New developments in epidemiology

Session 2

Causes of death in 36 patients with CFS was compared to deaths in non-CFS patients by Rosamund Vallings, (Manukau, NZ). Causes of death in CFS patients did not differ from non-CFS patients or NZ norms apart from a higher rate of accidental deaths. It is probable that CFS patients can easily tire and overdo physical and mental activities, putting them at greater accident risk. Risks of late diagnosis of cancers were addressed, with a warning to make sure patients do report new symptoms and attend for regular screening.

Tokuzo Matsui (Osaka, Japan) reported the need to revise the exclusion criteria for mental health disorders in order for a diagnosis of CFS. The number of CFS patients diagnosed initially by the 1992 definition increased by 10% when the Japanese 2007 guidelines were used. Anners Lerdal (Drammen, Norway) also found that mental stress, such as PTSD symptoms are strongly associated with fatigue. Using multivariate analyses, demographic variables, mental stress, somatic conditions and self-rated health all made significant contributions.

Further work from the Dubbo Infection Outcomes Study was presented by Andrew Lloyd (Sydney, Australia). Q fever is a zoonotic illness caused by Coxiella burnetii infection. Some patients suffer long term serious disability. Prolonged symptoms of post-infective fatigue were associated with more severe illness, but not with persistence of the genomes of the infecting organism in peripheral blood cells, alterations in immune responses or changes in the proportions of immune cell subsets. The importance of prospective studies was stressed.

Eliana Lacerda (London, UK) had looked at work related risk factors for chronic Fatigue. Bank workers in Brazil were the subjects of this study. Fatigue and Chronic Fatigue in this group were strongly associated with RSI. Ergonomic variables were also important determinants of CFS/ME like syndrome. Looking at preventative measures in the work place seems essential, and also paying attention to such issues as breathing, posture and adequate organizational structures.

Roumiana Boneva (Atlanta, USA) found that in a community study, a positive gynaecological history, such as early menopause, hysterectomy, oophorectomy etc may be associated with CFS. The patients had more irregular periods than controls, more births, and pain associated endometriosis. 53% had had a hysterectomy compared to 40% of controls, 37% had had a D&C compared to 11% of controls. She recommends a larger study.

Classification of persons with ME/CFS by types of fatigue was a useful study by Aaron Boulton (Chicago, USA). Important subgroups emerged, and it is possible that the fatigue patterns in these people may represent different subtypes. The fatigue patterns are heterogeneous, and future research needs to focus on this.