The outbreak cluster index case was an 18-month-old girl puking all over her bed. And her mom. Case 2 was the mom, who spent 12 hours in and out of the bathroom a day later. Case 3 was the 18-month-old’s grandfather who was sharing a bathroom with the mom.

Our guest bathroom.

The grandfather, known to my kids as Pop-Pop, spent a next night in the bathroom and was still recovering when he set out on a 14 hour drive back to Canada.

I swear it wasn’t our cooking.

Through my amateur epidemiology I think my house is now contaminated with norovirus and it’s only a matter of time before it gets to me.  Even though I’ve hit the toilet with a bunch of chlorine (I went with the 5,000ppm CDC recommends) it’s a waiting game.

Puke and diarrhea from an individual ill with norovirus is particularly problematic as each gram of, uh, matrix contains millions of virus particles that are ready to infect, replicate and be expunged out towards the next host. It’s a pretty awesome biological cycle. Most of what is known about spread of noro from vomit to comes from outbreak investigations. Proximity to the event is related to attack rates (closer to the puddle and spray = increased likelihood for illness). Toilets can also be a source of spread (with a flush comes aerosolization).

In what has become one of my favorite ideas, some folks in the UK are testing out a vomit-spewing machine to evaluate spread of virus particles.

At the Health and Safety Laboratory in Derbyshire, northern England, where researcher Catherine Makisondeveloped the humanoid simulated vomiting system and nicknamed him “Vomiting Larry”, scientists analyzing his reach found that small droplets of sick can spread over three meters.

“The dramatic nature of the vomiting episodes produces a lot of aerosolized vomit, much of which is invisible to the naked eye,” Goodfellow told Reuters.

Larry’s projections were easy to spot because he had been primed with a “vomitus substitute”, scientists explain, which included a fluorescent marker to help distinguish even small splashes – but they would not be at all easily visible under standard white hospital lighting.

It may seem like an idea hatched in a dorm room, but machines like this are important for the food and food service industry.  Recommendations for cleaning and sanitizing after a puke event need to be built on the data that something like Vomiting Larry can provide – do I need to pay as much attention to the light switch or faucet as I did the toilet bowl, lid and handle? There isn’t a whole lot of evidence to dictate practices.