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.
BACKGROUND
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.
Alexander
S
S
Sexually Transmitted Bacteria Reference Laboratory, Health Protection Agency, 61 Colindale Avenue, London NW95HT, UK. sarah.alexander@hpa.org.uk
Ison
C
C
Parry
J
J
Llewellyn
C
C
Wayal
S
S
Richardson
D
D
Phillips
A
A
Smith
H
H
Fisher
M
M
D002690:Chlamydia Infections / Q000175:diagnosis*; D002692:Chlamydia trachomatis / Q000302:isolation & purification; D006069:Gonorrhea / Q000175:diagnosis*; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D009344:Neisseria gonorrhoeae / Q000302:isolation & purification; D021141:Nucleic Acid Amplification Techniques / Q000592:standards; D015588:Observer Variation; D010608:Pharyngeal Diseases / Q000175:diagnosis*; D010614:Pharynx / Q000382:microbiology; D012002:Rectal Diseases / Q000175:diagnosis*; D012007:Rectum / Q000382:microbiology; D012648:Self Care; D012680:Sensitivity and Specificity; D013048:Specimen Handling / Q000592:standards