Impact of laboratory cross-contamination on molecular epidemiology studies of tuberculosis.

Laboratory cross-contamination by Mycobacterium tuberculosis is known to be responsible for the misdiagnosis of tuberculosis, but its impact on other contexts has not been analyzed. We present the findings of a molecular epidemiology analysis in which the recent transmission events identified by a genotyping reference center were overestimated as a result of unnoticed laboratory cross-contamination in the original diagnostic laboratories.

Influence of gender on long-term prognosis of patients with chronic heart failure seen in heart failure clinics.

BACKGROUND Controversy exists concerning the influence of gender in the prognosis of patients with heart failure and no evidence is available from specific heart failure clinics. HYPOTHESIS Women with ambulatory heart failure are managed differently than men, although their prognosis might be better than men. METHODS AND RESULTS We analyzed the clinical characteristics, complementary test results, treatment, and prognosis in 4720 patients with chronic heart failure seen in 62 specialized clinics forming part of a multicenter registry during a mean follow-up of 40 months. The mean age was 65 +/- 12 years and 71% were men. The men were younger than the women and more often had a history of hyperlipidemia and ischemic heart disease. The men had a more advanced heart failure New York Heart Association (NYHA) functional class (III-IV) than the women and a greater frequency of systolic ventricular dysfunction. The men more often received treatment with beta-blockers, vasodilators, and antiplatelet aggregators as well as higher mean doses as compared with the women. The overall survival after the follow-up was similar for both genders, although the women had lower rates of survival free of admission for heart failure. CONCLUSIONS Despite the mortality of women and men with heart failure being similar, the rate of readmission for heart failure is greater in women in specialized heart failure clinics. These results may be associated with the pharmacological treatment differences observed.