Vaginal self-sampling for STIs

Vaginal self-sampling using a proprietary device (HerSwab) gets high ratings from users and represents a suitable method for the diagnosis of Chlamydia trachomatis and Neisseria gonorrhoeae infections, according to the findings of a recently published study that compared the HerSwab with physician-collected vaginal samples.

The device, which is still investigational in the United States, was developed for sexually transmitted infection (STI) screening. It allows for self-collection of vaginal samples that are transported dry inside the device, to a laboratory for analysis.

“Screening programs are in place to detect and treat STIs in the lower genital tract as these infections may be asymptomatic and ascend into the upper tract, causing complications. Because of privacy concerns and a variety of other reasons, teenage girls and women may be reluctant to undergo specimen collection performed by a healthcare provider,” said Max A Chernesky, PhD, senior author and professor emeritus, Departments of Pediatrics, and Pathology and Molecular Medicine, McMaster University.

“Our assessment of the self-collection device indicates it is a viable option for overcoming this barrier to STI screening."  Larger studies are needed to evaluate the accuracy of the self-collected specimens.

The study evaluating patient acceptance and the diagnostic performance of the self-sampling device was conducted by researchers at St. Joseph’s Healthcare Hamilton/McMaster University, Hamilton, Ontario, Canada, and published in the February 2016 issue of Sexually Transmitted Diseases.

It included 189 women ages 16 to 41 years who were recruited from a street youth clinic or therapeutic abortion clinic. All women performed self-collection and underwent physician sampling using a commercially available product that uses specimen transport media (Aptima, Hologic). For each participant, the order of the two sampling techniques was determined by randomization.

Analyses of responses from questionnaires completed by the study participants showed they were almost unanimous in considering the self-collection easy (97.1%). Most women also rated it as comfortable (88.3%), preferred self-collection over physician collection (80.9%), and said they would consider using the self-collection device at home (79.7%).

Greater comfort was the leading reason cited for preferring the self-collection device. Of the minority of the participants who preferred physician collection, two-thirds expressed concern about collecting an inadequate sample.

Laboratory testing identified C. trachomatis infection in 20 participants (10.6%) and N. gonorrhoeae in 5 participants (2.6%). The self-collection method detected 4 more C. trachomatis infections and 3 more N. gonorrhoeae infections than the physician collected method but the number of infections was too few to measure significance. Overall, there was a high level of agreement between the two methods for both C. trachomatis (94.7%) and N. gonorrhoeae (98.4%).

Additional analyses showed that participant’s positive impressions about the self-collection procedure were robust across a variety of individual characteristics. There were no significant relationships between ratings of either ease or comfort of use and presence of vaginal symptoms, history of an STI, the order in which specimen collection was performed, or the participant’s preference for the self-collection technique. In addition, preference for self-collection versus physician-collection was not associated with age or willingness to consider self-collection at home, and participants were similarly likely to consider self-collection at home whether or not they had a history of STI or current symptoms.

Dr Chernesky noted that other research conducted by his group indicate that despite the absence of storage in transport media, specimen analysis remains accurate as long as the dry sample is processed within 7 days.

“Avoiding the need for transport media may also increase user acceptance of this product considering that we have also learned that concern about spilling transport media on themselves is an issue some women raise with the use of other vaginal self-collection kits,” he said.