Self-taken pharyngeal and rectal swabs are appropriate for the detection of Chlamydia trachomatis and Neisseria gonorrhoeae in asymptomatic men who have sex with men
- S Alexander1,
- C Ison1,
- J Parry2,
- C Llewellyn3,
- S Wayal3,
- D Richardson4,
- A Phillips4,
- H Smith3,
- M Fisher4
- 1Sexually Transmitted Bacteria Reference Laboratory, Health Protection Agency, London, UK
- 2Virus Reference Division, Health Protection Agency, London, UK
- 3Division of Primary Care and Public Health, Brighton and Sussex Medical School, Falmer, Brighton, UK
- 4Department of Genitourinary Medicine/HIV, Brighton and Sussex University Hospitals, Brighton, UK
- Dr S Alexander, Sexually Transmitted Bacteria Reference Laboratory, Health Protection Agency, 61 Colindale Avenue, London NW9 5HT, UK;
- Accepted 12 August 2008
Introduction: Self-taken specimens from men who have sex with men (MSM) could be important in reducing high levels of demand on sexual health services. The performance of self-taken specimens for the detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) from both pharyngeal and rectal sites in asymptomatic MSM was assessed.
Methods: MSM were examined according to clinic protocol: a rectal and pharyngeal swab for GC culture and a rectal swab for the CT strand displacement assay. An extra set of nurse-taken and self-taken pharyngeal and rectal specimens were also requested and were tested using the Aptima Combo 2 assay and the result compared with the routine clinic result, which was considered the gold standard.
Results: A total of 272 MSM was recruited and the sensitivity and specificity of nurse-taken and patient-taken swabs, respectively, was as follows: rectal GC: 94.9% and 90.1% (nurse); 92.3% and 87.9% (patient); pharyngeal GC: 88.2% and 91.8% (nurse); 100% and 87.8% (patient); rectal CT: 80.0% and 99.6% (nurse); 91.4% and 98.2% (patient). No significant difference in sensitivity or specificity was observed between the nurse-taken and the patient-taken rectal swabs for either GC or CT. For the detection of GC from the pharynx, comparable sensitivities were achieved between nurse-taken and patient-taken swabs (p = 0.5); however, a significant difference in specificity was observed (p = 0.006). This was due to a higher number of false GC-positive self-taken pharyngeal swabs from patients with high rates (90.9%; 10/11) of confirmed concurrent GC infection in different anatomical sites.
Conclusions: MSM are able to collect self-taken rectal and pharyngeal swabs that are comparable to those taken by clinicians.
Funding: This study was funded by a grant awarded from the Medical Research Council (MRC) Sexual Health and HIV Research Strategy Committee. The views expressed in this manuscript are those of the authors and not necessarily those of the MRC or the health department.
Competing interests: None.
Ethics approval: Approval for the study was obtained from the Brighton and Mid-Sussex Ethics Committee.
Patient consent: Individuals were only recruited into the study after giving informed consent according to Good Clinical Practice Guidelines.
Brighton Home Sampling Steering Group Membership: Sarah Alexander, Gerald Bloom, Gillian Dean, Martin Fisher, Cathy Ison, Carrie Llewellyn, John Parry, Nicky Perry, Alan Phillips, Daniel Richardson, Garth Singleton, Helen Smith, Sonali Wayal.
Contributors: JP, CI, CL, DR, HS and MF were responsible for the design, progress and management of the study. AP and DR were responsible for patient recruitment and AP was reponsible for data collection. SW was responsible for study management and implementation and critical appraisal of the manuscript. SA performed the AC2 testing at STBRL and was responsible for the data analysis and production of the first draft of the manuscript.