This report describes the actions of public health experts in cooperation with specialists in sexually transmitted diseases (STD), epidemiologists and (molecular) microbiologists to investigate the possible introduction of the swCT variant in the Netherlands: 1. Investigating trends in CT epidemiology Result: STD surveillance and laboratory surveillance did not show any evidence of the introduction of the swCT variant in Holland. 2. Retesting samples by TaqMan PCR Result: Roche CT-negative samples suspected to be CT-positive on the basis of the clinical picture were retested by swCT TaqMan but did not harbour the swCT variant 3. Screening sample pools for the presence of the swCT variant Result: Four different sample pools covering a wide geographical range were tested by specific swCT Taqman assay, but the swCT variant was not detected in any of them. In conclusion, to date the swCT variant has not been found in the Netherlands. However, ongoing monitoring is needed until Roche and Abbott have adapted their CT nucleic acid amplification tests (NAATs) to detect the new variant.