*10.5. Cholera and Other Diarrhoeal Diseases*

Cholera remains one of the major diarrhoeal disease concerns with climate change. There has been a long history of associations between seasonality and weather as contributing factors in outbreaks. Cholera is also readily inserted into disaster situations and can contribute to morbidity and mortality. Examination of the weather relationship in El Niño years to the occurrence of cholera suggests that weather might be able to be used for predicting outbreaks in East Africa [146]. However, the assumptions in models are not necessarily always proven in practice [147–149]. As pandemics of cholera have occurred in the past, there is a strong need to reduce the risks of another pandemic arising out of a disaster situation. Changes in seawater temperature may contribute to changes in disease incidence [150]. The impact of water, sanitation and hygiene interventions are important in the

control of cholera [151]. Home water treatment and storage interventions can reduce diarrhoea and cholera [152]. This study demonstrated the dearth of good evidence. A SR looked at the environmental determinants of cholera in inland Africa [147]. They found that spread was linked to displaced populations and the poor water and sanitation associated with these settings. A similar review of coastal cholera by the same authors found that cholera seasonality is driven by rainfall-induced contamination of unprotected water sources [148].

The impact of a changing climate is most important when it comes to the quality of drinking water and diarrhoeal diseases, particularly in developing countries [37]. There are relationships between many of the bacterial infections and temperature, and evidence of links to heavy rainfall and flooding [32,110,117]. The sources of exposure may be agricultural [153] or from sewage, and the different sources contain different pathogens, with human viruses rarely being detected in animal waste [154]. Engagement with the water sector is important in reducing risks.
