January 15, 2004
Tina Tennessen 443-482-2325   tennessent@si.edu

Stalking West Nile Virus: Scientists looking for tell-tale signs in Cuba


Researchers from the Smithsonian Environmental Research Center's Avian Ecology Lab are stalking the backyard birdfeeders of American military personnel in Guantanamo Bay Cuba and hanging nets to trap birds across stretches of Cuba's Mangroves and scrublands. Every bird they can get their hands on, whether a year-round island resident or a winter visitor from up North, is a target for their traps.

These scientists are on a mission to seek out signs that West Nile Virus has reached the Island on its southward spread across the Americas. And they expect to find it. Three years ago they began a similar quest in Jamaica. And while no virus showed up that first year, by 2002, the scientists were turning up proof that it had arrived. "It's our first time in Cuba, and we expect to find West Nile Virus in the system here," says Avian Ecologist Peter Marra who heads the Avian Ecology lab at SERC.

The researchers detain their captives only long enough to take a small blood sample and record some data then they are released. When the scientists return from Cuba in mid-February, the samples they bring back will be sent to the New York Department of Health for testing. The results of that test will tell Marra and his team what they need to know to determine if the virus has in fact reached the island that lies a mere 90 miles from Miami where birds have tested positive for WNV for at least two years.

"We're looking for live virus in migratory birds," explains Marra, "or antibodies in year-round residents." Antibodies to West Nile Virus in year-round residents of the island would prove that the virus is present in the area because, according to Marra, a bird would only have such antibodies is if it had been exposed to WNV via a mosquito bite from an infected mosquito. Antibodies in migrants only tell you that the bird has come in contact with the virus somewhere on its journeys. However, if any of the migratory birds test positive for live virus, it's a pretty sure bet that the virus is either in the system already, or will be very soon.

It can take several months for the blood test results, but Marra says the information will be useful to World Health Organization officials who are tracking the spread of the disease, and to local communities that could be affected by it. "Finding West Nile Virus will serve as a warning to let us know we should be monitoring the area more intensely," he says. Armed with this knowledge, public health officials can be on the lookout for symptoms and educate the public about useful precautions. Livestock industries can protect their animals with vaccinations and other precautionary measures.

The SERC researchers have also been monitoring bird populations in Mexico and Puerto Rico for the past few years, and have been able to alert officials to its arrival. While the disease has spread to Mexico, Marra's team has yet to find it in Puerto Rico.


More about Avian ecology research at SERC.


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