Global warming, shifting ecozones and changing the climatology of large reasons, is expected to, and has already shown the ability to, affect distribution and incidence of various diseases. The brain-eating Ameba comes to mind. As it were. There is some new research by Michael Grigg of the NIH that addresses a different change.
Along with melting Arctic ice comes an erosion of natural barriers that once separated parasites from hosts.
That erosion has allowed at least two pathogens to infect marine mammals they were previously unknown in…
A newly identified parasite was once frozen safely away from grey seals (Halichoerus grypus). It has now infected some with disastrous consequences. In 2012, about 20 percent of healthy-looking grey seal pups born on Hay Island in Hudson Bay mysteriously died. The cause turned out to be a parasite that destroyed the livers of 404 pups and two adults, Grigg said.
Grigg and his colleagues found that the parasite… also infects about 80 percent of ringed seals (Pusa hispida) but doesn’t make them sick. The parasite, … Sarcocystis pinnipedi, invades cells and can cause inflammation that damages tissues…
The research was presented at the recent meeting of the American Association for the Advancement of Science, and is reported here, though it may be behind a paywall.
There are other examples. Beluga whales north of Alaska have been infected by Toxoplasma, previously unknown in the region.