Self-testing is accurate & removes the stigma of checking for STIs
If the COVID-19 pandemic taught us anything, it’s the value of testing for infection at home without the need to visit a health facility. Now a series of studies have found that testing for sexually transmitted infections (STIs) in the privacy of your own home has the potential to improve treatment by removing the stigma associated with maintaining sexual health.
The other thing that occurred over the years following the arrival of the COVID pandemic was an increase in STIs. According to the Centers for Disease Control and Prevention, between 2020 and 2021 reported US cases of chlamydia and gonorrhea increased by 4% and syphilis by 32%, making detection and treatment of these curable diseases a priority.
Self-testing already exists for HIV and the hepatitis C virus, prompting researchers, led by Monash University, to undertake a world-first global systematic review of studies of syphilis self-testing (SST) to evaluate its value.
“The COVID-19 pandemic has shown us the value of self-tests,” said Jason Ong, corresponding author of the study. “Syphilis self-testing is a key that unlocks the door to widespread testing and treatment, much like self-testing has done for HIV, hepatitis C and COVID-19.”
Transmitted during oral, vaginal and anal sex, in pregnancy and through blood transfusion, syphilis is a preventable, curable bacterial STI that can lead to serious health issues if untreated.
The researchers considered 11 publications from seven studies between 2000 and 2022 that included data on any syphilis rapid tests or dual HIV-syphilis tests. SST was defined as any test performed by someone who collects a specimen, performs the test, and interprets the results themselves.
Analyzing the data, the researchers considered test accuracy, usability, the proportion of participants who performed the test (uptake), the number of participants who tested positive for syphilis, linkage to sexual health services or confirmatory testing after testing positive, cost, and any harm that followed testing, such as self-harm, pressure to test or disclose results.
They found a relatively high uptake and acceptability of SST and a lower cost per person compared with facility-based testing. Participants reported convenience, privacy, rapid results, autonomy, empowerment, decreased contact with facilities and money or time savings as reasons for using SST. However, some important challenges were noted, including a lack of knowledge of SST and STIs, and privacy concerns when using apps or social media to report results.
Overall, though, the researchers found compelling evidence that SST was safe, acceptable, effective to implement, and cost-effective, particularly among individuals that would ordinarily fall outside of existing health services. They concluded that the potential benefits of SST outweighed any potential risks.
“If we can improve access to self-testing for syphilis, we can also have a major impact on the current syphilis epidemic in Australia and beyond,” said Ong. “This has global policy implications for countries to license and allow syphilis self-testing kits to be accessible, so that populations who are less likely to attend facilities to test are able to test themselves privately, accurately and at their convenience.”
Meanwhile, two studies presented at the 2023 Annual Scientific Meeting and Clinical Lab Expo in Anaheim assessed the reliability of self-tests to detect common STIs, human papillomavirus (HPV), chlamydia and gonorrhea. The Expo is put on by the Association for Diagnostic and Laboratory Medicine, formerly the American Association for Clinical Chemistry (AACC).
HPV is the leading cause of cervical cancer, a common virus that’s passed from one person to another during sex. Currently, HPV is detected by way of a cervical swab taken in a clinical setting.
In one study, researchers from LetsGetChecked Laboratories and the Permanente Medical Group compared the performance of 144 pairs of self-collected and provider-collected cervical swabs to test for HPV. Some of the self-collected specimens were exposed to temperatures that simulated extreme weather fluctuations. They found that most self-collected samples provided the same results as provider-collected ones. Discrepancies were due to smaller amounts of detectable virus on the samples, caused by exposure to extreme temperatures. Sample validity improved by 8.5% when participants were shown an instruction video.
In another study, researchers from the Los Angeles County Department of Public Health and LetsGetChecked Laboratories compared provider-collected and self-collected tests for the bacteria Chlamydia trachomatis and Neisseria gonorrhoeae, which cause chlamydia and gonorrhea.
Chlamydia is a very common STI that, if left untreated, can cause pelvic inflammatory disease in women and lead to chronic pain and infertility. In men, untreated chlamydia can cause testicular pain and swelling. Gonorrhea can cause infection in the genitals, rectum, and throat. It can lead to infertility in women if left untreated. Both STIs often present without symptoms.
The researchers compared results from 164 pairs of provider-collected and home-collected rectal swabs and 159 pairs of throat swabs. They also assessed urine and vaginal swabs for the impact of temperature fluctuations, hand contaminants, and under- or overfilling of self-collected urine samples.
Compared to provider-collected samples, the self-collected rectal swabs showed 95.5% agreement for detecting the bacteria that caused chlamydia and 100% for the gonorrhea bacteria. Self-collected throat swabs agreed with provider-collected swabs for both infections almost 100% of the time. Interestingly, several self-collected swabs picked up both bacteria, whereas the provider-collected ones didn’t. Hand contaminants were found to have little impact on test performance, and results were largely unaffected by temperature changes and improper filling of urine samples.
“Self-collected rectal and throat swabs could offer better sensitivity than those collected by physicians for detecting C. trachomatis and N. gonorrhoeae – without comprising the test’s analytical performance,” said Brendan Hockman, one of the study’s authors. “Therefore, specimens of STIs collected at home offer a viable option for improving access to STI screening and could offer a non-stigmatizing approach to sexual health.”
Each of these studies suggests that self-testing for STIs is not only accurate and cost-effective but could also reduce the global impact of these diseases in a way that is private and removes stigma.
The Monash University study was published in the journal The Lancet Public Health.