Six cases of rare disease raise family's suspicions

Cluster or not? - Health officials investigate multiple aplastic anemia cases but say it's hard to prove a cause

FACTBOX• Aplastic anemia



Sunday, September 10, 2006  ANDY DWORKIN

Last February, doctors diagnosed Chuck and Jacqueline Roberts' young daughter, Victoria, with a rare and life-threatening bone marrow disease, aplastic anemia.

Since then, the Robertses say, they have heard of five other cases in Columbia County, where they live, or across the river in Washington's Cowlitz County.

To the couple, six cases in counties with 150,000 residents combined looks suspicious. But is it? Is it just bad luck? Or is something, perhaps a pollutant, causing illness in the area?

Oregon and Washington officials are tackling those questions as they try to figure out whether Victoria, 7, is part of a disease cluster. So far, they have no proof of a cluster. But workers from seven agencies in two states have spent weeks gathering initial information, including climate data from a Kalama, Wash., plant that legally emits tons of benzene, a chemical that can damage the blood of people exposed to large enough amounts. This week, investigators will share their data and discuss whether there is enough suspicion to push ahead.

Cluster investigations are long, demanding and usually frustrating. Teasing true clusters from suspicious-looking but random spikes of disease is so complicated and arduous that few studies ever get to even this early stage. Almost none go on to prove a cluster is real, much less find a cause.

"It is a long and involved process. And in close to 100 percent of cases -- well over 99 percent -- these investigations have not led to a confirmation," said Dr. Michael Heumann, an epidemiologist with Oregon's Department of Human Services. But such studies have proved some important health risks, such as linking asbestos and tobacco smoke to lung cancers. So "we take these requests from citizens very seriously."

In aplastic anemia, a person's bone marrow loses the ability to make blood cells that stop bleeding, battle infections and move oxygen through the body. In the United States, an estimated 200 to 1,800 new cases are found each year. Many things can cause the disease: genetic flaws, radiation, some drugs, chemicals such as benzene, even pregnancy. Most commonly, something spurs the body's immune system to attack the marrow, said Dr. Grover Bagby, an aplastic anemia expert at Oregon Health & Science University. But in most cases, no root cause is found.

Victoria's doctors ruled out genetic flaws and certain infections, Jacqueline Roberts said. "All along, they said you'll probably never be able to find what caused this," she said. "But it bothered me."

While Victoria was being treated, the family met a 3-year-old girl from Longview, Wash., diagnosed with aplastic anemia in early 2005. Later, a drive to raise $350,000 for a bone marrow transplant, publicized in The Oregonian and elsewhere, drew a call from a 23-year-old Rainier man, also diagnosed in early 2005.

Three cases so close in time and space seemed significant, Jacqueline Roberts said. She soon heard of more cases, reports the family is still trying to collect. And she started calling local industrial plants, asking what they produced, looking for some pollutant that could explain the cases. She discovered a chemical plant in Kalama, across the river from their home in Goble, was permitted to emits tons of benzene a year.

"A huge red flag went up," she said. "I think it's them. I'd bet my life on it." State workers began investigating last month and are taking the family's suspicions about benzene seriously. But no one has decided the plant, or benzene, is involved in any illness, said Steven Macdonald, an epidemiologist with the Washington State Department of Health, which is leading the investigation. "It's premature to point fingers now," he said. And "that plant is not necessarily the only source or even the main source of benzene in that area." Common benzene sources include auto exhaust, buried gasoline tanks, factories, wood stoves and cigarette smoke.

At this point, health workers are mostly confirming reported cases and searching hospital records to gauge how common aplastic anemia is in the area. Washington's Department of Labor and Industries has sifted workers' compensation records for complaints of blood disorders, since workers might be more prone to illness if an industrial chemical is involved. Some work does center on Emerald Kalama Chemical, a plant that makes several chemicals for use in food and fragrances. As a byproduct of that work, the plant puts out about 6 tons of benzene over the course of a year, company spokesman Chris Wrobel said. Wrobel said the company monitors workers yearly for benzene exposure and "have never had any issues." Dr. David Bonauto, an occupational medicine physician at the Department of Labor and Industries, said there were no workers' compensation records of blood disorders at the plant. The Southwest Clean Air Agency, which regulates the plant, said it is within its emissions limits. "We haven't had air quality issues in recent years" with the plant, agency Executive Director Robert Elliott said. Climate data show wind blows from the plant toward Goble about 2 percent of the time, Elliott said. Investigators this week will share that information and other facts they've gathered and try to figure out whether there is enough evidence of a suspicious cluster to continue. Since these studies take so many resources, Washington's health department approaches them in measured steps, gathering a little information and then assessing whether more work has a decent chance of proving a pattern. If officials move ahead on the aplastic anemia study, they'll have to define a time period and geographic area to focus on, calculate the expected disease rate in that span and uncover how many actual cases happened. Then they would try to see whether the victims were exposed to some disease-causing agent, perhaps benzene, in the amount and ways needed to develop disease. "It's just so hard to turn up any causal relationships in these cluster investigations. . . . We rarely turn up anything," Macdonald said. He said he's finished one investigation in 10 years, of a reported spate of fetal deaths in Cowlitz County, which showed there was no actual cluster. While the state workers investigate, the Robertses are enjoying a surprising improvement in Victoria's health. In July, her marrow was so ravaged that the family went to Seattle for a transplant. But days later, doctors discovered her marrow had recovered, a blessing they could not explain. Family members said they had prayed for such an improvement. They also wonder whether a change of address helped: On June 25, they moved from Goble to St. Helens, to be closer to health care in Portland. If pollutants caused the illness, they reason, maybe moving helped fix it. Victoria is not completely healthy. Counts of her blood cells, including platelets that clot the blood and disease-fighting white cells, remain low, though weekly tests show they are improving. Her parents won't let her ride a bike, for fear of cutting herself, and are schooling her at home, to limit infections. But if her marrow stays healthy and her blood improves, she might not need a transplant, Chuck Roberts said. In that event, the roughly $300,000 in remaining donations would go to the Children's Organ Transplant Association. "Her appetite is fantastic. She has unending energy," Jacqueline Roberts said. "We believe the Lord is going to finish what he started."

jill

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