title: Tuberculosis risk varies with the duration of HIV infection: a prospective study of European drug users with known date of HIV seroconversion.
abstract: BACKGROUND
  It is not known whether the risk of active tuberculosis disease varies with the length of time that individuals are infected with HIV.
  
  
  OBJECTIVE
  To study how, independently of CD4 T cell count, the risk of tuberculosis varies with the duration of HIV infection.
  
  
  METHODS
  Using Poisson regression analysis, the incidence of and risk factors for tuberculosis were studied in 683 injecting drug users (IDU) with a documented date of HIV seroconversion followed in seven cohorts in six European countries until 1998.
  
  
  RESULTS
  Overall incidence was 11.5/1000 person-years. Adjusted for CD4 T cell count and geographic region, the risk ratio (RR) for tuberculosis (both pulmonary and extrapulmonary), compared with the first 3 years of HIV infection, was 2.8 for years 4 to 6 of HIV infection [95% confidence interval (CI), 1.3-6.3], 1.2 for year 7 to 9 (95% CI, 0.3-4.2) and 4.6 after 9 years (95% CI, 1.4-15.0). The adjusted RR for geographic region was 13.1 (95% CI, 4.3-40.0) for Amsterdam and 15.8 (95% CI, 4.8-52.0) for the Valencian region of Spain compared with all other sites combined.
  
  
  CONCLUSIONS
  The risk of tuberculosis is increased relatively early in HIV infection (year 4 to 6) and also later (after year 9) with possibly a relatively silent period between. As expected, IDU in Southern Europe have a substantially higher risk of tuberculosis than IDU in Northern and Central Europe. Amsterdam forms an exception for Northern Europe, with very high incidence rates.
authors.affiliation: Municipal Health Service, Cluster Infectious Diseases, Amsterdam, The Netherlands.
authors.forename: Liselotte
authors.initials: L
authors.lastname: van Asten
authors.forename: Miranda
authors.initials: M
authors.lastname: Langendam
authors.forename: Robert
authors.initials: R
authors.lastname: Zangerle
authors.forename: Ildefonso
authors.initials: I
authors.lastname: Hernández Aguado
authors.forename: Faroudy
authors.initials: F
authors.lastname: Boufassa
authors.forename: Veronique
authors.initials: V
authors.lastname: Schiffer
authors.forename: Raymond P
authors.initials: RP
authors.lastname: Brettle
authors.forename: J Roy
authors.initials: JR
authors.lastname: Robertson
authors.forename: Arnaud
authors.initials: A
authors.lastname: Fontanet
authors.forename: Roel A
authors.initials: RA
authors.lastname: Coutinho
authors.forename: Maria
authors.initials: M
authors.lastname: Prins
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology / Q000209:etiology*; D000328:Adult; D018791:CD4 Lymphocyte Count; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006679:HIV Seropositivity / Q000150:complications; D006801:Humans; D015994:Incidence; D008297:Male; D016012:Poisson Distribution; D011446:Prospective Studies; D012307:Risk Factors; D013223:Statistics as Topic; D015819:Substance Abuse, Intravenous / Q000150:complications*; D013997:Time Factors; D014376:Tuberculosis / Q000453:epidemiology / Q000209:etiology*