Diarrheal Diseases

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

Headline

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

Trends

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

Prevention

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.

Sanitation

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.

https://www.youtube.com/watch?v=82pmo53FQIY

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

https://www.youtube.com/watch?v=A47slzMItAI

Diarrheal Diseases

Headline

Deaths from Diarrhoea

Trends

Diarrhoeal diseases in Children

Causal organisms

Risk Factors

Prevention

Diarrheal Diseases in Older People

Causal organisms

Risk Factors

Novel Solutions for Sanitation and Clean Water

Sanitation

Further reading