Nearly 14 per cent of Canadian youth and adults may be infected with a sexually transmitted herpes virus, the vast majority of them unknowingly, according to a new report.

As part of a study, urine and blood samples were collected between 2009 and 2011 from about 3,250 Canadians.

Participants were asked if they had ever been diagnosed with a sexually transmitted infection. None of those who tested positive for chlamydia reported having received a diagnosis of an STI.

Of those who tested positive for herpes simplex 2, only six per cent were aware that they carried the virus. The remainder were unaware they were infected.

Statistics Canada called Wednesday's report the first to analyze lab-confirmed cases of chlamydia and herpes simplex type 2 virus using a nationally representative sample.

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Public health campaigns aim to spark awareness about the importance of getting tested for chlamydia, a silent infection. (Supplied)

The infections can have serious immediate and long-term physical and psychological consequence. Most people with chlamydia have no symptoms. The infections can be treated with antibiotics. In women, chlamydia infection can lead to infertility or ectopic pregnancies — pregnancies where the fertilized egg begins to develop in a fallopian tube or outside the uterus.

Infections with herpes simplex 2 often also cause no symptoms though it can lead to blisters and sores around the genitals, rectum or mouth. Medication will not cure herpes, but can help to reduce discomfort from blisters and other symptoms,  HealthLink BC's website said.

"The results of this analysis show that at ages 14 to 59, the prevalence of chlamydia is less than one per cent, and that HSV-2 affects about 14 per cent of the people in this age range," the agency's authors concluded.

"A comparison of laboratory confirmed infections with self-reports of diagnoses suggests that almost all respondents testing positive for chlamydia or HSV-2 were unaware that they were infected."

Silent infection

Although it is a reportable disease, chlamydia is what's known as a silent infection. Most people have no symptoms. Antibiotics can cure the infection.

In men, complications of chlamydia are rarer, though infertility can occur.

The researchers did not delve into specifics behind the rates of chlamydia infection, given its low prevalence in the study.

For the herpes infections, however, they did look report on prevalence based on gender, socioeconomic and educational status, age and racial background.

With files from The Canadian Press