Botulism Outbreak

(This column was first published in the August 13, 2001 Buffalo News.)

    Regional waterfowl are in trouble again this year.

    Last fall the New York and Ontario, Canada shores of eastern Lake Erie were littered with dead birds. Along the south shore 1110 birds were picked up in a canvass of just eight sites the first week in December. The dead birds included 427 ring-billed gulls, 424 red-breasted mergansers, 106 common loons, and lesser numbers of horned grebes, buffleheads and Bonaparte's, herring and great black-backed gulls. State wildlife biologists extrapolate from these figures to estimate 8000 birds killed in New York alone.

    Dr. Ward Stone of the Department of Environmental Conservation Wildlife Pathology Unit identified the killer -- avian botulism.

    Botulus is Latin for sausage, the etymology deriving from the fact that preserved meats gone bad have historically been a source of human food poisoning. The affliction occurs when a toxic bacterium, Clostridium botulinum,is ingested.

    Death for an infected bird follows a slow but inevitable progression that is pathetic to observe. Muscles become progressively paralyzed. Early in the course of the sickness, paddling through the water tilts the bird's body back and forth as its reluctant legs are coerced into service. Then when the legs fail completely, it is forced to employ a kind of breaststroke with its wings. But meanwhile neck muscles fail. Avian botulism is often called "limber neck," because the neck of a bird picked up at this stage is limp and its head hangs down. If the bird cannot reach shore, it drowns. If it does manage to pull itself onto land it soon suffocates as its lungs become paralyzed.

    The only positive aspect of this decline is that parallel nerve destruction probably prevents the dying bird from feeling pain.

    There are seven strains of botulism, each represented by a letter from the beginning of the alphabet. Dr. Stone identified the 2000 outbreak as Type E. Type C botulism is the more common killer of waterfowl on their breeding grounds in western North America. From 1994 to 1996, for example, body counts of over 175,000 birds suggest more than a million killed there.

    Type E botulism has been spreading east through the Great Lakes in recent years but the 2000 outbreak was the first identified here by Dr. Stone in his 32 years as a pathologist.

    Now authorities are again finding dead or dying gulls along eastern Lake Erie beaches.

    The toxins of botulism microbes are extremely poisonous. One estimate is that it would take only a half pound of them to kill every human on earth! And blowfly maggots feeding on the dead birds effectively become poisonous pills. For this reason New York Department of Environmental Conservation official Ken Roblee urges people to handle carcasses with care, using gloves or a shovel, and to keep their pets away from our shorelines. Generally, however, humans are only occasionally infected by this type of botulism through eating raw or cold-smoked fish.

    Both Roblee and Canadian Wildlife Service officer Jeff Robinson ask anyone observing either fish or waterbird die-offs to contact their offices by phone or e-mail (US: 851-7010 or kjroblee@gw.dec.state.ny.us; Canada: 519-823-8800 ext 4662 or ccwhc@uoguelph.ca). Report time, location, number of fish or birds, species if known and, if possible, whether birds have leg bands. These agencies cannot provide clean-up and landowners should dispose of dead birds or fish with a minimum of handling. Reports from Lake Ontario, where botulism has not recently been noted, are of special concern.

    The source of the outbreak is unknown but Roblee suggests the possibility that it is related to an earlier die-off of mudpuppies, common amphibians of regional lakes.-- Gerry Rising