Category: News | CATIE Blog

Exploring new recommendations for doxyPEP

February 17, 2026 • By Public Health Agency of Canada

You may have heard of doxyPEP, which stands for doxycycline post-exposure prophylaxis. It involves taking an antibiotic called doxycycline after having sex without a condom. This can help prevent certain bacterial sexually transmitted infections (STIs), such as chlamydia, syphilis and possibly gonorrhea. This prevention strategy is relatively new but has been gaining attention across the country as another way to help reduce high rates of STIs. Although interest in using doxyPEP is growing, there is no global standard for its use. This prompted the Public Health Agency of Canada (PHAC) to publish recommendations that give health professionals evidence-based advice to...

DoxyPEP and antibiotic resistance: What have we learned so far?

February 17, 2026 • By Sean Hosein

Studies have found that the antibiotic doxycycline, when taken after sexual exposure, can significantly reduce the risk of some bacterial sexually transmitted infections like chlamydia and syphilis. However, it is generally less effective at reducing the risk of gonorrhea. Some researchers are concerned that over the long term, widespread use of doxycycline as post-exposure prophylaxis (doxyPEP) may diminish the antibiotic’s effectiveness, or even weaken the efficacy of some other antibiotics. Is this concern realistic? And if so, are the benefits worth the risk? Clinical trials The initial clinical trial of doxyPEP in San Francisco and Seattle found low rates of...

Estimating how many people in Canada inject drugs

November 17, 2025 • By Public Health Agency of Canada

People who inject drugs that are not prescribed to them often experience complex health challenges and have a difficult time accessing healthcare. To make sure we can provide the services and resources that better support this community, we first need to know how big the community is and where they live. That’s why the Public Health Agency of Canada has created the report, Estimating the population size of people who inject drugs in Canada, which estimates, in 2021: The process for creating these estimates involved several steps, so let’s review them in greater detail. How we estimate the number of...

Advancing awareness: Canadian Positive People Network’s U=U Task Force and the fight against HIV stigma

November 11, 2025 • By Breklyn Bertozzi

At the Canadian Positive People Network (CPPN), we strive to end HIV stigma. We also recognize that people living with HIV provide the movement’s strongest guiding voices. That’s why our U=U Task Force is led by people living with HIV and is dedicated to sharing one of the most groundbreaking messages in public health: Undetectable = Untransmittable. U=U means that when a person living with HIV is on effective treatment and has an undetectable viral load, they cannot transmit the virus to their sexual partners. It’s a message that transforms lives, dismantles stigma and redefines what it means to live...

Sexual health for all: Lessons from the HIV & STI 2025 World Congress

October 16, 2025 • By Dan Miller

This July, CATIE joined 1,500 researchers, advocates and policy makers from around the world for the STI and HIV 2025 World Congress in Montreal, Quebec. Held every two years, the event provides a venue for global leaders in sexual health research to discuss the latest evidence and most pressing challenges in STI prevention, testing and care. Four particularly timely and significant topics stood out, each with important implications for bacterial STI prevention, testing and treatment. DoxyPEP for cis women A key theme of the event was the lack of research on doxycycline post-exposure prophylaxis (doxyPEP) effectiveness in cis women and...

Health workers shouldn’t have to go to court to stop online abuse

September 15, 2025 • By Andrew Brett

Last month, CATIE won a landmark $1.75M defamation case against an individual who undertook a sustained online hate campaign against our staff and volunteer board members. The attacks were driven by our commitment to publishing sexual health information and, as the judge acknowledged, by homophobia. The decision affirms that this kind of abuse is unlawful. But it also highlights a systemic failure: we should never have had to go to court to defend our right to do our work. We are not alone. Other HIV organizations and public health workers were defamed by the same individual. 2SLGBTQIA+ health advocates continue...