Population-level diagnosis and care cascade for chlamydia in Australia

Richard T Gray; Denton Callander; Jane S Hocking; Skye McGregor; Hamish McManus; Amalie Dyda; Clarissa Moreira; Sabine Braat; Belinda Hengel; James Ward; David P Wilson; Basil Donovan; John M Kaldor; Rebecca J Guy

doi:10.1136/sextrans-2018-053801

Population-level diagnosis and care cascade for chlamydia in Australia

Sex Transm Infect. 2020 Mar;96(2):131-136. doi: 10.1136/sextrans-2018-053801. Epub 2019 Jun 5.

Authors

Richard T Gray¹, Denton Callander^{2

3}, Jane S Hocking⁴, Skye McGregor², Hamish McManus², Amalie Dyda⁵, Clarissa Moreira⁶, Sabine Braat⁴, Belinda Hengel⁷, James Ward⁸, David P Wilson⁶, Basil Donovan^{2

9}, John M Kaldor², Rebecca J Guy²

Affiliations

¹ The Kirby Institute, Faculty of Medicine, UNSW Sydney, Kensington, New South Wales, Australia Rgray@kirby.unsw.edu.au.
² The Kirby Institute, Faculty of Medicine, UNSW Sydney, Kensington, New South Wales, Australia.
³ NYU Spatial Epidemiology Lab, School of Medicine, New York University, New York, NY, USA.
⁴ Melbourne School of Population and Global Health, University of Melbourne, Carlton, Victoria, Australia.
⁵ Faculty of Medicine, Kirby Institute, Sydney, New South Wales, Australia.
⁶ The Burnett Institute, Melbourne, Victoria, Australia.
⁷ Apunipima Cape York Health Council, Cairns, Queensland, Australia.
⁸ Infectious Diseases Research, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia.
⁹ Sydney Sexual Health Centre, Sydney, New South Wales, Australia.

PMID: 31167824
DOI: 10.1136/sextrans-2018-053801

Abstract

Objectives: Key strategies to control chlamydia include testing, treatment, partner management and re-testing. We developed a diagnosis and care cascade for chlamydia to highlight gaps in control strategies nationally and to inform efforts to optimise control programmes.

Methods: The Australian Chlamydia Cascade was organised into four steps: (1) annual number of new chlamydia infections (including re-infections); (2) annual number of chlamydia diagnoses; (3) annual number of diagnoses treated; (4) annual number of diagnoses followed by a re-test for chlamydia within 42-180 days of diagnosis. For 2016, we estimated the number of infections among young men and women aged 15-29 years in each of these steps using a combination of mathematical modelling, national notification data, sentinel surveillance data and previous research studies.

Results: Among young people in Australia, there were an estimated 248 580 (range, 240 690-256 470) new chlamydia infections in 2016 (96 470 in women; 152 100 in men) of which 70 164 were diagnosed (28.2% overall: women 43.4%, men 18.6%). Of the chlamydia infections diagnosed, 65 490 (range, 59 640-70 160) were treated (93.3% across all populations), but only 11 330 (range, 7660-16 285) diagnoses were followed by a re-test within 42-180 days (17.3% overall: women 20.6%, men 12.5%) of diagnosis.

Conclusions: The greatest gaps in the Australian Chlamydia Cascade for young people were in the diagnosis and re-testing steps, with 72% of infections undiagnosed and 83% of those diagnosed not re-tested: both were especially low among men. Treatment rates were also lower than recommended by guidelines. Our cascade highlights the need for enhanced strategies to improve treatment and re-testing coverage such as short message service reminders, point-of-care and postal test kits.

Keywords: care cascade; control; genital chlamydia trachomatis; high-income setting; incidence; sti guidelines; surveillance and monitoring.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Anti-Bacterial Agents / therapeutic use*
Australia
Chlamydia Infections / diagnosis*
Chlamydia Infections / drug therapy*
Contact Tracing*
Female
Humans
Male
Models, Theoretical
Outcome and Process Assessment, Health Care
Sentinel Surveillance
Sexual Partners*
Young Adult

Substances

Anti-Bacterial Agents