C. trachomatis and N. gonorrhoeae surveillance in New Zealand: comparison of laboratory and clinic data.

OBJECTIVE

To determine the extent to which clinic-based sexually transmitted infection (STI) surveillance underrepresents the number of laboratory-confirmed cases of Chlamydia trachomatis and Neisseria gonorrhoeae in the Waikato and Bay of Plenty regions of New Zealand; and to estimate incidence rates for these two infections.

METHODS

Data on C. trachomatis and N. gonorrhoeae were collected from diagnostic laboratories in the study regions for the year 2000, and compared with routine clinic-based STI surveillance data.

RESULTS

Most laboratory-confirmed C. trachomatis (65.5%) and N. gonorrhoeae (55.7%) infections were diagnosed by healthcare providers outside the clinic-based STI surveillance system. The estimated incidence rate for C. trachomatis was 501 per 100,000, and 50 per 100,000 for N. gonorrhoeae.

CONCLUSIONS AND IMPLICATIONS: Laboratory surveillance of C. trachomatis and N. gonorrhoeae provides a more complete picture of disease burden. Given the high infection rates reported, developing a national strategy for the management of STIs should be a public health priority in New Zealand.