TY - JOUR
T1 - Chlamydia trachomatis incidence and re-infection among young women - behavioural and microbiological characteristics
AU - Walker, Jennifer
AU - Tabrizi, Sepehr N.
AU - Fairley, Christopher K.
AU - Chen, Marcus Y.
AU - Bradshaw, Catriona S.
AU - Twin, Jimmy
AU - Taylor, Nicole
AU - Donovan, Basil
AU - Kaldor, John M.
AU - McNamee, Kathleen
AU - Urban, Eve
AU - Walker, Sandra
AU - Currie, Marian
AU - Birden, Hudson
AU - Bowden, Francis
AU - Gunn, Jane
AU - Pirotta, Marie
AU - Gurrin, Lyle
AU - Harindra, Veerakathy
AU - Garland, Suzanne M.
AU - Hocking, Jane S.
PY - 2012/5/25
Y1 - 2012/5/25
N2 - Background: This study aimed to estimate rates of chlamydia incidence and re-infection and to investigate the dynamics of chlamydia organism load in prevalent, incident and re-infections among young Australian women. Methods: 1,116 women aged 16 to 25 years were recruited from primary care clinics in Australia. Vaginal swabs were collected at 3 to 6 month intervals for chlamydia testing. Chlamydia organism load was measured by quantitative PCR. Results: There were 47 incident cases of chlamydia diagnosed and 1,056.34 person years of follow up with a rate of 4.4 per 100 person years (95% CI: 3.3, 5.9). Incident infection was associated with being aged 16 to 20 years [RR = 3.7 (95%CI: 1.9, 7.1)], being employed [RR = 2.4 (95%CI: 1.1, 4.9)] and having two or more new sex partners [RR = 5.5 (95%CI: 2.6, 11.7)]. Recent antibiotic use was associated with a reduced incidence [RR:0.1 (95%CI: 0.0, 0.5)]. There were 14 re-infections with a rate of 22.3 per 100 person years (95%CI: 13.2, 37.6). The median time to re-infection was 4.6 months. Organism load was higher for prevalent than incident infections (p<0.01) and for prevalent than re-infections (p<0.01). Conclusions: Chlamydia is common among young women and a high proportion of women are re-infected within a short period of time, highlighting the need for effective partner treatment and repeat testing. The difference in organism load between prevalent and incident infections suggests prevalent infection may be more important for ongoing transmission of chlamydia.
AB - Background: This study aimed to estimate rates of chlamydia incidence and re-infection and to investigate the dynamics of chlamydia organism load in prevalent, incident and re-infections among young Australian women. Methods: 1,116 women aged 16 to 25 years were recruited from primary care clinics in Australia. Vaginal swabs were collected at 3 to 6 month intervals for chlamydia testing. Chlamydia organism load was measured by quantitative PCR. Results: There were 47 incident cases of chlamydia diagnosed and 1,056.34 person years of follow up with a rate of 4.4 per 100 person years (95% CI: 3.3, 5.9). Incident infection was associated with being aged 16 to 20 years [RR = 3.7 (95%CI: 1.9, 7.1)], being employed [RR = 2.4 (95%CI: 1.1, 4.9)] and having two or more new sex partners [RR = 5.5 (95%CI: 2.6, 11.7)]. Recent antibiotic use was associated with a reduced incidence [RR:0.1 (95%CI: 0.0, 0.5)]. There were 14 re-infections with a rate of 22.3 per 100 person years (95%CI: 13.2, 37.6). The median time to re-infection was 4.6 months. Organism load was higher for prevalent than incident infections (p<0.01) and for prevalent than re-infections (p<0.01). Conclusions: Chlamydia is common among young women and a high proportion of women are re-infected within a short period of time, highlighting the need for effective partner treatment and repeat testing. The difference in organism load between prevalent and incident infections suggests prevalent infection may be more important for ongoing transmission of chlamydia.
UR - http://www.scopus.com/inward/record.url?scp=84861462756&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0037778
DO - 10.1371/journal.pone.0037778
M3 - Article
SN - 1932-6203
VL - 7
JO - PLoS ONE
JF - PLoS ONE
IS - 5
M1 - e37778
ER -