RAT PACK

University researchers track urban rat movements in Vancouver, British Columbia.

Story by Gabriel Brenner | Photos by Serena Cueva

Kaylee Byers, a doctoral candidate at University of British Columbia, inspects a rat for an ear clip. Every captured rat is marked and labeled before they are released, in order to track disease movements.

Welcome to Blood Alley: a place where used needles and garbage line the dimly lit street, and makeshift homes are created from broken pieces of furniture and tattered blue tarps. Kaylee Byers, dressed in a bright green rain jacket with her hair pulled back in a ponytail, greets the local residents as she kneels in a rain-soaked gutter to check a rat trap she placed there a few months earlier.

Byers is a University of British Columbia student researcher working for the Vancouver Rat Project, testing rats in the Downtown Eastside neighborhood of Vancouver, British Columbia for signs of MRSA, a bacterial strain resistant to common antibiotics. The study, which began in 2010, is one of the first of its kind to study how rat movements relate to the spread of disease.

Chelsea Himsworth, the lead researcher at the Vancouver Rat Project, identified MRSA in 22 of the 637 rats they tested. The researchers found identical bacterial strains in both the urban rats and the local human and animal populations, leading them to believe MRSA is spreading between people and rats scavenging trash in alleyways.

MRSA, or methicillin-resistant Staphylococcus aureus, can be life-threatening, with symptoms including sores and boils that may eventually lead to serious skin infections. Welcome to Blood Alley: a place where used needles and garbage line the dimly lit street, and makeshift homes are created from broken pieces of furniture and tattered blue tarps. Kaylee Byers, dressed in a bright green rain jacket with her hair pulled back in a ponytail, greets the local residents as she kneels in a rain-soaked gutter to check a rat trap she placed there a few months earlier.

Now, Byers and her team are trying to determine if traditional pest control is worsening the problem of MRSA and other diseases spreading from animals to humans.

The probability of a MRSA infection varies from one block to another, according to the Vancouver Rat Project. Urban rats live in tightly packed colonies, where pathogens like MRSA spread easily. The rat researchers suspect conventional pest control displaces these rat packs, and infected rats can spread out and infect other colonies.

Each week, researchers check traps, collect blood, saliva and stool samples from any captured rats, and then release the rodents in the same places they were caught. “We’ve been out for four months and we’ve caught 400 rats,” Byers says.

This project also acts as a framework for a future rat surveillance program the Vancouver Rat Project hopes to start with current federal pest control programs.

“There are no rat surveillance programs in any of the cities, which is concerning,” Byers says.

Beneath the faux gas lamp lights, the Downtown Eastside, also known as Gastown, is Vancouver’s central cosmopolitan neighborhood. Despite the art galleries and boutiques, the neighborhood is also one of the poorest in Canada. The Downtown Eastside contains Canada’s only two safe injection sites, where residents can bring drugs and obtain sanitary needles.

“Gastown is one of the swankier areas of Vancouver,” Byers says, turning a corner onto busy Hastings street. “And then you have tent city right next to it.”

A rat sits in a cage in an alley in Vancouver, British Columbia. Each alley is marked by numbers, allowing the scientists to carefully track where rats are found.

Back in Blood Alley, Byers winds her way from trap to trap with methodical precision. She pushes away trash bags of soiled napkins and diapers, checking to see if a rat has fallen for the peanut butter bait.

Most people are excited about the project, Byers says, lifting a baby rat out of a trap and putting it in a cage. “People want to see fewer rats, but at the same time they don’t want rats harmed,” she says. Many local residents tell Byers and her team whether they have seen any rats scurrying around in the alleys.

Byers and her team work out of a white panel van they park alongside the alleyways. Two bright orange biohazard stickers mark the back doors, hinting at the cargo it carries. Inside, graduate student Michael Lee gently places a recently-caught rat on a stainless steel operating table. While working with the Vancouver Rat Project, Lee is writing his thesis to determine if rat ecology and the urban environment affect the spread of diseases between humans and animals.

“Most of our work is taking samples,” Lee says, as he places a breathing mask of anesthesia over the mouth snout of the rat. The team collects vials of urine, feces, blood and saliva and places them in separate cubbies that go to the main lab for further testing.

In order to keep rats warm in the winter and prevent hypothermia, the team puts out basins of hot water and small heat packs. “It’s like they go to a little rat spa,” Byers says as she places the cages of sleeping rats above large plastic basins to collect any more feces and urine they might excrete overnight.

The researchers give each rat they catch an ear tag with a laser-etched number, so if they catch the rat again, they can tell if it has been infected.

The ear tags also act as surveillance devices, showing if the rat has traveled to a different alleyway or zone in the Downtown Eastside.

“Are rats a source of MRSA for us? Probably not. They probably got it from us,” Byers says as she takes off her dirt-stained surgical gloves.

Even though there have been no definitive cases of rats transmitting MRSA to humans, Byers and her team believe this work adds important information to the study of how diseases spread and our understanding of the way rats live.

The Vancouver Rat Project plans to eventually expand into other areas of Vancouver, testing rats to see if MRSA or other pathogens are present.

“If your concern is that people are going to get ill from rat-associated diseases, then you should really be studying the population most at risk for that,” Byers says. “And that is the Downtown Eastside.”