IN THE UNITED STATES, CHLAMYDIA and gonorrhea rates are highest among persons aged 15 to 19 years, many of whom attend high school.1 Chlamydia and gonorrhea screening in high schools has been used successfully to identify substantial numbers of infections among adolescents in other cities.2–4 In San Francisco, previous efforts at high school-based screening did not efficiently identify chlamydial nor gonococcal infections.5 However, these previous efforts did not target schools in high-morbidity neighborhoods and did not systematically offer screening to all students. In addition, in 2005 the San Francisco Department of Public Health (SFDPH) identified increases in gonorrhea among black heterosexuals aged 15 to 19 years.6,7 In response to this increase in gonorrhea, and by using a new screening model developed in Philadelphia3 to increase participation, SFDPH conducted school-based screening among 11th and 12th graders at 2 high schools located in neighborhoods with high rates of chlamydia and gonorrhea among adolescents.
Planning at SFDPH and approval by school district administrators took place during an 8-month period (September 2006 to May 2007). Two high schools with total enrollment >500 students located in neighborhoods with high adolescent chlamydia (2945–7598 per 100,000 population) and gonorrhea rates (491–2669 per 100,000)8 and with student populations ≥15% black (San Francisco is 7% black)9 were selected for chlamydia and gonorrhea screening. The selected schools were academic schools and did not have specific admission criteria; they were not charter, magnet, or alternative/disciplinary schools. After approval was obtained at the school district level, we met with school nurses, teachers, principals, students, and parents to inform them and to obtain their input on the screening program. Parents were also informed by mailed letter. By California law, parents can opt their child out of sexually transmitted disease (STD) education sessions but not screening.
Testing and follow-up procedures were modeled after a similar program used successfully in Philadelphia3 and were designed to maximize student privacy and participation. Screening activities (except specimen collection) took place in students’ English classroom. Students attending English class viewed a 10-minute presentation about chlamydia and gonorrhea and describing testing procedures. Each student received a form to collect demographic and locating information, a paper bag, urine cup, STD fact sheets, and referral cards to local clinics. Students indicated their desire to test by returning a urine specimen in the cup provided and enclosed in a paper bag; those students declining testing returned a paper bag containing an empty cup. Nonsexually active students were discouraged from testing. To ensure confidentiality, students decided whether to test in a private bathroom stall. All students were encouraged to fill out a demographic form and to visit the bathroom, and all students returning a bag (whether they returned a urine specimen) and the demographic form were eligible for a prize drawing. There were 12 prizes available ranging in value from $10 to $80. To minimize disruption to school and maximize efficiency of program procedures, 11 SFDPH staff were used per day. Specimens were tested for Chlamydia trachomatis and Neisseria gonorrhoeae by using transcription-mediated amplification (Aptima, Gen-Probe, Inc., San Diego, CA).
A single SFDPH staff member used the students’ preferred contact information supplied on the demographic form to contact students who tested positive or who won a prize. Students who tested positive were supplied with field-delivered therapy at a time and location convenient for the student. They were also given treatment to take to their sex partners (patient-delivered partner treatment) according to routine SFDPH practice.10,11 Test results were available to students only; not parents or teachers.
Screening occurred during 5 days in May 2007. A total of 967 students were eligible for testing on the basis of student enrollment rosters; 114 were absent from school on testing days, leaving 853 students (88%) who viewed the presentation (Table 1). Of these, 21 students (2%) declined to participate, 295 (35%) did not return a urine specimen, and 537 (63%) returned a urine specimen for testing. Students who returned a urine specimen were predominately heterosexual (93%) and nonwhite (65% Asian/Pacific Islander; 14% black; 19% Hispanic). Participation was highest among our primary target population of black adolescents; participation was 80% (74 of 93) among blacks, 74% (98 of 132) among Hispanics, and 59% (342 of 581) among Asian/Pacific Islanders. Participation increased with increasing age.
No students tested positive for gonorrhea; 7 (1.3%) tested positive for chlamydia (Table 1). Chlamydia positivity by sex was 2.2% (5 of 227) for female students and 0.6% (2 of 310) for male students. Chlamydia positivity by race/ethnicity was 5.4% (4 of 74) for blacks, 2.0% (2 of 98) for Hispanics, 0.3% (1 of 342) for Asian/Pacific Islanders, and 0% (0 of 4) for whites. The subgroup with the highest positivity was black female students: 9.3% (4 of 43). All students testing positive were provided treatment and patient-delivered partner therapy. Not including planning, follow-up, and school district staff time, the 5 test days expended 440 hours of SFDPH staff time; each case identified used 63 SFDPH staff hours.
As has been previously demonstrated in San Francisco and elsewhere, we determined that high school-based STD screening in San Francisco was feasible. However, despite high participation rates among students attending school in high-morbidity neighborhoods, only a limited number of chlamydial infections and no gonococcal infections were identified.
Published reports from school screening programs in other cities have demonstrated positivity to be higher than identified in this program. In Philadelphia and New Orleans, chlamydia positivity was 8.1% and 9.7% among female students and 2.5% and 4.0% among male students, respectively.3,4 The reasons for low numbers of infections identified are likely multiple. First, among 61 states and cities participating in the 2005 Youth Risk Behavior Surveillance Survey, San Francisco high school students in 9th to 12th grades had the lowest prevalence of lifetime sexual intercourse (29.9% among female students and 32.6% among male students; 32% among 11th graders and 42% among 12th graders).12,13 Second, although attendance was high, adolescents who are at highest risk for STDs might not be enrolled in school,14 they might be incarcerated, or they might attend an alternative/disciplinary school.3 Third, public school students in San Francisco do not necessarily attend neighborhood schools but can be assigned to schools throughout the city for multiple reasons, including parent choice, academic achievement, and student diversity. This might have diminished the impact of selecting schools on the basis of neighborhood STD rates. An additional reason for the low prevalence of infection identified might, in part, be explained by nonsexually experienced students submitting a specimen for testing. Although the brief presentation and individual staff discouraged nonsexually active students from testing, the participation rate (63%) was approximately double the rate of sexual experience among San Francisco high school students participating in the 2005 Youth Risk Behavior Surveillance Survey. However, participation increased with increasing age, a pattern expected if only sexually experienced students participated.
Positivity (and participation) was highest among black students as was demonstrated in Philadelphia.3 Positivity was substantially higher among female students compared with male students. This was also demonstrated in other cities3,4 and settings (e.g., youth detention centers).15 The positivity among black female students in our program approached the positivity found in other successful screening programs.3,4 This might justify targeting screening to female students only if such a policy were determined to be acceptable to students, parents, administrators, and public health officials.
School screening did have substantial benefits. The program provided evidence that STD rates are low in this population, information that is important for future program planning. It once again facilitated important collaboration between SFDPH and the school district, and it reminded approximately 1000 students of the importance of maintaining their reproductive health through regular STD screening and condom use. Nevertheless, school screening involved a substantial investment of resources.
Although other school screening programs have successfully identified a high prevalence of infection in geographic regions with high chlamydia and gonorrhea rates,2–4 the yield from screening in high schools in San Francisco has been consistently low.5 Screening in high schools might not be an efficient use of limited resources in jurisdictions with moderate to low prevalence of chlamydia and gonorrhea. STD control programs considering screening in schools should consider local epidemiology and whether schools have substantial proportions of students likely to be at high risk for STDs. If found to be locally acceptable, control programs might consider screening female students only. Finally, SFDPH is considering other methods for reaching black adolescents including using fewer DPH staff to screen students at nontraditional high schools (e.g., charter schools or alternative/disciplinary schools) that have a higher proportion of black students and through social network interventions.
1. Centers for Disease Control and Prevention. Sexually Transmitted Disease Surveillance, 2005. Atlanta, GA: US Department of Health and Human Services, 2006. Available at: http://www.cdc.gov./std/stats05/toc2005.htm
. Accessed June 2007.
2. Burstein GR, Waterfield G, Joffe A, et al. Screening for gonorrhea and chlamydia by DNA amplification in adolescents attending middle school health centers. Opportunity for early intervention. Sex Transm Dis 1998; 25:395–402.
3. Asbel LE, Newbern EC, Salmon M, et al. School-based screening for Chlamydia trachomatis
and Neisseria gonorrhoeae
among Philadelphia public high school students. Sex Transm Dis 2006; 33:614–620.
4. Cohen D, Nsuami M, Etame R, et al. A school-based chlamydia control program using DNA amplification technology. Pediatrics 1998; 101:E1.
5. Kent CK, Branzuela A, Fischer L, et al. Chlamydia and gonorrhea screening in San Francisco high schools. Sex Transm Dis 2002; 29:373–375.
6. San Francisco STD Prevention and Control Services. San Francisco Sexually Transmitted Disease Monthly Report, January 2006. San Francisco, CA: San Francisco Department of Public Health, 2006. Available at: http://www.dph.sf.ca.us/Reports/STD/STD0601.pdf
. Accessed June 2007.
7. San Francisco STD Prevention and Control Services. San Francisco Sexually Transmitted Disease Monthly Report, September 2005. San Francisco, CA: San Francisco Department of Public Health, 2005. Available at: http://www.dph.sf.ca.us/Reports/STD/STD0509.pdf
. Accessed June 2007.
10. Steiner KC, Davila V, Kent CK, et al. Field-delivered therapy increases treatment for chlamydia and gonorrhea. Am J Public Health 2003; 93:882–884.
12. Eaton DK, Kann L, Kinchen S, et al. Youth risk behavior surveillance—United States, 2005. MMWR Surveill Summ 2006; 55:1–108.
13. Steiner KC, Kent CK, Pham P, et al. Risk factors associated with sexual behaviors and STDs in San Francisco High School Students. Presented at: the National STD Prevention Conference; 2004; Philadelphia, PA. Poster; not available online.
14. Crosby RA, Diclemente RJ, Wingood GM, et al. The protective value of school enrolment against sexually transmitted disease: A study of high-risk African American adolescent females. Sex Transm Infect 2007; 83:223–227.
15. Barry PM, Kent CK, Scott KC, et al. Optimizing sexually transmitted infection screening in correctional facilities—San Francisco, 2003–2005. Sex Transm Infect 2007; Aug; 83(5):416–418.