The Current

Rising urban rat population pose health risks to humans, says researcher

As a growing number of Canadian cities report increases in rat populations, The Current turns to a researcher and a rodentologist for their insight into the potential health risks to humans and how to get rid of rats. Yes, that's right - a rodentologist.
'Rats have been causing human illness in Brazil long before Zika,' says Chelsea Himsworth, lead researcher for the Vancouver Rat Project. (Tony Hisgett/Flickr cc)

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This season, pest control companies in Montreal, Toronto and Halifax all say they're getting more rat calls than usual.

The rising urban rat population is on the radar for Chelsea Himsworth. She's the lead researcher of the Vancouver Rat Project and is conducting the first and only research into urban rats in Canada.

"There's surprisingly little known about rat populations or the health risks they pose in modern cities," Himsworth tells The Current's host Anna Maria Tremonti.

According to Himsworth, rats are more dangerous to human health than we knew previously. "You don't have to be near a rat to acquire a bacteria-related illness from a rat," she said.

Research for The Vancouver Rat Project found that people and rats in Vancouver were carrying the same human strains of MRSA, C-difficile and e-coli.

The potential that bacteria could mutate into something like a superbug is of great concern to Himsworth as it could pose a real risk to humans who have no antibiotics to combat the new bacteria. 

Beyond the health risks to humans, rats are destructive and can cause real damage.

New York is familiar territory for rats. The Big Apple's rat expert, Bobby Corrigan, has spent his career trying to help cities manage their rat population. He says getting rid of rats is unlikely ever going to happen. To him, it's all in the battle strategy.

The former rodentologist says, "To manage rats, you're managing an urban environment. You're not putting out poison baits and trying to kill them every single day... That will go forever and you'll end up in the same spot," says former rodentologist,

Corrigan has seen first hand both the "cunning" side of rats but also their "aggressive" side — a trait that plays out when they destroy infrastructure. He as seen how dangerous they can be from prompting fires by gnawing on wires to and could even derail a train. 

He's not a rat lover in the least but his strategy to reduce rats in cities is to alter human behaviour on how to manage them. 

Listen to our full conversation with host Anna Maria Tremonti at the top of this post.

This segment was produced by Vancouver network producer, Anne Penman.