Diarrhea is a leading cause of death for young children around the world, and cases often increase after heavy rains and floods. But drought conditions can also increase the risk of diarrhea, which is an ominous sign as the world continues to warm due to climate change.
In a new study, Yale researchers found higher rates of diarrhea in children who endured a prolonged drought. The situation was even worse in households that had to travel long distances to fetch water or lacked soap and water to wash their hands. But even adequate sanitation could not offset the risk of diarrhea associated with drought.
Kai Chen, an assistant professor in the Department of Epidemiology (Environmental Health) at the Yale School of Public Health, said, “You can’t completely eliminate the impact of drought on diarrhea risk, especially in an environment where more people will be in the future.” .” There will be more droughts.” and a senior author of the study. “We need to reduce greenhouse gas emissions.”
The study was the largest to date to examine the impact of long-term drought on diarrhea risk in children living in low- and middle-income countries (LMICs). It was also the first of its kind to use a new measure of drought that takes into account both water supply and water demand.
Diarrhea can be caused by contact with contaminated food or water, animal feces, or another infected person. While the relationship between precipitation and diarrhea has been extensively studied, evidence for dryness and diarrhea is scarce.
Young children most at risk
To better understand the link between drought and diarrhea, the authors drew on international health surveys and climate data. Drought was measured at a resolution of 10 square kilometers using a metric called the Standardized Precipitation Evaporation Index (SPEI).
Data on recent diarrheal attacks was collected between 1990 and 2019 by the Demographic and Health Survey, a collaboration between USAID and dozens of countries around the world. The surveys included more than 1.3 million children under the age of 5 living in 51 countries in sub-Saharan Africa, South and Southeast Asia, Latin America and the Caribbean.
In all countries examined, 14.4% of the children had diarrhea in the last 2 weeks. The risk was highest in children between the ages of 6 and 23 months.
In the worst-hit country, Niger, about 36.4% of children were recently sick. Other badly affected countries are Bolivia, Liberia, Central African Republic, Burundi, Malawi and Haiti, where 1 in 5 children were recently affected.
Six months of drought increases the risk of diarrhea by 5% if the drought is mild or 8% if the drought is severe. Access to good water, sanitation and hygiene (WASH) facilities, such as Sufficient soap and water, for example, offers little to moderate protection against the risk of diarrhea.
Likewise, children in households where fetching water takes longer – more than half an hour – or where there is no access to soap and water to wash hands are at greater risk.
The deadly toll of diarrhea
Children who survive diarrheal illness may suffer from growth and developmental disorders and may be more susceptible to chronic diseases. But many others do not survive.
In 2016 alone, approximately 446,000 children under the age of 5 died from diarrheal diseases worldwide, making it the fifth leading cause of death in this age group. Death is often caused by severe dehydration or excessive infection.
Those numbers are likely to get worse as climate change is expected to worsen and prolong droughts.
Drought can increase concentrations of dangerous bacteria and viruses in water sources. Even when water is scarce, drinking is preferable to personal hygiene. For many people in LMIC, it can take hours to reach the water.
Preventing diarrhea requires simple measures like access to safe drinking water and sanitation.
But the negative effects of drought-related diarrhea cannot be completely eradicated.
“International collaborative efforts are needed to improve WASH infrastructure, particularly in these resource-poor communities. For those kids, it definitely helps,” said Chen, who is also research director of the Yale Center on Climate Change and Health at the Yale School of Public Health. “But washing your hands is not enough to protect you. We must tackle the causes of climate change.”
Study appears online nature communicationThe research was funded by the Reckitt Global Hygiene Institute.