West Nile Virus cases soar as summer steams on
Pastor Dale Morgan
West Nile Virus cases soar as summer steams on*
By Anita Manning, USA TODAY
The summer's sauna-like weather is making it a bad year for West Nile
virus, a federal health official says.
By last week, 308 cases had been reported to the Centers for Disease
Control and Prevention, up from 192 at the same time last year, and
"it's going to almost double every week for a few weeks," says Lyle
Petersen, director of the CDC's Division of Vector-Borne Infectious
Diseases in Fort Collins, Colo.
At least 11 deaths have been reported to the CDC, five of them in
California, where Gov. Arnold Schwarzenegger declared a state of
emergency this month in three counties.
The worst may be ahead. In years past, Petersen says, 90% of cases have
occurred after Aug. 1. There is a lag time in reporting cases, he says,
so the most recent CDC numbers show a snapshot of what was happening in
mid-July.
"I can't predict what's going to happen with the weather in August, but
if it stays hot and dry, we are going to have a pretty significant
year," Petersen says. "If it keeps tracking like it is, we will be well
above last year's total."
West Nile virus is carried by birds and passed into mosquitoes that feed
on them. The virus grows inside mosquitoes and is transmitted to people
when the bugs bite. Mosquitoes love dry weather, though not droughts,
Petersen says. Dry spells prompt irrigation of farmland and shrink ponds
and puddles, concentrating organic matter into a nutrient-rich
environment perfect for growing larvae.
West Nile virus had not been seen in the USA until it appeared in New
York City in 1999, then spread quickly across the country. Now, the CDC
estimates that about 1.5 million Americans have been exposed to the
virus and are immune to it.
About 70% of those infected have no symptoms, 20% to 30% develop West
Nile fever, and one in 150 people suffer severe neurological infections
that can be fatal or cause lifelong disability. "One thing people don't
realize," Petersen says, "is that if you get sick, you get really sick."
He speaks from experience. He had West Nile fever in 2003. "There's this
prolonged fatigue syndrome — you feel horrible for 30 days," he says.
Even after recovering, many people complain of lingering symptoms,
feeling unwell and having difficulty thinking.
"I don't know what to make of it," he says. "It's kind of a hidden
epidemic — nobody realizes the significance of this so-called mild disease."
The experience has made him a strong advocate for mosquito repellent:
"It's a matter of putting on a little bug spray vs. getting sick for a
month."