New global study pinpoints main causes of childhood diarrheal diseases, suggests effective solutionsMay 14, 2013
Karachi: A new international study published today in The Lancet provides the clearest picture yet of the impact and most common causes of diarrheal diseases, the second leading killer of young children globally, after pneumonia. The Global Enteric Multicenter Study GEMS is the largest study ever conducted on diarrheal diseases in developing countries, enrolling more than 20,000 children from seven sites across Asia and Africa.
GEMS, coordinated by the University Of Maryland School Of Medicine’s Centre for Vaccine Development, confirmed rotavirus as the leading cause of diarrheal diseases among infants and identified other top causes for which additional research is urgently needed. GEMS found that approximately one in five children under the age of two suffer from moderate-to-severe diarrhoea MSD each year, which increased children’s risk of death 8.5fold and led to stunted growth over a two month follow up period.
“When it comes to childhood morbidity and mortality, diarrheal diseases remain a leading culprit.” said Dr. Anita Zaidi from the Aga Khan University, who served as Principal Investigator at the Pakistan study site. “The GEMS data are the most conclusive evidence we have to date on which pathogens we must target and suggest ways to improve prevention and treatment.”
Despite many causes, GEMS found that targeting just four pathogens – rotavirus, Shigella, Cryptosporidium, and STETEC – could prevent the majority of MSD cases. Expanding access to existing tools targeting these pathogens and accelerating research on new treatments, diagnostics and vaccines to help control them could save thousands of lives. Prior to GEMS, Cryptosporidium was not considered a major cause of diarrheal disease and as a result there is currently little research on this pathogen underway.
“The GEMS findings help set priorities for investments that could greatly reduce the burden of childhood diarrheal diseases,” said Dr. Thomas Brewer, deputy director of the Enteric & Diarrheal Diseases team at the Bill & Melinda Gates Foundation, which funded the study. “Vaccines and treatments available today can save thousands of children right now but targeted research to develop new tools to combat severe diarrhoea could save many more lives in the future.”
The GEMS findings also suggest that longer term monitoring and care of children with diarrheal diseases could reduce mortality and nutritional deficits. Children with MSD grew significantly less in height in the two months following the diarrheal episode when compared with control children without diarrhoea, and were 8.5 times more likely to die over the course of the two month follow up period. Notably, 61 percent of deaths occurred more than a week after the initial diarrheal episode, with 56 percent of deaths happening after families had returned home from a healthcare facility.
The GEMS study in Pakistan was conducted in coastal villages near Karachi by the Aga Khan University. Similar to other sites, rotavirus, Shigella, Cryptosporidium and STETEC were leading causes of diarrheal disease. Uniquely in the Pakistan and Bangladesh sites, Aeromonas, another type of bacteria, was the second leading cause of MSD, confirming its regional importance as a pathogen. Linear growth delays were significant among children ages 15 years old in Pakistan, and a single episode of MSD increased children’s risk of death more than thirteen fold.
“GEMS strongly indicate that follow up care after the initial diarrheal episode is critical to protect the health and wellbeing of children,” said Professor George Griffin, Senior Co-Chair of the GEMS International Strategic Advisory Committee and Professor at St. George’s, University of London. “By focusing only on the acute diarrhoea that brings children to hospitals, we overlook a significant portion of diarrheal diseases’ burden.”
Expanding access to existing interventions that protect against or treat all diarrheal diseases, including oral rehydration solutions, zinc supplements, clean water and sanitation, can save lives and improve the health of children immediately.
“GEMS are a landmark study for the child health community,” said Professor Fred Binka, Co-Chair of the GEMS International Strategic Advisory Committee and Vice Chancellor at the University of Health and Allied Sciences, Ghana. “By using consistent methods across countries, GEMS sites generated data that can guide evidence based decision making at both the local and global levels.”
Release of the GEMS findings follows last month’s announcement by the World Health Organization and UNICEF of the first ever Integrated Global Action Plan for the Prevention and Control of Pneumonia and Diarrhoea GAPPD. The GEMS findings add to the scientific evidence cited in the GAPPD strategy for effectively controlling pneumonia and diarrhoea, which together are the two leading causes of death among young children globally.