I had missed the big news last month, with the publication in Science of Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome.
Updated: see Mouse hanging by thread
XMRV is xenotropic murine leukemia virus-related virus and is related to a mouse retrovirus that causes cancers. It does not seem to be airborn, and presumably can be spread by fluids, but does not seem to be as virulent as HIV. (However, in an interview with Dr Klimas on YouTube, who has both HIV and CFS patients, she mentioned that she would prefer having HIV to CFS, since HIV treatment is so successful.) It seems that there needs to be some other immunological trigger for CFS, and that the retro-virus has active and inactive phases like HIV.
The other known infectious human retrovirus are HIV (which causes AIDS) and HTLV-1 and 2 (which cause T-Cell Lymphoma and T-Cell Leukemia.) The exact connection between XMVR and CFS is not clear yet, but the research was prompted when XMRV was discovered in some prostate cancer patients with similar symptoms. There are a raft of other hitherto somewhat mysterious diseases which this may impact.
The original Science article found 4% XMRV infection in the control population (320 people, surprisingly high) and 67% from the 101-person CFS-diagnosed population (68 people). Subsequent to the Science article, very fast, other tests have been developed (anti-body) and it seems that 99 out of 101 have markers for XMRV. Very high. (A subsequent small independent study of 20 people also found significant numbers, so it is looking very promising indeed.)
In one of the interesting comments along the way was how many more people are infected, devastatingly, with CFS compared to all the fuss with H1N1: but H1N1 has had so much attention in the media. Swine Flu is scarier than Mouse Virus perhaps. According to Wikipedia, CFS is found in 4 out of 1000 Americans, and only 5 to 10 % fully recover, but figures of a million CFS sufferers are also sometimes quoted. I once talked to a lady whose husband had his first attack while surfing: just keeled over from sudden fatigue and had to be rescued!
What is particularly heartening about this XMRV discovery is that it opens the door for treatment, whether it is a cause or a symptom. And a more merciful attitude by people who may have thought (as was the case in the 50s, 60s and 70s, but even recently) that CFS was a primarily a mental issue or malingering. And more hope for CFS sufferers.