Risk-Aversion Practices At One's Peril

"Even though the patient was taking the drug every day, the HIV virus overpowered the medication and infected him."
"It could be someone in Toronto [transmission origin], it could have been someone who was travelling through. We don't know for sure but, yes, this resistant [HIV] strain could be in Toronto."
Dr. David Knox, HIV specialist, primary care physician, Maple Leaf Medical Clinic, Toronto

"[This case is a reminder that] nothing in this world is one hundred percent. Taking medication as a preventive measure may not give you the protection that you think."
Dr. Gary Garber, chief of infection prevention and control Public Health Ontario

"Yes, this was an unfortunate exemption [sic] that occurred in our community. But science has also suggested this is a highly effective method of preventing HIV."
Chris Thomas, spokesperson, AIDS Committee of Toronto

A spokesperson for the biopharmaceutical company who manufactures the drug said the Toronto case is the first failure they are aware of.  (Gilead Sciences Inc.) 

Researchers in Toronto have identified a 43-year-old man who contracted a rare, drug-resistant strain of the HIV virus in the wake of unprotected anal sex with multiple sexual partners, despite having taken preventive precautions with daily use of the "miracle" drug Truvada, known to block HIV transmission. This represents the first documented instance of a patient taking the antiretroviral drug daily as instructed, but who became infected nonetheless.

This instance of failure was reported by Dr. Knox at the Conference in Retroviruses and Opportunistic Infection that took place in February, in Boston, Mass. Dr. Knox emphasized the message in the case: that gay or bisexual men cannot afford to let down their guard, and must continue wearing condoms rather than solely rely on the drug to protect them from HIV. Truvada's manufacturer admits that this is the first case of its kind to come to its attention.

They cite "several large-scale clinical trials" that have demonstrated that the medication is safe and effective. "It is important to note, however, that no single intervention is one hundred percent effective in preventing HIV", wrote Ryan McKeel of Gilead Sciences Inc. The individual in this case "contracted the virus after  he was exposed to a rare strain of HIV that is resistant to both of the drugs included in Truvada."

Health Canada emphasizes that health care providers must prescribe the drug as "part of a comprehensive prevention strategy, including safer sex practices, as Truvada is not always effective in preventing the acquisition of HIV-1 infection."  Health Canada approved the drug for preventive use in late February of this year. It was a first-line treatment for HIV-positive people even before it was approved for daily preventive use in the U.S., in 2012. Its profitability came to $2-billion in sales last year in the United States.

Truvada is not listed in Ontario under the drug benefit program as a HIV prevention prescription; but rather for HIV treatment. Dr. Knox's patient had been taking the drug through off-label prescription for two years when he became infected The daily cost was a whopping $28.57 per tablet. Regarded as a reliable 'fail-safe' method of prevention, many gay men set aside other precautions urged upon them such as condom use. This will certainly serve as a wake-up call.

The use of the pill is regarded as effective when taken consistently, and not simply before sex. This is known in scientific circles as preexposure prophylaxis, referring to the use of the drug by healthy, non-infected people as a pseudo-biochemical condom in the prevention of HIV onset. The HIV Prevention Clinic at St.Michael's Hospital in Toronto is undertaking a study to measure the prevention pill's effect on safe-sex practices. This case in and of itself should speak volumes.

Aside from the impact of the case, early results from the St. Michael's study indicates that condom-less sex between HIV-positive and HIV-negative men using the drug is on the increase. It is not as though public health experts have been unaware of the problem. Warnings that the medication's use may come with a false sense of security resulting in riskier sex eroding the use of condoms have been previously issued by public health experts.

The Public Health Agency of Canada recognizes, as it must, that HIV transmission remains "an issue of concern", with data indicating that over 2,500 total new infections surfaced in 2014 alone, more than half of them accounted for by male-to-male sexual encounters.