Chlamydia trachomatisgenotypes in a cross-sectional study of urogenital samples from remote Northern and Central Australia

Abstract

ObjectivesThe objective was to determine the frequency of trachoma genotypes of Chlamydia trachomatis-positive urogenital tract (UGT) specimens from remote areas of the Australian Northern Territory (NT).SettingThe setting was analysis of remnants of C. trachomatis positive primarily UGT specimens obtained in the course of clinical practice. The specimens were obtained from two pathology service providers.ParticipantsFrom 3356 C. trachomatis specimens collected during May 2012–April 2013, 439 were selected for genotyping, with a focus on specimens from postpubescent patients, in remote Aboriginal communities where ocular trachoma is potentially present.Primary and secondary outcome measuresThe primary outcome measure was the proportion of successfully genotyped UGT specimens that were trachoma genotypes. The secondary outcome measures were the distribution of genotypes, and the frequencies of different classes of specimens able to be genotyped.ResultsZero of 217 successfully genotyped UGT specimens yielded trachoma genotypes (95% CI for frequency=0–0.017). For UGT specimens, the genotypes were E (41%), F (22%), D (21%) and K (7%), with J, H and G and mixed genotypes each at 1–4%. Four of the five genotyped eye swabs yielded trachoma genotype Ba, and the other genotype J. Two hundred twenty-two specimens (50.6%) were successfully genotyped. Urine specimens were less likely to be typable than vaginal swabs (p<0.0001).ConclusionsUnlike in some other studies, in the remote NT, trachoma genotypes of C. trachomatis were not found circulating in UGT specimens from 2012 to 2013. Therefore, C. trachomatis genotypes in UGT specimens from young children can be informative as to whether the organism has been acquired through sexual contact. We suggest inclusion of C. trachomatis genotyping in guidelines examining the source of sexually transmitted infections in young children in areas where trachoma genotypes may continue to circulate, and continued surveillance of UGT C. trachomatis genotypes.

Chlamydia trachomatis infection prevalence and serovar distribution in a high-density urban area in the north of Italy

“…The present finding is similar to many other surveys conducted in both high-risk and low-risk subjects (Petrovay et al, 2009;Weill et al, 2010;Yang et al, 2014;Veersteg et al, 2015;Giffard et al, 2016). Effectively, in many countries worldwide, serovars E, F, D, G and K represent the most common serovars among patients with urogenital infections, accounting for 60-80 % of positive patients (Millman et al, 2006;Pedersen et al, 2009;Lagerga rd et al, 2010;Veersteg et al, 2015).…”

“…Anyway, other studies found no correlations between serovar distribution and specific patient characteristics (Weill et al, 2010;Lagerga rd et al, 2010;Veersteg et al, 2015;Giffard et al, 2016).…”

Chlamydiae from Down Under: The Curious Cases of Chlamydial Infections in Australia

“…Instead, the unique and genetically distinct strains clustered within lineages that were previously occupied exclusively by UGT isolates (namely genotypes D-K) [39]. Additionally, both ompA genotyping [40] and novel Ct molecular genotyping (CtGEM; developed as a method for high throughput surveillance of strains and the major phylogenetic lineages [41]) of UGT samples obtained from remote indigenous communities also confirmed that Australian ocular strains are distinct from global and Australian UGT strains [40](). Such clustering indicates the polyphyletic evolution of Australian isolates and certainly raises questions around the origins of Ct strains in Australia [39,42], which is an area of continued research.…”

What doesChlamydia trachomatisdetection in a urogenital specimen from a young child mean?

“…They recently reported a study designed to illuminate the question of self-inoculation, by determining if trachoma genotypes were circulating in sexual networks in the remote Northern Territory of Australia. No such evidence was found 10. It was concluded that genotyping C. trachomatis from paediatric UGT specimens has the potential to indicate whether or not the organism in the specimen was epidemiologically connected to adult sexual networks.…”