Purpose of review: A state-of-the-art overview of molecular Chlamydia trachomatis typing methods that are used for routine diagnostics and scientific studies.
Recent findings: Molecular epidemiology uses high-resolution typing techniques such as multilocus sequence typing, multilocus variable number of tandem repeats analysis, and whole-genome sequencing to identify strains based on their DNA sequence. These data can be used for cluster, network and phylogenetic analyses, and are used to unveil transmission networks, risk groups, and evolutionary pathways. High-resolution typing of C. trachomatis strains is applied to monitor treatment efficacy and re-infections, and to study the recent emergence of lymphogranuloma venereum (LGV) amongst men who have sex with men in high-income countries. Chlamydia strain typing has clinical relevance in disease management, as LGV needs longer treatment than non-LGV C. trachomatis. It has also led to the discovery of a new variant Chlamydia strain in Sweden, which was not detected by some commercial C. trachomatis diagnostic platforms.
Summary: After a brief history and comparison of the various Chlamydia typing methods, the applications of the current techniques are described and future endeavors to extend scientific understanding are formulated. High-resolution typing will likely help to further unravel the pathophysiological mechanisms behind the wide clinical spectrum of chlamydial disease.
aSTI Outpatient Clinic, Public Health Service of Amsterdam (GGD Amsterdam)
bCenter for Infection and Immunology Amsterdam (CINIMA), Academic Medical Center (AMC), University of Amsterdam
cDepartment of Dermatology, Academic Medical Center (AMC), University of Amsterdam
dDepartment of Research, Public Health Service of Amsterdam (GGD Amsterdam)
ePublic Health Laboratory, Public Health Service of Amsterdam (GGD Amsterdam), Amsterdam, the Netherlands
Correspondence to Henry J.C. de Vries, STI Outpatient Clinic, Public Health Service of Amsterdam (GGD Amsterdam), PO Box 2200, 1000 CE, Amsterdam, the Netherlands. Tel: +31 205555063; e-mail: firstname.lastname@example.org