Chlamydia testing in New Zealand: analysis of the 2014/15 National Health Survey.

BACKGROUND Diagnosis rates of Chlamydia trachomatis are high in New Zealand, 1.3% of men and 3.7% of women aged 15-29 were diagnosed in 2016. As testing rates are also higher in women, we sought to understand chlamydia testing by demographic and behavioral characteristics. METHODS Chlamydia testing in the past year, sexual behavior and demographic characteristics were reported in the population-based 2014/15 New Zealand Health Survey. Those aged 16-44 who had a sexual partner in the past year were included. Testing prevalence was calculated and associations modelled. RESULTS 1,677 men and 2,323 women participated (89% response rate). Of these, 5.6% (95% CI 4.3-7.2%) of men and 16.6% (14.7-18.7%) of women were tested in the past year. Likelihood of testing in men was associated with having multiple partners and any condomless sex (adjusted relative risk 11.93, 95% CI 5.70-24.98) and multiple partners with consistent condom use (3.77, 1.40-10.15), compared with one sexual partner and consistent condom use; and with Māori ethnicity (1.87, 1.05-3.31, compared with European/Other). Among women, testing was associated with multiple partners with and without condomless sex (3.61, 2.69-4.85, and 2.81, 1.95-4.05, respectively), pregnancy (1.61, 1.18-2.18), and Asian ethnicity (0.52, 0.30-0.89). CONCLUSION The study confirms New Zealand men are much less likely to be tested than women; a potential reason for ongoing high chlamydia incidence among both sexes. The high testing rate in women includes many at low risk and this divergence from recommendations is another issue to address.