Authors: Alice Greenway, Future Science Group
A team of researchers at the University Of Maryland School Of Medicine (UM SOM; MD, USA) recently published an article in the Pediatric Clinics of North America outlining the main impact and challenges of diarrheal diseases as well as identifying the key pathogenic causes. Rotavirus, Cryptosporidium, Shigella and enterotoxigenic Esherichia coli (ETEC) were the top four pathogens responsible, with rotavirus having the highest incidence among infants.
These pathogens were identified by the Global Enteric Multicenter Study (GEMS)study set up by UM SOM, which is the largest study to-date conducted in a developing country and set up to investigate childhood diarrheal diseases.
“The findings from the GEMS study show that despite the many causes of diarrhea, targeting just four pathogens could prevent the majority of serious cases,” explained author Karen Kotloff, from the UM SOM.
Diarrheal diseases are responsible for one in eight deaths among young children under the age of 5, most of whom live in developing countries and have inadequate access to clean drinking water or sanitation.
The study, which was funded by the Bill & Melinda Gates Foundation (WA, USA), was conducted in seven countries in which the incidence of diarrheal diseases is most prevalent; namely, Gambia, Kenya, Mali, Mozambique, Bangladesh, India and Pakistan.
The research exposed key facts and statistics for the year of 2015 – specifically the team discovered that diarrheal disease accounted for 2.3 billion illnesses and 1.3 million deaths worldwide. In total, 40% of those affected were under the age of 5 and a staggering 90% resided in sub-Saharan Africa and South Asia.
“We are on the cusp of a dramatic shift in the epidemiology of pediatric diarrheal diseases since rotavirus vaccines became available,” declared Kotloff, “However, adoption of a rotavirus vaccine regime is lagging in low-resource settings where the most severe cases occur.”
Other interventions are available, including oral rehydration solutions and antibiotic treatment; however, these resources are scarce in developing countries where the burden highest.
The WHO has recommended that the rotavirus vaccine (which is derived from a live but mild strain of the virus) be included in all national infant immunization programs, including those in developing countries.
The team from UM SOM are investigating the efficiency and safety of an alternative thermostable rotavirus vaccine called RotaTeqTM, which could provide a version of the vaccine with increased resistance to temperature fluctuations.
“The GEMS study showed that children who had a serious diarrheal disease episode were 8.5-times more likely to die in the 2 months after their illness than children in their neighborhood who were the same age but did not have an episode. This highlights the importance of preventing these episodes from occurring in the first place, and paying close attention to those who do have an episode,” Kotloff concluded.
Sources: Kotloff KL. The burden and etiology of diarrheal illness in developing countries. Pediatr. Clin. North Am. 64(4) 799–814 (2017); http://news.medschool.umaryland.edu/?z=106&a=3643