More than 1.5 million people died from diarrhoeal diseases across the globe in 2017 . One-third of the figure were children under the age of five years . Even with mortality rates steadily declining over the last 3 decades, and the availability of simple treatment solutions, diarrhea still remains a leading cause of death among young children today , .
Around the 1970s, it had become recognized that diarrhea was a major cause of death in low- and middle-income countries (LMICs) . To address this issue, the World Health Organization (WHO) launched a Programme for Control of Diarrhoeal Diseases in 1978 when it was realized that an oral rehydration salt (ORS) solution could prevent mortality through treatment of dehydrating diarrhea . By 2015, global childhood mortality rates from diarrhoeal diseases had declined by over 80% .
Despite the considerable decline, it is estimated that about 525,000 children under five years are killed by diarrhea each year . Most cases however are more concentrated in low- and middle-income countries. Mortality may be as high as 50 to 150 per 100,000 as in the case of the Sub-Saharan Africa and South East Asia regions and even over 150 per 100,000 in Central African Republic and Chad rates . In the South Pacific region, Solomon Islands, Fiji, Kiribati, and Papua New Guinea have some of the highest rates of the region at over 15 per 100,000 to more than 50 per 100,000 . In contrast to LMICs, most other countries average about 5 per 100,000, while high-income countries experience only about 1 in 100,000 childhood deaths from diarrhoeal diseases per year .
Diarrhea is oftentimes a symptom of an infection of the intestinal tract . It is defined by WHO as the passage of watery or loose stool more than three times a day . The cause of infection is primarily due to bacterial and viral organisms and sometimes from parasitic organisms, most of which are spread by feces-contaminated water .
Common risk factors include unsafe drinking water, poor sanitation, and malnutrition – shared challenges faced in developing countries , .
Even though bacterial organisms are the major group of pathogens responsible for diarrhoeal diseases in children, the rotavirus is the single most causative agent responsible for most of the severe cases in children, accounting for about 215,000 deaths each year .
In 2006, the United States approved the first widely-used rotavirus vaccine, while other vaccines following shortly thereafter . There are currently four oral rotavirus vaccines approved by the World Health Organization: Rotarix, RotaTeq, RotaSiil, and Rotavac .
The use of rotavirus vaccines has greatly influenced the reduction in rotavirus-related deaths . In an article published in 2018, about 28,900 child deaths globally were prevented in 2016 by the use of rotavirus vaccines . In addition, a large part of the decline in diarrhoeal mortality has been attributed to the use of oral rehydration salt (ORS) solutions, improved nutrition, increased breastfeeding, measles immunization, improvement in hygiene and sanitation, better supplemental feeding, and female education .
Other vaccines against diarrhoeal pathogens, such as E. coli and Shigella spp. also prove effective in preventing childhood intestinal infections .
Since each episode of diarrhea deprives the child of necessary nutrients for growth, frequent diarrhea may lead to malnutrition which in turn increases the child’s risk of diarrhea . Therefore proper measures must be taken to prevent and treat diarrhea.
As suggested by the World Health Organization, key measures to prevent diarrhea include:
Access to clean, safe drinking-water ;
Using improved sanitation ;
Washing hands with soap ;
Breastfeeding for the first six months of a child’s life ;
Clean foods and good personal hygiene ;
Education on the spread of infections; 
Getting a rotavirus vaccination .
On the other hand, treatment of diarrhea includes:
Rehydration with oral rehydration salts (ORS) solution or in severe dehydration or shock, rehydration with intravenous fluids; 
Zinc supplements; 
Nutrient-rich foods; 
Consulting a health professional. 
Despite the simple prevention and treatment measures for diarrhoeal diseases, according to Our World in Data, the two biggest factors for the high mortality rates in children were the prevalence of diarrhea-associated risk factors and the lack of access to essential treatment .
For instance, according to UNICEF, only about 44% of children suffering from diarrhea received ORS treatment, even though ORS solutions are affordable and have been shown to speed up recovery and reduce the likelihood of dying . In addition, immunization of children below one year was estimated to be approximately 35% in 2018, even though it has been recommended for rotavirus vaccinations to be initiated 15 weeks after birth to the 32nd week .
In order for global childhood mortality rates from diarrhoeal disease to further decline, an earnest cooperative effort is needed between governments, non-government organizations, communities, and healthcare providers .
Governments can provide rotavirus vaccines, invest in clean water and sanitation infrastructure, collect and analyze data, and support relevant health programs . Non-government organizations can promote community awareness on safe drinking water, sanitation, hygiene infrastructure, ensure the sustainability of interventions, and increase the adoption of proven methods of diarrhea treatment and prevention . Health care workers can also ensure the availability of adequate medical supplies, improve the training programs for staff to treat diarrhoeal cases, encourage proper antibiotic use, train community workers, and ensure proper sanitation and clean water at all healthcare facilities . In addition, communities can play a role by supporting hygiene and sanitation initiatives, ensuring safe water near people’s homes, supporting and promoting the importance of community health workers, encouraging proper disposal of human wastes, and constructing basic sanitation facilities .
Even though diarrhea still remains one of the top causes of death in children under 5 years today, much progress has been made in addressing this issue . However, there is still much work needed especially in developing countries around the world. Only by a cooperative effort will this burden cease to have such a strong influence on child mortality.
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