# Presentation: 674038

## Repeat Chlamydial Infections in Region III Family Planning Clinics:Implications for Screening Programs

- Pamela G. Nathanson, Family Planning Council, Inc.
- Mary Dupuis Sammel, ScD and
- Michelle Berlin, MD, MPH
- Center for Clinical Epidemiology and Biostatistics
- University of Pennsylvania Medical Center
- Philadelphia, PA

## Background

- The Region III Chlamydia Project has provided chlamydia screening and treatment for women as part of CDC’s National Infertility Prevention Program (IPP) since 1994.
- All women under age 30 who undergo a pelvic exam are routinely screened for chlamydia in family planning (FP) clinics.
- Approximately 300,000 women are screened annually throughout the 8 project areas (Baltimore, Delaware, Maryland, Pennsylvania, Philadelphia, Virginia, West Virginia, Washington DC).

## Screening Program Issues

- Anecdotal reports from providers suggested high levels of repeat chlamydia infections among women attending family planning clinics.
- Increased efforts around partner management were initiated, with little concrete data on repeat infection rates.
- Some providers wanted to avoid repeat screenings of women testing negative on prior visits, but had no data to support this change in screening practices.

## Objectives

- To determine rates of repeat infections among women screened for chlamydia in family planning clinics in Region III between 1996 and 1998.
- To determine if a low-risk group could be identified that might not require repeat screening over time.

## Methods

- Analysis was conducted on 174,278 tests performed on 73,107 women from 1996 to 1998 in 6 of 8 project areas (Baltimore, Delaware, Pennsylvania, Philadelphia, Virginia, Washington DC).

## Description of Data

**990,847****	****Number of records between 1996-1998**
** ****- 30,139****	****Excluded records from males**
**-161,327****	****Excluded records from non-family planning clinics**
**-247,698****	****Excluded records from 2 areas without unique Ids**
**-----------**
**551,683**** ****	****Records from women with at least 1 visit**
**-354,889****	****Excluded records with only 1 visit**
**----------**
**196,794****	****Records for 85,175 women with multiple visits  **
** ****-22,516****	****Records with discrepancies (mismatched age, etc.)**
**---------- **
**174,278****	****Total  records for 73,107 women****	**

## Methods

- Positivity rates for women with prior positive chlamydia tests were compared to those for women with prior negative tests.
- Variables in the analysis included:
-  age
- time since prior visit
- project area where patient was tested.

## Number of Visits Per Woman

| # of Visits | Frequency | % |
| --- | --- | --- |
| 2 | 53,775 | 73.6 |
| 3 | 14,020 | 19.2 |
| 4 | 3,436 | 4.7 |
| 5 | 1,096 | 1.5 |
| 6-7 | 590 | 0.8 |
| 8-9 | 139 | 0.2 |
| 10-12 | 46 | <0.1 |
| 13-16 | 5 | <0.1 |
| TOTAL | 73,107 | 100.0 |

## Demographic Distribution

| TOTAL | 73,107 | 100.0% |
| --- | --- | --- |
| PROJECT AREA | N | Percent |
| Baltimore
Delaware
Maryland
Pennsylvania
Philadelphia
Virginia
Washington DC
West Virginia | 2,048
6,218
0
31,920
21,589
10,479
853
0 | 2.8%
8.5%
0.0%
43.7%
29.5%
14.3%
1.2%
0.0% |
| AGE (years) | N | Percent |
| 12-14
15-19
20-24
25-29
30+ | 1,346
23,939
22,982
14,487
10,123 | 1.8%
32.8%
31.5%
19.9%
13.9% |

## Infection Rates by Infection Status at Prior Visit

|  | Infected at
Prior Visit | Uninfected at Prior Visit | Rate Ratio |
| --- | --- | --- | --- |
| OVERALL | 19.7% | 3.7% | 5.4 |
| Baltimore n=2,048 | 20.6% | 3.5% | 5.9 |
| Delaware n=6,218 | 13.6% | 3.6% | 3.7 |
| Pennsylvania n=31,920 | 13.1% | 1.8% | 7.2 |
| Philadelphia n=21,589 | 25.7% | 6.1% | 4.2 |
| Virginia n=10,479 | 15.6% | 4.1% | 3.8 |
| Wash DC n=853 | 9.3% | 2.7% | 3.4 |

## Infection Rates by Infection Status at Prior Visit –By Age Group

|  | Infected at
Prior Visit | Uninfected at Prior Visit | Rate
Ratio |
| --- | --- | --- | --- |
| OVERALL | 19.7% | 3.7% | 5.4 |
| 12 – 14 yrs  n=1,346 | 22.4% | 8.7% | 2.6 |
| 15 – 19 yrs n=23,939 | 23.5% | 6.0% | 3.9 |
| 20 – 24 yrs n=22,982 | 18.0% | 3.9% | 4.6 |
| 25 – 29 yrs n=14,487 | 14.8% | 2.3% | 6.5 |
| 30+  yrs     n=10,123 | 11.7% | 1.1% | 10.8 |

## Infection Rates by Infection Status at Prior Visit and Time Since Prior Visit

|  | Infected at
Prior Visit | Uninfected at Prior Visit | Rate
Ratio |
| --- | --- | --- | --- |
| OVERALL | 19.7% | 3.7% | 5.4 |
| < 10 months | 21.5% | 4.3% | 5.0 |
| 10-14 months* | 12.8% | 2.6% | 4.9 |
| > 14 months | 13.2% | 3.8% | 3.4 |

***10-14 months analogous to “routine” or annual visit.**

## Limitations

- Unable to distinguish between new infections, reinfections, and persistent infections.
- Women do not get all of their care at FP clinics, and therefore, we may be missing additional infections diagnosed in other settings.
- Many clinics do not use unique identifiers, and therefore patients from those clinic sites are excluded from the analysis.
- Data on clinical signs and risk history are collected inconsistently, and could not be used in the model.

## Conclusions

- Women screened for chlamydia in family planning clinics who have an initial positive test are at high risk for subsequent infection.
- Chlamydia positivity among women previously infected is higher among young women and women from urban areas, reflecting the higher prevalence of disease in these populations.
- The relative risk of reinfection is greater among women over age 30, perhaps reflecting the higher risk status of women over 30 who are infected at all.

## Conclusions

- Chlamydia positivity among women tested less than a year after a previous infection was higher than that of women tested at an annual visit.
- The relative risk of reinfection was the same for women tested before or at an annual visit, while those tested less often had a lower relative risk of reinfection.

## Implications for the Screening Program

- Are there high levels of repeat chlamydia infections among women attending family planning clinics?
- Yes – With an overall reinfection rate of 19.7%, the data support the rescreening of women testing positive for chlamydia who return for care in FP clinics.
- Should providers screen women only once a year?
- No – Based on substantial chlamydia positivity among women tested less than 10 months from a prior test, rescreening is warranted even if the next visit is within a year of a prior visit.

## Implications for the Screening Program

- Should providers stop screening women who tested negative on a prior visit?
- No - Since chlamydia positivity for women testing negative at a prior visit was greater than 2% overall within the regional screening criteria (age <30), continued screening of all young women attending family planning clinics in Region III is warranted.

## Implications for Future Research

- Since most project areas in Region III have switched to more sensitive amplified testing methods since 1998, this analysis should be performed on more recent data.
- Future studies of repeat infection may be useful in evaluating current Region III enhanced partner management strategies.