A new study by researchers in Netherlands has triggered doubt on recent claims that a human retrovirus known as XMRV is linked with chronic fatigue syndrome or ME (myalgic encephalitis), forming the third study to refute the original US study which reported the link.

The findings published in the British Medical Journal are reported to be latest to gainsay a recent study from the US that detected XMRV in nearly 66% of patients with chronic fatigue syndrome, however, failed to pose a conclusion to prove a direct link between the virus and the disease.

In January 2010, a research team in UK reportedly found no evidence of XMRV in 186 patients with chronic fatigue syndrome in the United Kingdom. A third study, published earlier this month, was also unable to identify XMRV in
170 patients.

So, a team from the Netherlands, examined the DNA from XMRV in the blood cells of 32 Dutch patients with chronic fatigue syndrome and 43 healthy controls, matched by age, sex and geographical area. Two highly sensitive tests were carried out on two different target genes.

"Although our patient group was relatively small and we cannot formally rule out a role of XMRV, our data cast doubt on the claim that this virus is associated with chronic fatigue syndrome in the majority of patients," say the authors.