Infection and immunity
Infection and immunity

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

Free course

Infection and immunity

3.8.1  Diarrhoeal diseases

Cholera, caused the by the presence of Vibrio cholerae bacteria in drinking water, is a potentially life-threatening diarrhoeal disease. The disease is widespread in many parts of the developing world, but cholera was also a major cause of death in industrialised Western countries in the 19th century as discussed in Section 2.4.

However, many other pathogenic bacteria also cause diarrhoea, particularly those transmitted in contaminated food and water. They include Salmonella in raw eggs and undercooked poultry, and pathogenic varieties of Escherichia coli [esh-err-ish-ee-ah koh-lye], mainly in red meat or raw (unpasteurised) milk, but also in unwashed fruits and vegetables contaminated with faeces. Diarrhoeal diseases are also caused by some viruses and protists.

Around 1.5 million (1 500 000) people die from diarrhoeal diseases every year, most of them young children (Figure 14). If untreated, the loss of tissue fluids and essential salts in diarrhoea rapidly results in dehydration, disruption of body chemistry, and malfunction of the nervous system and vital organs. The loss can be replaced by drinking a simple oral rehydration solution (ORS) of sugar and salt dissolved in clean water until the diarrhoea subsides. Distribution of millions of sachets of ORS powder and teaching parents how to administer it is slowly reducing the mortality from diarrhoea in childhood. In severe cases, the solution may have to be given intravenously (directly into a vein).

Described image
Figure 14  Diarrhoeal diseases are easily transmitted wherever people lack sanitation and are a major cause of death among children aged under five years.

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371