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Untreated chlamydial infection among adolescents and young adults in Baltimore, MD

Elizabeth Eggleston, DrPH1; Susan M. Rogers, PhD1; Charles F. Turner, PhD2, Anthony Roman, MA3; Sylvia Tan, MS1; Emily Erbelding, MD, MPH4

(1) Statistics and Epidemiology, Research Triangle Institute, Washington, DC; (2) Queens College, City University of New York; (3) Center for Survey Research, University of Massachusetts-Boston; (4) Johns Hopkins University School of

Medicine, Baltimore, MD.

Presented atThe 136th Annual Meeting of the American Public Health Association

San Diego, CA • October 25–29, 2008

Phone: 202.728.2080 Email: eeggleston@rti.org

Chlamydia Trachomatis (CT)

Most frequently reported bacterial sexually transmitted infection in the U.S.

348 cases per 100,000 population reported to CDC in 2006 – up 5.6% from 2005

Reported rate among women 3 times higher than among men

Chlamydia: morbidity

Among women, untreated chlamydia may result in pelvic inflammatory disease (a major cause of infertility, ectopic pregnancy, chronic pelvic pain)

Among men, CT associated with urethritis & epididymitis.

Untreated CT infections facilitate HIV transmission among both men & women

Chlamydia surveillance

Laboratories and medical providers required by law to report diagnosed cases of chlamydia.

Reported cases represent only those infections that are detected and, presumably, treated.

Chlamydia infections are usually asymptomatic; 75% women and 50% men have no symptoms.

Surveillance data reflect standard screening practices – CDC recommends testing all sexually active women under age 26 annually.

Monitoring STIs Survey Program (MSSP)

Continuous monitoring of three STIs (CT, Tv, GC) over three years in Baltimore, starting in 2006

Designed to address shortcomings of current surveillance methods (incomplete coverage, skewed in response to screening norms)

Funding provided by NICHD

Collaboration between RTI, Univ. of Mass-Boston, UNC-Chapel Hill, Johns Hopkins Univ. School of Medicine/BCHD

MSSP, continued

Data collection via TACASI interview and mailed-in urine specimens

Study participants: aged 15-35, male and female, English speaking

MSSP, Year 1 analysis

In Year 1 (Sept 06 – Aug 07), 1248 Baltimore residents aged 15-35 completed a TACASI interview; 69% (n=866) provided a urine specimen.

We calculate prevalence estimates of CT in the population.

We assess associations between demographic/behavioral characteristics and CT prevalence using chi-square tests.

We compare our study data to BCHD surveillance data.

All MSSP data are weighted.

MSSP: Estimated prevalence of chlamydia, overall and by gender and race

6.5%

4.2%

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

Pre

va

len

ce

5.1%

1.6%

Female Male Black Nonblack(p=.649) (p=.038)

Overall

4.6%

MSSP: Estimated prevalence of chlamydia by age group

2.2%

11.7%

1.2%

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

15-17 18-23 24-35

Pre

va

len

ce

(p=.0001)

MSSP: Estimated prevalence of chlamydia by marital status and education

0.2%

6.5%

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

Pre

va

len

ce 5.1%

1.6%

Married Not married <HSHS grad

(p=.02)(p=.0001)

MSSP: Estimated prevalence of chlamydia by risk factors

3.1%3.2%

1.4%

3.2%3.3%

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

18.0%

20.0%

Pre

va

len

ce 11.9%

9.4%

(p=.002) (p=.001)

# partners, lifetime # partners, past yr # partners, past yr

15.2%

0-20 21+

10.5%

18.9%

Rsp/partner jailed, past yr?Partner faithful?

yes no/DK no yes

(p=.001) (p=.01) (p=.0003)

0-4 5+ 0-1 2+

MSSP: Estimated prevalence of chlamydia by STI history

4.7%4.2%

3.5%

0.0%

2.0%

4.0%

6.0%

8.0%

10.0%

12.0%

14.0%

16.0%

18.0%

20.0%

Pre

va

len

ce

no

yes

10.6% 10.9%

(p=.006) (p=.007)

Previous Ct diagnosis? Ct Diagnosis in past yr? Partner diagnosed withCt in past yr?

17.3%

(p=.044)

Surveillance data

Cases of CT infection reported to Baltimore City Health Dept. (BCHD) by medical providers and laboratories

Percentages for population prevalences calculated using 2000 U.S. Census reports of population size as denominator

Surveillance data grouped by age using U.S. Census age categories

MSSP data presented for comparison with same age categories

Surveillance data v. MSSP: Estimated chlamydia prevalence, ages 15-34

4.6%

3.6%

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

BCHD Surveillance MSSP

Pre

va

len

ce

Surveillance data v. MSSP:Estimated CT prevalence, by gender and race

1.3%

4.6%

1.1%

5.7%5.3%

6.3%

4.0%

0.0%0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

Female Male Black White

Pre

va

len

ce

BCHD Surveillance

MSSP

Gender Race

Surveillance data v. MSSP:Estimated CT prevalence, by age

4.6%

1.9%

0.7%

8.5%

7.2%

0.7%1.1%

7.1%

0.0%

1.0%

2.0%

3.0%

4.0%

5.0%

6.0%

7.0%

8.0%

9.0%

10.0%

15-19 20-24 25-29 30-34

Pre

va

len

ce

BCHD Surveillance

MSSP

Age Group

Conclusion

Nearly 5% of 15-35 year-olds had an undetected chlamydial infection in MSSP.

CT prevalence slightly higher among males and among blacks, but small sample sizes limit generalizability of these findings.

Infections most prevalent among 18-23 year olds, those with least education

Having multiple partners strongly associated with CT infection, even as few as 2 in past year.

Previous infection strong predictor of current infection.

Conclusion, continued

Comparison of MSSP to surveillance data suggests that undiagnosed, untreated CT infections among 15-34 year-olds exceed diagnosed/reported infections by a factor of 1.3.

Ct prevalence in MSSP higher among males than females, while opposite pattern emerges in surveillance data -- suggesting need for increased Ct screening among males.