West Nile Reaches New Mexico, Montana; U.S. Cases Near 300

The number of Americans who have contracted West Nile virus this year approached 300 Thursday as the mosquito-borne virus extended its reach to Montana and New Mexico.

The disease has now killed at least 14 people and infected animals or humans in all but seven of the lower 48 states. Virginia officials are waiting to confirm their first case, a 33-year-old Richmond man they believe contracted the virus last month. The death toll will rise if the Centers for Disease Control and Prevention confirm that case and two fatal cases of West Nile reported Thursday in Georgia.

State officials said the victims were a 51-year-old Atlanta man and a 77-year-old man from Columbus, Ga., but did not say when they died.

“West Nile virus arrived in Georgia last year, and there is currently no way to eradicate it, so we expect it to be with us every summer for the foreseeable future,” said Dr. Kathleen Toomey, director of the state Division of Public Health.

At least 33 people have died since the virus appeared in the United States in 1999.

Most of this year’s deaths and the 296 reported human cases have occurred in the South. Louisiana accounts for 147 illnesses and eight fatalities.

Dr. Lyle Petersen, a CDC expert on the virus, said it should continue to be worse in the South because warm weather means more mosquitoes. “But outbreaks could eventually happen anywhere.”

Montana health officials on Thursday confirmed finding West Nile in a horse. New Mexico officials said two horses were infected.

“I’m sure if we keep looking hard enough we’ll find some more,” said Thurman Reitz, assistant New Mexico state veterinarian. “I don’t have any reason to think it’s going to quit at the Texas border.”

Meanwhile, zoos across the country are vaccinating some of their most susceptible animals.

Cleveland Metroparks Zoo is using a commercial vaccine for domestic horses to inoculate its equine species--zebras, donkeys and miniature horses.

And many zoos are taking prevention a step further, vaccinating equine and bird populations, even though the vaccine has not been proved effective in birds.

“This is an emerging disease, so for any emerging disease, you study it intensively to figure out how bad it’s going to be,” said Dominic Travis, a veterinarian epidemiologist at Chicago’s Lincoln Park Zoo and a national coordinator of West Nile zoo response. “It has spread from New York to Colorado and Wyoming in three years, and that is of concern.”

The St. Louis Zoo began vaccinating its most susceptible birds, as well as its equine species, about two weeks ago, said Eric Miller, the zoo’s director of animal health and conservation. Susceptible birds include crows, raptors, flamingos, parrots and outdoor birds.

The zoo has confirmed several cases of West Nile deaths in birds, and the Audubon Zoo in New Orleans lost two flamingo chicks to the disease. A penguin also died at a zoo in Rochester, N.Y., and the National Zoo in Washington, D.C., reported that two flamingo chicks and a duck died from the virus, which the zoo also believes killed a dozen more of its birds.

Zoo and health officials have stressed that people shouldn’t fear visiting zoos, because they’re no more likely to be bitten by a virus-carrying mosquito at a zoo than elsewhere. People can’t get West Nile from each other or by touching an infected animal.

But zoo officials worry that the virus could endanger valuable animals. “Many of the species at this zoo and others are endangered, and we don’t want to be losing them to disease,” Miller said. The virus can cause flulike symptoms and encephalitis, a potentially fatal brain infection. Most people bitten by an infected bug never get sick.

The virus is most dangerous for children, the elderly and people with weak immune systems. There is no cure for humans.

West Nile is common in Africa and the Middle East. Since 1999, when the virus reached New York, mosquitoes have spread the virus to the South and West.

The CDC has repeatedly said the virus will reach the West Coast.

“We fully expect the virus will make it to the West,” Petersen said.