title: Molecular evidence of endogenous reactivation of Mycobacterium tuberculosis after 33 years of latent infection.
abstract: Since Robert Koch described the cause of tuberculosis in 1882, the natural history of the disease after primary infection has been subject to debate. Only approximately 10% of infected individuals develop active disease, which may appear years to decades after infection. Late onset has been attributed to the endogenous reactivation of dormant bacteria. However, this has not been documented by molecular means for latencies of more than a few years. In Denmark, we have recently recultured 205 freeze-dried Mycobacterium tuberculosis strains obtained from 1961 through 1967. These "historical" strains are analyzed by DNA restriction fragment-length polymorphism testing, and their DNA patterns are compared with those of 4008 recently obtained clinical specimens. This has, surprisingly, yielded molecular evidence of M. tuberculosis reactivation after 33 years of latent infection. A father and son who developed tuberculosis in 1961 and in 1994, respectively, were the only patients infected with strains that share an identical DNA pattern.
authors.affiliation: International Reference Laboratory for Mycobacteriology, Statens Serum Institut (National Institute for Prevention and Control of Infectious Diseases and Congenital Disorders), Statens Serum Institut, DK-2300 Copenhagen S, Denmark. tll@ssi.dk
authors.forename: Troels
authors.initials: T
authors.lastname: Lillebaek
authors.forename: Asger
authors.initials: A
authors.lastname: Dirksen
authors.forename: Inga
authors.initials: I
authors.lastname: Baess
authors.forename: Benedicte
authors.initials: B
authors.lastname: Strunge
authors.forename: Vibeke Ø
authors.initials: VØ
authors.lastname: Thomsen
authors.forename: Ase B
authors.initials: AB
authors.lastname: Andersen
mesh_terms: D000328:Adult; D004269:DNA, Bacterial / Q000032:analysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000145:classification / Q000235:genetics / Q000502:physiology*; D012008:Recurrence; D013997:Time Factors; D014376:Tuberculosis / Q000209:etiology*
chemical_list: D004269:DNA, Bacterial