London's health unit deals with about 1,500 chlamydia cases a year
Syphilis also remains a concern, particularly among people who are homeless
The term "contract tracing" may bring bad back memories of the dark days of the COVID-19 pandemic, but it's something that still happens at the London-Middlesex Health Unit (MLHU).
These days, however, it's not COVID cases; health unit staff are so busy chasing. Often, it's chlamydia, a sexually transmitted infection (STI) that continues to have stubbornly high case numbers locally. It's the most commonly reported disease to the health unit.
Of the more than 2,000 STI cases reported to the health unit in 2024, a total of 1,571 were chlamydia. Already up to the end of May of this year, there were 631 chlamydia cases reported to MLHU.
"Our rates are high," said Shaya Dhinsa, a nurse who oversees the health unit's sexual health program. "On average, we have about 1,600 cases a year."
Their rates aren't historically high. There were almost 1,800 cases in 2022, and the following year, there were more than 1,900.
Dhinsa said the primary concern is that the case numbers are staying persistently above 1,000 a year.
"That is a fair amount of cases, and it doesn't seem to be drastically dropping," she said. "It is a highly transmittable disease without condom use, and sometimes people don't even know they have it."
Chlamydia is spread through unprotected vaginal, anal and oral sex with an infected partner.
Dhinsa said the number of cases is particularly high among the 15- to 29-year-old age group. Also, most people who have chlamydia don't know they have it.
When someone tests positive for chlamydia (most commonly through a urine test), the health unit is notified, and the person who tested positive is confidentially contacted to ensure they have access to treatment.
Also, the health unit will ask the person who tested positive if they feel comfortable reaching out to past sexual partners. In some cases, health unit staff does the contact tracing.
"We do encourage people to get tested if they have multiple partners or if they're in a new relationship," said Dhinsa.
Although it's easily treated, chlamydia can lead to serious health problems, including a greater risk of acquiring and transmitting HIV. Also, it can make it harder for a woman to get pregnant.
Treatment generally involves a single-dose antibiotic, which MLHU provides for free.
Syphilis continues to be a challenge
Dhinsa said syphilis is another STI the health unit is dealing with. Once considered all but eradicated, the disease is making a comeback with high infection rates among women and newborns, who can get the disease from their mothers during pregnancy.
London's health unit is seeing about 170 cases a year. Many of the cases involved people who are unhoused or who have addiction and mental health challenges that limit their access to health care.
"That's where we're seeing a large increase," said Dhinsa. "They may not be accessing health care as frequently as other people."
Dhinsa said MLHU has an outreach team and a network of partners, including operators of homeless shelters, to help connect people with syphilis to health care.
There are effective treatments for syphilis, but left untreated, it can cause brain and nerve damage, temporary vision loss, heart damage, abnormal tissue growth and death.
You can get more information about syphilis, including how to access testing and treatment, on the health unit's website.