Suspected poisonings of people by the microorganism Pfiesteria piscicida have moved beyond the Pocomoke River, with seven new cases from the Chicamacomico River and one apiece from two waterways that have not yet been closed by the state -- the Nanticoke River and Wicomico Creek.
TC All nine of the new patients, examined during the past week by a state-appointed medical team, reported symptoms including short-term memory loss, the apparent neurological trademark of Pfiesteria poisoning.
Dr. David Oldach, a member of the medical team, said doctors still must evaluate the results of extensive testing, but they probably will reach "some pretty firm conclusions" by the end of next week.
Regardless of the diagnosis, he expects these won't be the last patients examined.
"We are still pulling in people who were exposed in the summer, and I think we will continue to," Oldach said.
The seven patients from the Chicamacomico River are all employees of the Maryland Department of Natural Resources.
They journeyed to the river to help take water samples and monitor a fish kill discovered Sept. 13, the day before the state closed a 6-mile stretch of the river as a health precaution.
The Chicamacomico has been closed since then, as have a 4-mile section of Kings Creek that was closed a week earlier and a 7-mile section of the lower Pocomoke River closed Aug. 29.
All of the 27 patients previously reported by the state had been exposed to Pfiesteria along the Pocomoke.
Doctors have so far concluded that 11 of them were almost certainly poisoned, and the total could rise when follow-up tests are completed later this fall.
The most worrisome aspect of the new findings for state health officials could be the two patients from Wicomico Creek and the Nanticoke River, indicating possible further presence of Pfiesteria throughout the watershed feeding Tangier and Pocomoke sounds on the lower Chesapeake Bay.
Somerset County Health Officer Curtis Dickson summed up the state's dilemma yesterday, saying, "We are finding individuals with apparent Pfiesteria-related health problems who have never been on a waterway diagnosed with Pfiesteria.
"We probably need to develop the capability to caution the public without major hysteria."
State officials are due to receive the new findings today from the medical team.
It will be up to Dr. Martin P. Wasserman, secretary of the Department of Health and Mental Hygiene, and Gov. Parris N. Glendening to decide what, if any, action should be taken.
One factor arguing for keeping Wicomico Creek and the Nanticoke River open is that both patients from those waterways suffered symptoms only after prolonged daily immersion in the water over a period of weeks.
One patient is a commercial diver who inspects bridge abutments for a private firm and was doing extensive diving in Wicomico Creek.
The other is an individual who swam almost daily near the mouth of the Nanticoke River.
Both were first examined by Dr. Ritchie Shoemaker, the Somerset County physician whose persistence helped bring the illnesses of watermen along the Pocomoke to the attention of state officials in August.
In the case of the diver, Shoemaker said he has been told the results of extensive neuro-cognitive tests -- the most important diagnostic tool, doctors say -- and that they indicate a strong case for Pfiesteria poisoning.
Twice this week the state tested the waters of Wicomico Creek for signs of Pfiesteria, which generally announces its presence with fish kills or fish swimming erratically, scarred with deep, dime-sized lesions.
One test caught 49 fish of 10 species, with no lesions.
The other caught 60 menhaden, of which 45 percent had lesions, although the sores were deemed inactive.
The state has also continued testing the closed waterways.
The Department of Natural Resources said yesterday that initial tests of water samples from the Chicamacomico River show the presence of a Pfiesteria-like microorganism.
Dickson said the medical team has recommended criteria for deciding when to reopen rivers.
Under the proposed rules, rivers could be reopened after 14 days have passed without a fish kill or evidence of fish with active lesions.
It will be up to Glendening to approve or reject the guidelines.
Whatever his decision, most scientists expect colder weather will soon make Pfiesteria dormant until spring.
Public interest in possible health problems, however, remains active.
As of Sept. 18, the most recent information available, a state telephone hot line had received 126 calls from people worrying they might have been poisoned by Pfiesteria.
Of those, 27 were deemed worthy of further review by the medical team.
All those calls came from Maryland, although the remainder included six from Pennsylvania, five from Virginia, two from the District of Columbia, and one apiece from Delaware and New Hampshire.
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Pub Date: 10/03/97