Tuesday, June 22, 2010
Researchers Determine Split between Blastocystis and D. fragilis in IBS patients
These celebrities all have IBS. According to international researchers, it's likely their symptoms are being caused by an infectious disease that the US medical researchers are ignoring.
Irritable bowel syndrome (IBS) may sound like a funny disease, but it's anything but funny to the people who have it. The symptoms are severe enough that many patients are unable to function normally in soceity. Patients with IBS have all of the symptoms seen in many gastrointestinal infections - abdominal pain, diarrhea, fatigue, and constipation. (Yes, some gastrointestinal infections will produce constipation.) But the medical community in the United States believes that people with IBS don't have an infectious disease. They think that symptoms in IBS patients are caused by something the patient is doing wrong, or some kind of defect in the patient's digestive system.
This has been an issue of contention between the US medical community and researchers overseas for almost 20 years. International groups have pointed to the high prevalence of IBS, which now reaches 30% in developing countries, and indicated that it's unlikely this many people would develop chronic gastrointestinal illness for no particular reason. Scientists at a public health lab in the UK have published studies specifically urging that doctors exclude infectious diseases before diagnosing their patients with IBS, while US researchers have generally sidestepped the issue of infectious diseases while promoting their own research projects. Most US grant funding for IBS goes to physicians who indicate that patients with IBS have something wrong with them, such as as a psychiatric illness.
Presumably, if the US researchers are wrong, it would be possible to examine IBS patients and find infectious diseases in them, and then show those diseases produce illness in animal studies. This is exactly what many researchers are doing. The two infectious diseases which repeatedly turn up in IBS patients are Blastocystis and D. fragilis. Together with Giardia, E. histolyitca, and Cryptosporidium, these diseases make up the "Big 5" protozoal infections which make up most of the protozoal infections found in humans. All of the organisms are single-celled parasites which are transmitted through contaminated food and water. Some of these organisms - such as Cryptosporidium - will only produce temporary symptoms in human, others seem to be able to establish themselves for life in some otherwise healthy patients. Blastocystis and D. fragilis are frequently cited as the two "neglected protozoal diseases." The research done to date suggests the clinical diagnostics used for these diseases are inadequate, and the treatments for Blastocystis are also unreliable.
Studies looking at Blastocystis in IBS patients are more common, but D. fragilis has also been found in those individuals. A study from the Center for Digestive Diseases in Australia reported that a half-dozen patients diagnosed with 'IBS' actually had D. fragilis infection. One patient reported their symptoms were life-long. The patients recovered after the infections were treated.
Blastocystis / D. fragilis Split
Some studies have found Blastocystis in IBS patients, while other studies have found D. fragilis in IBS patients, but until recently, no study has looked at both infections. By looking for both infections similar methods, it's possible to get a picture of the extent to which each disease contributes to the IBS population.
Researchers at the Department of Medicine of Aga Khan Medical School in Karachi Pakistan have published the first combined Blastocystis-D. Fragilis study. The study was performed on 330 patients - 171 with diarrhea predominant IBS, and 159 healthy controls. By culturing stool specimens, the researchers found Blastocystis in 53% (90/171) of the IBS patients, and D. fragilis in 4% (7/171) of that group. Blastocystis and D. fragilis were present in 16% (25/159) and 1.3% (2/159) of the healthy controls.
Some researchers have complained that looking for Blastocystis in patients is meaningless, because there may be other "hidden" organisms present. While this problem would potentially be present in any infectious disease study, the complaint appears to be more common in Blastocystis studies, and researchers at the Pasteur Institut have noted this with some frustration, describing the "impossibility of excluding all infectious organisms in a study." For this study, the Pakistani researchers screened specimens for all other common gastrointestinal infections, including Giardia, Cryptosporidum, Salmonella, Campylobacter jejuni, Clostridium difficile, and Vibrio Cholerae.
The study also compared three diagnostic techniques - microscopy, PCR analysis, and culture. In prior Blastocystis studies, researchers using microscopy have reported that they could only detect about a third of the samples that were positive by PCR or culture. In this study, the researchers were able to detect 91% of the culture-positive samples, suggesting the possibility that technician skill may impact the reliability of lab tests performed.
This research says that IBS is largely a disease created by a problem in the medical system. Studies similar to the most recent work have been available for 13 years, yet the NIH and CDC have refused to take any action in examining infectious diseases in IBS patients. US patients with IBS may have a great deal to complain about: research currently sponsored by the NIH portrays IBS patients as malingerers, mentally deficient, and incapable of dealing with normal life stresses.
"When you tell a patient with chronic illness that they have IBS, the focus shifts from the infection to the patient. IBS is a popular explanation because it is a blame-shifting tool. IBS stops patients from asking questions like 'Where did I contract this disease?' and 'Why is there no treatment available?' The problem is no longer the infectious disease - the question becomes what is the patient doing wrong" according to Ken Boorom, founder of the Blastocystis Research Foundation. The rate of Blastocystis infection in the US has skyrocketed.BRF publications suggest that 30-60 million US citizens have contracted Blastocystis infection in the last 15 years. BRF has advocated addressing IBS as a public health problem by diagnosing patients and treating the disease, and working to prevent further infection.
"We're seeing the impact of the epidemic in everyday life. IBS commercials and IBS products are all being produced to target the population of Blastocystis patients which the NIH and CDC will not address. The NIH hasn't approved a single Blastocystis grant in 15 years. "
To help address this issue, BRF has proposed Federal legislation that will create formulas to determine how research money is divided among infectious diseases, replacing the current system which allocates money to researchers who have the most clout. Criteria for allocating funding would consist of the prevalence of the disease in the US population, the severity of symptoms in the disease, and the reliability of diagnostics and treatments. The act is intended to help prevent special interest groups from shutting down research into infectious diseases as they become epidemic in the US.
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