Sharing a sanitation facility between households can be linked to increased risk of moderate-to-severe diarrhea (MSD) in children under 5 years of age at some sites, according to Global Enteric Multicenter Study (GEMS) study findings published this week in PLOS Medicine. The study, conducted by Kelly Baker, assistant professor of occupational and environmental health at the University of Iowa College of Public Health, and colleagues, suggests that access to private sanitation facilities should remain a global health priority.
Diarrhea kills about three-quarters of a million young children every year. Interventions to improve sanitation and hygiene may benefit the roughly 2.5 billion people who do not use improved sanitation, including the 1 billion who defecate in the open. GEMS is a case-control study of pediatric diarrhea in children under 5 years of age at seven sites in Africa and South Asia. This study compared 8,592 children under 5 y with clinically and laboratory confirmed MSD matched to 12,390 asymptomatic children to uncover associations between household sanitation and incidence of diarrhea.
Compared to having a private household sanitation facility, sharing a facility with one or two households was found to be associated with an increased risk of diarrhea in young children at the study sites in Nyanza Province, Kenya (adjusted matched odds ratio 1.41 [95% confidence interval 1.11-1.79]), Bamako, Mali (1.23 [1.02-1.48]), and Karachi, Pakistan 1.58 [1.19-2.09]). Sharing a facility with three or more households was associated with further increased MSD risk. Sharing a sanitation facility was not found to be associated with increased MSD risk at the sites in Basse, The Gambia (1.69 [0.96-2.97]), Mirzapur, Bangladesh (0.83 [0.70-0.99]), or Kolkata, India (1.04 [0.78-1.39]).
As the study is observational, confounding by related characteristics such as hand washing may limit interpretation of results. In a linked Perspective, Jonny Crocker and Jamie Bartram of University of North Carolina at Chapel Hill, United States, discuss study limitations but argue that “Baker and colleagues present the best dataset yet on diarrheal disease associated with sanitation and hygiene. They provide compelling evidence on sanitation and hygiene risk factors for MSD and variability in that risk.” (originally published on EurekAlert!)
Two recent related studies co-authored by Baker:
Joanna Krajewski – a doctoral candidate in the School of Journalism and Mass Communication and CPH alumna (MPH ’13) – recently returned from her third trip to Haiti where she has worked on issues involving water quality and availability.
Krajewski first travelled to Haiti in 2012 as part of her practicum project for her Master’s in Public Health at the UI. During that time she worked with the Iowa-based Community Health Initiative-Haiti group on their Clean Water Project.
Specifically, Krajewski has worked with a system that aims to eliminate cholera and other waterborne diseases from drinking water, which if untreated can be fatal for infants and young children in developing countries around the world.
CPH faculty member Kelly Baker studies the cascade of health issues connected to water, sanitation, and hygiene.
Water has been a consistent theme running through Kelly Baker’s work, one that has led her from her home state of Oklahoma to California, Mexico, India, Ghana, and elsewhere around the globe.
“I’ve always been a bit of a vagrant,” says Baker, who joined the College of Public Health in 2014 as an assistant professor of occupational and environmental health. “Even before getting into global health work, I traveled a lot.”
After completing her undergraduate studies in biology and ecology, Baker moved to California intending to earn a PhD in oceanography.
“I wound up a bit disillusioned with the potential for career success in that field,” says Baker, who took time to rethink things. “I’d work then travel – typically into Mexico and Ecuador – and I settled on the concept of public health because it tied into a lot of the problems I observed in my travels.”
Baker then attended the University of Maryland-Baltimore, where she completed a PhD in microbiology and immunology.
“I started off studying bacterial pathogenesis and molecular diagnostics,” Baker says. “It was very bench-based work and I enjoyed it, but I realized it wasn’t where my interests were. I wanted to do fieldwork.”
After Baker graduated, she was offered a fellowship with the University of Maryland’s Global Enteric Multicenter Study (GEMS), one of the largest, most comprehensive studies of childhood diarrheal diseases ever conducted in developing country settings.
“My role was the environmental component of the study – understanding how water sanitation and hygiene affected a child’s odds of diarrhea,” Baker explains. “In Bangladesh, I designed questionnaires to understand the practices specifically related to water quality in the home or to hand washing. I collected environmental samples, and identified and measured how much contamination was in these samples. That was really my introduction to a lot of different disciplines, from field epidemiology to environmental microbiology to behavioral data collection methodologies.
“It resonated very strongly as the pathway I wanted to go in,” Baker continues. “In low-income countries, people are exposed over time to many different organisms. For me, improvements in fundamental environmental health offered a panacea against disease spread. You could prevent exposure to lots of different things over time, and, hopefully, prevent a child from ever getting to the point where they would have diarrhea or be malnourished from it.”
Baker’s next stop was Accra, Ghana, where she worked as an in-country investigator for the Emory University-based SaniPath study, an assessment of exposure to human waste in low-income urban environments. That experience in Ghana helped inform Baker’s current work in understanding the relationship between water and contamination.
“Water is a means by which we consume contamination, such as through drinking water or accidentally swallowing water while swimming,” Baker says. “But water is also is a mechanism by which contamination is introduced into the environment. For example, at an open defecation site, water can move beyond one centralized location and wind up contaminating a much broader area and exposing a broader population. It all leads back to containment of waste being a really important component of preventing the disease cycle from occurring again.”
Baker’s experience strengthens the College of Public Health in several areas, says Peter Thorne, CPH professor and head of occupational and environmental health.
“We’re pleased to have Kelly’s expertise in water quality, sanitation, and global public health,” says Thorne. “These are important areas of environmental health where we have needed more scholarship and student mentoring. While Kelly is doing great international work, we also look to her expertise to address problems with water quality in Iowa.”
Baker’s current research falls into three interconnected areas. “On the exposure side of things, my lab is developing a tool that simultaneously detects and quantifies over 20 known types of microorganisms that cause diarrheal disease,” Baker says. “We’re going to use this tool to better understand waterborne, watershed exposure risks in a low-income country.”
Worldwide, the lack of adequate sanitation facilities allows diarrheal pathogens to enter the environment, Baker explains.
“So the overall likelihood of being infected and experiencing illness is extremely high for those living in those areas,” she says. “We’re going to use this tool to identify the pathways by which groups of organisms spread in the environment and come into contact with people. We can use this information as a baseline for evaluating the impact of sanitation-related interventions on environmental safety and human health risks.”
The research team will be conducting projects this summer in Kenya and Iowa. “While Iowa may be relatively clean in terms of human waste, there’s zoonotic transmission through wildlife and livestock. Comparing the patterns we find in Iowa versus in Kenya will help us better understand what the inherent risks are in a place where there are good human sanitation systems versus a place where there are not.”
Maternal and Child Health
Another part of Baker’s work is exploring whether and how water and sanitation impact maternal and child health.
“We’re in the process of completing a project in India where we’re exploring what the patterns of sanitation use are for women across the life course, and how it impacts their health,” Baker says. “In India, for a number of reasons, open defecation is rampant even where public toilets are available. For women, fear of violence is an issue.”
Women’s struggles to access safe, private sanitation and obtain clean water create extremely stressful mental and physical environments, Baker explains. One finding from the project is that women with poor sanitation access are twice as likely to experience pre-term birth or give birth to a low-birth-weight infant.
“The next phase of our work is to understand why,” Baker says. “And not just why, but what are the downstream ramifications? Is the stress related to poor water and sanitation access something that is biologically linked to preterm birth? We want to understand what these pathways are so that we can design interventions that potentially can alleviate stressors for pregnant women.”
Baker emphasizes that the impact is not just on the woman, but also the child. “We hypothesize that how and when a child enters the world is a major predictor of whether that child, two years from now, will have a higher incidence of diarrheal disease, or is more likely to be stunted (low height for age) and wasted (low weight for height). We’re trying to understand that cascade — how is the disparity from poor water and sanitation access passed from mother to offspring, and what are the consequences?”
Baker’s third area of work is, as she puts it, “How do we identify effective interventions, and how do we understand whether those interventions work?”
Baker is collaborating with Safe Water Network, a non-governmental organization that partners with communities in Ghana and India to develop market-driven, financially sustainable, locally owned and managed water systems. Safe Water Network plans to conduct a heath-impact assessment, Baker explains, and her role is to help them understand when and how their programs are working.
“I have a lot of irons in the fire,” Baker admits, but the passion for her work is evident. “The three parallel tracks of my work are all really engaging, and none of them really stand alone. I’m a big picture person, and I really like projects where I have collaboration with and can learn from other people.”
This story originally appeared in the spring 2015 issue InSight magazine for alumni and friends of the UI College of Public Health.
Q&A: Osterberg discusses polices and practices to protect Iowa’s waterways
Water quality issues are making the news in Iowa and nationwide. This spring, the Des Moines Water Works announced its intention to sue three Iowa counties for polluting waterways in violation of the Federal Clean Water Act.
David Osterberg, CPH clinical professor of occupational and environmental health, advocates for water quality through the Iowa Policy Project, a nonprofit, nonpartisan research organization he co-founded in 2001. Osterberg, a former state legislator who chaired the House agriculture committee, discusses clean water and recommendations to strengthen Iowa’s Nutrient Reduction Strategy, a voluntary framework to cut nitrogen and phosphorus discharges into Iowa waterways.
What are some of the concerns about Iowa’s water quality?
Since Iowa was settled in the 1840s, our water quality has suffered. This isn’t unusual for a farm state, where millions of acres of wetlands were converted into cropland. First, we’re losing lots of soil. Our rivers run brown, not clear. Even if soil loss didn’t make Iowa’s rivers run brown, they’d run green because of algae—the result of heavy doses of nutrient runoff.
So, nutrients—primarily nitrogen and phosphorus—are a second cause of impaired water quality. On farm fields, nutrients aren’t a pollutant since their purpose is to make crops grow. But in water, nutrients are out of place and become pollutants.
Third, pesticides (insecticides and herbicides) wash into waters, although some herbicides like atrazine are less prevalent nowadays. Wastewater treatment plants discharge pollutants from industrial chemicals and home cleaning products, although the Environmental Protection Agency (EPA) sets limits.
How does polluted water affect environmental health?
Iowa lakes and rivers increasingly have algae blooms, which reduce recreational uses and pose health risks. Phosphorus can feed blue-green algae, including a type that causes extremely toxic organisms called microcystin. In July 2014, the city of Toledo, Ohio, temporarily lost its water supply due to microcystin in Lake Erie. You couldn’t even boil the water to make it drinkable. Since 2010, the Iowa Department of Natural Resources (DNR) has seen statewide a ten-fold increase in the microcystin at beaches, from two cases to 22.
In the Gulf of Mexico, oxygen loss has created the dead zone. People often say we “poisoned” the water, but we actually over-enriched it. Since nitrogen and phosphorus make plants like corn and soybeans grow, they also make algae grow, which in turn consume all the oxygen, and fish die or leave.
What is the Nutrient Reduction Strategy?
Iowa introduced the Nutrient Reduction Strategy (NRS) in 2013 in response to the EPA directive for states along the Mississippi River to reduce the dead zone. The goal is to reduce nitrogen and phosphorus runoff by 45 percent.
The DNR, Department of Agriculture and Land Stewardship, and Iowa State University (ISU) determined that 90 percent of the nitrogen from Iowa that ends up in the dead zone comes from nonpoint sources, meaning from agriculture. The other 10 percent comes from point sources, primarily wastewater treatment plants. Nearly 66 percent of the phosphorus comes from nonpoint sources and 33 percent from point sources.
Taking reduction steps is voluntary for nonpoint sources, despite accounting for 90 percent of Iowa’s nitrogen contribution, yet mandatory for the point sources.
What can be done to improve water quality through policy and practice?
In July 2014, the Iowa Policy Project (IPP) published a paper on how to improve the NRS. One of the basic problems is the lack of resources to implement the program. Besides needing to change course and assure sufficient funding, there are other problems with a voluntary program. There’s no date by which to achieve the 45 percent reduction goal; we need to set a date. Also, monitoring isn’t required, and should be.
But the crux of the NRS weakness is that it’s voluntary for farmers. Many farmers are doing positive things. But many farmers aren’t doing anything and should. An ISU Agriculture and Rural Life poll in 2011 of 1,300 farmers found that 51 percent of landowners spent nothing on conservation practices in the prior 10 years. If you’re spending nothing, you’re likely doing nothing. IPP thinks farmers should be required to pick two conservation practices from several choices.
What practices help reduce soil and nutrient loss?
One effective practice is cover crops, which keeps soil in place and utilizes nitrogen and phosphorus. However, they can be hard to get started if row crops aren’t harvested until November. Buffer zones between crops and waterways are very effective. The Environmental Working Group showed that a relatively small number of acres taken from production can help. Buffer zones attract wildlife such as pheasants. Farmers could charge people to hunt on their land. Other practices include reintroducing wetlands, contour farming and terracing, and grassed waterways.
If the NRS is sufficiently funded, more technicians could be hired to help farmers successfully adopt these practices. In Iowa, we have the best farmland in the world. We ought to use it to grow corn, but we should be able to grow crops and not contaminate the land and water.
This story originally appeared in the spring 2015 issue InSight magazine for alumni and friends of the UI College of Public Health.