mind & bodyOur World in Data

Diarrhoeal diseases kill 1.2 million people a year, including 340,000 under five

the gist

Diarrhoeal diseases killed about 1.2 million people in 2021, and around 340,000 of them were children under five. They are caused by viruses, bacteria and parasites that spread through contaminated water and food, especially where sanitation is poor. The main danger is dehydration, because diarrhoea drains fluid and salts faster than the body can replace them. Oral rehydration salts, a cheap mix of salts and sugar dissolved in clean water, prevent most of these deaths. Vaccines against rotavirus have also sharply reduced severe infant cases.

how it works

Diarrhoea occurs when the gut lining secretes fluid instead of absorbing it, so the body loses water and electrolytes quickly. Oral rehydration salts work because sodium and glucose help the intestine absorb water again. Rehydration therefore keeps the body going while the infection clears.

so what

These deaths are largely preventable, so the numbers point to clean water, toilets and cheap treatments as life-saving priorities. Diarrhoeal disease is one of the clearest examples of how basic infrastructure saves children's lives.

Our World in Data · CC BY 4.0

Image: Our World in Data, CC BY 4.0