Diarrhoea still kills almost half a million children under 5 years old each year worldwide, despite the death toll being reduced by a third between 2005-2015.

A new Global Burden of Disease study published in The Lancet Infectious Diseases journal finds that diarrhoea is the fourth leading cause of death for children and responsible for 8.6 per cent of all deaths of children aged under 5.

Forty-two per cent of these deaths occur in India and Nigeria alone.

“Diarrhoeal diseases disproportionately affect young children,” says lead author Dr Ali Mokdad, from the Institute for Health Metrics and Evaluation (IHME) at the University of Washington.

“Despite some promising reductions in mortality, the devastating impact of these diseases cannot be overlooked. Immediate and sustained actions must be taken to help low-income countries address this problem by increasing healthcare access and the use of oral rehydration solutions.” 

The study estimates that, in 2015, there were 2.39 billion episodes of diarrhoeal disease globally, with 957.5 million of these being in children.

There were a total of 1.31 million deaths as a result of diarrhoea globally in 2015, including 499000 child deaths.

While mortality rates have reduced substantially (by 20.8 per cent overall and 34.3 per cent in children), the incidence of the disease has not reduced nearly as fast (5.9 per cent reduction overall and 10.4 per cent reduction in children). As a result, diarrhoea still causes a significant amount of disability that mostly affects children under 5 years old.

Chad and Niger had the highest child mortality rates for diarrhoeal disease, with 594 and 485 deaths per 100,000 children each year, respectively.

However, the largest number of deaths occurred in India and Nigeria, contributing 42 per cent of all 499,000 child deaths in 2015 (105,000 and 103,000 deaths, respectively).

Diarrhoeal diseases are most common in low-income countries with poor access to clean water, sanitation, and urgent medical care, but are also a frequent cause of hospitalisation in high-income countries – making diarrhoea an important health problem globally.

Between 2005 and 2015, the largest reductions occurred in sub-Saharan African countries, where the mortality rate reduced by more than 100 deaths per 100,000 in western (from 445 to 277 deaths per 100,000), eastern (from 243 to 131 deaths per 100,000), and southern sub-Saharan Africa (from 214 to 113 deaths per 100,000).

Globally, unsafe water and sanitation were still the leading risk factors for diarrhoea in 2015. However, better access to clean water, improved sanitation, and fewer cases of malnutrition are likely to be responsible for the reductions in mortality rates for children under 5.

In Australia, diahorrea killed, on average, 11.5 children under five annually between 2005 - 2015.