Some Countries Still Using Salmonella Rat Baits to Curb Leptospirosis

This has been an issue in Central and South America and Asia for over a decade. Before that, the United Kingdom used it. I’m talking about Salmonella based rodenticides. The latest is an announcement by the Healthcare and Nutrition Ministry of Sri Lanka of their decision to import “Biorat” from a Cuban company in an effort to curb leptospirosis.

With the heavy rains and flooding in the country, leptospirosis is spreading particularly amongst vulnerable people like farmers, mine workers and those that clean drains. In addition, people who play and swim in contaminated water are at risk.

Certainly Sri Lanka and other nations with a leptospirosis problem should seek out a method of getting the rat population under control, but a salmonella based bait?

But what about the use of “Biorat”? This is a product made in Cuba which is made by coating rice grains with a combination of Salmonella enteritidis and the anticoagulant warfarin.

Interesting thing is the packaging doesn’t mention anything about a risk to humans of getting salmonella. In fact it states that the strain of salmonella they use is pathogenic to animals but not to humans!

Is this product a public health hazard to humans? For decades Salmonella enteritidis has been a major cause of food borne illness. As a matter of fact it is the most common type of Salmonella isolated from humans worldwide.

People could easily contaminate themselves by inadvertently eating this pathogenic rice bait.

Could places like Sri Lanka take care of its rat and ultimately its leptospirosis problem with something other than Salmonella based rodenticides? Yes. These rat baits already contain enough warfarin to kill rats and any addition of salmonella has not been shown to increase its effectiveness.