- Rates of syphilis have increased in Canada, including in Indigenous populations in the Arctic
- Montreal researchers developed a model simulating the syphilis epidemic in Arctic communities
- They found that the introduction of rapid testing could reduce syphilis by 37% over a decade
Rates of new syphilis diagnoses have been increasing over the past 20 years. As a result, there is now an epidemic of syphilis across Canada. The initial symptoms of syphilis—a sore or chancre on or inside the genitals, mouth or other parts of the body—may be painless or go unnoticed. The germs that cause syphilis (called treponemes) quickly spread from the site of first contact. These germs can attack nerves, eventually causing problems in the ears (hearing loss) and eyes (loss of vision). What’s more, if left untreated, over time syphilis can cause injury to vital organs, including the brain, bones, heart and circulatory system, liver and kidneys. Syphilis during pregnancy can harm the fetus and baby (congenital syphilis). Symptoms of syphilis can mimic many other diseases; however, syphilis can be easily diagnosed with a simple blood test. Most people can recover with a single course of antibiotic therapy.
In the Arctic
According to researchers at McGill University in Montreal, “Indigenous populations often bear a disproportionately high burden of syphilis.” They added that in 2021 in the region of Nunavik, the rate of syphilis was about 18 times greater than the average rate in the rest of Canada that year. The researchers noted that “surges in cases of congenital syphilis are already observed as a consequence [in Canada’s Arctic regions].”
The McGill researchers (who study epidemics and syphilis) say that potential contributors to the high levels of syphilis transmission in the Arctic include “diagnostic and treatment delays. These delays stem from the lack of local laboratory capacity. Collected specimens must be sent to distant laboratories—up to 1,900 kilometres south—for diagnosis. The typical resulting delay between sample collection and analysis is 6 to 19 days.”
The researchers say that implementing rapid syphilis diagnostic testing could play a major role in reducing delays between testing, diagnosis and treatment to just one clinic visit.
The model
The McGill team developed a mathematical model of the syphilis epidemic in Canada’s Arctic. They used data collected from Arctic health surveys, research studies and databases to develop their simulation. The researchers assumed that 90% of people diagnosed with syphilis via rapid testing would be linked to care within seven days after a positive test result.
The researchers assumed that the DPP Syphilis Screen and Confirm assay, made by Chembio, would be used. This assay requires a small amount of blood from a finger prick and provides results in 15 minutes.
The study was funded by the Canadian Institutes of Health Research (CIHR).
Results
The researchers found that syphilis rapid testing could reduce new infections by 33% over the next five years. If availability of rapid testing was extended for the next 10 years, 37% of syphilis cases could be prevented during that time.
The researchers emphasized the importance of continuing to ask people who test positive for syphilis for their sexual contacts so that healthcare professionals can contact them and tell them that they have been exposed to syphilis and require testing.
Bear in mind
Rapid syphilis tests are highly accurate and could play an important role in helping to reduce the spread of syphilis in Canada’s Arctic and other regions. The researchers stated that rapid syphilis tests “are a flexible tool that requires minimal training and laboratory capacity and can be extended to non-traditional settings to reach individuals [who] face barriers to accessing healthcare.” What’s more, the researchers emphasized that “increasing syphilis testing rates is pivotal for outbreak control.”
—Sean R. Hosein
Resources
Winnipeg researchers warn about rising cases of syphilis-related stillbirths – CATIE News
Views from the front lines: Congenital syphilis – CATIE
Congenital syphilis – NCCID
Early access to syphilis screening and treatment needed to prevent stillbirths – CATIE
Rapid combined syphilis-HIV testing found accurate and useful in an Alberta study – CATIE News
Alberta study underscores the importance of syphilis testing in people who use stimulants – CATIE News
New HIV infections in Manitoba intersect with housing and methamphetamine use – CATIE News
Understanding the impact of the antibiotic doxycycline on the sexual well-being of users – CATIE News
REFERENCE:
Xia Y, Caya C, Morin V, et al. The population-level impact of introducing rapid diagnostic tests on syphilis transmission in Canadian arctic communities—a mathematical modeling study. Lancet Regional Health – Americas. 2024 Jul 20; 37:100845.