The initial excitement of the news — “You’re so exotic!” one friend squealed — melted into worry as I browsed the medical literature and called a few experts:
“. . . late-onset flaccid paralysis …”
“. . . people complain of lingering symptoms for up to a year . . .”
“. . . suggestions that even mild infections may leave another lasting burden — kidney disease.”
On one of my broiling, zombified days, I recalled the mosquitoes of my youth in the Upper Midwest. We were “eaten alive” (Mom’s words) every summer at the lake. If you couldn’t flatten six or eight mosquitoes with a swift backhand, you weren’t really trying.
And yet, pervasive parental admonishments to cover up and wear bug spray were aimed at preventing nothing more serious than a bad itch (and to stem the attendant complaining, no doubt). Thirty years ago, nobody knew about this exotic virus from equatorial Africa. It was not part of American life; no one yet feared this thing.
Well, West Nile is here now, and the experts say it’s here to stay, circulating between moquitoes and some 300 species of birds, notably crows and jays.
The blame goes to the dual juggernauts of our time: globalization and climate disruption.
Near as anyone can tell, globalization brought West Nile to America via a stowaway mosquito on a transcontinental flight. Then our warming world provided fertile ground for the virus to flourish, helping to push the disease to almost every state so far.
Here’s what the late public health giant Paul Epstein wrote in 2001, two years after West Nile first terrorized New York City: “The conditions underlying the outbreak of West Nile virus can be traced to global environmental change.” He continued, “Mild winters coupled with prolonged droughts and heat waves” offer ideal conditions for West Nile.
Mild winters, prolonged droughts, heat waves? It’s as if Epstein foresaw the nation’s weather this year.
Laura Kramer studies West Nile for New York state. “We had almost no winter, so everybody was pretty certain it was going to be bad this year,” she told me. Cold winters kill the Culex mosquitoes that carry the virus, which they pick up from feasting on birds. But in warm winters, moquitoes can “overwinter already infected and come out in spring and start the cycle again,” Kramer said.
Drought, counterintuitively, also boosts Culex mosquitoes. These degenerates of the arthropod kingdom thrive in squalor.
“They breed so well in horrible water,” said Kramer, meaning the filthy standing pools that survive even prolonged droughts. What looks like pond scum to you and me is a feast for these egg-spewing mini-monsters.
The big heat of 2012 brings more West Nile whammies: Mosquitoes reproduce quicker in hotter weather, and they bite more in the heat, too, said Kim Knowlton, an expert on climate change and health at the Natural Resources Defense Council. And laboratory experiments show that the virus replicates faster in warmer mosquitoes. Just a few degrees can mean the difference between a mosquito able to transmit West Nile and a mosquito that dies before it can. (The same is true for malaria parasites and the mosquitoes that carry them, as Epstein and journalist Dan Ferber documented in their 2011 book “Changing Planet, Changing Health.”)
Simply put, more heat means more mosquitoes carrying more virus sickening more people.
And yet, as a reporter, I rarely see the effects of climate change on human health discussed outside public health circles.
A few years back, Knowlton and colleagues estimated that the 2002 West Nile season cost the United States about $200 million in direct medical costs. But the price of disease “is not part of the ledger sheet when we talk about costs of climate change,” said Knowlton. “We talk about damage to infrastructure, disappearing shorelines, damage to ecosystems, and those are all totally important. But we need to put in the costs of health care, emergency room visits, doctors, hospitalizations, too.”
As for me, the zombie departed with the summer heat. He did leave some calling cards, though: the up-and-down malaise, the pseudo-fever, weakness and tingling in my arms and feet. I figure that puts me right in sync with the planet: overheated and with an uncertain outlook.
Someday, though, I’m confident that the malign finger of climate change will no longer be tapping on my shoulder. He’ll find other people to bother, and they too will experience what’s sure to be a popular sensation in this new century we’ve created: a sick little suspicion that the heat will never end.