Internet-Based Screening for Chlamydia trachomatis to Reach Nonclinic Populations With Mailed Self-Administered Vaginal Swabs

Abstract

Background: 

Testing for Chlamydia trachomatis by nucleic acid amplification tests (NAATs) using self-collected vaginal swabs (VS) is acceptable and accurate. The objectives were to implement an educational Internet-based program for women to facilitate home screening, to determine whether women would request and use self-collected VS kits, to determine associated risk factors for infection, and to determine satisfaction with the process.

Methods: 

The website, www.iwantthekit.org, was designed to encourage women ≥14 years to obtain home-sampling kits. Kits could be obtained in the community, requested by Internet/e-mail, or telephone. Users mailed the self-collected VS to the laboratory. Swabs were tested by 3 NAAT assays. Respondents called for results.

Results: 

Forty-one of 400 (10.3%) women were chlamydia positive; 95.1% were treated. Questionnaires indicated 89.5% preferred self-collection, 93.5% rated collection easy/very easy, and 86.3% would use the Internet program again. Black race and age <25 years were associated independently with being chlamydia positive, while use of birth control and nonconsensual sex were protective. Thirty-six of 41 (87.8%) positive samples were positive by all 3 NAATs, 5/41 (12.2%) were positive by only 2 NAATs, and none were positive by only 1 NAAT. The Internet/e-mail request method was better than the community pick-up approach because 97.2% of kit requests were e-mailed and 87.5% of kits returned for testing were e-mail requested.

Conclusions: 

Women will use the Internet to request and use home-sampling kits for chlamydia. NAAT testing performed well on dry-transported VS. High prevalence was detected and questionnaires indicated high-risk sexual behavior.

In Brief

Screening for chlamydia using Internet recruitment and mailed self-collected vaginal swabs yielded a prevalence of 10.3% in 400 women.

FEMALES HAVE THE HIGHEST rates of infection with Chlamydia trachomatis, the most prevalent bacterial sexually transmitted disease (STD) in the United States.^1,2 Many women do not attend clinics for screening, due to the asymptomatic nature of chlamydia infections. Additionally, many women fear pelvic examinations, have financial barriers, or wish to avoid parental involvement.^3,4 Early diagnosis of chlamydia and treatment are necessary to prevent transmission of the disease and its sequelae, i.e, pelvic inflammatory disease, ectopic pregnancy, infertility, and chronic pelvic pain.^5–8 Thus, widespread screening of asymptomatic women for chlamydial infection is important.

Nucleic acid amplification tests (NAATs) for detection of chlamydia offer specimen options and the ability to avoid clinics and invasive examinations.^9,10 NAATs can be performed using urine, vaginal, or cervical specimens for chlamydia.^11,12 Self-collected vaginal swabs (VS) are highly acceptable,^13–15 easy to collect, and do not require a clinician.¹⁶ VSs, tested by NAATs, have been used for chlamydia testing, with results similar to standard diagnostic tests.^11,17,18 VSs offer the advantage of allowing a woman to obtain her own sample and visit a clinician only if she is infected.^19,20

Women are Internet users and access websites for information regarding STDs.²¹ The Internet is also used by people seeking sex partners, and they appear to be at greater risk for STDs.²² The proportion of children reporting a personal computer in their home increased by 13 percentage points (from 73% to 86%); from 1999 to 2004, 8 in 10 Internet users have looked for health information online, and 79% of Internet users have searched online for information on at least 1 major health topic, according to the Pew Charitable Trusts.²³ One patient recently reported favoring the use of e-mail to communicate with a physician.²⁴ We offered women the ability to acquire information about chlamydia and the opportunity to obtain self-screening in a confidential manner through the Internet. Assisted by focus groups,²⁵ an Internet-based chlamydia program was developed to encourage women to participate in a VS screening program. Objectives of this study were to institute an educational Internet-based program for women to facilitate home screening for chlamydia using self-collected VS kits, to determine whether women would request and use the kits, to determine associated risk factors for infection, and to determine their satisfaction with the process.

Methods

The study provided free kits, testing, and treatment to women ≥14 years, who resided in the state of Maryland. We advertised the study by placing flyers in schools, hospitals, and the community, as well as announcements on a local radio station. There were notices placed in the City Paper and the magazine Smart Woman. The study was approved by the institutional review boards of Johns Hopkins University, the Baltimore City Health Department, and the state of Maryland. Step-by-step simple written collection instructions, including a diagram of the female genital tract showing where to collect the sample, were included in the kits, as well as shown on the website.

Website Design and Development

Using results of the prestudy focus groups, Fingerprint, Interactive, Philadelphia, PA, assisted with the structure and composition of the website, www.iwantthekit.org. The home page was designed to be attractive to women (Fig. 1). Several linked pages covered educational topics about chlamydial disease, testing, and treatment. Text was designed at an 8th-grade reading level. The page headings included “About Chlamydia,” “Chlamydia Testing,” “Chlamydia Treatment,” “Resources,” and “Questionnaire” (Appendix A).

Fig. 1: Home Internet webpage of www.iwantthekit.org.

Obtaining a Kit and Placement of Kits in the Community

Included under “Chlamydia Testing” on the website was a map of Maryland. Viewers could click on a jurisdiction (Baltimore City or any of 23 counties) for locations that could provide kits. Approximately 250 community sites that agreed to stock kits included 6 major pharmacy chains (identified by the individual pharmacy’s name and address), recreation centers, and the emergency department of a hospital. A visitor could also select a link on the website to initiate a confidential e-mail message requesting a kit and provide her addresses to the study coordinator, who would mail a kit to her home in a plain envelope. The website provided a toll-free and a local number that could be used to request a kit through the mail.

Components of the Self-Collected VS Kit

Prenumbered kits consisted of kit instructions, a sterile swab, a contact information form, a questionnaire, 2 consent forms (1 copy for the participant to keep), instructions including a female anatomy diagram for self-sampling the vagina, and postage-paid return mailer. All kits were prenumbered, and community placement locations or zip codes for mailed kits were recorded. Users were asked to read the instruction sheet, to sign a consent form, and to complete the contact form, indicating a reminder method (cell phone, e-mail, or post card) in case they did not call for their results. Participants were instructed to self-collect the VSs, to place them in the swab holders in a “dry state,” and seal them in the plastic biohazard sealable bags. The swabs, the consent forms, the contact forms, which also collected basic demographic information without identifiers, and the completed questionnaires with the kit number were mailed to the laboratory. A preaddressed, postage-paid envelope was provided in accordance with U.S. Postal Service publication number 22, “Hazard, Restricted, and Perishable Mail” (July 1999). Questionnaires could also be completed on the Internet. Respondents were instructed to call a toll-free number for test results in 1 to 2 weeks with their kit numbers and passwords.

Test Methods

In the laboratory, the “dry” swabs were rehydrated with 800 μl of Tris borate buffer (pH 7.4), aliquoted into 3 tubes, and tested by 3 different NAATs: polymerase chain reaction (PCR, Roche Amplicor, Indianapolis, IN), strand displacement amplification (SDA, Becton Dickinson ProbeTec, Sparks, MD), and transcription mediated amplification (TMA, Gen Probe APTIMA Combo 2, San Diego, CA). At least 2 positive tests were required before calling a specimen positive, so that all positive samples were confirmed by another test.

Results and Treatment.

When a participant called for results, she was required to give her kit number and password. The project coordinator worked with the infected women individually to select a treatment clinic, to which results were faxed. Participating clinics were listed on the website so that women could see clinic locations. After an appointment was scheduled by the coordinator, the individual was notified. The coordinator contacted the clinic later to verify that treatment was given. Treatment consisted of 1 g of azithromycin in accordance with the Centers for Disease Control and Prevention (CDC) STD treatment guidelines.²⁶

Statistical Analysis.

χ² tests of the questionnaire data were performed for the univariate analysis, and logistic regression was performed using the statistical software package Statistical Analysis Software (SAS, version 9.0; Cary, NC). P values of ≤0.05 were considered significant.

Results

Kit Placement in the Community and Requests for Kits

A total of 1254 kits with instructional letters were placed in the community after approval from the pharmacy corporate offices or sites. Of the 1168 kits requested for direct mailing to homes, 97.2% of requests were received by website e-mail and 2.7% by telephone.

Kits Received for Testing

Between July 2004 and January 2005, 400 kits were received by mail for testing. The majority of kit submitters, 350/400 (87.5%), requested kits by e-mail. Only 31/400 (7.8%) kits were requested by telephone; 15/400 (3.8%) were picked up at pharmacies, and 4/400 (1%) came from other community sites. Most participants (67.8%) came from Baltimore City and 32.2% were from Maryland counties. The mean and median for the transit times from date of collection to receipt by the laboratory of the samples that tested positive for chlamydia (range 1–40 days) were 6.3 days and 4 days, respectively.

Demographics of Study Participants

Of the 400 women, 65.5% were black and 26% were white, 7.3% were other races, and 1.3% were unidentified (Table 1); 89% were non-Hispanic, 3.3% were Hispanic, and 7.8% did not report. The mean age was 26.1 years (median age 23 years, range 14–63 years), while the mean and median ages of positives were 21.8 and 19 years, respectively. By age, 28.5% were ages 14 to 19 years, 26.2% were 20 to 24 years, and 45.3% were ≥25 years (3 did not report).

TABLE 1: Demographic and Risk Factor Data From Questionnaires Completed by 400 Self-Administered Swab Users

Results of Testing Procedures

Of mailed swabs, 41/400 (10.25%) were chlamydia positive. Treatment was verified for 39/41 (95.1%) women. Prevalence by race included 13.7% for black, 2.9% for white, and 6.9% for all other races: 15.4% for those listing “other race” and no prevalence for 5.3% of additional races (Asian, Native American, or multiple races). The prevalence for blacks was statistically higher than all other races combined (3.8%) (P = 0.0027). None of 13 Hispanic participants were chlamydia positive. Prevalence was 18.6% for those 14 to 19 years, 9.6% for 20 to 24 years, and 5.6% for ≥25 years (Table 1). There was no statistical difference between the prevalence for the 2 younger age groups; however, the aggregate prevalence for those <25 years (14.4%) was statistically higher than for those women ≥25 years (5.6%) (P = 0.0076). Thirty-six of 41 (87.8%) positive samples were positive by all 3 NAATs, while 5/41 (12.2%) were positive by only 2 NAATs. There were no samples only positive by 1 NAAT.

Results of demographic and risk factor analysis are shown in Table 1. Questionnaire data obtained from kit users demonstrated a high behavioral risk: vaginal sex in the previous 3 months (88.9%), new or multiple sex partners (∼50%), lack of consistent condom use (85.4%), previous history of an STD (48.7%), drinking during sex (∼50%), and having a partner with a history of an STD (17.1%). Only 29% reported a pelvic examination in the last year. Oral sex and rectal sex were reported with high frequency, as was nonconsensual sex (Table 1). The only significant behavioral differences between those who were infected with chlamydia and those uninfected by univariate analysis were a history of oral and nonconsensual sex, both of which were protective (Table 1).

Logistic regression analysis with backward selection performed in the model indicated that factors independently associated with being chlamydia positive were black race and age <25 years (Table 2). Both nonconsensual sex and use of birth control were protective of being chlamydia positive (Table 2). Variables included in the model were race, age, number of partners, oral sex, use of birth control (including condom use), having a partner with an STD, nonconsensual sex, and prior chlamydia infection.

TABLE 2: Logistic Regression Analysis of Factors Associated With Chlamydia trachomatis Infection

Preference Results

Of 400 questionnaires received from swab submitters, 89.5% preferred to collect a self-administered test sample, Table 3. Preference of sampling method included self-collected VS, 54.3%; urine, 8.8%; either self-collected VS or urine, 12.8%; and pelvic examination, 12.8%. The total percentage of women preferring a self-collected sample was 75.9%. Although 87.8% thought self-collected VS was safe, there were some (1.8%) who thought it was not safe. For ease of collection, 90.5% rated collection easy or very easy, and 86.3% would use the Internet sampling method again. Most women (72.5%) stated they would prefer to have a kit mailed directly to their homes rather than pick one up in a pharmacy (6.3%).

TABLE 3: Preference of Use of the Internet and Self-Administered Vaginal Swabs (SAS) From 400 SAS Users (Participants Taking the Questionnaire Provided With the Kit or “On-Line” After Collecting the Swab) and From 108 Nonusers of Kits Who Took the Questionnaire “On Line” (χ² for Kit Users Versus Internet Respondents; P Value ≥0.05 Considered Significant)

There were 108 women who did not use the self-collected VS kit but took and submitted the questionnaire on the Internet to express their opinions about home sampling and the use of VSs (Table 3). Most answers were similar to those given by users of the kit, except for preferences for pelvic examinations, use of urine as a sample, and a preference to pick up kits from a pharmacy. The number who stated they preferred to have a pelvic examination for sample procurement was 27/108 (25.0%); this was statistically different from the users of the home sampling kit (12.8%) (P = 0.003). More expressed a preference for urine as a sample (P = 0.003) and more preferred to pick up a kit at a pharmacy (P = 0.003) (Table 3). Counts of “hits” for accessing the website indicated an average of 31,882 hits per month during the study period. The educational component of the website appeared to be well used because data for time spent per page indicated that participants spent the most time on the “how to stay healthy” page.

Discussion

Results of our study indicate that women will use the Internet to request and use home collected VSs for chlamydia testing. The Internet/e-mail request method was much better than the community pick-up approach because 97.2% of kit requests were e-mailed and 87.5% of kits returned for testing were requested by e-mail. Previous focus group discussions about the website design and collection kits had indicated enthusiasm for the availability of a home sampling kit.²⁵ The concerns expressed were used to guide implementation of the study and were similar to those reported in other studies: issues of privacy, confidentiality, stigma, fear of doctors and pelvic examinations, cost, and embarrassment of being seen at STD clinics.^3,27 Almost all women in this study used Internet-linked e-mail to request a kit be mailed to their homes, supporting a preference for “Internet ordering.”

A high prevalence of chlamydia infection was detected, which was higher than that observed in family planning clinics in Baltimore.^28,29 The 10.3% overall prevalence was similar but slightly lower than that observed in high schools in Baltimore; however, the prevalence for the 14- to 19-year age group was almost identical.^30–32 As in other studies and surveillance reports, the prevalence was statistically higher for blacks and those women <25 years of age.^2,9,10,33

High-risk behavior was found in users of the kit, similar to that reported in other epidemiologic studies.^9,34 Especially noteworthy was that 33.7% reported a previous history of chlamydia infection, which has been noted by the CDC as a highly predictive risk factor for a repeat infection.³⁵ Because 85.6% reported “not consistent condom use” in our study, reinfection from an untreated partner would appear to have a high probability.³⁶ In Denmark, where Kjaer and colleagues³⁷ have pioneered use of mailed samples, 84% of chlamydia-positive patients who were rescreened demonstrated a reinfection rate of 29%. Frequent rescreening of previously infected women, as recommended by the CDC, could be accomplished by Internet self-collected VS recruitment of previously infected individuals.³⁵ This option for follow-up could be discussed with infected women during their clinic encounters.

Logistic regression indicated 2 demographic factors, namely, black race and age <25 years, as being independently associated with chlamydia positivity, similar to other studies.^9,10,34 Both nonconsensual sex and report of use of birth control, which also included condom use, were significantly associated with being protective of chlamydia infection. We could not explain why the nonconsensual sex was associated with protection, except to hypothesize that abusers may have also used condoms.

Supporting the hypothesis that the Internet screening method may reach a group of high-risk women not accessing traditional health care was the finding that only 29% of the kit users had received a pelvic examination within the previous year. A limitation of this conclusion is that the women may have been screened elsewhere by noninvasive NAAT assays. However, knowledge of being chlamydia infected did prompt most women (95.1%) to report to a clinic for treatment. Although we did not ask for names of partners or perform partner notification, women who were treated were given a “referral card” with the address of the STD clinics to give to their partners. It may have been beneficial to offer partner-delivered treatment for the infected woman to give to her partner³⁸; however, this approach is controversial, and there is merit in having the partner visit a clinic to have a complete examination for other STDs.

As indicated by our focus groups,²⁵ almost 90% of women in this study preferred to collect their own specimens. Over half of the women who used “the kit” stated a preference for the VS, while almost 13% said either a swab or urine was preferred, and 8% preferred a urine sample. Conversely, some preference studies have found that adolescent women preferred to collect a urine sample rather than a VS, whereas self-collection using the VS was preferred to a physician visit and a pelvic examination.³⁹ Similar to our study, female prisoners and females in various community settings demonstrated either a preference for self-sampling using VSs or no preference between swab and urine.^13,15 Female military recruits reported that urine was the easier method but generally found self-collected VSs acceptable, especially at home.¹⁴ Our data support the concept that the VS method is an acceptable alternative to being tested in a clinic. In our study, 86.3% of participants reported they would use the Internet-based swab system again.

Women requested that nearly 1200 kits be mailed to their homes; 400 kits were received for testing in the first 6 months. It is unknown why more kits were not returned, but our participation rate appeared similar to postal home sampling studies.⁴⁰ Systematic postal screening for chlamydia in the United Kingdom demonstrated that of 19,773 men and women, 73% were contacted and 34.5% accepted chlamydia screening, a percentage similar to our return of 34.2% of requested kits.⁴⁰ Unlike our prevalence rate of 10.3%, with an 18.6% prevalence in those 14 to 19 years and 14.3% in those ≤25 years, the United Kingdom study detected a prevalence of 3.6% in women and of 6.2% in women <25 years.⁴⁰

Mailing of the VSs in a dry state was satisfactory for maintaining DNA or RNA for analysis in the 3 different commercial tests used.¹⁷ Because 2 tests were required to be reactive for a positive result, the likelihood of a false-positive test in any low-prevalence population using the SAS was reduced. False-negative results could have occurred using dry-transported swabs for NAAT testing, as these tests are not perfect, but we believe that there is good nucleic acid stability of the dry-transported swab based on previous experience in our laboratory.

Although nearly half of the women in this study were ≥25 years, with a prevalence of 5.6%, the Internet-SAS method of screening may be especially appealing to those adolescents who desire confidentiality. The American College of Obstetricians and Gynecologists’ Committee on Adolescent Health Care reported that privacy and confidentiality are important and limit access to STD services. Sexually active teens may not seek clinical care and testing for STDs.¹⁹ The National Initiative to Improve Adolescent Health by the Year 2010 has emphasized the need to reduce the proportion of young adults with C trachomatis infections and “challenges the Nation to create new ideas, methods, and strategies to move forward in promoting adolescent health.” Because adolescents are frequent users of the Internet, often accessing it for information regarding STDs,²¹ innovative Internet-SAS programs to promote chlamydia screening could help meet this challenge. Better advertising of the availability of the program in high schools and colleges, as well as on websites that teens use, may better focus this program towards those less than 25 years, who appear to have more risk.

Offering information about chlamydia and home screening using the Internet self-collected VS may be most beneficial among young sexually active women who might not seek STD services in a clinic. Parental support and costs are often barriers to accessing clinic services for adolescents.⁴ The ease, confidentiality, and privacy afforded by the Internet program may encourage these young women to use “Internet-recruited” chlamydia screening.^19,20 Because the Internet has been frequently used by sexually active individuals to meet and recruit sexual partners, an Internet method, which included men, may reach individuals and their partners who are at high risk for STDs.²² We acknowledge that lack of a computer, income level, and educational level may be limiting factors to Internet-based recruiting women at the highest risk for chlamydia infection. Some data exist to support the Internet can be considered reasonably accessible to urban, low-income blacks who have diabetes.⁴¹ That telephone survey in Baltimore indicated that 40% of urban blacks have a computer but that 82% had friends or family that would let them use a computer. About one third had a mean yearly income ≤$7000, while educational level was not statistically significant for self-reported use of a computer.⁴¹

This study indicated the feasibility of an Internet-based information and testing program for chlamydia using VSs mailed in a dry state. The overall prevalence of chlamydia infection of 10.3%, with an 18.6% prevalence in 14- to 19-year-olds, demonstrated our program provided a valuable service to women in need of testing and treatment. As it represents a new strategy to promote sexual health for a wide age group, it merits further study, assessment of feasibility, cost-effectiveness, ability to return results online in a protected web environment, and usefulness in other geographic areas. We will evaluate possible website changes, our marketing program, and the manner in which information, specimens, and treatment are currently managed.