Every 60 seconds, somewhere in the world, a child dies of diarrhoea.
Of the 32 foodborne diseases identified by the WHO, 11 of them were diarrhoeal agents. Thus, diarrhoeal agents are currently the leading global cause of foodborne disease burden. These agents caused 230,000 deaths across the world, with the largest burden in children under 5, particularly those living in regions of South Asia and sub-Saharan Africa.
Percentage of deaths among children under age 5 attributable to diarrhoea, 2015
Source: WHO and MCEE Group provisional estimates 2015
Diarrhoea and bacteria
Diarrhoea has the clinical presentation of frequent passing of loose or watery stools, the characteristic feature of infection in the intestinal tract caused by parasitic organisms. It causes in a depletion of body fluid and can therefore cause severe dehydration and loss of essential nutrients. This results in severe malnutrition and can lead to death. Malnourished children in the poorest regions of the world are also likely to have much weaker immune systems, making them more susceptible to disease. Low and middle-income countries account for 92% of diarrhoea deaths, whilst high-income countries account for less than 1%.
Diarrhoeal disease is primarily a disease of poverty. The huge disparity that exists can be largely attributed to the disparity in food handling and hygiene across the globe. Around 60% of deaths associated to diarrhoea are due to non-potable water and insufficient sanitation and hygiene. The most prominent infectious agents are Rotavius and Escherichia coli (E-coli) bacteria. Dysentery is a common type of diarrhoeal disease, in which blood can be found in the diarrhoea. It is most commonly caused by the Shigella or Entamoeba histolyica bacteria, prominent in developing countries. Another diarroheal disease of global significance is cholera, an infection caused by Vibrio cholerae. Often, only a very small amount of exposure to bacteria is required for someone to be infected. These germs can spread from person to person, or from water, food or other objects contaminated with faeces.
Thousands of lives around the world, especially children living in low-income subregions, may be saved with the correct prevention and treatment of diarrhoeal disease.
With such high incidence in the developing world, it is disappointing to note that diarrhoeal disease is largely preventable. Immunization with rotavirus vaccine ensures protection from one of the most common causes of childhood mortality. Prevention includes ensuring clean drinking water and sanitation, and promoting handwashing with soap. Personal hygiene improvement is very important, in particular proper human waste disposal to prevent germ spreading from stools to mouths. Breastfeeding should also be promoted, to reduce infant contact with pathogens in water. Effective refrigeration facilities are also important to avoid diarrhoeal disease – keeping cold food under 5°C and hot food above 6o°C can help prevent bacterial growth. There is sound evidence showing a direct relationship between improved sanitation facilities and reduced diarrhoea-related deaths in children under 5, as shown by the figure below.
Relationship between population with improved sanitation facilities and under-5 deaths due to diarrhoea
Treatment options for diarrhoeal diseases are basic, low cost and effective. Dehydration accounts for most deaths from acute diarrhoeal diseases.Recommended treatment of acute diarrhoea is with low-osmolarity oral rehydration salts or solution (ORS). Oral rehydration salts are administered as a glucose-electrolyte solution, and is the most widely used treatment for diarrhoeal disease. ORS treatment is simple, and evidence exists that this intervention could reduce mortality rates by 93%, however children from the poorest 20% of the population, and those living in rural areas are much less lively to receive ORS treatment. Currently, only 40% of sick children are treated with ORS.
ORS salt packets
Other intervention measures include zinc supplements, increased intake of appropriate fluid, and continued feeding. More severe cases may require rapid administration of intravenous fluids. These measures also help prevent dehydration, which is particularly important for children and the elderly. Antibiotics may be helpful for symptom relief and to reduce the risk of spreading the infection.
Vitamin A deficiency is a public health problem, particularly in regions where adequate nutrition is not assured. Vitamin A effectively boosts the immune system, and can reduce diarrhoeal disease incidence by 15%. Two doses of vitamin A supplements per year is all it takes to protect vulnerable children against diarrhoeal disease.
Simple intervention, policies and promotion can have a profound impact on health care and treatment accessibility. Increased investment and support in low-income counties is fundamental to improving the impact of diarrhoeal disease. Further improvement in the quality of care with health programs and health care worker training at the community level is also urgently required, to bridge the gap in the source of care available to the most disadvantaged populations.
- Department of Health (AU). Shigella infection and dysentery (Internet). Perth: Department of Health (AU); (cited 2017 Feb 18). Available from: http://healthywa.wa.gov.au/Articles/S_T/Shigella-infection-and-dysentery
- World Health Organization. WHO Estimates of the Global Burden of Foodborne Diseases [Internet]. Geneva: World Health Organization; 2015 [cited 2017 Feb 18]. Available from: http://apps.who.int/iris/bitstream/10665/200046/1/WHO_FOS_15.02_eng.pdf
- United Nations International Children’s Emergency Fund. Diarrhea management in children under 5 in sub-Saharan Africa: does the source of care matter? (Internet). United Nations: United Nations International Children’s Emergency Fund; 2016 Aug (cited 2017 Feb 18). Available from:http://data.unicef.org/wp-content/uploads/2016/10/Carvajal_Amouzou_Perin_et-al_Diarrhoea-Management-in-U5s-SSA.pdf
- Centers for Disease Control and Prevention. Global Diarrhea Burden (Internet). Atlanta: Centers for Disease Control and Prevention; 2015 Dec (cited 2017 Feb 18). Available from https://www.cdc.gov/healthywater/global/diarrhea-burden.html
- Department of Health (AU). Rotavirus (Internet). Canberra: Department of Health (AU); 2015 Apr (cited 2017 Feb 18). Available from: http://www.immunise.health.gov.au/internet/immunise/publishing.nsf/Content/immunise-rotavirus