Louise Causer

Dr. Louise Causer

orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
25 March 2015 in Clinical Infectious Diseases
Verified
Journal Article
Open access
PDF file
LCLouise Causer
Louise Causer
JKJohn M. Kaldor
John M. Kaldor
DCDamian P. Conway
Damian P. Conway
DLDavid E. Leslie
David E. Leslie
IDIan Denham
Ian Denham
RGRebecca J. Guy
Rebecca J. Guy
Background. Most syphilis point-of-care (POC) tests detect treponemal antibodies, which persist after successful treatment. Subsequent POC tests are positive, despite no active infection, and can lead to unnecessary treatment. We evaluated a new POC test, incorporating a nontreponemal component, to distinguish active from past infection. Methods. Sera stored at 2 Australian laboratories were tested with DPP Screen and Confirm Assay. Treponemal and nontreponemal test lines were compared to corresponding conventional treponemal and nontreponemal reference test results: immunoassays and rapid plasma reagin (RPR), respectively, with RPR quantification by endpoint titration. POC test outcome concordance with conventional test results was assessed according to serological and clinical categories. Results. Among 1005 serum samples tested, DPP treponemal line sensitivity was 89.8% (95% confidence interval [CI], 87.3%–91.9%) and specificity was 99.3% (95% CI, 97.0%–99.9%). DPP nontreponemal line sensitivity was 94.2% (95% CI, 91.8%–96.0%) and specificity was 62.2% (95% CI, 57.5%–66.6%). DPP test outcome (pair of test lines) was concordant with both reference test results for 94.3% of 404 high-titer infections, 90.1% of 121 low-titer infections, 27.5% of 211 past/treated infections, and 78.1% of 242 infections classified as not syphilis. Among 211 past/treated infections, 49.8% were incorrectly identified as active infection and a further 22.8% as not syphilis. Conclusions. DPP test use would result in identification of >93% of active syphilis infections, whereas just over half of past infections would be diagnosed as past or not syphilis, avoiding unnecessary treatment compared with other POC tests. This may be at the expense of missing some active infections; thus, its potential benefits will depend on the prevalence of past vs active infection in a population.

10 May 2018 in Sexually Transmitted Infections
Verified
Journal Article
Closed access
PDF file
LCLouise Causer
Louise Causer
RGRebecca J Guy
Rebecca J Guy
STSepehr N Tabrizi
Sepehr N Tabrizi
DWDavid David Whiley
David David Whiley
DSDavid John Speers
David John Speers
JKJohn M Kaldor
John M Kaldor
Objectives: A new molecular test for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) (GeneXpert CT/NG) has been demonstrated to be as accurate as conventional nucleic acid amplification tests (NAAT), but performance has not been evaluated in routine primary care, performed at the point of care by clinicians. We aimed to examine its diagnostic performance when used by clinicians in remote community health services in Australia with high prevalences of CT and NG infection. The trial was registered with the Australian and New Zealand Clinical Trials Registry (#12613000808741)Methods: At 12 health services, training was provided to 99 clinicians in the use of the GeneXpert CT/NG assay who tested specimens from all patients undergoing STI screening. Specimens were also sent in parallel for conventional laboratory-based NAATs and the concordance of results was evaluated.Results: Clinicians conducted 2486 tests: CT concordance was 99.4% (95% CI 99.1 to 99.7) with a positive concordance of 98.6% (95% CI 95.9 to 99.7) and negative concordance of 99.5% (95% CI 99.1 to 99.8); NG concordance was 99.9% (95% CI 99.7 to 100.0) with a positive concordance of 100.0% (95% CI 97.5 to 100.0) and negative concordance of 99.9% (95% CI 99.7 to 100.0).Conclusions: In this first study reporting routine point-of-care use of GeneXpert CT/NG by primary care clinicians, we found excellent concordance with conventional NAATs. The use of the GeneXpert CT/NG at the point of care could potentially transform management and control of these infections in many endemic settings, including low/middle-income countries.

18 October 2013 in BMC Infectious Diseases
Verified
Journal Article
Open access
PDF file
RGRebecca J Guy
Rebecca J Guy
LNLisa Natoli
Lisa Natoli
JWJames Ward
James Ward
LCLouise Causer
Louise Causer
BHBelinda Hengel
Belinda Hengel
JKJohn M Kaldor
John M Kaldor
High prevalence rates of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) have been reported in Aboriginal people in remote and regional areas of Australia for well over two decades, and repeat positivity rates are high. To interrupt disease transmission and reduce the risk of complications, early diagnosis and treatment is important. However in many remote and regional areas there are long delays between testing for these curable sexually transmissible infections and providing treatment, due to both physical distance from laboratories and difficulties when recalling patients for subsequent management once results are available. Point-of-care (POC) tests have the potential to provide more timely diagnosis, to increase treatment and contact tracing, and in turn reduce CT and NG infection rates. TTANGO (Test, Treat, ANd GO) is a cross-over cluster randomised controlled trial in 12 regional or remote Australian health services, which predominantly provide clinical services to Aboriginal people. The overall aim of TTANGO is to measure the clinical effectiveness, cost-effectiveness and cultural and operational acceptability of molecular POC testing for CT and NG infection. The primary outcome is repeat positivity at three months after treatment of an initial CT or NG infection. Participating health services will undertake the clinical management of CT and NG under two different modalities for one year each. In the first year, six health services will be randomly assigned to manage these infections under current diagnostic guidelines. The other six will supplement current diagnostic guidelines with POC testing, whereby diagnosis is made and subsequent treatment for those with positive POC tests is offered at the initial consultation. In the second year, the health services will cross over to the opposite management modality. TTANGO will be conducted over four years; 1.5 years of trial initiation and community consultation, 2 years of trial conditions and evaluation, and 6 months of data analysis and feedback. TTANGO is the first cluster randomised trial of POC testing for CT and NG internationally. The results of this trial will provide crucial information to guide sexual health clinical practice in remote Aboriginal communities and other high prevalence settings. Australian and New Zealand Clinical Trials Registry ACTRN12613000808741

11 March 2014 in PLOS ONE
Verified
Journal Article
Open access
PDF file
LCLouise Causer
Louise Causer
JKJohn M. Kaldor
John M. Kaldor
CFChristopher K. Fairley
Christopher K. Fairley
BDBasil Donovan
Basil Donovan
TKTheo Karapanagiotidis
Theo Karapanagiotidis
RGRebecca J. Guy
Rebecca J. Guy
Syphilis point-of-care tests may reduce morbidity and ongoing transmission by increasing the proportion of people rapidly treated. Syphilis stage and co-infection with HIV may influence test performance. We evaluated four commercially available syphilis point-of-care devices in a head-to-head comparison using sera from laboratories in Australia. Point-of-care tests were evaluated using sera stored at Sydney and Melbourne laboratories. Sensitivity and specificity were calculated by standard methods, comparing point-of-care results to treponemal immunoassay (IA) reference test results. Additional analyses by clinical syphilis stage, HIV status, and non-treponemal antibody titre were performed. Non-overlapping 95% confidence intervals (CI) were considered statistically significant differences in estimates. In total 1203 specimens were tested (736 IA-reactive, 467 IA-nonreactive). Point-of-care test sensitivities were: Determine 97.3%(95%CI:95.8–98.3), Onsite 92.5%(90.3–94.3), DPP 89.8%(87.3–91.9) and Bioline 87.8%(85.1–90.0). Specificities were: Determine 96.4%(94.1–97.8), Onsite 92.5%(90.3–94.3), DPP 98.3%(96.5–99.2), and Bioline 98.5%(96.8–99.3). Sensitivity of the Determine test was 100% for primary and 100% for secondary syphilis. The three other tests had reduced sensitivity among primary (80.4–90.2%) compared to secondary syphilis (94.3–98.6%). No significant differences in sensitivity were observed by HIV status. Test sensitivities were significantly higher among high-RPR titre (RPR≥8) (range: 94.6–99.5%) than RPR non-reactive infections (range: 76.3–92.9%). The Determine test had the highest sensitivity overall. All tests were most sensitive among high-RPR titre infections. Point-of-care tests have a role in syphilis control programs however in developed countries with established laboratory infrastructures, the lower sensitivities of some tests observed in primary syphilis suggest these would need to be supplemented with additional tests among populations where syphilis incidence is high to avoid missing early syphilis cases.

27 November 2014 in Sexual Health
Verified
Journal Article
Closed access
PDF file
LCLouise Causer
Louise Causer
BHBelinda Hengel
Belinda Hengel
LNLisa Natoli
Lisa Natoli
ATAnnie Tangey
Annie Tangey
SBSteven G Badman
Steven G Badman
RGRebecca J Guy
Rebecca J Guy
Background: Point-of-care (POC) tests could be important public health tools in settings with treatment delays and high rates of sexually transmissible infections (STIs). Use is limited due to suboptimal performance. The performance and ease-of-use of a new molecular-based POC test for simultaneous detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) was assessed, alongside two single-organism immunochromatographic tests (ICT). Methods: The evaluation occurred between May 2012 and March 2013 during community STI screens in two remote Aboriginal health services. Urine was tested with the GeneXpert®CT/NG and if sufficient volume, also with Diaquick CT and Gonorrhoea Card. The gold standard comparison was laboratory nucleic acid amplification testing (NAAT). Operational characteristics were also assessed. Results: Among 198 samples, GeneXpert CT sensitivity and specificity was 100% [95% confidence intervals (CI): 75.9–100] and 99.5% (95% CI: 96.5–100), and NG was 100% (95% CI: 96.5–100) and 100% (95% CI: 97.5–100), respectively. Among a sample subset, Diaquick CT (n = 104) sensitivity and specificity was 27.3% (95% CI: 7.3–60.7) and 66.7% (95% CI: 12.5–98.2), and Gonorrhoea Card (n = 29), was 66.7% (95% CI: 12.5–98.2) and 76.9% (95% CI: 56.0–90.2), respectively. GeneXpert required 1 mL of urine, four steps, 1 min specimen preparation and 90 min to result. ICTs required 15 mL of urine, eight steps, 18 min preparation and 10–15 min to result. Conclusion: The accuracy and operational benefits of GeneXpert CT/NG make it very suitable in these settings where delays to treatment are encountered.

1 December 2004 in Clinical Infectious Diseases
Verified
Journal Article
Open access
PDF file
LCLouise Causer
Louise Causer
Scott G FillerScott G Filler
Scott G Filler
MWMarianna Wilson
Marianna Wilson
SPStephen Papagiotas
Stephen Papagiotas
RNRobert D. Newman
Robert D. Newman
Background. Travelers to malarious areas are at risk of acquiring malaria; however, with chemoprophylaxis and prompt, effective therapy, serious comp