Sexually transmitted and blood-borne infections profile in a mid-sized Saskatchewan City

Abstract

Background

Sexually transmitted and blood-borne infections (STBBIs) pose major public health challenges. The World Health Organization reports that sexually transmitted infections (STIs) alone lead to approximately 374 million new cases annually worldwide, averaging about one million per day. Blood-borne infections also considerably contribute to the global health burden. In Canada, the 2018 Pan-Canadian Framework aims to mitigate the effects of STBBIs through collaborative initiatives. Saskatchewan has experienced rising incidence rates of chlamydia, gonorrhea, syphilis, and congenital syphilis.

Methods

We examined the epidemiology of STBBIs in the Regina area of Saskatchewan from 2019 to 2024 using data from the provincial public health surveillance system, Panorama. The analysis focused on reported case numbers and demographic characteristics. Poisson regression models assessed associations between demographic factors and diagnoses. Sex was recorded as biological sex (male or female) in the surveillance system; gender identity was not collected. The study was part of a Quality Improvement initiative using de-identified data and did not require formal ethical review.

Results

Between 2019 and 2024, there were 11,739 reported cases of sexually transmitted and blood-borne infections (STBBIs), including chlamydia, gonorrhea, syphilis, HIV, hepatitis B, and hepatitis C. Syphilis cases increased significantly, while chlamydia and gonorrhea cases declined. Females had higher rates of chlamydia, while males showed elevated rates of gonorrhea, syphilis, and blood-borne viruses (BBVs). Risk factors included inconsistent condom use, multiple sexual partners (20% reported more than two partners in three months), and substance use (7.1% used injectable drugs, and 6.8% used non-injectable substances). Street involvement and a history of STBBIs were also significant predictors for these infections.

Conclusion

STBBIs remain a significant public health issue in Regina, with syphilis rates rising sharply from 2019 to 2022. Overall, cases increased, primarily driven by syphilis and BBVs. Public health responses include dedicated STI clinics and harm-reduction programs for BBVs, but challenges persist.

Background

Sexually transmitted and blood-borne infections (STBBIs) are a global health concern. Sexually transmitted infections (STIs) alone account for approximately one million new infections acquired daily worldwide, primarily chlamydia, gonorrhea, syphilis, and trichomoniasis [1]. Blood-borne infections such as HIV, hepatitis B, and hepatitis C also contribute substantially to the overall burden. Most STBBIs are treatable and can be managed to prevent complications or long-term health consequences that significantly influence global sexual and reproductive health [1].

STBBIs are transmitted in the context of other social and health challenges; unless these underlying issues are addressed, the likelihood of recurring exposure and infection is high, requiring a multidisciplinary approach to care [2]. Risk factors that increase the transmission of STBBIs include unprotected sexual contact with multiple partners, previous history of STBBIs, sexual assault, alcohol use, sex work, having a partner who has had concurrent sexual contacts or a history of an STBBI, recreational drug use, and intravenous drug use [3].

Recognizing the burden posed by STBBIs, the Pan-Canadian Sexually Transmitted and Blood-Borne Infections Framework for Action was published in 2018 and describes national strategic initiatives to reduce the impact of STBBIs in Canada [4]. The document also outlined strategic objectives and guiding principles to address STBBIs in Canada and achieve global STBBI targets by 2030 [4]. To achieve these goals, primary care and public health professionals must collaborate to decrease the number of STBBIs in Canada, increase access to diagnostic procedures and medical care, and reduce the stigma and discrimination that lead to STBBI vulnerability [4].

Assessing the impact of STBBI prevention and control programs entails gathering and analyzing information on the incidence and prevalence of infection, identifying the populations most affected and their locations, and identifying behavioural risk factors contributing to STBBI acquisition and transmission [5]. Research shows that STBBI rates continue to rise globally, including in Europe, America, and across Canada; Saskatchewan has the second-highest rate of infectious syphilis in Canada after Manitoba, and infection rates have rapidly increased since 2010 [6–9].

Publicly available data indicate that the most frequently reported STBBIs in Saskatchewan are chlamydia and gonorrhea, but the rise in the prevalence of syphilis is a cause for concern. Syphilis is caused by the spirochaete bacterium Treponema pallidum and is usually transmitted through sexual contact with an actively infected partner [10]. Syphilis can also be acquired congenitally (in utero or during birth canal passage) or by blood-borne transmission [11]. With significantly increasing syphilis rates in Saskatchewan, we have seen an increasing proportion of late infection, and congenital syphilis has seen a resurgence in the last five years [12]. The majority (86%) of confirmed early congenital syphilis cases in 2020 were reported in Alberta, Manitoba, and Saskatchewan. In 2019, Saskatchewan saw its first cases of congenital syphilis since 2011 [13, 14]. Since then, the province has had 185 cases of congenital syphilis per 100,000 live births in 2021.

Although data on the provincial burden of STBBIs in Saskatchewan are available, there is a paucity of information on the epidemiological breakdown of STBBIs in smaller geographic areas across the province. This deficiency led the Regina Public Health Communicable Disease Program to conduct a study on the impact of STBBIs in our community. The primary objective was to analyze the epidemiology of STBBIs in the Regina area of Saskatchewan from 2019 to 2024.

Materials and methods

This retrospective cohort study analyzed the epidemiology of STBBIs in the Regina area of Saskatchewan, Canada, from 2019 to 2024. The sample size was determined by the total number of reported cases of the selected STBBIs in the Regina area between 2019 and 2024. No additional sampling technique was necessary, as the entire population of reported cases during this period was included in the analysis.

Study population

The study included all individuals residing in the Regina area who were diagnosed with chlamydia, gonorrhea, syphilis, HIV, hepatitis B, or hepatitis C during the study period. Individuals diagnosed with STBBIs outside the Regina area, those without complete demographic or clinical data, or those for whom data on sex, age, or risk factors were missing, were excluded from the analysis.

Data collection

Data were extracted from the Panorama system, the provincial electronic public health surveillance system, using the MicroStrategy application [15]. Variables included age, biological sex (male or female, as recorded in the database), residence location, and risk factors such as sexual behaviour and substance use. Sexual behaviour was categorized based on the number of partners in the past three months: 0–1 versus ≥ 2 partners, consistent condom use versus inconsistent/no use and history of STBBIs, yes versus no. Substance use was categorized as injectable or non-injectable based on client-reported history in the case investigation forms.

Data analysis

Data analysis was performed using SAS 9.4 and Microsoft Excel 2016. Descriptive statistics were initially employed to summarize the demographic and clinical characteristics of the study population. To calculate rates for various STBBIs, the numerator was the number of reported cases for each STBBI, while the denominator was the total population covered under the Saskatchewan eHealth program on June 3 of the previous year, providing a measure of the region’s at-risk population. These rates were expressed as cases per 100,000 population.

Additionally, Poisson regression models were used to estimate incidence rate ratios (IRRs) for each STBBI, with 95% confidence intervals, to evaluate the relationship between specific demographic or risk factors and the incidence of STBBI diagnoses over time. This analysis facilitated the identification of trends and the assessment of potential associations between risk factors and STBBI incidence.

Ethical approval and consent to participate

This study was part of a Quality Improvement (QI) initiative and, as such, did not undergo formal ethical review by a Research Ethics Board (REB). The project adhered to local institutional guidelines for QI activities, which do not require full ethical approval when using de-identified, routinely collected public health data. Since the study utilized only aggregate, anonymized data from the Panorama system, individual consent to participate was not required. The data were analyzed in compliance with established protocols to ensure participant confidentiality and data security.

Results

Between 2019 and 2024, a total of 11,739 STBBI cases were reported within the Regina area. The most notable increase was observed in syphilis cases, with rates escalating from 22.3 per 100,000 population in 2019 to 189.5 per 100,000 in 2024. Although the incidence rates of chlamydia and gonorrhea remained elevated, they experienced a slight decline over the same period, as illustrated in Fig. 1.

Fig. 1.

Overall disease counts and disease-specific rates of confirmed STBBI cases, 2019–2024, Regina, Saskatchewan

Overall, females accounted for a slightly larger proportion of reported STBBI cases due to higher rates of chlamydia, while males represented a greater proportion of cases for most other infections (Table 1). The Regina area has an estimated population of approximately 290,000, with Saskatchewan’s total population around 1.3 million. The population distribution is relatively balanced, but younger age groups (20–40 years) represent a larger proportion of STBBI diagnoses.

Table 1.

Characteristics of individuals diagnosed with STBBIs in the Regina area, 2019–2024

	Female	Male
Number of cases (%)	6637 (56.6)	5096 (43.4)
STBBI cases by disease type
Chlamydia Infection	3902 (63.2)	2275 (36.8)
Gonococcal Infection	1298 (53.9)	1109 (46.1)
HIV	150 (48.9)	157 (51.1)
Hepatitis B	106 (41.2)	151 (58.8)
Hepatitis C	230 (38.3)	371 (61.7)
Syphilis	942 (48.2)	1013 (51.8)
STBBI cases and rates per 100,000 by Regina area residents
Regina 1 (North)	1408 (771.4)	898 (487.0)
Regina 2 (East)	870 (482.4)	632 (327.8)
Regina 3 (South)	1146 (603.5)	851 (443.8)
Regina 4 (Central)	2575 (1434.0)	1524 (827.7)
Regina NA	638 (284.6)	1191 (565.5)

Geospatial analysis indicated that more than one-third of cases had residential addresses in Regina Central, which represents slightly less than one-fifth of the city’s population. Regina North, comprising approximately 30% of the city’s population, accounted for 20% of the cases.

The average age of individuals diagnosed with STBBIs was 28.3 years. Patients diagnosed with chlamydia were generally younger, with an average age of 25.2 years, whereas those diagnosed with HIV and hepatitis B exhibited higher mean ages of 48 and 40.4 years, respectively. A comprehensive analysis of age distributions by infection type is available in Appendix 1, which includes the univariate analysis of age by disease.

Risk factor analysis indicated that inconsistent or no use of condoms and multiple sexual partners were prevalent among STI cases. Approximately 24% of individuals reported having more than two sexual partners in the past three months. “Sex without protective barriers” primarily refers to the use of condoms (both male and female) and other barrier methods such as dental dams. Table 2 presents the additional risk factors identified among cases. Further details on the distribution of risk factors across specific diseases (chlamydia, gonorrhea, HIV, hepatitis C, hepatitis B, and syphilis) are provided in Appendix 2.

Table 2.

Risk factor profile of STBBI cases in Regina, 2019–2024

	Frequency
STI-related risk factors
Sex without protective barriers	2820 (27.8)
Sex with two or more partners in the last three months	2481 (24.4)
Sex with an anonymous partner	1720 (16.9)
Cases meeting partners online	757 (7.5)
Sex with a known case	622 (6.1)
BBV-related risk factors
Cases with a history of non-injectable substance use	1163 (11.4)
Cases with a history of injectable substance use	211 (2.1)
Cases who are street-involved	387 (3.8)

The analysis revealed a substantial increase in syphilis incidence across all stages of the disease. When categories were merged into the four principal stages, primary syphilis (Primary) accounted for 31.3% of cases, secondary syphilis (Secondary) for 16.4%, latent syphilis (Early latent, Late latent, and Latent syphilis of unknown duration) for 50.4%, and tertiary syphilis (Tertiary other than neurosyphilis, Neurosyphilis and syphilitic stillbirth accounted for 1.9%. Additionally, seven cases of congenital syphilis were documented. An increasing proportion of cases has been categorized as “unknown duration,” highlighting the difficulties in obtaining complete staging information.

Potential predictors of STBBIs included street involvement, a history of previous STBBI, and having more than two sexual partners in the three months preceding diagnosis. After adjustment for confounding factors, individuals who were street-involved demonstrated a significantly higher incidence of STBBIs (IRR = 1.17, 95% CI: 1.17–1.18). A prior history of STBBI was also correlated with an increased incidence (IRR = 1.08, 95% CI: 1.07–1.08). Male sex was associated with a reduced incidence of STBBIs (IRR = 0.94, 95% CI: 0.94–0.94), as illustrated in Table 3.

Table 3.

Poisson regression analysis of STBBI risk factors in Regina, 2019–2024

Parameter	Incidence rate ratio	95% CI	Pr > ChiSq
Cases who are street-involved	1.17	1.17 to 1.18	P < 0.001
Cases with a previous STBBI	1.08	1.07 to 1.08	P < 0.001
Sex with two or more partners in the last three months	1.01	1.01 to 1.01	P < 0.001
Male sex	0.94	0.94 to 0.94	P < 0.001

Discussion

The rising prevalence of STBBIs observed in Regina, Saskatchewan, mirrors a broader resurgence of these infections at both the national and international levels. Throughout Canada, the incidence rates of syphilis, gonorrhea, and chlamydia have consistently increased with particularly notable surges in infectious and congenital syphilis [16]. The current analysis indicates an almost eightfold escalation in syphilis cases in Regina from 2019 to 2024, exceeding the overall provincial trend reported in Saskatchewan and corresponding with national growth patterns. Comparable increases have been documented in Saskatchewan (n = 1,913), Alberta (n = 2,380), and Manitoba (n = 1,487) in 2023, suggesting that local transmission dynamics reflect a broader re-emergence of STBBIs across Western Canada [16].

The higher rates of infection among younger adults (ages 20–40 years) in this study align with national age distributions reported by the Public Health Agency of Canada and findings from studies in other high-income settings where younger populations show elevated risk behaviours such as limited condom use and multiple partners [17]. The observed sex distribution, with higher chlamydia incidence among females but greater syphilis and HIV among males, mirrors Canadian surveillance data and global epidemiological trends [1]. The protective association seen with male sex (IRR = 0.94, 95% CI: 0.94–0.94) may reflect gendered patterns in healthcare-seeking behaviour and testing rather than biological differences, as routine screening programs more often target sexually active women [18].

Our results also identified street involvement, previous STBBI diagnosis, and multiple sexual partners as independent predictors of infection, consistent with findings from both national studies and global surveillance reports [17]. The Canadian Public Health Association has identified unstable housing, substance use, and transactional sex as key determinants of risk in urban centers [19]. Similarly, studies have reported that individuals experiencing homelessness or housing insecurity have two to three times higher odds of acquiring STIs compared with the general population [20–23]. These consistent patterns highlight the structural and social determinants of STBBI vulnerability, reinforcing the need for interventions that extend beyond biomedical treatment to address social inequities.

In response to these challenges, the introduction of Street Outreach and Intervention Worker (SOIW) programs in Regina aligns with evidence-based harm reduction and outreach models used in other Canadian contexts. The Edmonton initiative showed measurable increases in testing and linkage to care among high-risk and hard-to-reach populations [24]. Similarly, mobile testing and peer-supported outreach interventions have been effective in increasing testing among low-resource settings and priority populations globally [25]. These study findings suggest that Regina’s adoption of a similar model effectively complements traditional clinic-based care, especially for populations disproportionately affected by STBBIs.

The overlap between the COVID-19 pandemic and the rise in syphilis cases requires careful consideration. Around the world, many jurisdictions reported disruptions to sexual health services during the pandemic due to resource reallocation and clinic closures [26]. The temporary drop in chlamydia and gonorrhea cases seen in our results may partly result from reduced screening opportunities rather than an actual decrease in transmission. Post-pandemic monitoring has shown quick rebounds in case numbers once regular services resumed [16, 27]. These trends highlight the importance of maintaining access to services and adopting innovative care models such as telehealth, self-testing, and community-based testing to ensure continued progress in STBBI prevention and treatment.

Despite robust surveillance methods, several limitations should be recognized. Our analysis was based on reported and tested cases; therefore, undiagnosed infections likely remain underrepresented. Additionally, behavioural data were self-reported, introducing potential reporting bias. Nonetheless, this study provides valuable local evidence to inform targeted interventions in Regina and similar urban centers. Overall, the findings highlight the intersection of biomedical, social, and structural determinants driving STBBI transmission. The growing burden of syphilis and persistent disparities across geographical and demographic subgroups underscore the need for continued public health investment in outreach, education, and testing infrastructure. Sustained cross-sectoral collaboration, supported by community engagement and integrated care pathways, remains essential for reversing these upward trends and achieving provincial and national STBBI reduction targets.

Conclusion

STBBIs continue to be a significant public health issue in Regina, with a notably rapid increase in syphilis cases from 2019 to 2024. This health concern shows uneven distribution, characterized by higher rates among younger adults and in specific geographic areas. Social and structural factors, including street involvement, inadequate housing, and participation in sexual risk behaviours, influence its prevalence.

The findings underscore the importance of targeted, community-focused strategies, including specialized STBBI clinics and outreach programs such as Street Outreach and Intervention Workers, to improve testing, linkage to care, and ongoing support for priority populations. Continuous efforts in surveillance, integrated service delivery, and multisectoral collaboration will be essential in preventing further increases in STBBIs and in meeting provincial and national goals for STBBI prevention and control.

Abbreviations

BBV

Blood-borne viruses

IRR

Incidence Risk Ratio

QI

Quality Improvement

REB

Research Ethics Board

SOIW

Street Outreach and Intervention Worker

STTBI

Sexually transmitted and blood-borne infections

Appendix 1

Table 4.

Univariate analysis of age by disease

	Chlamydia	Gonorrhea	HIV	Hepatitis B	Hepatitis C	Syphilis
Number of cases	4583	1847	230	170	476	1255
Mean	25.3	28.5	35.3	40.4	38.3	32.2
Std. deviation	8.0	9.1	11.2	12.7	13.0	10.9
Mean	25.3	28.5	35.3	40.4	38.3	32.2
Median	23	27	34	40	37	31
Mode	20	26	32	42	43	33
Range	68	72	76	72	75	86

Appendix 2

Table 5.

Risk factor counts by individual STBBI diseases

	Chlamydia	Gonococcal	Hepatitis B	Hepatitis C	HIV	Syphilis
STI-related risk factors
Sex without protective barriers	943	283			6	1588
Sex with two or more partners in the last three months	1200	553	2	46	3	677
Sex with an anonymous partner	634	404		1	67	614
Cases meeting partners online	346	168			13	230
Sex with a known case	136	43	5	60	21	357
BBV-related risk factors
Cases with a history of non-injectable substance use	5	2	1	86	13	1056
Cases with a history of injectable substance use				99	112
Cases who are street-involved	11	10		1	23	342

Authors’ contributions

PM, HB, and OM conceived the idea for the manuscript and led the analysis and writing. MT, AS, and OM were involved in pulling, cleaning, and analyzing the Panorama data. PM, HB, OM, MH, CB, MT, AS, MS and TD were involved in various aspects of STBBI public health programming in the Regina area. They were also involved in drafting and revising the final version of the manuscript. All authors participated in preparing the final draft of the manuscript, revising it, and critically evaluating its intellectual content. All authors read and approved the final manuscript.

Funding

This research did not receive any funding.

Data availability

Aggregated data used during this study are available from the corresponding author on reasonable request.

Declarations

Ethics approval and consent to participate

This study was part of a Quality Improvement (QI) initiative and, as such, did not undergo formal ethical review by a Research Ethics Board (REB).

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.