Last updated October 11, 2018 at 1:35 pm
Study links drier rivers to rises in dangerous pathogens.
Australia’s crippling drought could have more than the obvious consequences. Scientists have warned of a possible spike in gastroenteritis around the country.
Researchers from the Australian National University say reported cases of the gastro bug cryptosporidiosis rose significantly in parts of the Murray Darling Basin during the last big drought, then quickly fell again once it ended in 2009.
Dr Aparna Lal from ANU’s Research School of Population Health says droughts reduce river volume and flow, potentially increasing the concentration of pathogens, including those that cause gastro.
“As these gastro bugs can also be spread from livestock, land-use change may also contribute to this pattern, due in part to access around waterways,” she says. “This study highlights the very real risks that climate change, drought and environmental change, more broadly, pose to people’s health.”
More than 60% of water-related disease outbreaks worldwide between 2011 and 2016 were caused by cryptosporidiosis.
Australia reports the second highest rate of cryptosporidium illness in humans across developed nations, with high rates in remote areas. Children under five years old are particularly at risk from the disease.
In a paper published in the Journal of Water and Health, Lal says that while the data cannot demonstrate a causal relationship between environmental extremes and disease transmission, the association of reported cryptosporidiosis with drought conditions is consistent with its predominantly waterborne route of spread.
The results also suggest, she says, that catchment interventions appropriate to delivering safe water need to be location- and season-specific
“Rates of reported cryptosporidiosis are highest in rural and remote areas, communities that are typically not a focus for water infrastructure improvements in response to drought,” she writes.