Contaminated fingers: a potential cause of Chlamydia trachomatis-positive urine specimens

Abstract

ObjectivesThe detection of an STI agent in a urogenital tract (UGT) specimen from a young child is regarded as being indicative of sexual abuse. However, the probabilities of contamination events that could conceivably lead to STI positive specimens in the absence of sexual contact are unclear. The objective was to estimate the potential for fingers that have come in contact with Chlamydia trachomatis-positive urine to detectably contaminate C. trachomatis-negative urine.MethodsThe study design was based on self-experimentation. Dilutions of C. trachomatis elementary bodies (EBs) were prepared. A participant contacted an EB dilution then a urine surrogate specimen. The experiment was performed by three participants using three C. trachomatis isolates, of genotype E, F and B. Two surrogate urine contact methods were used to mimic contamination of a carer assisting with a child’s urine collection. All EB dilutions and urine surrogate specimens were subjected to C. trachomatis assay and quantification in a real-time PCR-based diagnostic system.ResultsThe amplimer crossing point (Cq) for EB dilutions was 10.0±1.6 less than for corresponding finger contacted urine specimens, which corresponds to ~10 µL of EB suspension transferred. This was largely independent of participant identity, C. trachomatis strain or EB dilution. Hand decontamination led to large reductions in EBs transferred, but transfer remained consistently detectable. Recent Cq data from C. trachomatis-positive clinical urine specimens were collated, and 20% clearly contained sufficient C. trachomatis to detectably contaminate another specimen by finger-mediated transfer, as in this experiment.ConclusionsThis study directly demonstrated the potential for urine contaminated fingers to convert a C. trachomatis-negative urine specimen to C. trachomatis positive as a result of contact. Accordingly, procedures for urine specimen collection, particularly from children, need to be designed to prevent contamination.

The Effectiveness of Single-Dose Azithromycin Versus its Combination With Moxifloxacin Based on the Treatment of Chlamydial Cervicitis: A Study Protocol for a Randomized Clinical Trial

“…In frequent infections, salpingitis, tubular ovarian abscess, and infertility are also possible, and ectopic pregnancy is an indirect complication of this infection. The tissue damage following chlamydia trachomatis is noteworthy because it happens due to late diagnosis and treatment (6)(7)(8)(9)(10). According to the World Health Organization (WHO) guidelines, only treatment regimens that have more than 95% efficacy are recommended for STIs (40).…”

Urogenital chlamydia trachomatis treatment failure with azithromycin: A meta-analysis

“…The results from previous studies suggest that chlamydia trachomatis infection entails the risk of cervicitis, urinary tract infections, prostatitis, epididymitis, peritonitis, lower respiratory tract diseases, chronic fatigue syndrome, and reactive arthritis. It also doubles the risk of ectopic pregnancy (6,7) and increases the risk of developing the inflammatory pelvic disease in recurring chlamydial infections or treatment failures by 4–6 times (8). Chlamydia infection also increases the likelihood of Human Immunodeficiency Virus (HIV) comorbidity.…”

Highlights from this issue

“…It’s always important to consider the potential downside of new developments—which may vary between settings. This month Giffard and colleagues report on an experiment with contamination which re-emphasises the need to get the basics of specimen collection right 1. Eagle eyed readers will remember this team’s editorial exploring the meaning of a positive nucleic acid test for Chlamydia trachomatis in the Australian context where—shockingly—trachoma remains endemic in indigenous areas where STI is often reported in young adolescents 2.…”