Sexual health experts say infections like chlamydia, gonorrhea and syphilis are on the rise in Canada and around the world — and they say declining condom use is partly to blame.

The topic is one of many that will be discussed at the STI & HIV World Congress in Vancouver this week.

Nathan Lachowsky, assistant professor in the School of Public Health and Social Policy at the University of Victoria, will be one of several Canadian researchers presenting his work at the congress.

Lachowsky says condom use has been declining among the general population and LGBT men for years, and researchers are still working to determine why.

"It's really unfortunate," Lachowsky said. "Condoms are a tool for prevention that we've had for a long time and we've actually gotten better in terms of making them more comfortable."

Statistics from the B.C. Centre for Disease Control show that some sexually transmitted infections in B.C. and Canada have increased exponentially since 2003.

Learning from the past

Those increases come at a time when the rates of HIV, especially in B.C., have decreased considerably.

Last month Vancouver Coastal Health said the number of new HIV infections in the region has fallen by 52 per cent since 2011 and is expected to continue to decrease to record-low levels.

Dr. Julio Montaner, executive director of the B.C. Centre for Excellence in HIV/AIDS, credits B.C.'s aggressive fight against the disease.

Researchers say there are many reasons why people are using fewer condoms. (Purple Anvil/Shutterstock )

But he warns against assuming that people use condoms less today because they think medication will keep them from getting infected. Montaner says past studies have shown that's not the case.

Instead, Montaner thinks sexual health researchers can learn from B.C.'s approach in the fight against HIV/AIDS, which includes targeting at-risk populations and offering prophylactic treatment to prevent the disease's spread.

"What we need to recognize is that further efforts are required so that we can expand that kind of success to other areas," Montaner said.

Buying condoms daunting for some

Kristen Gilbert, education director at Options for Sexual Health, concedes that the AIDS epidemic isn't as prevalent in popular culture.

But she says youth are just as scared today about getting an STI as they were 30 years ago.

"The argument that kids these days aren't scared enough doesn't compute for me as why they're using condoms less," Gilbert said.

Syphilis is one of several sexually transmitted infections on the rise in Canada. (Getty Images)

Gilbert says young people are making different choices about their sexual health — including waiting longer to have sex, and using hormonal birth control when they do. And most of them are using condoms, albeit a bit less than before.

She argues that the key to fighting sexually transmitted infections is to provide people with comprehensive sexual education that includes teaching how to choose the right kind of condoms and how to use them effectively.

Despite advances in sexual education in B.C. schools, Gilbert says, she still encounters students in their late teens who have never seen a condom or been shown what to do with it.

"Buying condoms can seem extraordinarily daunting to someone without a lot of confidence, without a lot of knowledge, and without a lot of experience," she said.