RESUMO
INTRODUCTION: Previous studies found conflicting results regarding associations between urogenital Chlamydia trachomatis infections and ethnicity or urogenital symptoms among at-risk populations using either ompA-based genotyping or high-resolution multilocus sequence typing (MLST). This study applied high-resolution MLST on samples of individuals from a selected young urban screening population to assess the relationship of C. trachomatis strain types with ethnicity and self-reported urogenital symptoms. Demographic and sexual risk behaviour characteristics of the identified clusters were also analysed. METHODS: We selected C. trachomatis-positive samples from the Dutch Chlamydia Screening Implementation study among young individuals in Amsterdam, the Netherlands. All samples were typed using high-resolution MLST. Clusters were assigned using minimum spanning tree analysis and were combined with epidemiological data of the participants. RESULTS: We obtained full MLST data for C. trachomatis-positive samples from 439 participants and detected nine ompA genovars. MLST analysis identified 175 sequence types and six large clusters; in one cluster, participants with Surinamese/Antillean ethnicity were over-represented (58.8%) and this cluster predominantly consisted of genovar I. In addition, we found one cluster with an over-representation of participants with Dutch ethnicity (90.0%) and which solely consisted of genovar G. No association was observed between C. trachomatis clusters and urogenital symptoms. CONCLUSIONS: We found an association between urogenital C. trachomatis clusters and ethnicity among young screening participants in Amsterdam, the Netherlands. However, no association was found between C. trachomatis clusters and self-reported urogenital symptoms.
Assuntos
Infecções por Chlamydia/genética , Chlamydia trachomatis/genética , Busca de Comunicante/métodos , Emigrantes e Imigrantes/estatística & dados numéricos , Tipagem de Sequências Multilocus , Comportamento Sexual/estatística & dados numéricos , Adolescente , Adulto , Infecções por Chlamydia/diagnóstico , Infecções por Chlamydia/epidemiologia , Chlamydia trachomatis/isolamento & purificação , Análise por Conglomerados , Etnicidade , Feminino , Genótipo , Humanos , Masculino , Países Baixos/epidemiologia , Reação em Cadeia da Polimerase , Prevalência , Análise de Sequência de DNA , Suriname/epidemiologia , Sexo sem Proteção , População UrbanaRESUMO
BACKGROUND: In general, point-of-care (POC) tests for Chlamydia trachomatis (Ct) show disappointing test performance, especially disappointing sensitivity results. However, one study sponsored by the manufacturer (Diagnostics for the Real World) reported over 80% sensitivity with their Chlamydia Rapid Test (CRT). We evaluated the performance of this CRT in a non-manufacturer-sponsored trial. METHODS: Between July 2009 and February 2010, we included samples from 912 women in both high- and low-risk clinics for sexually transmitted infections (STIs) in Paramaribo, Suriname. Sensitivity, specificity, positive- and negative predictive values (PPV and NPV) for CRT compared to NAAT (Aptima, Gen-Probe) were determined. Quantitative Ct load and human cell load were determined in all CRT and/or NAAT positive samples. RESULTS: CRT compared to NAAT showed a sensitivity and specificity of 41.2% (95% CI, 31.9%-50.9%) and 96.4% (95% CI, 95.0%-97.5%), respectively. PPV and NPV were 59.2% (95% CI, 47.5%-70.1%) and 92.9% (95% CI, 91.0%-94.5%), respectively. Quantitative Ct bacterial load was 73 times higher in NAAT-positive/CRT-positive samples compared to NAAT-positive/CRT-negative samples (p<0.001). Human cell load did not differ between true-positive and false-negative CRT results (pâ=â0.835). Sensitivity of CRT in samples with low Ct load was 12.5% (95% CI, 5.2%-24.2%) and in samples with high Ct load 73.5% (95% CI, 59.9%-84.4%). CONCLUSIONS: The sensitivity of CRT for detecting urogenital Ct in this non-manufacturer-sponsored study did not meet the expectations as described previously. The CRT missed samples with a low Ct load. Improved POC are needed as meaningful diagnostic to reduce the disease burden of Ct.