PT  - JOURNAL ARTICLE
AU  - Nicole Bender
AU  - Björn Herrmann
AU  - Berit Andersen
AU  - Jane S Hocking
AU  - Jan van Bergen
AU  - Jane Morgan
AU  - Ingrid VF van den Broek
AU  - Marcel Zwahlen
AU  - Nicola Low
TI  - Chlamydia infection, pelvic inflammatory disease, ectopic pregnancy and infertility: cross-national study
AID  - 10.1136/sextrans-2011-050205
DP  - 2011 Dec 01
TA  - Sexually Transmitted Infections
PG  - 601--608
VI  - 87
IP  - 7
4099  - http://sti.bmj.com/content/87/7/601.short
4100  - http://sti.bmj.com/content/87/7/601.full
SO  - Sex Transm Infect2011 Dec 01; 87
AB  - Objectives To describe, using routine data in selected countries, chlamydia control activities and rates of chlamydia infection, pelvic inflammatory disease (PID), ectopic pregnancy and infertility and to compare trends in chlamydia positivity with rates of PID and ectopic pregnancy.Methods Cross-national comparison including national data from Australia, Denmark, the Netherlands, New Zealand, Sweden and Switzerland. Routine data sources about chlamydia diagnosis and testing and International Classification of Disease-10 coded diagnoses of PID, ectopic pregnancy and infertility in women aged 15–39 years from 1999 to 2008 were described. Trends over time and relevant associations were examined using Poisson regression.Results Opportunistic chlamydia testing was recommended in all countries except Switzerland, but target groups differed. Rates of chlamydia testing were highest in New Zealand. Chlamydia positivity was similar in all countries with available data (Denmark, New Zealand and Sweden) and increased over time. Increasing chlamydia positivity rates were associated with decreasing PID rates in Denmark and Sweden and with decreasing ectopic pregnancy rates in Denmark, New Zealand and Sweden. Ectopic pregnancy rates appeared to increase over time in 15–19-year-olds in several countries. Trends in infertility diagnoses were very variable.Conclusions The intensity of recommendations about chlamydia control varied between countries but was not consistently related to levels of chlamydia diagnosis or testing. Relationships between levels of chlamydia infection and complication rates between or within countries over time were not straightforward. Development and validation of indicators of chlamydia-related morbidity that can be compared across countries and over time should be pursued.