MIAMI — At-home tests involving self-collected vaginal samples that are sent to a lab for analysis are effective at identifying women with sexually transmitted diseases, suggests a pilot study presented at the annual meeting of the American College of Preventive Medicine.
“This may be another tool that we can use to reach out of the clinic and to save money. You can save a lot of money if you don't have to pay clinicians to collect the samples,” said Charlotte A. Gaydos, Dr.P.H., a microbiologist in the division of infectious diseases at Johns Hopkins University, Baltimore.
The researchers established a Web site (www.iwantthekit.org
Data from 778 samples that had been analyzed as of Jan. 31, 2007, 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 kit includes swabs for collecting vaginal samples and a questionnaire on demographics, sexual history, and the participants' opinions about at-home testing.
“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. Participants received their test results via a toll-free number. A study coordinator arranged treatment appointments at a free local clinic for women with positive results.
So far, most 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 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, but those who tested positive tended to be younger. 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 controlling 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.
More than half of the participants reported a history of STDs; 40% had a history of chlamydia and 15% reported a history of gonorrhea.
Results of the questionnaires showed that on a Likert scale of 1 to 5, 96% said the sampling process was “easy” or “very easy” and 93% said 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 current protocol, participants calling the toll-free number give the kit number and a password that they chose to ensure confidentiality.
Even with the phone-in method of requesting results, the success in recruiting patients for home sampling and treating those who test positive is encouraging, Dr. Gaydos added.
A test kit for men is also promoted on www.iwantthekit.org