Diseases Spread to New Territories

The L.A. Times (2/25) carries an article about the small, very small, effects of climate change. Small referring the organisms that cause disease. Germs are on the move. Environments that were previously too cold for them to survive are now warmer and the preferred destination for pathogens on the move. Vibrio, a bacteria in oysters that causes the runs in people who eat them, used to be confined in temperate waters in the Gulf of Mexico. In 2004, it turned up in Prince William Sound off the coast of Alaska.
Encephalitis-carrying ticks are moving further north in Sweden and up into the mountains of the Czech Republic. "This shift of the ticks is clearly connected with climate changes," says Milan Daniel, a parasitologist the Institute for Postgraduate Medical Education in Prague.
Malaria is turning up in the cool, mountainous regions of Africa. The villages of formerly snow-covered Mt. Kenya are now warm enough that germ-laden mosquitos are able to advance up the mountain.
Diseases spread by many methods: with the movement of people, by developing resistance to medications, breeding in environments with poor sanitation, etc. If bacteria or parasites are carried into a hostile environment they won't survive. But if they are able to colonize a newly hospitable site, they surely will. Like the mountain pine beetle ravaging Canada's spruce forests, diseases will soon lay waste to populations that have never before experienced them.