ST. LOUIS' long hot summers are made for outdoor living. Although West Nile Virus had been reported in the area, Stanley the African grey's family did not worry too much about taking him outside to enjoy the weather, too. After all, what were the odds a pet parrot would be bitten by a mosquito infected with the disease?

West Nile Virus has been deadliest among crows, raptors and horses, killing thousands. Dead crows can signal arrival of the disease in an area.

Sadly, in Stanley's case the odds turned out to be good. His owner, who preferred not to be identified, reported in an e-mail that the 25-year-old bird succumbed to the virus this fall.

"This is a short warning for parrots in St. Louis," the distraught owner wrote ParrotChronicles.com Oct. 1. "Stanley died Sept. 30, 2002, and is missed tremendously."

Virus on the march
The West Nile Virus is forcing parrot owners throughout the country to join zoos, avian rescue organizations and other animal collectors in rethinking the practice of keeping birds outside. Some worry that even indoors is not safe anymore.

"I find mosquitoes in my house and become quite the nut running around trying to kill the thing before it can bite Jasmine," said Jamie Cain, an owner in Canton, Ohio, who fears her red-lored Amazon will become a victim.

Pet owners have a right to be concerned. Over two dozen varieties of mosquitoes are now capable of carrying the West Nile Virus, a encephalitic disease that causes the brain to swell. Symptoms include lethargy and difficulty walking.

So far the virus has claimed nearly 150 human lives in the United States and killed thousands of animals. Horses and wild birds have been the most severely affected but other species, including parrots, dogs and cats, also are susceptible. Some victims recover, but many do not.

Long a concern in Africa, Europe and the Middle East, the West Nile Virus appeared in this country in 1999, when it killed dozens of people in the New York City area. The human and animal death toll peaked again this year, especially in the hard-hit south and midwest. By October, the virus had reached the west coast and all but four states had reported cases.

Equine stopgap
So far, the only widely available vaccine for West Nile Virus is one made for horses. Its effectiveness in birds seems to vary widely depending on the species, but that hasn't stopped many zoos from trying experimental doses to protect their valuable collections.

After losing six birds - a crow, three magpies, a pheasant and a condor chick - to West Nile Virus, the National Aviary in Pittsburgh decided to administer the equine vaccine to the most susceptible of its 500-bird collection, said James Mejeure, curator of birds. Since then, the virus has not claimed any more birds. However, he can't credit the vaccine because some untreated birds apparently have sickened and recovered naturally.

"A number of birds tested positive but didn't die," said Mejeure. "Our snowy owl came up positive. She was off her feed for a couple of days and had a high white blood cell count, but now she's fine." None of the zoo's parrots, most of which are kept indoors, have tested positive so far.

Once an animal is ill with the virus, there's not much caretakers can do to affect the outcome, other than offer supportive care. The National Aviary's sick birds were given saline injections to combat dehydration and antibiotics to guard against secondary infections, said Mejeure.

Using the equine vaccine is a tough judgment call, not only because it may not work but because it's so difficult to administer, said Mejeure. Birds have to be injected three times, a week apart. "The Houston Zoo did over 200 of their birds and had to catch every one of them every few weeks," he noted. "When I last spoke with them, they had not lost any to West Nile Virus. However, they did lose some in capture."

Crows respond to new bird vaccine
Scientists are working feverishly to create a more effective version of the equine vaccine for birds. In the first round of trials this year, researchers at the Centers for Disease Control in Fort Collins, Colo., tested lab crows with a new recombinant-DNA avian vaccine under development. (Recombinant-DNA vaccines replace a virus' own DNA with that of another living but benign virus that continues to replicate and prompt the immune system to develop antibodies.)

Initial results were encouraging, said Gavin Shire, a representative of the American Bird Conservancy, one of the groups funding the effort. While no crow inoculated with the equine vaccine survived exposure to West Nile Virus, 60 percent that received the new avian vaccine did.

The next step will be to test the new vaccine on other types of birds, said Shire.

A "fairly broad range of institutions," probably selected from membership of the American Zoo and Aquarium Association, another research supporter, will host a field trial slated to begin in mid- to late spring, he said. "The next stage is a real-world situation of zoos and breeding facilities. Some of these will include parrots, given that many facilities are breeding rare species, but none have been selected yet," said Shire.

The CDC also is working on an oral vaccine for wild-bird populations, and scientists in Israel are working on a "killed" avian West Nile Virus vaccine. Killed vaccines, which use a dead virus to stimulate the immune system to produce antibodies, are safer than live recombinant-DNA vaccines but aren't as effective.

Money needed
Of paramount importance in developing any new vaccine is funding, note researchers and zoo representatives. With no support forthcoming from government entities that might be expected to take an interest, such as the Department of the Interior, funding the research effort for an avian West Nile Virus vaccine has been left up to the private sector.

That's not good news, said Dr. Tracey McNamara, head of the department of pathology for the Wildlife Conservation Society, which manages the Bronx Zoo and New York Aquarium and performs their diagnostic and research pathology. In fact, it may prevent a widely available vaccine for pet birds from ever materializing, she said.

"It’s taken three years to even get a human vaccine and that’s not even commercially available yet," noted McNamara, who was the first to link the neurological problems she was seeing in crows to encephalitic human deaths in the New York area, leading to West Nile's discovery in the United States in 1999.

"All of the work that’s been done so far (for animals) is validating the equine vaccine to see if it provides any protection. It would take at least three years to get (the recombinant-DNA vaccine) licensed and released. But drug companies say the market is too small."

A zoo network of some 100 members formed to track the West Nile Virus will continue to pin its hopes on some form of the equine vaccine, said McNamara. "Between now and this spring, it's the only game in town."

"We can put this together"
Branson Ritchie, a distinguished research professor at the University of Georgia whose 7-member Psittacine Disease Research Group has spearheaded fund-raising efforts for other pet-bird vaccines, including one for psittacine beak and feather disease, is more optimistic about seeing an avian West Nile Virus vaccine someday.

"We've got the crew that can put this together," he said, referring to his group and two other high-profile proponents of a bird vaccine, colleagues Dr. Pat Redig, head of the Raptor Center at the University of Minnesota, and Dr. Tom Tully, service chief of zoological medicine at the LSU Vet School. The three discuss the fund-raising situation in a conference call every week with a dozen other colleagues or groups who are working together to develop and test a vaccine for use in companion and zoo birds, Ritchie said.

It's likely these private contributors will come through with the approximately quarter of a million dollars needed to get a vaccine to the manufacturing stage, said Ritchie. Those interested in raptors - rather than the psittacine community, surprisingly - are stepping forward with the bulk of the money, he said.

A manufacturer will have to spend another half million to a million dollars to take the vaccine through the government approval process, said Ritchie. However, none of the manufacturers he's spoken with have stepped up to the plate yet.

"I don’t know who it would be. One that's interested in helping companion birds and there aren't very many." After a vaccine proceeded to manufacturing, the USDA registration process would require at least a year, he said.

Battening down the hatches
In the meantime, parrot owners will have to fend for themselves against the West Nile Virus. With the 2002 mosquito season drawing to a close and aviary birds coming indoors for the winter, owners are getting a few months' break from their disease worries. However, many anticipate having to take steps next year to protect their birds.

Parrot owners and rescuers are having to rethink their outdoor facilities to protect birds like this cockatoo from the West Nile Virus.

"The mosquito threat seems to be over for now, since we had our first hard freeze last night and the birds came inside, but many questions remain unanswered," said Carol Lee of Safe Haven, a small bird rescue service of about 50 psittacines in Nebraska. The state did not report its first avian case of West Nile Virus until June, but it has led the nation in equine infections.

"We are currently networking with Nebraska's Wildlife Group, a fellow wildlife rehab volunteer who is a docent at the zoo, and Omaha's Henry Doorly Zoo to try and formulate a plan for next year," said Lee. "I am sure we will know more by next spring when the season begins again." At the least, she expects to have to rework Safe Haven's aviaries with a finer mesh to keep mosquitoes out.

Other parrot facilities plan to do the same: rather than bring birds indoors, they will foil mosquitoes by adding regular doorscreen to outdoor structures. Sybil Erden of The Oasis Sanctuary, an Arizona rescue facility that houses several hundred birds, said she will probably drape fiberglass screen over aviaries. "But we're not sure yet; it's still several months away."

Mike Hutchins of Iowa Parrot Rescue did some quick aviary retrofitting this summer when he got word that the West Nile Virus had reached eastern Iowa. He spent about $100 to add window screen around the outside of an 8 X 8 X 8-foot structure's 2-by-4 meshed frame, leaving a 3 1/2-inch gap. "The mesh keeps the birds in and the screen keeps the bugs out," he said. Hutchins checks the screen daily to make sure predators haven't torn it.

For those handy with a hammer, retrofitting aviaries may not be too burdensome. But clearly, parrot lovers would rather not be dealing with the virus at all. Most hope it will simply go away.

"There is no explanation why Nebraska and Iowa are being hit so hard," lamented Safe Haven's Lee. "We can only hope that a natural immunity builds up in the birds and animals."

We shouldn't hold our breaths, warned the Bronx Zoo's McNamara. "States that already had West Nile had heavy losses this summer. Anything that survived (the first time around) should have been immune to the virus - but it wasn't.

"Every prediction that has been made about the virus has turned out to be wrong. So people should sugarcoat their words - in case they have to eat them later."

EXPERTS SAY that when it comes to protection from the West Nile Virus, the usual tactics for avoiding mosquito bites are our best bet: Eliminate standing water on your property or treat it with a natural larvacide such as Dunk (don't forget drains), don't take your bird (or self) outdoors in the early morning or late evening when mosquitoes are most active, and make sure screens are in good repair and doors kept closed. Parrot owners can add to the list protection for an outdoor aviary, if they have one. Since parrots need to climb and no commercial net manufacturer makes mesh fine enough to keep out mosquitoes, you'll have to double-wall aviaries with regular doorscreen set off a few inches from the structure's mesh. Inside the house Parrots kept inside are safest. But if you're still worried, consider planting a natural mosquito repellant such as mint or basil around the perimeter of the house and in containers for inside. To find out more about your state's West Nile Virus status, check your department of public health’s Web site. Find yours at the CDC's Links to State and Local Government Sites page. To find out how active West Nile Virus mosquitoes are in your neighborhood, contact your mosquito control district. You can find a list at American Mosquito Control Association. -- CT

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