Duke Alumnus pushes land to be the first state to close infested waters

[Guest guest]

PFIESTERIA MYSTERIA

Duke Alumnus pushes land to be the

first state to close infested waters

http://development.mc.duke.edu/medalum/man/sp98/man1_3.html

Ritchie Shoemaker, MD, family practitioner and ecologists, liks

copper to pfiesteria fish kills in land.

The hard rain hitting hot pavement one night last August in

Salisbury, MD, suited Ritchie Shoemaker's mood-he was steamed.

Shoemaker, T'73, MD'77, dodged fat drops of rain as he hurried to

his car following a scientific conference that had been hastily

called by land state officials. Despite what he considered

compelling evidence, he had failed to convince the officials to

alert people to possible health risks from pfiesteria, a marine

micro- organism blamed for recent fish kills in land, Virginia,

and North Carolina. " Even now, the words 'the river is safe and

there is no proof of human illness from pfiesteria' annoy me, " says

Shoemaker, a School of Medicine alumnus who practices family

medicine in Pocomoke City, a small farming and fishing community

near the mouth of the Pocomoke River on land's eastern shore.

Frustrated, Shoemaker puzzled over the pfiest-eria case all the way

home that night. Later, as the rain drummed overhead, he wrote in

his journal. He wondered if, as he suspected, another major fish

kill would follow. " Boy, did it ever, " he remembers. " That was the

big kill that got the state's attention. " This fish kill also

confirmed, at least in Shoemaker's mind, his theory that copper

mixed with an agricultural fungicide and stirred up from the river

bottom by the rain-not nutrients from water pollution-was the true

culprit causing the usually benign pfiesteria organism to unleash

its poison. Shoemaker also was convinced pfiesteria toxin was behind

the mysterious rashes, breathing difficulties, headaches,

neurological deficits, abdominal cramps, and diarrhea reported by

the local watermen and vacationers who were his patients. The quest

to prove his case would be an exciting, bizarre, and finally, a

satisfying adventure.

A Water-Skier Falls Victim

" I think I've got the pfiesteria thing, " said a young man who called

Shoemaker's office in late July, about one week before the Salisbury

conference. The water-skier described how, three days earlier, he

had spent an hour skiing on the Pocomoke River. Soon after coming

home, he developed a headache and began having trouble remembering

simple things. The next morning, the man was astonished to find

about 30 flat red lesions all over his body. Shoemaker examined the

water-skier and two other patients who came in the following day

with similar symptoms, and he had medical photographs taken of their

skin. It wasn't long before the local media picked up the story, and

on August 1, the state held the scientific conference in Salisbury

to calm what was turning into " pfiesteria hysteria. " When Shoemaker

was invited, he went armed with photographs of his patients' skin

and a demonstration using live fish in tanks to show how an active

fish kill could be stopped by neutralizing pfiesteria toxin in the

water.

At the conference, he met JoAnn Burkholder, PhD, the North Carolina

State University aquatic botanist who discovered pfiesteria and

pioneered much of the early scientific research on fish kills in

North Carolina's Neuse River and Pamlico Sound. In 1995, Burkholder

and others in her lab had developed respiratory problems, diarrhea,

memory loss, and skin lesions after working around the pfiesteria

organism in the lab. But, despite Shoemaker's evidence and

Burkholder's corroboration, the land officials insisted on 100

percent certainty of a link between pfiesteria and human illness

before alerting the public.

Evidence Points to a Culprit

Eager to prove a link between pfiesteria toxin and human illness,

Shoemaker made a call to Duke environmental neurologist

Schmechel, MD, who had evaluated Glasgow, PhD, a member of

Burkholder's staff. Shoemaker flew two of his patients to Duke, and

Schmechel assisted with their evaluation. Shoemaker then provided

case summaries and medical records on his patients to land

officials. Finally, on September 6, just thirty days after the water-

skier's illness had been publicly reported, the State of land

closed pfiesteria-infested waters to fishing and recreation. Later

that month, the Centers for Disease Control and Prevention launched

a multi-state pfiesteria disease surveillance project.

Finding Clues in the Environment

Now Shoemaker directed his energy toward proving the cause of

pfiesteria poisoning and finding a cure. A passionate

conservationist who spends much of his free time raising funds and

working on projects to restore wetlands in the Pocomoke River basin,

Shoemaker had at first been reluctant to believe pfiesteria was

behind the dead fish his watermen friends began pulling from the

Pocomoke back in October 1996. The river is one of the state's most

prized natural areas, classified as wild and scenic and home to

osprey, otters, eagles, and game fish. Compared to North Carolina's

muddy and polluted Neuse, the Pocomoke is pristine. Shoemaker knew

that routine annual tests showed only minuscule amounts of

nutrients, including phosphates and nitrates, in the water.

" I began looking at alternative explanations, what the two rivers

did have in common, " says Shoemaker. He found farmland lining both

rivers, and copper- " huge amounts of copper. " Copper is used to

prevent spoilage in hog and chicken feed and is sprayed with

dithiocarbamate (DTC) on tomatoes and tobacco weekly as a fungicide.

Particularly with new methods of no till and black plastic

agriculture, copper and DTC sprayed on crops washes into rivers.

Heavy copper salts are present in hog and chicken manure that also

leaches into rivers.

A Deadly Chain of Events

According to Shoemaker, the copper settles into the river sediment

until heavy rain sets in motion a bizarre and deadly chain of

events. Within six hours, the copper salts begin to kill algae and

tiny organisms that pfiesteria dine on in their harmless large-

amoeba phase. Hungry pfiesteria then go into attack mode,

transforming into fast-swimming dinoflagellates that can shoot

poison to immobilize fish. The toxin weakens fish defenses and they

die from exposure to flesh-eating organisms. During this brief

pfiesteria feeding frenzy, the air smells peppery, the water feels

warm, and airborne toxins become a danger to people. Larger

organisms that would ordinarily eat dinoflagellates are also killed

or immobilized by the copper when it complexes with the DTC.

Unchecked, pfiesteria massacres fish for miles around.

A Possible Cure

Shoemaker has demonstrated that a dilute solution of potassium

permanganate, a compound that binds or neutralizes toxin, will stop

an active fish kill. Further, he says he has successfully treated

patients with cholestyramine, a substance that binds bile salt.

Cholestyramine has relieved not only the severe diarrhea associated

with pfiesteria poisoning, but also has helped improve memory loss

and asthma-like symptoms, according to an article Shoemaker

published in the December 1997 issue of the land Medical

Journal. Another article, published in the February 1997 issue,

deals with treatment of the persistent health problems associated

with pfiesteria. Shoemaker and his partner, Barry Spinak, MD, have

opened a clinic specializing in pfiesteria-human illness syndrome,

and have treated over 60 patients from land, North Carolina, and

Virginia.

Persistence Pays Off

Now, Shoemaker says, his copper theory is beginning to get attention

from scientists at the national level, including the National

Academy of Natural Sciences. Mark Poli, PhD, a researcher at Fort

Detrick, MD, the US Army biomedical research center, is also

interested in Shoemaker's use of cholestyramine to treat pfiesteria

illness. Poli is studying brevetoxin,

a toxic substance released by a different dinoflaggellate, that is

known to cause human illness and fish-killing red tides in Florida.

The NIEHS has recently committed major grant funding to pfiesteria

research, and scientists at the University of Miami, Duke, s

Hopkins, NCSU, the University of North Carolina, East Carolina

University, and others are investigating pfiesteria-how it becomes

toxic, how much of a threat it poses to humans, how to isolate and

identify its several toxins, how it affects the brain, and how to

prevent it from causing future fish kills. At Duke, researcher

Levin, PhD, has linked pfiesteria to learning problems in

animals. (Please see DUMC in the News, page 16.)

Although Shoemaker considers the pfiesteria case far from closed, he

is proud of his role in bringing the danger, a probable cause, and

an effective treatment to public attention. " People called me a

kook, a know-nothing doctor, and a fear monger, " says Shoemaker. In

fact, P. Wasserman, land's Secretary of Health and Mental

Hygiene, says he remembers " waking up one night and thinking, 'I

wish Ritchie would go away.' " " But, " he adds, " Ritchie has been what

doctors should be-a patient advocate and well trained in the

science...I have to applaud his persistence. " s

Shoemaker's book, Crossing Dark Waters details his experience.

Interested alumni are encouraged to contact him at Box 25, Poconoke

City, MD 21851.

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Ritchie Shoemaker, MD, family practitioner and ecologist, links

copper to pfiesteria fish kills in land.