MIAMI — At-home tests that involve self-collected vaginal samples that are sent to a lab for analysis are effective at identifying women with sexually transmitted diseases, suggest findings from a pilot study presented at the annual meeting of the American College of Preventive Medicine.
“We thought maybe we could reach out and get out of the clinic and encourage asymptomatic women to collect samples at home,” said Charlotte A. Gaydos, Dr.P.H., a microbiologist in the division of infectious diseases at Johns Hopkins University, Baltimore.
Surmising that the Internet might be an effective way to promote such at-home tests, the researchers established a Web site (www.iwantthekit.org
Data from 778 samples that had been analyzed as of Jan. 31 show 71 samples (9%) were positive for Chlamydia trachomatis and 12 (1%) were positive for Neisseria gonorrhoeae. Four samples showed coinfection with chlamydia and gonorrhea. Samples collected since September 2006 were tested for Trichomonas vaginalis, and 13 of 115 samples (11%) tested positive.
The test kit includes sterile swabs for collecting vaginal samples and a questionnaire seeking demographics, sexual history, and the participants' opinions about at-home testing and their preferences for methods to receive test results.
“We require two positive assays for a positive diagnosis,” Dr. Gaydos said. Samples are analyzed using nucleic acid amplification tests (NAATs), which are more than 90% sensitive, compared with the 85% sensitivity associated with cultures. “The NAATs are the best tests there are today; they are very powerful,” Dr. Gaydos said.
Participants received their test results via a toll-free number. A study coordinator arranged treatment appointments at a free local clinic for those women with positive test results.
So far, most of the women who tested positive have been treated, Dr. Gaydos noted. All 11 patients with gonorrhea were treated, as were 66 of 69 (96%) chlamydia cases.
Of the 760 participants who identified their race, 70% were black, 22% were white, and the remainder were another race or mixed race. Chlamydia rates were significantly higher among black women, compared with white women (12% vs. 2%).
The participants ranged from 14 to 63 years of age, with an average age of 23 years, but those who tested positive tended to be younger, and the average age at first sex was 15 years, Dr. Gaydos noted.
Positive tests were most common in the 15- to 19-year-olds (16%), followed by 20- to 24-year-olds (8.5%) and 25- to 29-year-olds (8%).
After the researchers controlled for multiple factors including age and race, the strongest risk factors for positive test results were use of birth control, nonconsensual sex, and multiple partners.
In addition, more than 50% of the participants reported a history of STDs; 40% reported a history of chlamydia, and 15% reported a history of gonorrhea.
Results of the questionnaires that accompanied the kits suggest participants were receptive to the idea of at-home STD testing. On a Likert scale of 1 to 5, 96% said that the sampling process was “easy” or “very easy” and 93% said that they would use it again.
Nearly 25% said they preferred to receive results by e-mail, but a secure Web site to provide results is too expensive at this time, Dr. Gaydos said. Under the current protocol, participants calling the toll-free number give the kit number and a secret password that they chose to ensure confidentiality.
Even with the current phone-in method of requesting results, the success of the Web site in recruiting patients for home sampling and in treating those who test positive is encouraging, he added.
A test kit for men was recently developed, and it is promoted on www.iwantthekit.org