Correlates of Chlamydia trachomatis infection in a primary care sentinel surveillance network.
BACKGROUND
Chlamydia is the most commonly notified infection in Australia. Prevention strategies should be informed by routine data on at-risk populations.


METHODS
We calculated chlamydia positivity and correlates of infection using multivariable logistic regression for data collected between April 2006 and June 2009.


RESULTS
Chlamydia positivity was 5.6% in 12233 females, 7.7% in 10316 heterosexual males and 6.2% in 7872 men who have sex with men (MSM). Correlates of chlamydia positivity among females included younger age (odds ratio (OR) 2.27, 95% confidence interval (CI) 1.92-2.69), being born overseas (OR 1.50, 95% CI 1.25-1.82), multiple sex partners in the past year (OR 1.72, 95% CI 1.40-2.11) and inconsistent condom use with regular sex partners (OR 3.44 ,95% CI 1.65-7.20). Sex work was protective for females (OR 0.68, 95% CI 0.53-0.86). Among heterosexual males, correlates of positivity were younger age (OR 1.87, 95% CI 1.62-2.17), being born overseas (OR 1.35, 95% CI 1.16-1.58), symptoms at the time of testing (OR 1.64, 95% CI 1.40-1.92) and multiple sex partners in the past year (OR 1.83, 95% CI 1.46-2.30). Correlates of positivity among MSM were being born overseas (OR 1.23, 95% CI 1.00-1.51), being HIV-positive (OR 1.80, 95%CI 1.32-2.47), and reporting six or more anal sex partners in the past 6 months (OR 4.45, 95% CI 1.37-14.5).


CONCLUSIONS
Our analysis identified subgroups at the highest risk of chlamydia in Victoria. These estimates will provide important baseline information to measure the impact of chlamydia control strategies.
Centre for Population Health, Burnet Institute, Melbourne, Vic. 3004, Australia. lim@burnet.edu.au
Megan S C
MS
Lim
Jane L
JL
Goller
Rebecca
R
Guy
Judy
J
Gold
Mark
M
Stoove
Jane S
JS
Hocking
Christopher K
CK
Fairley
Dot
D
Henning
Kathy
K
McNamee
Louise
L
Owen
Penny
P
Sheehan
Margaret E
ME
Hellard
D000328:Adult; D017677:Age Distribution; D002690:Chlamydia Infections / Q000453:epidemiology* / Q000382:microbiology; D002692:Chlamydia trachomatis / Q000302:isolation & purification*; D017280:Condoms / Q000706:statistics & numerical data; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D005260:Female; D020010:Heterosexuality / Q000706:statistics & numerical data*; D018452:Homosexuality, Female / Q000706:statistics & numerical data; D018451:Homosexuality, Male / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011320:Primary Health Care / Q000706:statistics & numerical data*; D012307:Risk Factors; D018571:Sentinel Surveillance; D017678:Sex Distribution; D047568:Unsafe Sex / Q000706:statistics & numerical data; D014739:Victoria / Q000453:epidemiology; D055815:Young Adult