Four pathogens kill millions of children in Africa, Asia

Before a vaccine to protect children was added to the national immunisation schedule in July 2014, rotavirus – the leading cause of severe diarrhoea in young children worldwide – was responsible for the hospitalisation and death of thousands of children under age five.

Since then, researchers have been keen to find out the impact of the vaccine on the health of children under age five.

An ongoing study in The Gambia, Kenya and Mali, to assess the causes and burden of diarrhoea in children under age five following the introduction of the rotavirus vaccine, has confirmed that rotavirus is the leading pathogen among the top four identified, during the first year of a child’s life, with its incidence being two times higher than any other pathogen.

The top four pathogens – rotavirus, cryptosporidium, Shigella and enterotoxigenic Esherichia coli (ETEC) – are responsible for the vast majority of diarrhoeal diseases, and their identification could help in the development of new treatments.

They were identified during research on the burden and causes of diarrhoea in developing countries, with a focus on The Gambia, Kenya, Mali, Mozambique, Bangladesh, India and Pakistan, countries which have a high burden of diarrhoeal disease.

1.3 MILLION DEATHS IN 2015

The findings published in the journal Pediatric Clinics of North America, showed that in 2015, these pathogens caused 1.3 million deaths worldwide, of which 40 per cent were children under the age of five and 90 per cent of the deaths occurred in Sub-Saharan Africa and South Asia.

The researchers drew from the Global Enteric Multicenter Study (GEMS), the largest study of childhood diarrhoeal diseases in developing countries.

“The findings from the GEMS study show that despite the many causes of diarrhoea, targeting just four pathogens could prevent the majority of serious cases,” said Dr Karen Kotloff, Professor of Pediatrics at University of Maryland’s School of Medicine, who was involved in the study.

Dr Kotloff said that a single case of moderate to severe diarrhoea in a child was enough to produce lasting negative health effects such as impaired growth and cognitive development.

“The GEMS study showed that children who had a serious diarrhoeal disease episode were 8.5 times more likely to die in the two months after their illness than children in their neighbourhood who were the same age but did not have an episode.

“This highlights the importance of preventing these episodes from occurring in the first place, and paying close attention to those who do have an episode,” said Dr Kotloff.

She added that diarrhoeal diseases could be prevented using five key strategies – vaccination, oral rehydration salts, zinc, good nutrition and proper hygiene (washing hands).

The World Health Organisation recommends the rotavirus vaccine for infants as part of national immunisation programmes, especially in countries where deaths from diarrhoea account for more than 10 per cent of mortality in children under age five.