While SARS dominated public attention during the past weeks, the discoveryin March of a dead blue jay and two dead sparrows in Louisiana signaled thereawakening of another looming public health threat - West Nile virus.
The mosquito-borne illness swept across 40 states last year, making morethan 4,000 people seriously ill and killing 284. Four other states recordedthe infection in animals but not in people.
The virus that migrated to this country in 1999 also provided surpriseslast year for public health officials who discovered that the illness could bespread through blood transfusions, organ donation and breast-feeding, and froma pregnant woman to her unborn child.
Dr. Bruce Lenes, medical director for Community Blood Centers of SouthFlorida, said a test to screen the blood supply for West Nile is indevelopment and is expected to be available nationwide by July. In themeantime, blood donation centers are likely to turn away anyone with fever orheadache and to ask them to report back if they develop those symptoms soonafter donating blood.
"Our main message is these diseases are preventable," said Dr. Lisa Conti,director of environmental health for the Florida Department of Health, "so weurge people to take precautions to keep from being bitten, especially olderpeople who are out and about."
She urged people to get rid of mosquito breeding places on their property,to stay indoors at dawn and dusk when mosquitoes are most active, and to dressin long sleeves and pants and use an insect repellent containing deet if theymust be outside.
"We certainly are concerned that we may have an outbreak [this year] thatis fairly robust," Conti said.
While the majority of people who contract the virus do not have symptoms,about 20 percent develop West Nile fever. In mild cases, the symptoms caninclude body aches, fever and headache, sometimes with a rash on the trunk andswollen lymph glands.
In severe infections, brain inflammation can develop, with headache, highfever, neck stiffness, stupor, disorientation, coma, tremors, convulsions,muscle weakness and paralysis. People 50 and older have the highest risk ofsevere disease.
The winter months provided a respite from the virus in most parts of thecountry, but yesterday two Harvard experts predicted the disease will soonre-emerge.
"It is entirely reasonable to expect that the North American impact of WestNile virus will be as significant in 2003 as it was in 2002," said Dr. PaulEpstein, associate director of the Center for Health and the GlobalEnvironment at the Harvard Medical School.
Epstein said West Nile is a greater threat than SARS because it hasinfected 230 types of animals, including 138 species of birds.
Douglas Causey, senior biologist at the Harvard University Museum ofComparative Zoology, said the virus has spread into animals and birds in theCaribbean and is the leading suspect in a tenfold drop in several bird speciesin Costa Rica during the past year.