Changes in the epidemiology of tuberculosis: the influence of international migration flows

Abstract

Introduction: The epidemiological characteristics of patients with tuberculosis (TB) in European hospitals have changed in recent years.

Methods: A prospective study of patients with culture-proven pulmonary TB admitted to our institution from 1997 to 2008 is shown.

Results: We analyzed 661 patients with pulmonary TB. An increase in the incidence of TB was confirmed during the study period (P<.001). The proportion of patients with HIV infection decreased from 26% during 1997-2000 to 12% during 2005-2008. However, the proportions of older (>40 years old) and foreign-born patients increased significantly, from 37% to 59% and from 12% to 35%, respectively. Multivariate analysis confirmed previous antituberculous therapy and immigration as factors associated with resistance to isoniazid and to isoniazid+rifampin. After the year 2000, mortality was independently associated with extrapulmonary TB (OR: 3.1; CI 95%: 1.4-7.2), hepatitis C virus infection (OR: 6.0; CI 95%: 2.2-16.3), and diabetes (OR: 6.4; CI 95%: 2.4-16.8).

Conclusion: Immigration from countries with high rates of TB infection has replaced HIV infection as the most relevant risk factor associated with TB. The increase in the number of older patients with TB and the presence of specific comorbid conditions, especially chronic liver dysfunction, could explain the more difficult management and increased mortality.