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

Sex Transm Infect. 2008 Nov;84(6):488-92. doi: 10.1136/sti.2008.031443.

Abstract

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.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chlamydia Infections / diagnosis*
  • Chlamydia trachomatis / isolation & purification
  • Gonorrhea / diagnosis*
  • Homosexuality, Male*
  • Humans
  • Male
  • Neisseria gonorrhoeae / isolation & purification
  • Nucleic Acid Amplification Techniques / standards
  • Observer Variation
  • Pharyngeal Diseases / diagnosis*
  • Pharynx / microbiology
  • Rectal Diseases / diagnosis*
  • Rectum / microbiology
  • Self Care
  • Sensitivity and Specificity
  • Specimen Handling / standards