Abstract
We examined the blood of 94 North American Chronic Fatigue Syndrome (CFS) patients using forensic polymerase chain reaction and found that a subset (10.6%) of CFS patients show evidence of Brucella spp. infections compared to one of 70 control subjects (Odds Ratio = 8.2; 95% Confidence Limits (CL) 1–66; P < .01). Rural patients showed a higher incidence of Brucella spp. infections over urban patients (OR = 5.5, 95% CL 1.3–23.5, P < .02). Since CFS patients also have a high prevalence of one of four Mycoplasma species and sometimes show evidence of infections with Chlamydia pneumoniae, we examined Brucella-positive patients for other bacterial infections. Previously we found that 8% of the CFS patients showed evidence of C. pneumoniae and about 50% show evidence of Mycoplasma spp. infections. Since the presence of one or more chronic systemic infections may predispose patients to other infections, we examined the prevalence of C. pneumoniae and Mycoplasma spp. infections in Brucella-positive patients. We found only one Brucella-positive patient with C. pneumoniae and four other patients with evidence of Mycoplasma spp., suggesting that such bacterial infections occur independently in CFS patients. Control subjects (N = 70) had low rates of Brucella spp. (1.4%), Mycoplasma spp. (7.2%) or C. pneumoniae (1.4%) infections, and there were no co-infections in control subjects. The results indicate that a subset of CFS patients show evidence of infection with Brucella spp., and some of these patients also have other bacterial infections.