Quantifying Contact with the Environment: Behaviors of Young Children in Accra, Ghana

Peter Teunis; Heather Reese; Clair Null; Habib Yakubu; Christine L. Moe

To better understand the risks of exposure for young children to fecal contamination in their environment, we systematically characterized and quantified behaviors of 154 children, 0–5 years old, in four high-density, low-income neighborhoods in Accra, Ghana. A repertoire of six different activities and five different compartments (categories of locations within the household) was developed, and about 500 hours of ordered structured observations of activities and locations of individual children were collected. These records were analyzed using a competing hazards model, estimating (Weibull) hazard rates for each state (activity/compartment combination), dependent on the present state and the preceding state. The estimated rates were used to simulate sequences of behavior and describe days in the life of a child in low-income, urban Africa. Children younger than 1 year spent most time playing or sleeping off the ground, older children frequently played on floors. Relatively little time was spent in drains or wet trash areas. Critical combinations of activities, like handwashing after defecation or before eating were estimated to occur rarely. These quantitative behavior estimates can inform future risk assessments that examine the relative roles of various fecal–oral exposure pathways in low-income urban settings.


Journal of Water and Health | 2016

Quantification of exposure to fecal contamination in open drains in four neighborhoods in Accra, Ghana

Stephanie R. Gretsch; Joseph Ampofo; Kelly K. Baker; Julie A. Clennon; Clair Null; Dorothy Peprah; Heather Reese; Katharine Robb; Peter Teunis; Nii Wellington; Habib Yakubu; Christine L. Moe

In low-income countries, rapid urbanization adds pressure to already stressed water and sanitation systems that are critical to the health of communities. Drainage networks, designed for stormwater but commonly used for disposing of waste, are rarely covered completely, allowing residents to easily come into contact with their contents. This study used spatial mapping, documentation of physical drain characteristics, microbiological analysis of drain samples, and behavioral observation to comprehensively examine drains as a route of exposure to fecal contamination in four low-income neighborhoods in Accra, Ghana. A stochastic model of six likely exposure scenarios was constructed to estimate childrens exposure to drain water. Regardless of the age of the child, any exposure scenario considered resulted in exposure to a high level of fecal contamination. Fecal contamination levels in drains were high (Escherichia coli: geometric mean (GM), 8.60 cfu log(10)/100 mL; coliphage: GM, 5.56 pfu log(10)/100 mL), and did not differ by neighborhood or physical drain characteristics, indicating that frequency of contact with drains, and not drain type or location, drives exposure risk. To mitigate health risks associated with this exposure, drains should be covered, with priority given to large concrete and small to medium dirt-lined drains that children were most commonly observed entering.


American Journal of Tropical Medicine and Hygiene | 2015

Pilot Cluster Randomized Controlled Trials to Evaluate Adoption of Water, Sanitation, and Hygiene Interventions and Their Combination in Rural Western Kenya

Garret Christensen; Holly N. Dentz; Amy J. Pickering; Tomoé Bourdier; Benjamin F. Arnold; John M. Colford; Clair Null

In preparation for a larger trial, the Water, Sanitation, and Hygiene (WASH) Benefits pilot study enrolled 72 villages and 499 subjects in two closely related randomized trials of WASH interventions in rural western Kenya. Intervention households received hardware and promotion for one of the following: water treatment, sanitation and latrine improvements, handwashing with soap, or the combination of all three. Interventions were clustered by village. A follow-up survey was conducted 4 months after intervention delivery to assess uptake. Intervention households were significantly more likely than controls to have chlorinated stored water (36-60 percentage point increases), covers over latrine drop holes (55-75 percentage point increases), less stool visible on latrine floors (16-47 percentage point reductions), and a place for handwashing (71-85 percentage point increases) with soap available (49-66 percentage point increases). The high uptake in all arms shows that combined interventions can achieve high short-term adoption rates if well-designed.


American Journal of Tropical Medicine and Hygiene | 2017

Assessment of Fecal Exposure Pathways in Low-Income Urban Neighborhoods in Accra, Ghana: Rationale, Design, Methods, and Key Findings of the SaniPath Study.

Katharine Robb; Clair Null; Peter Teunis; Habib Yakubu; George Armah; Christine L. Moe

Abstract. Rapid urbanization has contributed to an urban sanitation crisis in low-income countries. Residents in low-income, urban neighborhoods often have poor sanitation infrastructure and services and may experience frequent exposure to fecal contamination through a range of pathways. There are little data to prioritize strategies to decrease exposure to fecal contamination in these complex and highly contaminated environments, and public health priorities are rarely considered when planning urban sanitation investments. The SaniPath Study addresses this need by characterizing pathways of exposure to fecal contamination. Over a 16 month period, an in-depth, interdisciplinary exposure assessment was conducted in both public and private domains of four neighborhoods in Accra, Ghana. Microbiological analyses of environmental samples and behavioral data collection techniques were used to quantify fecal contamination in the environment and characterize the behaviors of adults and children associated with exposure to fecal contamination. Environmental samples (n = 1,855) were collected and analyzed for fecal indicators and enteric pathogens. A household survey with 800 respondents and over 500 hours of structured observation of young children were conducted. Approximately 25% of environmental samples were collected in conjunction with structured observations (n = 441 samples). The results of the study highlight widespread and often high levels of fecal contamination in both public and private domains and the food supply. The dominant fecal exposure pathway for young children in the household was through consumption of uncooked produce. The SaniPath Study provides critical information on exposure to fecal contamination in low-income, urban environments and ultimately can inform investments and policies to reduce these public health risks.


PLOS ONE | 2016

Soil-Transmitted Helminth Eggs Are Present in Soil at Multiple Locations within Households in Rural Kenya

Lauren Steinbaum; Sammy M. Njenga; Jimmy H. Kihara; Alexandria B. Boehm; Jennifer Davis; Clair Null; Amy J. Pickering

Almost one-quarter of the world’s population is infected with soil-transmitted helminths (STH). We conducted a study to determine the prevalence and location of STH—Ascaris, Trichuris, and hookworm spp.—egg contamination in soil within rural household plots in Kenya. Field staff collected soil samples from July to September 2014 from the house entrance and the latrine entrance of households in Kakamega County; additional spatial sampling was conducted at a subset of households (N = 22 samples from 3 households). We analyzed soil samples using a modified version of the US Environmental Protection Agency (EPA) method for enumerating Ascaris in biosolids. We found 26.8% of households had one or more species of STH eggs present in the soil in at least one household location (n = 18 out of 67 households), and Ascaris was the most commonly detected STH (19.4%, n = 13 out of 67 households). Prevalence of STH eggs in soil was equally likely at the house entrance (19.4%, N = 67) as at the latrine entrance (11.3%, N = 62) (p = 0.41). We also detected STH eggs at bathing and food preparation areas in the three houses revisited for additional spatial sampling, indicating STH exposure can occur at multiple sites within a household plot, not just near the latrine. The highest concentration of eggs in one house occurred in the child’s play area. Our findings suggest interventions to limit child exposure to household soil could complement other STH control strategies.

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Holly N. Dentz

Innovations for Poverty Action

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