Editor's note: No type-specific HSV blood tests are covered by the province in Ontario, according to Darrell Tan. Incomplete information appeared in an earlier version of this story.
In a random sampling of thousands of Canadians, nearly 14 per cent tested positive for genital herpes, according to a Statistics Canada report released this week that also found 94 per cent of this group had no previous symptoms and therefore no idea that they were infected.
These findings, the first national set of statistics on genital herpes in Canada, suggest many people are unknowingly passing on the virus to their sexual partners.
“An individual may not have overt symptoms, but they’re still a carrier,” said Michelle Rotermann, lead author of the study. “Those who don’t know that they are infected are at greater risk of passing an infection on to a sexual partner.”
Blood tests conducted on 3,247 people between 2009 and 2011 found that 13.6 per cent of the tests turned up antibodies positive for HSV-2 – one of two incurable viral infections that causes genital herpes. Based on this random sample, conducted with respondents aged 14 to 59 years old, the researchers estimate that 2.9 million Canadians would test positive for HSV-2.
The report found that HSV-2 affects higher percentages of women than men and that people aged 35 to 49 are most vulnerable to infection because they’ve been exposed to more partners than younger age groups. In this cohort, 19 per cent had HSV-2. “With age, you accumulate years of risk,” said Rotermann.
The researchers didn’t test for HSV-1, the virus that causes oral herpes and is characterized by cold sores. This more common strain of herpes is increasingly being transmitted to the genitals. According to previous research cited in the current study, herpes simplex virus type 1 is now “accounting for an estimated 40 per cent of genital infections in Canada.” Were HSV-1 and HSV-2 numbers for genital herpes tallied together, experts suggest the current figures would be much higher.
Still, some argue that herpes, though life-long, is essentially an “inconvenience” – especially given that many people show few or no symptoms and can take antiviral drugs to suppress infections when they do arise. Nevertheless, infected mothers can pass herpes through the birth canal, risking their newborns, and stigma remains because the condition is incurable. Despite this, most patients are only swabbed by a doctor once an outbreak occurs, rather than undergoing blood tests for antibodies if no symptoms are present.
“Testing, especially for something like herpes, may be unfeasible in certain circumstances,” said Alex McKay, research co-ordinator with the Sex Information and Education Council of Canada. “When you meet a potential sexual partner, you’re going to have to delay having sex until you can get them to the clinic, have them tested and then wait for the results to come back, and assume that they haven’t had sex with anybody else in the meantime.”
McKay said that while testing can be an important part of prevention, there are other things people should consider first. “If you want to minimize your risk of getting STIs, the message hasn’t changed: Use condoms every time you have sex, limit your number of sexual partners and get tested if you’ve been engaging in risky behaviour, including multiple partners.”
While blood tests for herpes are increasingly available, Canadians have to pay for them. Blood screening at Gamma-Dynacare lab locations in Canada costs $140, and gets patients tested for both HSV-1 and 2 antibodies with a 13-day turnaround time, spokesperson Scott Hickey confirmed.
Manav Gill, director of nursing and clinical services at Options for Sexual Health in British Columbia, said testing is done by the province only under certain circumstances, including pregnant women whose sexual partners have been diagnosed with the virus and people who have tested positive for HIV.
Cost “is absolutely the issue” in Ontario, where no type-specific HSV blood tests are covered by the province, says Darrell Tan, infectious-diseases physician at St. Michael’s Hospital in Toronto. “You don’t test the whole population, but there are definitely clinical scenarios in which this would be quite informative and could help improve care.… In the face of not having a publicly reimbursed test, we have to very judiciously decide in which situations is a potential gain enough that we would recommend that a patient pay out of pocket for a test.”
McKay and other experts agree that herpes has gotten a social blot it does not deserve: “It’s a common manageable infection which for most people does not have serious health outcomes,” he said. “There is definitely a stigma attached to herpes, but as people get more knowledgable about it, that stigma reduces.”