Nowhere near the point of diminishing returns: correlations between chlamydia testing and notification rates in New South Wales

Abstract

Objective: To examine the relationship between chlamydia testing and chlamydia detection rates in New South Wales, Australia, from 1999 to 2001. Methods: Correlations between population‐based chlamydia testing and notification rates‐stratified by age group, area of residence, and year‐were determined by linear regression. Results: Strong positive correlations between chlamydia testing and notification rates were observed for both women (r=0.91, p<0.001) and men (r=0.94, p<0.001). Between 1999 and 2001, the chlamydia test positivity rate increased from 4.3% to 7.3% for women (p<0.0001) and from 7.8% to 10.5% for men (p<0.0001). Conclusions and Implications: This study suggests that Australia could benefit from a major chlamydia screening program.

The highs and lows of opportunistic Chlamydia testing: uptake and detection in Waikato, New Zealand

“…We found high rates of Chlamydia test uptake and detection, particularly among local 15–24-year-old females, which may explain the high Waikato surveillance rates and supports findings that “the more you look, the more you find.”2 3 Comparing our testing data, a similarly high test uptake has been reported by others, for example 30% of Swedish women aged 20–24 years,4 and compares favourably with laboratory test estimates of 15% per annum in England 5. McNamee et al found considerably lower Chlamydia testing among young Australian women, with 7.8% being the highest proportion of any subgroup, whereas, like these data, testing among young Australian men was lower 6…”

“…Waikato DHB on the North Island has a population of about 340 000, of whom approximately 20% are Māori compared with 15% nationally. Studies suggest that high rates of Chlamydia diagnosis may reflect an increase in test uptake,2 3 but this cannot be assumed for New Zealand where testing coverage among young people is unknown. Hence, our aim was to ascertain Chlamydia testing and detection rates by age group within Waikato DHB.…”

Heterogeneity in the spatial distribution of bacterial sexually transmitted infections

“…Factors potentially contributing to the increasing trend in chlamydia reporting in Australia are currently the subject of much discussion 3 24 25. With the proportion of infections that are asymptomatic estimated at up to 80%,26 it is clear that testing practices will greatly influence chlamydia case detection.…”

Where are we going with chlamydia?

“…Because it is a largely asymptomatic condition, chlamydia statistics are vulnerable to testing artefact, 14,15 making notification data very difficult to interpret. A rise in notifications could be plausibly interpreted as either success (because more asymptomatic cases are being detected and treated) or failure (because more transmission is occurring) of a more widespread testing campaign.…”