Riding high: seroprevalence of SARS-CoV-2 after 4 pandemic waves in Manitoba, Canada, April 2020-February 2022.

BACKGROUND: Canada is emerging from the largest SARS-CoV-2 Omicron wave to date, with over 3.3 million confirmed cases. Unfortunately, PCR confirmed cases illuminate only a small portion of infections in the community and underestimate true disease burden. Population based seroprevalence studies, which measure antibody levels against a virus can more accurately estimate infection rates in the community and identify geographical and epidemiological trends to inform public health responses. METHODS: The Manitoba COVID-19 Seroprevalence (MCS) study is a population-based cross-sectional study to assess the prevalence of SARS-CoV-2 antibodies across the province. Residual convenience specimens (n = 14,901) were tested for anti-SARS-CoV-2 nucleocapsid and spike IgG antibodies from April 1, 2020 to February 31, 2022. We estimated the monthly and cumulative prevalence using an exponential decay model, accounting for population demographics, sensitivity/specificity, and antibody waning. This approach generated estimates of natural infection as well as total antibody including vaccine-induced immunity within the community. FINDINGS: After four waves of the pandemic, 60.1% (95%CI-56.6-63.7) of Manitobans have generated SARS-CoV-2 antibodies due to natural exposure independent of vaccination. Geographical analysis indicates a large portion of provincial prevalence stems from increased transmission in the Northern (92.3%) and Southern (71.8%) regional health authorities. Despite the high mortality rates reported by Manitoba, infection fatality ratios (IFR) peaked at 0.67% and declined to 0.20% following the Omicron wave, indicating parity with other national and international jurisdictions. Manitoba has achieved 93.4% (95%CI- 91.5-95.1) total antibody when including vaccination. INTERPRETATION: Our data shows that more than 3 in 5 Manitobans have been infected by SARS-CoV-2 after four waves of the pandemic. This study also identifies key geographical and age specific prevalence rates that have contributed greatly to the overall severity of the pandemic in Manitoba and will inform jurisdictions considering reduction of public health measures.

A descriptive study of syphilis testing in Manitoba, Canada, 2015-2019.

Background: In 2018, Manitoba had the highest reported rate of infectious syphilis in Canada, at over three times the national average. Infectious syphilis in Manitoba is centred on young, marginalized heterosexual couples in Winnipeg's inner-city. Subsequently, a public health crisis involving congenital syphilis emerged in Manitoba, just prior to the coronavirus disease 2019 pandemic. Testing and screening (in the case of pregnancy) for syphilis is thought to be an effective measure to reduce the incidence of syphilis and its sequelae. The aim of this study is to describe syphilis testing practices in the general population and amongst pregnant women, during a period of shifting syphilis epidemiology. Methods: We used population-based syphilis testing data from Cadham Provincial Laboratory (Winnipeg, Manitoba) for 2015 to 2019. Directly age-standardized rates are reported, and Poisson regression used to model the determinants of testing rates. Rates of prenatal screening are also reported. Results: From 2015 to 2019, a total of 386,350 individuals were tested for syphilis. The rate increased annually, from 462 per 10,000 population in 2015 to 704 per 100,000 in 2019, while the female-to-male ratio decreased from 1.8 to 1.6. Prior to 2019, the majority of pregnant women (approximately 60%) were screened once, during the first trimester; however, 2019 saw more women having more than two tests during the course of their pregnancy. Conclusion: An overall increase in the number of individuals tested was observed, reflecting the increased rate of syphilis in Manitoba. Prenatal screening patterns shifted in 2019, likely in response to rising congenital syphilis numbers.

Closing the gap in postfracture care at the population level: a randomized controlled trial.

BACKGROUND: Postfracture care is suboptimal, and strategies to address this major gap in care are necessary. We investigated whether notifications sent by mail to physicians and patients would lead to improved postfracture care. METHODS: We conducted a randomized controlled trial (ClinicalTrials.gov identifier NCT00594789) in the province of Manitoba, Canada, from June 2008 to May 2010. Using medical claims data, we identified 4264 men and women age 50 years or older who recently reported major fractures, and who had not undergone recent bone mineral density testing or treatment for osteoporosis. Participants were randomized to three groups: group 1 received usual care (n = 1480), patients in group 2 had mailed notification of the fracture sent to their primary care physicians (n = 1363), and group 3 had notifications sent to both physicians and patients (n = 1421). Bone mineral density testing and the start of pharmacologic treatment for osteoporosis within the following 12 months were documented. RESULTS: Among participants in group 1 (usual care), 15.8% of women and 7.6% of men underwent testing for bone mineral density or started pharmacologic treatment for osteoporosis. Outcome measures improved among participants in group 2 (30.3% of women and 19.0% of men, both p < 0.001) and group 3 (34.0% of women and 19.8% of men, both p < 0.001). No additional benefit was seen with patient notification in addition to physician notification. Combining groups 2 and 3, the absolute increase for the combined end point of bone mineral density testing or pharmacologic treatment was 14.9% (16.4% among women, 11.8% among men). The number needed to notify to change patient care was 7 (6 for women, 6 for men). The adjusted odds ratio (OR) to change patient care in group 2 was 2.45 (95% confidence interval [CI] 2.01-2.98); for group 3 the OR was 2.82 (95% CI 2.33-3.43). INTERPRETATION: This notification system provides a relatively simple way to enhance post-fracture care.

Closing the postfracture care gap using administrative health databases: design and implementation of a randomized controlled trial.

Postfracture care is suboptimal, and strategies to address this major care gap are urgently required. Case management is effective but is resource intensive and difficult to deliver to a widely scattered population. We describe the design and successful implementation of a randomized controlled trial (NCT00594789), which uses provincial administrative health databases to notify eligible physicians and patients after a major osteoporotic fracture that such fractures warrant additional assessment or pharmacologic treatment to prevent subsequent fractures. Men and women aged 50 yr or older residing in the Province of Manitoba, Canada, with a recently reported clinical fracture (hip, spine, humerus, and forearm) from medical claims data, and without recent bone mineral density (BMD) testing (in the last 3 yr) or osteoporosis therapy (in the last year), were randomized to 3 groups: group 1 received usual care, group 2 (physicians only) had mailed notification to the primary care physicians (alert letter, BMD requisition, and management flowchart), and group 3 (physicians and patient) had both physician notifications and patient notification (alert letter). During the initial 10 mo (from June 2008 to March 2009), 2901 fracture patients meeting the inclusion criteria were randomized. Groups were well balanced. Direct costs related to the initiative (programming, case identification, and mailings) were Canadian dollars (CAD$)12,379 during the pilot phase, which translates to CAD$6.50 per notification (groups 2 and 3). Ongoing costs (which exclude the initial programming costs) are estimated at CAD$1.25 per notification. This postfracture intervention, based on medical claims data, provides an easy way to enhance postfracture care. The approach is scalable, can be delivered to a widely scattered population, and requires minimal infrastructure. This low-cost intervention may complement more resource-intensive programs based on case managers.