One of the leading causes of child mortality in South Asia and Africa is preventable diarrhoea. In developing countries, a severe lack of access to sanitation infrastructure, clean water and health facilities makes it all the more difficult to prevent and contain the spread of infectious diseases. According to a recent study published in the journal Proceedings of the National Academy of Sciencesincreased frequency of droughts and heavy rainfall is linked to increased rates of diarrheal disease in children under 3 years of age.
“Climatic conditions are increasingly conducive to the transmission of various waterborne and vector-borne diseases. At the same time, increased incidence of extreme weather events attributed to climate change have been shown to enhance disease transmission channels, such as the accumulation of pathogens in limited water supplies and contact with contaminated water following flooding,” the researchers wrote in their study.
The climate crisis is destabilizing and altering the global water cycle – exacerbating a phenomenon known as “dry gets drier, wet gets wetter”. Heavy unseasonal rainfall during a dry season can cause a sudden and drastic increase in pathogen concentrations entering water sources.
In an effort to further investigate the link between rainfall shocks like droughts and floods and diarrhea in children, researchers analyzed survey data from an international development group that included 611,154 children under 3-year-olds from 51 countries between 2000 and 2019. The families of the children were interviewed to determine when and how they started experiencing symptoms of diarrhea.
Anna Dimitrova, a researcher at UC San Diego’s Scripps Institution of Oceanography, and her colleagues then correlated the survey data with climate data. They observed that children from tropical savannas and humid subtropics reported the highest incidence at 18.5% and 18.3%, respectively. The lowest incidence of diarrhea (16.6%) was observed in children from the humid subtropical zone.
Drafts were associated with an increased risk of diarrhea in tropical savanna regions, and in humid subtropical regions, heavy rainfall was linked to a higher incidence of diarrhea.
The researchers pointed out that certain interventions can go a long way in reducing the risk of diarrheal disease in children. This includes safe disposal of children’s stools, rotavirus vaccinations, hygienic eating practices, and water treatment before consumption.
“Our results suggest that interventions should aim to improve education on water treatment methods during heavy rainfall, especially among households with access to piped water in the dwelling who may be unaware of degraded water quality,” the researchers noted.
However, researchers further recognize that extreme weather events such as flooding can repeatedly damage and destroy sanitation facilities and cause sewage overflows. While droughts prevent communities from washing their hands regularly and continuing to practice other hygiene practices, increasing the risk of children contracting diarrhoea.
“Among other health risks, child undernutrition increases susceptibility to diarrheal disease and is a leading cause of child death. The results presented underscore the need to reach food-insecure households and incorporate minimum nutritional standards into food assistance programs targeting young children,” the researchers concluded. “Improving knowledge about healthy eating practices can also be implemented at low cost in places where these practices are not widely followed.”