ARTICLES ON HAWAIIAN BIRDS AND BIRDWATCHING AND OTHER PACIFIC WILDLIFE

By EDWIN TANJI, City Editor, Maui News, August 2002.

http://www.maui.net/~mauinews/lnews0b.htm

HONOLULU - Should the West Nile virus reach Hawaii, the segment of the population at highest risk will be older residents and visitors as the illness has been striking those in their mid-50s and above during its spread on the Mainland. But the disease is even more of a threat to native Hawaiian birds, especially one of the rarest birds in the world - the alala, or Hawaiian crow.

Carter Atkinson, a microbiologist with the Pacific Islands Ecosystem Resources Division, said corvids, or all species of crows, are particularly susceptible to the West Nile virus. If the virus is introduced to the Big Island, the last area in the world where the alala still lives in the wild, it could wipe out the remnant population that the federal and state governments have been trying to restore. State health officials have been planning for the possibility of the West Nile virus turning up in Hawaii for nearly two years, ever since it was clear that the disease that showed up in New York in 1999 was spreading.

Last week, health officials reported 11 deaths so far this year in Louisiana, Mississippi and Illinois, with three horses and a crow found infected in Colorado. Dr. Paul Kitsutani, an epidemiologist with the federal Centers for Disease Control and Prevention assigned to the Hawaii Department of Health, said the state is preparing a surveillance program to be able to detect the virus if it surfaces in the islands. The surveillance effort will build on protocols set up last year when the islands were hit by an outbreak of dengue fever - which is, like West Nile virus, a disease spread by mosquitoes. "To have an effective surveillance program, the state would need to add to the testing system," Kitsutani said. He said state health officials are consulting with the Centers for Disease Control on proper scientific protocols for confirming West Nile virus.

For people, the risk of infection is small, estimated by the CDC at less than 1 percent of the people who are bitten by a mosquito. Kitsutani said most people may be "asymptomatic," showing no effect from a bite by an infected mosquito or having general symptoms such as a fever and general aches. But some individuals, the elderly or those with a deficient immune system, may suffer severe symptoms, including West Nile encephalitis, an inflammation of the brain that can cause disabling illness or death. "We are taking it seriously. We would like to be prepared if it is introduced to Hawaii," Kitsutani said.

With the virus spreading across half the Mainland in the three years since it first appeared in New York, "the possibility always exists that it will get to Hawaii," he said. "If it appears, we will be able to react quickly," said James Foppoli, the state veterinarian who participated in discussions on a surveillance system. Foppoli explained that the reality of the national situation is that Hawaii must be prepared to react if the virus is introduced. There is little that the state can do to prevent it from getting to Hawaii.

Birds are the primary carriers of the West Nile virus, and Foppoli said there is no way for the state to screen potentially infected birds headed to Hawaii. The Department of Agriculture requires permits and health certificates for pet birds, he said. But the state has no control over thousands of birds shipped in the mail, nor can anyone control migratory birds that travel between the Mainland and Hawaii. He said the department estimates there may be 2,000 to 4,000 birds shipped by mail to Hawaii, including gamecocks and poultry such as ducks and chickens. As the virus moves west, it could eventually infect birds in the "Pacific flyway," the air route of migratory birds that travel from North America to South America, which in turn could cause infections in migratory birds that come to Hawaii such as ducks, geese, plovers and sanderlings.

Foppoli also noted that there is nothing to prevent an infected mosquito from arriving in a shipping container. When the West Nile virus turned up in New York, there was no way of knowing how it got to the East Coast. But he said one of the suspicions is "it may have been due to mosquitoes being carried in a cargo container." While the disease is potentially deadly, Foppoli said it is not considered a serious agricultural problem. Domestic poultry can be infected but chickens and ducks are able to resist the disease, he said. It can be fatal to horses, but he said there is a vaccine for horses and most horses will recover from an infection. Conversely, there are birds in Hawaii that can serve as a reservoir for the virus if it should be introduced. Foppoli said sparrows and finches are considered host species that gather in large flocks, can harbor the virus and are "efficient transmitters". "We don't know about mynahs yet," he said. A quarantine on birds coming to Hawaii is not an option, he said. It would not be effective "and we know how unacceptable a quarantine is as a method of control over disease in animals," he said.

Foppoli said there are natural limits on the spread of the virus. There is only a three- to five-day period when the virus can be picked up from an infected bird, he said. "With most species, the bird can be infected, but the virus doesn't get to high-enough numbers in the blood for the bird to be an effective transmitter," he said. But Foppoli noted that the research in New York indicates that the Culex mosquito species that is the vector for West Nile virus can hibernate in winter and still transmit the virus when it revives in spring. That would create a higher possibility of an infected mosquito hitching a ride to Hawaii in a cargo container, he said.

Atkinson said that a major factor in the threat to the alala is that the prefer the forest at about the 3,000-foot elevation, an area of Hawaii's forests that has been infested with mosquitoes The alala is an endangered species whose numbers are down to a few dozen, most of them in captive-breeding facilities on Maui and the Big Island. In the wild on the southwest slopes of Mauna Loa on the Big Island, there are believed to be no more than two, despite a release program that was intended to restore the population. Breeding facilities on Maui and the Big Island protect the alala from mosquitoes, he said. But if the remnant wild population is killed off by a mosquito-borne disease, there would be nowhere the captive alala could be safe except in their mosquito-proof cages.

Atkinson said other native forest birds may be somewhat protected since their habitat tends to be at higher elevations, above the mosquito zone. Mosquitoes in Hawaii also transmit avian malaria and a bird pox virus that has decimated native bird populations at lower elevations. But one native bird, the elepaio, appears to have developed resistance to malaria and pox, he said. One of the few common native Hawaiian birds, the elepaio can be found at lower elevations on the Big Island, Kauai and Oahu. That means the elepaio would also be at risk if the West Nile virus hit Hawaii's bird population. "I think everybody realizes it's a real serious situation," Atkinson said.

EDWIN TANJI, City Editor, Maui News, August 2002.

As a reminder, the state is currently (2002-2003) collecting carcasses of dead birds. This is where many of you can help. If you come across any dead birds, especially in large numbers or the species on the DOH list, the bodies can be turned into State DOH. Check out the DOH website for more details.

http://www.state.hi.us/health/wnv/#birds

Besides surveillance, the state is being very proactive in prevention and has implemented an embargo on the shipping of birds through the postal service and has implemented stricter pre-entry requirements on birds imported from the mainland. The state Dept of Ag is developing the final rules to keep these measures in effect. A WNV workshop is being planned for sometime in the next 3 months to prepare the State for the next major outbreak on the mainland, which is anticipated this spring and summer. The virus has not reached the west coast as of yet, but the risk to Hawaii would be far greater
than it is now, if and when the virus reaches the western states. There are lots of questions about how WNV may get to Hawaii, but one thing that everyone seems to agree on is that it would have devastating effects if it got established in the state. Additional information on WNV can be found on the CDC website.

http://www.cdc.gov/ncidod/dvbid/westnile/

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