Exactly how remains a bit fuzzy, but researchers have observed some trends. "Certainly, if you take a disease like dengue or West Nile virus, warmer temperatures allow the mosquito to replicate faster," he explained. "The virus replication rate in the mosquito is also increased, and then you shorten the period from when the mosquito becomes infected and when they're able to transmit."
In addition, Beard notes that the annual first frost tends to kill off mosquitoes, ticks and flies, but warmer temperatures are delaying frosts and pushing the frost line farther north. That creates the potential for year-round disease transmission in some parts of the country. "It's likely we'll see northward expansion of some of the diseases already here," he said.
Increased hurricanes, drought and torrential rainfall in endemic areas may push diseases into new regions as local economies and livelihoods are devastated. "We wish we had a crystal ball, but we don't. It's hard to know exactly what [the disease scenario] will look like," he said.
Researchers say they need more and better information. The "Neglected Infections of Impoverished Americans Act" (H.R. 528) offers some hope; it would require the secretary of the Health and Human Services Department to submit an annual report to Congress about these diseases. The bill, sponsored by Rep. Hank Johnson (D-Ga.) has passed the House twice but only passed committee this year, according to Andy Phelan, communications director for Johnson.
"Rep. Johnson's legislation is a good first step in fighting these diseases by raising awareness," said Phelan, in an email. "These are infections that we can treat, but we don't have a good grasp on what impact these diseases are having on poor communities throughout the nation."
Baylor's Hotez agreed. "We need to expand our data collection," he said, noting that the private sector does not have a strong incentive to address these diseases because they mainly affect the very poor. McDonald from NCEZID said outreach and education are also critical. "For a lot of people, just getting them to think about some of these things when they have extremely urgent daily survival tasks is difficult," she said.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500