A couple months ago, I wrote about a family suing PetsMart over a case of rat bite fever in a child.

Now, a San Diego family is suing PetCo after their ten-year-old son died of the same infection.  Rat bite fever is a bacterial infection caused by Streptobacillus moniliformis, and it is almost always associated with bites from rats.

The San Diego family’s situation is tragic.  Fortunately fatal zoonotic diseases from pets are rare. But when they happen, who’s to blame?

Part of figuring that out is thinking about what has to happen for an infection to develop, and where that cascade can be interrupted.

What has to happen for rat bite fever to develop?

The rat has to be carrying the bacterium in its mouth.

  • The bacterium is found in basically all rats, so you have to assume that every rat is infected. (So, it’s hard to blame the supplier.)

The bacterium has to get into the person’s body, usually by a bite.

  • Bite avoidance is therefore key, and involves proper handling of the rat and selecting a rat that has a good temperament.

When the bacterium gets into the body, it has to be able to cause disease.

  • Most often, the immune system takes care of it. However, the number of bacteria that get into the body, the weakness of the immune system, and the whims of biology all play roles. In an otherwise healthy child, bite first aid is critical to help remove as many bacteria as possible from the wound before they invade the rest of the body.

To me, it all boils down to education.

  • Pet stores need to inform purchasers about infectious disease risks and preventive measures.
  • People need to take responsibility to learn about any pets they may purchase (before they get them), and take measures to reduce the risk of zoonotic pathogen exposure.
  • Physicians need to be more aware of zoonotic diseases and ask about pet ownership and animal contact.

Would any of these have made a difference here? It’s hard to say. However, these are all relatively easy things to do and could probably prevent a lot of infections.

More information about Rat Bite Fever can be found on the Worms & Germs Resources – Pets page.