Dr De Meirleir announced last week that he has successfully developed a diagnostic test for Chronic Fatigue Syndrome (CFS), which is more of a breakthrough than it sounds. Now that the disease can be detected bio-medically, it proves that it has a biomedical basis - and not, as has long been assumed by a majority of the European medical profession, a psychological cause.

"I've been ridiculed for years for my biomedical stand, but this test is a victory over my critics," Dr De Meirleir said. "Even the interest groups that were always opposed to our research now have to admit that the test is a major step forward."

CFS, also known as myalgic encephalomyelitis (ME), is a debilitating disease characterised by extreme and persistent fatigue and joint and muscle pain, together with other symptoms like hypersensitivity, heart palpitations, headaches, depressed immune system and cognitive problems. The Belgian association of chronic fatigue patients, MEAB, estimates that there are between 30,000 and 40,000 people in the country with the disease. It affects women more often than men, and often first appears in the 40-50 age range.

Since 2002, the Flemish government has invested over €10 million in five "reference centres" across the region in Leuven, Antwerp, Ghent and Brussels for the diagnosis and treatment of the syndrome. However, sufferers and their supporters complain that the centres only offer cognitive behavioural therapy and physical rehabilitation.

"These people have been mistreated for years," Dr De Meirleir says. "CFS was treated as a psychosomatic complaint. But someone who runs 10 metres after a bus and then has to spend a week in bed recovering has a serious medical problem."

The test, manufactured by Protea Biopharma, in which Dr De Meirleir is a partner, detects the presence of hydrogen sulphide (H2S), which is produced in the intestines when bacteria come in contact with heavy metals. People with CFS have been shown to have higher concentrations of intestinal bacteria than normal, which leads to higher levels of H2S.

H2S is a gas present in minuscule concentrations in normal people but at toxic levels in CFS patients. The reasons for overproduction of bacteria can range from lactose intolerance to viral infection to stress.

According to the draft of a journal article soon to be published by the De Meirleir and his team, H2S causes intolerance to light and noise, a depressed immune system and low white blood cell count. It also leads to retention of mercury by the body, which in turn produces cell death and damage to energy metabolism. The biggest effects, though, are produced on the central nervous system, explaining the main symptoms of CFS.

The test will be sold at €15 and consists of a simple vial of reagent to which one drop of urine is added. In cases of CFS, the urine turns dark blue. While everyone produces H2S, the test shows if it is being produced in high concentrations.

The news on the medical cause of CFS may be a breakthrough, but "there's still a great deal of work to be done" to find a cure, Dr De Meirleir told Radio 1 listeners last week. "CFS is not an illness, it's a condition," he said - a set of symptoms with no single underlying cause, unlike, for instance, tuberculosis, which is a disease caused by a specific bacteria.

That means that the underlying causes of CFS could vary widely and that each would have to be treated on its own. On the other hand, a programme of testing children at an early age for signals of food allergies and higher levels of intestinal bacteria could provide a way to signal those at risk of developing the syndrome later.

www.meab.be