West Nile virus spreads through the Americas (1 Viewer)

West Nile virus spreads through the Americas
08-08-2003

West Nile virus (WNV), a mosquito-borne infection of birds that can affect people and other mammals, causing inflammation of the brain and surrounding tissues and sometimes leading to death, is spreading west and south in the Americas with an unknown, but potentially massive, impact.

The disease was originally found in the Middle East and has subsequently been discovered in Europe and Africa, where it is relatively harmless. However, in 1999 a particularly virulent form was detected in North America. Four years later and the disease has been recorded in 44 States of the US, Canada, northern Mexico, the Dominican Republic and El Salvador, possibly spread there by migratory birds. It is surely only a matter of time before WNV reaches Hawaii and South America. In its wake it has left at least 284 people, 4,300 horses, three alligators and hundreds of thousands of birds dead.

The virus is unusual both in its virulence and in the variety of hosts it can infect. These include 25 mammal and around 190 bird species. Crows are particularly susceptible to attack. The US Department of Agriculture recently approved a vaccine for horses against the disease, and researchers are now testing this and other experimental vaccines further. The disease’s spread could spell disaster for the rapidly dwindling native species on Hawaii and could be catastrophic for some threatened birds species programmes. Action is being taken where possible. For example, should captive California Condors Gymnogyps californianus (Critically Endangered) respond well to immunisation, there are plans to capture and inoculate the free-flying population.

Little is presently known about the short- or long-term impacts of WNV, but it is now firmly established in North America at least. It is likely that some species will remain largely unaffected by the disease, others are likely to evolve immunity and populations recover, whilst others may decline further and become confined to mosquito-free areas, or perhaps disappear altogether.

I was reading something the other day ( in the Sun I think ..... between the pictures !! ) about this spreading into Europe via some mossie or other being trapped inside car tyres imported from the far east.

Coincidentally, I read a Washington Post on-line article just last evening that said the Centers for Disease Control (CDC) has reported that WNV cases have TRIPLED in the last week. And three deaths have been reported in Colorado.

I anticipate it taking an enormous spike here, as well -- with all the rain in July, and the flooding, the mosquitos are ferocious beyond belief! A 20-30 foot walk from my front walk to my car means dashing through a gauntlet of them, and getting bitten.

We were very hard hit a year ago, and I'm afraid it'll happen again this year.

I can only imagine an analogy to what it must have been like for the native Americans with the diseases brought to this continent by white European settlers all those years ago: measles, smallpox, etc. A new disease introduced into an area where it was previously unknown an no immunity existed.

Alas, 2 dead bluejays in my neighborhood have been found to have died from the west nile disease. They have stepped up spraying to twice a week now. I am certainly ambivalent about the twice spraying. I certainly don't want to be bitten but I have already seen a dramatic drop in the butterfly population over the last two years.