Brandon Cronenberg received an added bonus – a movie.
"I was having this fever dream," recalls the 32-year-old, "half-consciously obsessing over the physicality of my illness and the fact I had something in my body that had come from someone else's body."
The result is Antiviral, a science fiction horror set in a world where celebrity worship has reached such an intensity that fans will pay to have their idols' viruses injected into them as a way of feeling close to the objects of their desire.
"That seems not totally implausible," laughs Cronenberg, whose film had its premiere at the London Film Festival last year and is now out on DVD.
If the surname sounds familiar it is because Brandon is the son of David Cronenberg, the director of such body horror classics as Scanners, The Fly and Dead Ringers.
Though having a famous filmmaker as a father could be seen as a dream scenario for anyone trying to break into a fiercely competitive business, Cronenberg resisted the move "for the longest time". His hesitation was due in part to wanting to write novels, but the dad factor was there too.
"I was put off it because people would approach me with preconceptions about who I was, 'I must love film and want to be in film', so I took great pleasure in telling them I had no interest in film-making. Then at a certain point that seemed a bad idea, a bad reason to avoid something interesting."
So, a degree in film from Ryerson University in Toronto, one flu dream and eight years later, Antiviral emerged. Peppered with scenes of injections, the film produced Mexican waves of wincing in the audience when it showed on the big screen. Special effects at their finest? Not quite.
"A lot of it wasn't trickery," says Cronenberg. Throwing himself into the thick of needles and swabs was Caleb Landry Jones, who plays Syd March, a salesman of celebrity viruses who gets too close for comfort to one of his products.
Cronenberg had seen Landry Jones in X-Men and No Country for Old Men, but had not met him. A test reel was proof enough that Cronenberg had found an actor sufficiently mesmerising to pull off the part of haunted, obsessed Syd. It helped immensely that he wasn't frightened around needles.
"Caleb is a very brave human being. We had to hold him back. He likes to feel it, and he likes to give you everything, so there were times we had to tell him 'No, you can't throw yourself on that concrete floor with no padding, we have to do this safely.'"
As his first feature, Antiviral was long in conception but brisk in execution, with shoot lasting just 21 days. Directing demanded Cronenberg adopt something of a new persona.
"I'm very introverted, it's not usually in my nature to speak in front of people, but when I'm on a film set for some reason I'm not bothered by it."
Though some of his father's films have dealt in body horror, Cronenberg did not see that as a reason why he should steer clear.
"He's had a very long and varied career. As much as people associate him with body horror he's done a very wide range of films. So it's hard to completely avoid anything he's done." Over the course of a five decades long career, David Cronenberg has indeed made everything from gangster thrillers (Eastern Promises) to studies of Jung and Freud (A Dangerous Method).
Understanding and dissecting celebrity culture could be said to be very much a young man's game, though, and Cronenberg junior, part of the generation that has grown up with reality TV, has thought a lot about it. Worshipping idols has been around for centuries, he says, but the celebrity industry is changing. People are now famous for just being famous, and the rate at which one celebrity is being replaced by another is increasing.
Now with a UK agent and on the back of toasty reviews for Antiviral, Cronenberg's film-making career should be getting into a higher gear too. He has no plans to move from his beloved Toronto, though.
"A lot of Canadians are ferociously proud and very defensive of Canadian identity. I wouldn't say I'm like that, but there is something to the culture, you can relax there and it feels very familiar."
He's now working on a new script. "It will probably have some horror elements, some science fiction elements. It could be a western by the time I'm done with it," he smiles. If he comes down with the flu again, who knows.
Antiviral is available on DVD and digital download.