Chronic fatigue syndrome (CFS) has been defined as “persistent or relapsing fatigue lasting 6 or more consecutive months in addition to cognitive difficulties.” Recent developments have revealed that infections - even those generally considered “mild” and easily treatable, one example being the protozoa Giardia lambia - may be involved in the cause of CFS.
Over the years, research has expanded our understanding of Chronic Fatigue Syndrome (CFS) and it is now recognized as a multi-system illness involving neurological, immunological, musculoskeletal, endocrine, and cardiovascular components. CFS is also known as myalgic encephalomyelitis (ME). Recently however, the Institute of Medicine suggested an alternative term – “systemic exertion intolerance disease” – to better reflect the defining feature of the condition, which is the fatigue itself (particularly after activity).
When it comes to the cause (or causes) of CFS, it has been proposed that various types of infections can either trigger or contribute to the disease in some way. Some of the most common infections seen in CFS patients and being investigated by researchers include viruses like Epstein-Barr, Human Herpes Virus-6, and cytomegalovirus, and also bacteria such as mycoplasma, Chlamydia pneumoniae and Borrelia burgdorferi.
Cause or Effect?
Even though it is widely recognized that underlying infections play a role in CFS, many in the medical field deny that these infections directly cause the condition. This belief is due to the fact that even though many individuals develop CFS after a bout with one of these infections, subsequent antibody tests often fail to offer definitive proof of “active” infection. However, this is based on an outdated diagnostic model taught in medical school. Antibody testing is not the most sensitive or accurate way of testing for these infections, particularly in those with CFS whose immune systems are not functioning normally and therefore will often not mount the same antibody response as those with a normal immune system. Also, new and old infections behave differently in terms of antibody production and yet this distinction is not widely understood by clinicians. DNA-based testing called Polymerase Chain Reaction (PCR) is a more sensitive and specific way to test for the presence of pathogens and therefore is now being used more often in research settings to study infections in CFS patients.
PCR testing was employed in a study published in Acta Pathologica Microbiologica et Immunologica Scandinavica on infections in CFS patients. The researchers discovered that out of 200 CFS patients, a whopping 52% of them were infected with mycoplasma compared to only 6% of controls. In addition, 30.5% had Human Herpes Virus-6 (compared with 9% of controls) and 7.5% had Chlamydia pneumoniae (compared with 1% of controls). In the Journal of Chronic Fatigue Syndrome, it was demonstrated (again using PCR testing) that a subset of CFS patients have evidence of B. burgdorferi infection (Lyme disease) and among this group, over half of them also had some form of Mycoplasma (mostly Mycoplasma fermentans), while those without Lyme disease were more likely to be infected with Mycoplasma pneumoniae.
After a Giardia lambia outbreak in Norway in 2004 from contaminated drinking water, large-scale studies showed that 30% of infected patients went on to develop CFS within 5 years (despite treatment) and 40% reported having developed irritable bowel syndrome. While the link between Giardia and CFS had been speculated about previously and even written about in a study published by Dr. Galland in the 1980s, it wasn’t until the Norway studies that the link was considered “definitive.” This finding is important because Giardia has historically been considered a mild infection and not one known for causing ongoing problems after adequate treatment. Some hypothesize that these findings provide further evidence that infections may act as a triggering event in already susceptible individuals.
Other Testing Considerations
While PCR testing is a step in the right direction, it does have its limitations in a clinical setting. You see, organisms break down after a few hours and therefore the test wouldn’t be as accurate if used in a practitioners’ office where a sample may sit for an extended period of time. Typically, a lab setting doesn’t have this problem, making PCR tests a good choice for researchers. But another consideration is that these organisms often “hide out” in tissues of the body in order to evade the immune system, so serum (blood)-based PCR testing may not be sensitive enough in some cases. Thankfully, there are other markers that can help determine the presence of underlying infections in CFS patients and other chronically ill individuals. Findings that may be indicative of chronic infection include:
- Low natural killer cell count
- Elevated IgG or early antigen (EA) antibodies
- High RNAse-L activity
- High ACE (>35)
- Coagulation activation
- High tumor necrosis factor (TNF)
- Low melanocyte stimulation hormone (MSH)
- High Interleukin-6
- Low white blood cell (WBC) count
- Elevated or decreased total IgA, IgM, or IgG levels
While many physicians are not trained to properly diagnose and treat the underlying causes of CFS and other complex conditions, there is help available if you look in the right places. Asking a specialist if they run some of these tests is one thing to look for when choosing a knowledgeable doctor to treat CFS. More research will help to sort out the question of why these infections cause long term consequences for some and not for others. For now, it’s just apparent that they do and that addressing them is an important step in patient recovery.