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Chlamydia and gonorrhoea contamination of clinic surfaces
  1. Natasha Lewis1,
  2. Gail Dube1,
  3. Christine Carter1,
  4. Rachel Pitt2,
  5. Sarah Alexander2,
  6. Catherine A Ison2,
  7. Jan Harding1,
  8. Louise Brown1,
  9. John Fryer3,
  10. James Hodson4,
  11. Jonathan Ross1
  1. 1Department of Genitourinary Medicine, University Hospital Birmingham NHS Trust, Birmingham, UK
  2. 2Sexually Transmitted Bacteria Reference Laboratory, Health Protection Agency, London, UK
  3. 3Virology Laboratory, Children's Hospital, Birmingham, UK
  4. 4Wolfson Computer Lab, Queen Elizabeth Hospital Birmingham, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
  1. Correspondence to Dr Natasha Lewis, Department of Genitourinary Medicine, University Hospital Birmingham NHS Trust, Whittall Street Clinic, Whittall Street, Birmingham B4 6DH, UK; natasha.lewis{at}


Introduction Nucleic acid amplification tests, with their ability to detect very small amounts of nucleic acid, have become the principle diagnostic tests for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) in many sexual health clinics. The aim of this study was to investigate the extent of surface contamination with CT and GC within a city centre sexual health clinic and to evaluate the potential for contamination of containers used for the collection of self-taken swabs.

Method Surface contamination with CT and GC was assessed by systematically sampling 154 different sites within one clinic using transcription-mediated amplification (TMA), quantitative PCR and culture. The caps of containers used by patients to collect self-taken samples were also tested for CT and GC using TMA.

Results Of the 154 sites sampled, 20 (13.0%) tested positive on TMA. Of these, five (3.2%) were positive for CT alone, 11 (7.1%) for GC alone and four (2.6%) for both CT and GC. The proportion of GC TMA-positive test results differed by gender, with 11 (18.3%) positive results from the male patient clinic area compared with one (1.6%) from the female area (p=0.002). Positive samples were obtained from a variety of locations in the clinic, but the patient toilets were more likely to be contaminated than examination rooms (p=0.015). Quantitative PCR and culture assays were negative for all samples. 46 caps of the containers used for self-taken swabs were negative for both CT and GC on TMA testing.

Conclusions Surface contamination with chlamydial and gonococcal rRNA can occur within sexual health clinics, but the quantity of nucleic acid detected is low and infection risk to patients and staff is small. There remains a potential risk of contamination of patient samples leading to false-positive results.

  • Contamination
  • Chlamydia trachomatis
  • Neisseria gonorrhoeae
  • false positive
  • NAAT
  • AIDS
  • genitourinary medicine
  • gonorrhoea
  • HIV
  • sexual health
  • chlamydia infection
  • antibiotic resistance
  • genital tract infect
  • antimicrobial resistance
  • Neisseria gonorrhoea
  • LGV
  • same day testing
  • syphilis serology
  • vaginal infections
  • STD surveillance
  • laboratory diagnosis
  • statistics
  • PID
  • genitourinary medicine services

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  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.