CDC reports West Nile cases triple AGAIN
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|Sat, 08-16-2003 - 12:17pm|
CDC: West Nile entering peak season
Friday, August 15, 2003 Posted: 3:19 PM EDT (1919 GMT)
The number of cases tripled, then tripled again over a couple of weeks as West Nile activity ramps up.
(CNN) -- Days after announcing the number of West Nile cases had tripled, federal health officials said Thursday that the tally has tripled again this week, with Colorado reporting almost half of the cases.
"We're just now getting into the peak period," said Dr. Stephen Ostroff, a West Nile expert with the Centers for Disease Control and Prevention, in a press conference.
The number of human West Nile cases this year rose by 240 to 393 this week. The numbers include nine deaths: five in Colorado and two each in Texas and Alabama, according to the CDC.
In Colorado, that hardest-hit state so far this year, officials have reported 195 cases, a massive jump from the state's 14 cases overall in 2002.
Colorado's higher numbers do not necessarily mean there is more disease there. "The decision to report West Nile encephalitis or West Nile fever or both really is a state decision," said Ostroff, the deputy director of the CDC's National Center for Infectious Diseases.
"It's based on the resources that states have available. In Colorado, because there has been utilization of a lot of the private labs, they have been able to identify more fever and they choose to report it to us."
The nation's tally is expected to climb rapidly in the next month. Last year, about two-thirds of new cases occurred in the six weeks after August 7, according to the CDC. Last year's season extended through October, with a final total of 4,156 cases of human infection, 284 of them fatal.
Ostroff said that unlike last year, early activity has centered in the High Plains and Rocky Mountain regions of the United States rather than the Mississippi River drainage area.
Arizona, one of only four states in the lower 48 spared West Nile activity in the past, was added to the infected area list after a mosquito pool testing positive for the virus was found, according to Ostroff.
"This represents expected continued expansion of West Nile into the far areas of the Western United States and certainly could be a trend that we would continue to see over the next month or two," Ostroff said.
Oregon, Nevada, and Utah remain the only continental states with no activity this year or in the past.
To prevent mosquito bites and the spread of West Nile, the CDC urges the public to take steps to rid their yards of pools of standing water that could be used by mosquitoes as breeding grounds, to wear long-sleeved shirts and pants outside and to wear repellent containing DEET before going out.
Last year, 23 people contracted the disease through blood transfusions, prompting a screening test for the virus, which has been in use since July 14 throughout the United States and Puerto Rico.
Of the nearly 1.1 million blood donations screened between mid-July and early August, 160 have tested positive and removed from the blood supply, said Dr. Tony Marfin, acting deputy director of CDC's Division of Vector-Borne Infectious Diseases, in Fort Collins, Colorado.
Though Marfin encouraged doctors to report to their local public health departments anyone who becomes sick soon after receiving a transfusion, he also urged people not to allow the risk to affect their decisions about treatment. "For those individuals who need a blood transfusion, the benefits strongly outweigh the risks," he said.
Efforts are also under way to screen organs for donation. Last year, an organ donor infected four recipients, Marfin said.
The virus, first identified in 1937 in the West Nile region of Uganda, spread to the United States four years ago.
The CDC reports that most infected people never show any signs of the illness, but about 20 percent may experience flu-like symptoms such as fever, headache and body aches. In a small number of cases, the virus causes sometimes fatal West Nile encephalitis or meningitis (inflammations of the brain or of the membranes around the spinal cord and brain).