A reader recently posed a question about the potential risk of rabies virus exposure from running over a rabid animal. I get the "can I get rabies from touching roadkill?" question regularly, but this person had a different concern.
“The other day I accidentally plowed right over an already-dead animal in the road. My air conditioning was blasting right on my face at the time. I am sure that something could have splattered under my car. Moreover, there could be a weakness or opening in my AC system that would allow the rabies virus to enter.”
We typically shy away from saying "never" with infectious diseases, but this would be as close to a "never" situation as you can get.
For this to be a concern:
- the animal would have to be rabid
- brain tissue and saliva containing rabies virus would have to be aerosolized
- virus particles would have to make it past the air filters…
- …and then come into contact with mucous membranes (e.g. mouth, eyes) or open skin lesions.
That’s just not a realistic concern. Non-contact-associated transmission of rabies is very rare and concerns are mainly limited to labs where large quantities of virus are manipulated, and people entering highly-infected bat caves.
Rabies is not an airborne virus, and beyond direct contact concerns would only relate to aerosol/droplet transmission, something I describe as "splash zone" transmission. Even with poor or absent air filters in the car, droplets aren’t going to make it through the whole ventilation system to the driver’s body.
The reader’s final question: “Or are you laughing while reading this?”
Trust me, I get stranger questions on a daily basis.