ROANOKE TIMES
Copyright (c) 1996, Roanoke Times
DATE: Monday, February 12, 1996 TAG: 9602130094
SECTION: NATIONAL/INTERNATIONAL PAGE: A4 EDITION: METRO
DATELINE: BALTIMORE
SOURCE: ASSOCIATED PRESS
Every summer at the mouth of the Pamlico River in North Carolina, thousands of fish die from killer algae that also can be a hazard to humans.
``We call it the fish-kill season,'' said JoAnn Burkholder of North Carolina State University. ``It happens every year now.''
In Baltimore, a random survey of clinic patients finds that 16 percent have been infected with leptospirosis, a disease carried by rats and easily spread to humans. It can cause liver and kidney failure.
``We think there is a lot of it out there that is unreported,'' said Gregory E. Glass of Johns Hopkins School of Public Health.
These are examples of what experts say is a changing picture of worldwide disease that perhaps is being influenced by global warming and by increased levels of pollution. Warmer, wetter weather is allowing subtle changes in disease organisms and increasing the range of animals, such as insects, that can carry disease.
Studies about the new disease threats were reported Sunday at the national meeting of the American Association for the Advancement of Science.
There has been a global increase in the past 10 years of harmful phytoplankton, microscopic plants that can carry harmful toxins, Burkholder said.
She has identified one new form, called Pfiesteria piscicida, that preys on fish along the East Coast, particularly in North Carolina.
``We are concerned that this may be related'' to global warming, she said, but noted that recent increased water pollution may also play a role.
Pfiesteria toxin kills fish quickly, paralyzing their breathing and causing sores that slough off skin on which the organism then feeds.
Burkholder said Pfiesteria also can be spread through the air, posing a hazard for fishermen and beach walkers.
A researcher in her lab, she said, became infected and the toxin attacked his brain. For three months, said Burkholder, the scientist lost the ability to read. She said there have been other cases, but no deaths.
``Pfiesteria is a voracious predator,'' she said. ``It not only kills fish, but can attack bacteria, small animals and even plants. And because it can be spread through the air, it could become a serious problem for humans.''
She advises people to avoid areas of fish kills.
For the rat-borne leptospirosis, Glass said he expects a steady increase in the disease, blaming it on an increasing number of rats living in the inner cities.
Leptospirosis has been known for 40 years, but in recent times it has become more common and deadly, he said.
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