Posted: Saturday, January 13, 2007 12:00 am
What scientists used to believe was an innocuous parasitic organism is now being blamed by some for causing a growing number of severe gastrointestinal disorders in the mid-Willamette Valley.
Meanwhile, Oregon State University researchers aren't sure if a more virulent strain of the parasite might have been brought here from the Middle East, or evolved on its own.
When Ken Boorom of Corvallis first started feeling pain in his gut and experiencing severe intestinal problems, he went to the doctor. Unfortunately, all the tests came back negative, and drug treatment relieved symptoms only temporarily.
After a year of testing, doctors determined he had blastocystis infection. Although it's the most commonly diagnosed parasite in Oregon, Boorom, 41, had never heard of it.
While Boorom, an engineer, finally had his answer, antibiotics didn't clear up the infestation, and he lost 20 pounds, and had to stop working. He began to suspect that he had an especially virulent form of the parasite, one that common antibiotics didn't cure.
When his two children developed symptoms and tested positive for the parasite as well, he was determined to discover why local families were becoming infected, and why antibiotics didn't seem to cure them.
When Boorom and his wife Tessa began talking with friends and neighbors about the parasite, they began to realize that many people they knew had similar symptoms, or had children who had been struggling with gastrointestinal problems that couldn't be diagnosed.
One of them was an 11-year-old Philomath boy, who had been having a series of intestinal maladies, including severe pain and diarrhea, as well as other symptoms. At first, the family doctor believed the boy was suffering from severe allergies, and treated his symptoms with allergy medication.
But the problems continued, and family became upset because the boy didn't seem to be able to eat without getting sick. His mother changed things in his diet and began researching his symptoms.
After talking with Boroom's family, they had the boy tested for the parasite, and the tests came back positive. With a three-week treatment of antibiotics, his symptoms disappeared.
Unfortunately, after completing the treatment, the boy tested positive again for blastocystis infection, and while his doctor is recommending another course of antibiotics, the family is afraid that if the additional drugs don't work, the parasites might come back stronger and make him even more ill.
OSU launches research
In hopes of raising awareness as well as money for research into testing for and treating the disease, Boorom has established the Blastocystis Research Foundation.
He contacted scientists at Oregon State University who became interested in researching blastocystis. Their project will include how to more easily test for the parasites, whether some forms of blastocystis cause problems and others don't, and how to treat the infestation.
Dr. Luiz Bermudez, a biomedical scientist at OSU, is leading the research. In the past, Bermudez said, scientists questioned whether blastocystis caused illness, or if it was simply present along with infestations of giardia or other sickness-causing parasites.
But after soldiers and civilians began returning home from Operation Desert Storm in 1991 with a high rate of blastocystis in their systems and with a number of intestinal problems, the opinion of the scientific community began to change.
"It brought to our attention the possible importance of this organism," Bermudez said.
According to Bermudez, up to 50 percent of people tested who were coming back from countries in the Middle East had blastocystis, although that doesn't mean they were all showing symptoms of an infestation.
Bringing back new parasites or variations of ones already existing in the United States isn't that uncommon, he said.
"People go overseas, they bring back all these different types of organisms and then they mix with the population here and the organisms, if they find the ideal conditions to persist in the new environment, they will."
Further research revealed that instead of one kind of blastocystis, there were actually seven or eight, making it possible that some forms lived "peacefully" in human systems, while others caused illness.
Part of the OSU research will focus on developing a test to detect the harmful variety.
"Oregon is a kind of haven for this parasite," Bermudez said.
The damp weather and moist soil allows the parasite to thrive, and humans pick up the parasite through oral-fecal transmission, most likely from water sources that have been infested.
Currently, state and federal water-quality laws do not require water systems be tested for the presence of blastocystis, and officials at the Taylor Water Treatment Plant confirmed that Corvallis city water is not tested for the parasite.
However, because the parasite doesn't appear to be widespread, Boorom said it's unlikely that Corvallis drinking water is the source of the infection.
Most of those diagnosed with the parasite either drink well water or frequently swim in local watering holes, including creeks and rivers, he said.
It appears that some forms of blastocystis cause irritable bowel syndrome-like effects, as in the case of Boorom. Bermudez said it's unclear which kinds might trigger a response, or whether the irritation and illness is stronger in those with a genetic predisposition toward irritable bowel syndrome.
Bermudez and other scientists at OSU will try to answer some of these questions, including whether an infestation can trigger illness that continues after the parasites die, and if certain populations are more at risk for illness than others.
By developing a serum test for blastocystis and by developing a DNA test to identify its presence, researchers will be better able to track the infection rate within the population, and determine what is causing some blastocysts to harm humans.
While research is in its preliminary stages and researchers are still looking for financial support to carry on the project, Bermudez believes it's an important enough study that they will find support.
"Initially we don't have a lot of funding, but nonetheless, if we start moving in the right direction a lot of institutions would be interested in that, and one of them is the military," he said, "because they have a major problem in terms of diarrhea and other manifestations such as irritable bowel syndrome in people who come back from the Middle East."
Bermudez said early research, which will be used to establish enough information on the project to apply for grants, should cost around $50,000.
Organism comes
and goes quickly
Charlie Fautin, deputy administrator of the Benton County Health Department, is aware of sporadic reports of residents who have tested positive for blastocystis infection, and said they've contacted local health care providers as well as state officials to discuss the issue.
"It's a fairly common organism," he said, "and in a vast majority of people, it's self-limiting," meaning it comes and goes quickly and doesn't cause long-term health problems.
Blastocystis is not a reportable pathogen, Fautin said, because there haven't been enough confirmed cases to consider it a public health threat. He is aware of the OSU study, and thinks it might shed some light on the parasite.
"There's probably good reason for looking at it," he said.
If health care providers started diagnosing blastocystis infection at a higher rate, then the county would take a closer look at a possible infestation, but for now reports are so scattered that Fautin said it's not considered a major risk.
Dr. Michael Wong, a pediatrician at the Corvallis Clinic, has seen some incidence of blastocystis in his patients. Symptoms include chronic diarrhea, gas, cramping and abdominal pain, and Wong said once possible viral or bacterial causes of the problem are eliminated, testing for parasites is the next step.
"(Blastocystis infection) is usually associated with some type of contamination," he agreed, either from well water or a contaminated stream.
He said the infection is usually easily treated by antibiotics.
Rich Eastburn is a parasitologist and laboratory manager for the Corvallis Clinic. In 2006, the laboratory saw 40 cases of blastocystis, versus 10 cases of giardia lamblia, a more commonly recognized parasite.
Eastburn said when a few stray blastocysts are spotted, there's usually no cause for concern, but when they appear in a sample in large numbers, the patient is usually given antibiotics to clear up the infestation.
Some patients go through several courses of antibiotics and still aren't rid of the parasite. But that doesn't necessarily mean the antibiotics aren't working, he said.
If the patient is on a well that contains the parasite, they may be continuing to drink the water and adding more parasites into their system.
"You honestly can't say whether or not they're being re-infected," he said. The only way to tell is to hospitalize the patient and monitor his drinking water as they go through several weeks of treatment, which really isn't feasible.
Also, Eastburn said, some people live with the parasite without appearing to have symptoms. They may be experiencing discomfort without really recognizing it, while others appear to be ultra-sensitive to the parasite's presence.
"How do I feel? It's sort of relative," he said. "I don't think anyone ever feels really good in all senses."
By THERESA HOGUE
Corvallis Gazette-Times