Diarrheal Diseases

The information here is provided by courtesy of the Network's short online course - "An Introduction to Global Health". 




Diarrhoeal diseases are treatable and preventable, but are the second leading cause of death in young children. 


Deaths from Diarrhoea


Diarrhoea is usually a symptom of an infection of the intestinal tract that may be caused by a variety of bacterial, viral and parasitic organisms. It can last several days and leave the body deprived of the water and salts necessary for survival. Oral Rehydration Therapy (ORT), which provides a mixture of water and the types of salts being lost by the body, is a mainstay of treatment.


Infection is spread through contaminated food or drinking water, or from person-to-person as a result of poor hygiene. As a consequence, infections occur more where drinking water is unsafe, and sanitation and access to handwashing facilities are poor. Deaths are more common in low income countries. (Map 1)


Map 1






Death rates from diarrhoeal diseases have been falling over the last 30 years in all age groups (Figure 1) 


Figure 1 






Diarrhoeal diseases in Children 


Despite diarrhoeal diseases being both preventable and treatable, they are the second leading cause of death in children under 5 years old, killing around half a million children under 5 each year.


In addition to the deaths caused by diarrhoeal diseases, there are many, many more cases of childhood diarrhoea each year. Diarrhoea is a leading cause of malnutrition in children under 5 years.


Causal organisms


Rotavirus and adenovirus are the most important organisms causing child deaths from diarrhoea (Figure 3) 


Figure 3





Risk Factors 


For children, the risk factors are similar to those in older people, but other factors, which influence child development, make a child more susceptible to the effects of diarrhoea. (Figure 3) Children who are malnourished or have impaired immunity e.g. from HIV/AIDS are at most risk of life threatening diarrhoea.


Figure 3







Exclusive breastfeeding for the first 6 months of life helps to prevent the newly born from being infected. There is now a vaccine effective against rotavirus, which will prevent the infection and so both reduce death rates and malnutrition. The parts of the world that would benefit most from this are Sub-Saharan Africa and South Asia. (Figure 4)


Figure 4 





Diarrheal Diseases in Older People 


Causal organisms 


Rotavirus, adenovirus and shigella are the main organisms that give rise to the diarrhoeal deaths  in older people (Figure 2)


Figure 2





Risk Factors


The main risk factors for catching these organisms , in order of priority, are (Graph 2)


  • drinking from unsafe water
  • unsafe sanitation
  • no access to handwashing facilities.



Figure 2





Novel Solutions for Sanitation and Clean Water


Low-income countries continue to face major issues related to sanitation and clean water. As people move from rural to urban areas, the challenge increases in much the same way as it did in England in the early 1800s and health deteriorated until steps were taken to develop better sanitation and provide clean water. This can be a very expensive exercise, but it is sometimes possible to overcome problems with modern technology, Sanitation is one potential example.  




The Gates Foundation is an example of a focused attempt to use technology to address the challenge of providing sanitation in urban and rural settings where water supply is limited and the cost of providing a complete sewerage system would be very high.


Follow this link to see Bill Gates setting out the challenge. 



Several practical solutions have been put forward. Click on the linke below to see a successful waterless toilet that could be used anywhere. 




Further reading 


Sustainable Development Goal 6 : Clean Water and Sanitation



Our World in Data : Diarrhoeal Diseases



Our World in Data : Vaccine Preventable Deaths



WHO : Key Facts about Diarrhoeal Diseases



WHO : Key Facts about E-coli



WHO : Key facts about Cholera



WHO : Key facts about Sanitation



WHO : Key facts about Food Safety





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