Chlamydia Testing in New Zealand: Analysis of the 2014/2015 National Health Survey

Diagnosis rates of Chlamydia trachomatis are high in New Zealand; 1.3% of men and 3.7% of women aged 15 to 29 years were diagnosed in 2016. Because testing rates are also higher in women, we sought to understand chlamydia testing by demographic and behavioral characteristics.

Chlamydia testing in the past year, sexual behavior, and demographic characteristics were reported in the population-based 2014/2015 New Zealand Health Survey. Those aged 16 to 44 years who had a sexual partner in the past year were included. Testing prevalence was calculated, and associations were modeled.

A total of 1677 men and 2323 women participated (89% response rate). Of these, 5.6% (95% confidence interval, 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% confidence interval, 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).

The study confirms that 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.