Air Date: Week of September 1, 2000

This week, facts about the West Nile Virus. This tropical zone, mosquito-borne virus is taking up permanent residence in North America.

Transcript

CURWOOD: This summer marks the second consecutive outbreak of West Nile virus in North America. Health experts say the disease is probably here to stay, so here's a short primer. The virus originated near the western branch of the Nile River in Uganda. It's fairly common in tropical climes, but nobody knows for sure how it got here. It could have been transported across the Atlantic by storm-blown birds, or by a human carrier unaware of the infection. Mosquitos store the virus in their salivary glands. They don't come down with the symptoms, but can transmit the virus from birds to people. Most human infections are mild, with flu-like symptoms, and people with healthy immune systems are safe if medical attention is sought early. But as with all kinds of encephalitis, the brain can become fatally inflamed if not treated. At least four states on the East Coast are spraying to curb the spread of West Nile. They're using the chemical Malathion and BT, a natural bacterium. While these pesticides are meant to target mosquitos, other arthropods may suffer. Some scientists, for example, suspect spraying may have contributed to the sudden collapse of the lobster population in Long Island Sound. And for this week, that's the Living on Earth Almanac.