title: No decrease in annual risk of tuberculosis infection in endemic area in Cape Town, South Africa.
abstract: OBJECTIVE
  To estimate the change in annual risk of tuberculosis infection (ARTI) in two neighbouring urban communities of Cape Town, South Africa with an HIV prevalence of approximately 2%, and to compare ARTI with notification rates and treatment outcomes in the tuberculosis (TB) programme.
  
  
  METHODS
  In 1998-1999 and 2005, tuberculin skin test surveys were conducted to measure the prevalence of Mycobacterium tuberculosis infection and to calculate the ARTI. All 6 to 9-year-old children from all primary schools were included in the survey. Notification rates and treatment outcomes were obtained from the TB register.
  
  
  RESULTS
  A total of 2067 children participated in the survey from 1998 to 1999 and a total of 1954 in 2005. Based on a tuberculin skin test cut-off point of 10 mm, the ARTI was 3.7% (3.4-4.0%) in the 1998-1999 survey and 4.1% (3.8-4.5%) in 2005. The notification rate for pulmonary TB increased significantly from 646 per 100 000 in 1998 to 784 per 100,000 in 2002. In Ravensmead, there was no significant change in ARTI [first survey: 3.5% (3.1-3.9%), second survey: 3.2% (2.9-3.6%)], but in Uitsig the ARTI increased significantly from 4.1% (3.6-4.6%) to 5.8% (5.2-6.5%). The difference in ARTI between the two areas was associated with differences in reported case rates and the proportion of previously treated cases.
  
  
  CONCLUSIONS
  Tuberculosis transmission remains very high in these two communities and control measures to date have failed. Additional measures to control TB are needed.
authors.affiliation: Desmond Tutu TB Centre, Stellenbosch University, Cape Town, South Africa.
authors.forename: Fiona E
authors.initials: FE
authors.lastname: Kritzinger
authors.forename: Saskia
authors.initials: S
authors.lastname: den Boon
authors.forename: Suzanne
authors.initials: S
authors.lastname: Verver
authors.forename: Donald A
authors.initials: DA
authors.lastname: Enarson
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Lombard
authors.forename: Martien W
authors.initials: MW
authors.lastname: Borgdorff
authors.forename: Robert P
authors.initials: RP
authors.lastname: Gie
authors.forename: Nulda
authors.initials: N
authors.lastname: Beyers
mesh_terms: D001500:BCG Vaccine / Q000276:immunology; D002648:Child; D018563:Disease Notification / Q000706:statistics & numerical data; D019353:Endemic Diseases; D005260:Female; D015658:HIV Infections / Q000453:epidemiology*; D006801:Humans; D008297:Male; D015995:Prevalence; D012307:Risk Factors; D013019:South Africa / Q000453:epidemiology; D014374:Tuberculin Test; D014376:Tuberculosis / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission
chemical_list: D001500:BCG Vaccine