Tuberculosis elimination in the Netherlands

This study assessed progress towards tuberculosis (TB) elimination in the Netherlands by using DNA fingerprinting. Mycobacterium tuberculosis strains were defined as new if the IS6110 restriction fragment length polymorphism pattern had not been observed in any other patient during the previous 2 years. Other cases were defined as clustered and attributed to recent transmission. In the period 1995-2002, the incidence of TB with new strains was stable among non-Dutch residents and declined among the Dutch. However, the decline among the Dutch was restricted to those > 65 years of age. Moreover, the average number of secondary cases per new strain did not change significantly over time. We conclude that the decline of TB in the Netherlands over the past. decade was mainly the result of a cohort effect: older birth cohorts with high infection prevalence were replaced by those with lower infection prevalence. Under current epidemiologic conditions and control efforts, TB may not be eliminated.