title: Decline of the new Swedish variant of Chlamydia trachomatis after introduction of appropriate testing.
abstract: OBJECTIVE
  The longitudinal epidemiological development of the new variant of Chlamydia trachomatis was studied after appropriate testing procedures had been introduced when the strain was detected in 2006.
  
  
  METHODS
  The number of cases of the new variant of C trachomatis was followed from 2007 through 2011 from the laboratory records. Testing for C trachomatis is centralised to one laboratory with around 80-85 000 persons being tested annually in a population of 1.1 million.
  
  
  RESULTS
  During the 5-year period, 410 973 patients were tested of which 25 723 cases were positive. The proportion of the new variant of all positive cases declined from 30% in 2007 to 6% in 2011. While the number of the new variant of C trachomatis declined, the ordinary wild-type strains remained largely unchanged.
  
  
  CONCLUSIONS
  A selective decline of the new variant of C trachomatis has occurred after appropriate laboratory testing was introduced. A new balance point between 5% and 10% for the new variant seems to be gradually approached.
authors.affiliation: Department of Laboratory Medicine, Medical Microbiology, University Hospital in Malmö, Malmö SE 205 02, Sweden. kenneth.persson@med.lu.se
authors.forename: Kenneth
authors.initials: K
authors.lastname: Persson
authors.forename: Berit
authors.initials: B
authors.lastname: Hammas
authors.forename: Håkan
authors.initials: H
authors.lastname: Janson
authors.forename: Carina
authors.initials: C
authors.lastname: Bjartling
authors.forename: Joakim
authors.initials: J
authors.lastname: Dillner
authors.forename: Lena
authors.initials: L
authors.lastname: Dillner
mesh_terms: D000293:Adolescent; D000328:Adult; D001431:Bacteriological Techniques / Q000379:methods*; D002692:Chlamydia trachomatis / Q000145:classification* / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D015994:Incidence; D008219:Lymphogranuloma Venereum / Q000175:diagnosis* / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult