1. Repeat Neisseria gonorrhea infections: A retrospective population-based analysis, 1999 - 2004
M Javanbakht, S Guerry, LV Smith, P Kerndt
County of Los Angeles Department of Health Services Public Health SEXUALLY TRANSMITTED DISEASE PROGRAM

2. Disease Burden Gonorrhea infections cause substantial morbidity
The 2nd most common reported notifiable disease
Over 330,000 cases reported to CDC in 2004
Estimated annual incidence of 718,000 cases
Although gonorrhea rates have declined dramatically since 1975 attributed in part to:
Widespread screening of women starting in 1972
And resulting treatment of asymptomatic persons and their sexual partners
Hyperendemic areas persist, particularly in urban areas
In addition, recent increases in certain areas

3. Reasons for Hyperendemicity
Increased rates and areas of hyperendemicity are most likely driven by:
High-risk individual (“core-transmitters”)
Gonorrhea reinfections account for as much as half of reported morbidity
Further complicating the issue:
Gonorrhea screening guidelines are vague
Most providers/programs use chlamydia screening guidelines as the basis for gonorrhea testing
Health department initiated partner referral and treatment are generally not offered because of limited resources and large disease burden

4. Significance of Reinfections
Consequently, in areas of high morbidity, especially areas experiencing increases in gonorrhea rates, there is a critical need for:
Estimation of reinfection rates
Understanding of epidemiology of reinfection
Which in turn can help to guide
Screening guidelines
Direct prevention efforts, especially in terms of partner referral and treatment

5. Objective
To examine the incidence and time to repeat gonorrhea infection among a representative population
To assess factors associated with repeat gonorrhea infections

6. Study Overview Retrospective cohort study
Among reported gonorrhea cases in Los Angeles County
Information collected on:
Demographics
Treatment information
Subsequent reported infections
Follow-up information collected for 5-years

7. Study Setting
Cohort based on reportable STD registry in Los Angeles County, which:
Comprises a geographic area of over 4,000 square miles
Home to ~10 million residents
Hispanics comprise the single largest racial/ethnic group (45%), followed by Whites (31%)
70% have at least a high school education
18% of population below poverty line
High rates of gonorrhea
Overall rate of 103 per 100,000
Highest rates among African American men (702 per 100,000)
Healthy People 2010 goal = 19 per 100,000

8. Study Design
Retrospective study conducted by constructing a cohort of patients from the Los Angeles County reportable STD registry
Inclusion criteria:
Initial treated infection reported between 1999 and 2000
Follow-up information collected through 2004, including information on:
Demographics: age, race/ethnicity, area of residence
Clinical information: presence of symptoms, clinic type, treatment information, subsequent reported gonorrhea infections

9. Statistical Analysis Outcome – repeat gonorrhea infection, defined as:
infection detected > 30 days after treatment for preceding infection
Risk estimation was conducted using Kaplan-Meier (product-limit) method
Factors associated with repeat infection were evaluated using Cox proportional hazards regression

10. The Cohort
Between January 1, 1999 and December 31, 2000, a total of 12,323 unique cases of gonorrhea were reported in Los Angeles County
Among this group, 7,591 (62%) were eligible and included in the study

11. Baseline Demographic Characteristics
Male
Female
40+
30-39
20-29
15-19
< 15
Other
Unknown
Hispanic
African American
White

12. Gonorrhea Reinfections
Among the 7,591 who were eligible and included in the study:
1,300 (17%) experienced > 1 gonorrhea reinfection over 5-years
Median number of reinfections 1 (range 1 – 7)
77% (n=995) with only 1-reinfection
16% (n=209) with 2-reinfections
7% (n=105) with > 3-reinfections
Resulting in 1,756 reinfections

13. Time to development of gonorrhea reinfection
Median time to reinfection = 13 months

14. Incidence of Gonorrhea Reinfection by Demographics
Female
Male
Other
White
Hispanic
African American

15. Incidence of Gonorrhea Reinfection by Age
35+
30-34
25-29
20-24
15-19
< 15

16. Factors associated with gonorrhea reinfection
Adjusted HR* (95% CI)
P value
Gender
Male
1.59 (1.40 – 1.80)
<.0001
Female
Reference
Age
< 15
2.62 (1.80 – 3.80)
15 – 19
1.57 (1.33 – 1.85)
20 – 24
1.21 (1.03 – 1.41)
0.0178
25 – 29
1.36 (1.15 – 1.61)
0.0004
30 – 35
1.16 (0.97 – 1.41)
0.1117
35+
*HR = Hazard Ratio; adjusting for age, gender, race, clinic type, and symptom status

17. Factors associated with gonorrhea reinfection
Adjusted HR* (95% CI)
P value
Race/Ethnicity
African American
1.82 (1.56 – 2.12)
<.0001
White
2.04 (1.69 – 2.47)
Other
1.30 (0.77 – 2.19)
0.3251
Hispanic
Reference
Clinic type
Public
1.20 (1.06 – 1.35)
0.0034
Jail/Corrections
0.88 (0.68 – 1.16)
0.3707
0.64 (0.40 – 1.03)
0.0689
Private
*HR = Hazard Ratio; adjusting for age, gender, race, clinic type, and symptom status

18. Factors associated with gonorrhea reinfection among men
Adjusted HR* (95% CI)
P value
Age
< 15
0.95 (0.32 – 2.86)
0.9283
15 – 19
1.23 (1.00 – 1.53)
0.0546
20 – 24
1.10 (0.93 – 1.30)
0.2464
25 – 29
1.39 (1.80 – 1.64)
<.0001
30 – 35
1.16 (0.97 – 1.40)
0.1105
35+
Reference
Race/Ethnicity
African American
1.52 (1.28 – 1.80)
White
1.89 (1.58 – 2.28)
Other
0.97 (0.58 – 1.61)
0.9037
Hispanic
*HR = Hazard Ratio; adjusting for age, race, and clinic type

19. Factors associated with gonorrhea reinfection among women
Adjusted HR* (95% CI)
P value
Age
< 15
7.11 (3.58 – 14.13)
<.0001
15 – 19
4.31 (2.36 – 7.88)
20 – 24
3.20 (1.74 – 5.90)
0.0002
25 – 29
2.09 (1.05 – 4.16)
0.0363
30 – 35
1.42 (0.63 – 3.20)
0.3973
35+
Reference
Race/Ethnicity
African American
2.87 (2.13 – 3.85)
White
0.93 (0.47 – 1.82)
0.8320
Other
2.27 (0.82 – 6.35)
0.1165
Hispanic
*HR = Hazard Ratio; adjusting for age, race, and symptom status

20. Limitations Data based on a passive surveillance system, consequently:
Rate of repeat infections underestimated because of under-reporting
Limited information, especially in term of sexual behaviors
Predictors maybe marker of greater screening/reporting
However, strengths of this project include:
Large number of cases from a population-based surveillance system
Ability to link gonorrhea infections in each individual regardless of where they sought care

21. Discussion Findings from this study suggest that:
Repeat gonorrhea infections are common
Overall, the greatest risk of repeat infection among:
Men, as well as African Americans and Whites, and those less than 30
However, factors predictive of repeat infection different by gender
Among men those aged as well as African Americans and Whites at greatest risk
Among women those in the youngest age groups and African Americans are at the greatest risk

22. Implications
Screening efforts should be targeted to those at highest risk and different by gender
Furthermore, frequent screening needs to be accompanied by enhanced efforts to treat cases as well as enhanced partner referral and treatment services

23. Marjan Javanbakht, MPH, PhD
(213)
SEXUALLY TRANSMITTED DISEASE PROGRAM