(Photo credit: Toronto Star)
Open Data TO: This post is part of a series based on City of Toronto open datasets. Visit their open data portal here.
There were nearly 10,000 new cases of chlamydia diagnosed in Toronto in 2014, the most recent year where complete datasets were available. Chlamydia is easily transmitted and was the most prevalent sexually transmitted infection (STI) across the city. The increase is due in part to better laboratory testing according to Toronto Public Health. “It is likely that these tests are picking up infections that would not have been detected with earlier generation tests,” said Dr. Rita Shahin, Toronto’s associate medical officer of health.
She adds that chlamydia is so common because it often remains symptomless, leading to a greater likelihood that those infected will spread the disease to others.
“STI rates in Toronto are high compared to other jurisdictions.”
Gonorrhea is the second most common STI in the city, and over the years doctors have come across a small number of drug-resistant cases. The majority of these have been seen in men who have sex with men, and the disease is “generally able to be treated with combinations of antibiotics,” said Dr. Shahin. But health officials in other countries have expressed concerns that drug-resistant gonorrhea could become untreatable.
When looking at the distribution of new cases of STIs across Toronto, denser pockets of infection emerge throughout the city’s 140 neighbourhoods. Rates of chlamydia in 2014 were higher in the city’s northwest corner—near Downsview, Jane and Finch, and York University—and downtown. Infection rates of hepatitis B were higher in the Steeles/Milliken area and Kensington – Chinatown. Hepatitis B is a serious liver infection that can increase the risk of organ failure and cancer. In general, there were higher rates of sexually transmitted infections in the Yonge – Church corridor.
In 2014, the rate of new HIV cases was highest in Cabbagetown – South St. James Town. There were 14 new infections within a population of 12,060, which is one in every 861 people. HIV infections overall have fallen across the city from 569 in 2004 to 407 in 2014.
With respect to chlamydia and gonorrhea, officials at Toronto Public Health believe the impact from improved lab testing has likely plateaued, but Dr. Shahin says it is very difficult to predict whether infection rates will rise or fall. “There are many factors that affect STI rates including condom use, testing behaviours, number of sexual partners, and increased use of online apps.”
Recently within Toronto’s gay community there has been growing interest in the use of PrEP (Pre Exposure Prophylaxis). “PrEP is the use of Truvada, a drug used to treat someone who is HIV-positive, by men who are HIV-negative,” explained Dr. Brennan. “If they take this medication before possibly being exposed to HIV and then continue to take it afterward, their chances of HIV infection are very low.”
To curtail the spread of infection, Toronto Public Health has, among other things, engaged in a large social media campaign to promote safe sex and responsible behaviour. The city has even created its own branded condom, condomTO, meant to “reinvigorate and normalize condom use, and combat sexual shame and stigma,” according to Dr. Shahin.
“The response has been very positive,” she said. Condoms still remain one of the most effective tools to protect against sexually transmitted infections.