Evaluation of Vaginal Specimens for the Detection of C. Trachomatis (CT) and N. Gonorrhoeae (GC) in High Risk Females Attending Sexually Transmitted Infection (STI) Clinics in Alberta, Canada

Gee, Susan

Thursday, September 22, 2016

Galleria Exhibit Hall

Jamil Kanji, MD, FRCPC¹, Susan Gee, MLT², Petra Smyczek, MD PhD FRCPC³, Marthe Charles, MD MSc⁴, Judith Brandley, RN⁵, Penny Parker, RN⁶, Brenda Blore, RN, BN⁷, Michelle Major, RN⁷, Ron Read, MD, PhD, FRCPC⁸ and Prenilla Naidu, MD, FRCPC⁹, 1Walter MacKenzie Centre, Provincial Laboratory for Public Health, Edmonton, AB, Canada, 2bacteriology, Provincial Laboratory for Public Health, Edmonton, AB, Canada, 3STI Services, Alberta Health Services, Edmonton, AB, Canada, 4Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada, 5Sexually Transmitted Infection Clinic, Alberta Health Services, 6Alberta Health Services-Edmonton STI Clinic, Edmonton, AB, Canada, 7Alberta Health Services, 8Alberta Health Services-Calgary STI Clinic, Calgary, AB, Canada, 9Bacteriology, Provincial Laboratory for Public Health, Alberta Health Services, Edmonton, AB, Canada

Background: Vaginal specimens could provide a non-invasive method of improved screening for gonorrhea (GC) and chlamydia (CT) genital infection in high risk populations potentially leading to decreased rates of transmission. We compared the performance of self-collected vaginal swabs (SCV) to urine screening, as well as health care provider collected vaginal swabs (HCV) to endocervical swabs (EC) for the molecular detection of GC and CT.

Methods: Female STI clinic attendees aged 15 to 52 years from three Alberta clinics were enrolled in this study. Patients undergoing a speculum examination had a HCV and EC collected. Those providing only urine samples also provided a SCV. Specimens were analyzed at the Provincial Laboratory for Public Health using the Aptima Combo 2 assay.

Results: We obtained a total of 606 vaginal specimens, 341 nurse collected and 265 self-collected. The sensitivity and specificity of SCV versus urine were 86.7% and 99.1% for CT, 100% and 100% for GC, respectively. For HCV versus EC the sensitivity and specificity were 100% and 97.9% for CT and 71.4% and 99.4% for GC, respectively.

Conclusions: With rising rates of GC and CT in recent years combined with concerns of rising costs in healthcare, innovative strategies for STI screening are desirable. Vaginal swabs have been shown to be equivalent or have higher detection rates of CT and GC when compared to HCV and urine specimens. This study evaluated the performance of SCV in our local settings to better inform public health on alternate screening methods for CT and GC .Our results demonstrate that SCV for detection of GC and CT provide a sensitive, specific, and convenient method for STI screening in our setting. SCV could be used as preferred specimens for outreach settings or for home based screening in populations currently without access to STI testing.

THP 45 Evaluation of Vaginal Specimens for the Detection of C. Trachomatis (CT) and N. Gonorrhoeae (GC) in High Risk Females Attending Sexually Transmitted Infection (STI) Clinics in Alberta, Canada