By Dr. Roberto Leon MD FRCSC (biography and disclosures) Disclosures: Received an honorarium from Bayer for speaking at CME events on IUDs, and from Allergan for speaking on Lolo and Fibristal. Advisor for Pfizer for Duavive. No conflict of interest. Mitigating potential bias: Recommendations are consistent with published guidelines.
What I did before
Until about 3-4 years ago, I obtained swabs from the endocervix for the diagnosis of chlamydia and gonorrhea. In women with symptoms of vaginitis, swabs were obtained from the lateral vaginal walls for bacterial vaginosis, trichomonas and yeast. I called them the “Big 5” when I explained to the patient what we were testing for (see attachment 1: STDs and infections tested for with the 3 vaginal swabs, and attachment 2: Testing for STDs).
For the endocervical swabs, I used the COBAS PCR Female swab sample package, and for the lateral vaginal wall, the COPAN M40 sample package. The swabs were then transported to the lab, where nuclear acid amplification testing (NAAT) was performed (NAAT has the best overall sensitivity and specificity for the diagnosis of chlamydia and gonorrhea).
What changed my practice
I noticed in the back of the COBAS swab a set of instructions for self-collection and handling. I came across a publication in the British Medical Journal by Sarah A. Schoeman: Assessment of best single sample for finding chlamydia in women with and without symptoms: a diagnostic test study 1. Participants took a vaginal swab before a routine gynecological exam, and clinicians then took an endocervical swab during examination.
Of the 3867 participants with complete results, 10.2% were infected with chlamydia. Self-collected vulvovaginal swabs were significantly more sensitive than endocervical swabs (97% vs 88%; P<.00001) and had equal septicity (99.9% vs 100%). In women with symptoms of a sexually transmitted infection (STI) or vaginitis, the sensitivity was 97% vs 88% (P<.0008); in those with no symptoms, the sensitivity was 97% vs 89% (P<.002). In those with symptoms, using endocervical samples rather than vaginal swabs would have missed 9% of infections, or 1 in every 11 cases of chlamydia in this study.
My personal interpretation of why the self-administered vaginal swabs (SAVS) are better than the physician administered ones is that the swabs should be in contact against the vaginal walls or the cervix for 30 seconds, and by watching the residents perform them in my office, most just touch the vaginal walls or the cervix for 5 seconds or so. And when they do an endocervical swab, they often don’t remove the cervical mucus (there are 2 Q-tips in the sample kit, one for mucous removal, one for sampling). The mucus is rich in antibodies, and less likely to test positive.
I then reviewed some of the literature on the self-collection for the other STI’s and vaginitis, and they all revealed at least an equivalent but often better detection rate with the SAVS than the physician performed swabs 2,3,4. In terms of patient’s preference, 90% of women found it very easy to self-collect a vaginal swab, and 67% preferred a vaginal swab over a pelvic examination5.
I also looked at the accuracy of urine testing’s comparing to vaginal swabs. According to a CDC report, first catch urine from women may detect up 10% fewer chlamydia and gonorrhea infections compared with vaginal and endocervical samples 6. In men, urine testing is the gold standard for diagnosing STIs, but not in women.
If SAVS were more accurate and preferred by patients, why not use them? I did not find any negative implications7, so I started offering them to my patients regularly since then.
A recent review in the New England Journal of Medicine in 20178 affirmed that ‘vaginal swabs are the preferred specimen type (for Chlamydia Trachomatis) because NAAT on vaginal swabs perform as well as those on cervical swabs, and collection is easy for most women to perform themselves. A first-catch urine specimen is also acceptable but may fail to detect up to 10% of cases.
What I do now
In a new patient, I still carry out a full gynecological examination but perform lateral vaginal swabs in all women presenting with vulvovaginitis symptoms and/or for STI screening (based on Health Canada recommendations, it includes all sexually active women under the age of 25, any woman who had sex with an infected person, who have a new sexual partner or more than 1 sexual partner in the last year, or vulnerable populations such as intravenous drug users, incarcerated individuals, sex trade workers, street youth etc.)9.
We offer the SAVS to women who were seen before, and now present for:
- STI SCREENING. If they have a new sex partner or if they think their partner contracted an STI. This is very important in women who use the copper IUD, as it may increase the risk of Pelvic inflammatory disease (PID).
- ASSESSMENT OF RECURRENT VULVOVAGINITIS. If they develop new symptoms, I ask them to come as soon as possible to obtain the SAVS. They can self-medicate if they can’t wait 3-6 days for the results, but after the swabs are taken.
- CONFIRMATION OF SUCCESSFUL TREAMENT. In selected cases, for women who were treated for an STI, and now need a test of cure or a test for reinfection.
My Medical Office assistant is trained that if the patient calls for a “selfie”, as we call SAVS in the office, they need to be seen within 24-72 hours. Patients are then asked to drop in at any time in the office to do the self-swabs. My MOA goes through the ‘how to do it’, and there are instructions in the bathroom wall as well (see attachment 3-4: self-administered vaginal swabs, “selfie”: Yellow Top and Red Top).
We notify the patient the swabs result by email or phone within 3-6 days. If they have a positive test for STIs, they are given an urgent appointment to discuss treatment.
I always emphasize to my patients the difference between STI screening, recommended in all sexually active women under the age of 25, and the Pap smear screening, for early detection of precancerous cells in the cervix, now only required after the age of 2510. (see attachment 5: The Pap smear ad testing for STDs.) I always take every opportunity to educate my patients on STIs prevention and failing that, the screening, diagnosis and the importance of early treatment.
General practitioners and gynecologist should look into incorporating SAVS, if not already doing so, to their practices because they:
- Have equal or better accuracy for STIs detection than physician performed swabs,
- Are preferred by patients, and can be better timed to their symptoms and needs,
- Can be performed promptly before self-medication for vaginitis, and avoid empirical treatment.
I include 2 case reviews (see attachment 6), and the steps required to initiate SAVS in your office (see attachment 7).
Not only independent physicians are offering the self-swabs testing. The BC Center for Disease Control 11 is now also offering self-swabbing (rectal and throat, but not vaginal), urine and blood tests for chlamydia, gonorrhea, HIV, syphilis and Hepatitis C. Patients can registered online, and then go to a LifeLab to get the blood and/or urine work, and they are given a self-kit to take home. What tests are performed depend on a sexual history questionnaire that is completed online. If the results are abnormal, and advise is needed, a Nurse calls the patient to discuss retesting or treatment. The family physician, if there is one, is not included in this drill. Self-swabbing is available in Vancouver, Kamloops, Nelson, Victoria, Langford and Duncan.
- Schoeman SA, Catherine M W Stewart, Booth RA, Smith SD, Wilcox MH, Wilson JD. Assessment of best single sample for finding chlamydia in women with and without symptoms: a diagnostic test study. BMJ. 2012;345:14-14. (View) DOI: 10.1136/bmj.e8013
- Catherine M W Stewart, Schoeman SA, Booth RA, Smith SD, Wilcox MH, Wilson JD. Assessment of self-taken swabs versus clinician taken swab cultures for diagnosing gonorrhoea in women: single centre, diagnostic accuracy study. BMJ. 2012;345:15-15. (View) DOI: 10.1136/bmj.e8107
- Huppert J, Hesse E, Bernard M, Bates J, Gaydos C, Kahn J. Accuracy and trust of self-testing for bacterial vaginosis. J. Adolesc. Health. 2012;51:400-405. (View) DOI: 10.1016/j.jadohealth.2012.01.017
- Barbara Van Der Pol, Williams JA, Taylor SN, et al. Detection of trichomonas vaginalis DNA by use of self-obtained vaginal swabs with the BD ProbeTec Qx Assay on the BD Viper System. J. Clin. Microbiol. 2014;52:885. (View) DOI: 10.1128/JCM.02966-13
- Chernesky MA, Hook 3, Edward W, Martin DH, et al. Women find it easy and prefer to collect their own vaginal swabs to diagnose chlamydia trachomatis or neisseria gonorrhoeae infections. J. Sex. Transm. Dis. 2005;32:729-733. (View with CPSBC or UBC) DOI: 10.1097/01.olq.0000190057.61633.8d
- Papp et al. Recommendation for the laboratory-based detection of chlamydia trachomatis and neisseria gonorrhea – 2014. Centres for Disease Control and Prevention. https://www.cdc.gov/mmwr/preview/mmwrhtml/rr6302a1.htm. Published March 14, 2014. Accessed August 18, 2016 (View) PMID: 24622331
- Page C, Mounsey A, Rowland K. PURLs: Is self-swabbing for STIs a good idea? Fam. Pract. 2013;62:651. (View) PMID: 24288710
- Wiesenfeld H. Screening for Chlamydia trachomatis Infections in Women. N. Engl. J. Med. 2017;376:765-773. (Request with CPSBC or view UBC) DOI: 10.1056/NEJMcp1412935
- Guidelines on sexually transmitted infections. Public Health Agency of Canada. http://www.phac-aspc.gc.ca/std-mts/sti-its/cgsti-ldcits/index-eng.php. Updated April 12, 2017. Accessed August 8, 2016. (View)
- van Niekerk D, Grennan T, Ogilvie G. STI testing and cervical cancer screening: Need for continued STI screening among young people in the era of new cervical cancer screening guidelines. BCMJ. 2016; 58(8):468. (View)
- GetCheckedOnline: Frequently asked questions for health care providers. BC Centre for Disease Control. http://www.bccdc.ca/resource-gallery/Documents/Educational%20Materials/STI/GCO_FAQs_Health%20Providers_February2016.pdf. Published February 10, 2016. Accessed August 8, 2016. (View)