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Outbreaks of human salmonellosis linked to reptiles are far from rare or noteworthy, but since they’re still common, clearly we still need to talk about them to help increase awareness.

The latest such outbreak in Canada involved 25 cases of Salmonella Muenchen infection in people linked to contact with geckos. Cases stretched from British Columbia to Newfoundland, with stops in Alberta, Manitoba, Ontario, Quebec and Nova Scotia, but most of the cases (13/25) were in Ontario. It’s been a slow going on at a slow burn for a while now, with infections dating back to August 2020 and right up to September 2024 (and probably beyond). The outbreak “curve” is shown in the graph below.

As ever, it’s safe to assume the 25 reported infections are a small minority of the actual number. To get included in the case count, a person has to get sick, and then go to the doctor and get a fecal sample tested for Salmonella. That usually doesn’t happen in mild cases, so if 25 were severe enough to be reported, there were actually probably a couple of hundred people who got infected.

The age range of patients in this outbreak so far is 1-103 . People at both ends of that range are more likely to get severe disease from something like Salmonella, but people of any age or health status are susceptible to this bacterium. Children tend to take the brunt of reported illness, likely in part because of some of their behaviours lead to increased exposure, because disease can be more severe in young kids, and because they may be more likely to be taken to the doctor to get diagnosed. Three people in this outbreak were hospitalized and one died. We don’t often see deaths in these Salmonella outbreaks, but they can definitely occur.

Detailed exposure information hasn’t been released but many affected people reported direct contact with geckos. Since most people in the population don’t have regular (or any) contact with geckos, that makes a strong link between this outbreak and gecko contact. Additionally, some people had been in the same house as a gecko, even though they didn’t handle the animal. My line is “the gecko may stay in its terrarium but Salmonella won’t.” There are lots of instances of people (especially infants) getting Salmonella with no known direct contact with the presumed source reptile. That’s because people track Salmonella out of the terrarium after handling the animal or terrarium contents, or by doing things like rinsing out food or water bowls in the kitchen sink and cross-contaminating items that then come in contact with other people (or their food).

This outbreak doesn’t change any of the risks or any of the messaging. Keep high risk people away from reptiles, including kids less than 5 years of age and adults over 65 years of age, as well as anyone who is pregnant or immunocompromised. That includes avoiding both direct handling of reptiles and being in households or other areas where they are housed.

Testing reptiles isn’t a way out of this problem either. We can test reptiles to see if they are carriers, but a single negative test doesn’t mean there’s no risk. They can test negative today but positive tomorrow, and I’d never say there’s no risk from a reptile, even if it’s tested multiple times.

I’m not against reptiles, I’m just against having them in high-risk households because it’s clear that they cause disease. It’s not common, but it’s likely massively underdiagnosed. There’s no denying that every year, many people get sick (and a few die) from Salmonella acquired from reptiles.

We don’t have a specific fact sheet for geckos, but the information about risks from turtles (and how to mitigate them) generally apply to geckos and other reptiles as well. Check out the factsheet on turtles on the Worms & Germs Resources – Pets page.