Reference
Pascual, M., Bouma, M.J. and Dobson, A.P. 2002. Cholera and climate: revisiting the quantitative evidence. Microbes and Infection 4: 237-245.
What was done
The authors note that "growing concerns over the effects of climate change and environmental deterioration are driving current interest in the influence of climate on disease dynamics." Hence, they assess "the quantitative evidence for a climate-cholera connection from the perspective of data analysis."
What was learned
In the words of the authors, "recent data analyses support a temporal association between ENSO and chloera's interanual variability" in certain regions of the world, as well as "a role of increased water temperature" in enhancing the survival and growth of the pathogen. They also note that "observations support a role of water temperature in the seasonality of cholera" in some areas, although they say "it is not yet possible to assess the strength of particular climatic drivers." In addition, they report that variations in water volume "can have dramatic effects on disease dynamics, perhaps more pronounced than those of factors affecting the pathogen's growth and survival."
What it means
Although climatic factors undoubtedly are involved in the dynamics of cholera, they have yet to be well defined; and even when they ultimately are understood, the importance of socio-economic factors for cholera - which is typically described as "the disease of poverty" - will likely far outweigh them. As Pascual et al. put it, "the importance of sanitary conditions is clearly indisputable," in support of which declaration they cite the fact that "infrastructure providing safe water and sewage treatment in industrialized nations has made the sustained transmission of cholera extremely unlikely." Hence, it would appear that the best long-term preventive measures to take against cholera would be those that enhance the wealth of nations and their citizens.
Reviewed 7 August 2002