How Is Climate Change Affecting the Spread of Vector-, Water-, and Food-Borne Diseases?

OBJECTIVES: Global temperatures have risen by ~1°C compared with pre-industrial times, causing rising sea levels, extreme weather events and population displacement. Vector-, water- and food-borne diseases are being aggravated by climate change. This review evaluates how climate change has influenced the spread and human burden of these diseases.

METHODS: A targeted literature review was conducted on reviews from the past 5 years investigating how climate change impacts vector-, water- and food-borne diseases. The search used terminology such as ‘climate change’, ‘global warming’, ‘vector-borne’, ‘water-borne’ and ‘food-borne’. Outcomes of interest included geographical distribution, the impact of extreme weather events and the human burden of these diseases.

RESULTS: Twenty-one studies were analysed, with 20 (95%) reporting on vector-borne, 10 (48%) on water-borne and seven (33%) on food-borne diseases in association with climate change. Fifteen studies reported on the unprecedented geographical spread of climate-sensitive diseases, eg a 30-fold global increase in dengue in the past 50 years. These studies also reported cases of disease in previously unexposed regions, including the USA and France. Eight studies described the impact of extreme weather events, such as flooding, on the spread of disease. This provided additional breeding sites for mosquitos – in Uganda in 2013 this increased malaria risk by 30%. Five studies reported on increased mortality, with some predicting that climate change will cause 250,000 additional deaths between 2030 and 2050, with 48,000 and 60,000 additional deaths due to diarrhoeal diseases and malaria, respectively.

CONCLUSIONS: Climate change increased both the spread of vector-, water- and food-borne diseases and the risk of acquiring them. Reporting of climate events and/or disease incidence is lacking in many countries, resulting in a relative shortage of studies on this topic. With global temperatures expected to rise, more research is needed to quantify the impact this will have on disease burden.