With the help of a barfing machine, researchers have found that vomiting aerosolizes virus particles, facilitating transmission and infection.
Lee-Ann Jaykus, one of the authors of a study published in the journal PLOS ONE, said that epidemiological evidence exists pointing to virus aerosolization, when a person vomits, as a possible means of spreading norovirus. Their work, they believe, confirms that it is probable for viruses to be spread that way.
"When one person vomits, the aerosolized virus particles can get into another person's mouth and, if swallowed, can lead to infection," she explained.
Infection is also possible if airborne particles land on surfaces nearby and these surfaces are handled. Norovirus can survive for weeks on a surface, so anyone with access to an infected area runs the risk of getting sick due to exposure.
The barfing machine used in the study was developed by the researchers, designed to be precisely controlled to adjust the pressure, viscosity and control of the simulated vomit. They then contaminated the fake vomit using a virus known as MS2 bacteriophage, a norovirus proxy commonly used in experiments since it is not harmful to humans.
For the study, the researchers wanted to know whether MS2 bacteriophage was bioaerosolized in simulated vomiting and, if it was, just how much of the virus has become airborne.
Francis de los Reyes III, a corresponding author for the study, said that not a lot of the virus was actually aerosolized in terms of overall percentage. After all, 0.02 percent doesn't sound like much. However, that much of a virus still translates into thousands of particles airborne, a level more than enough to get someone sick.
For future study, the researchers are looking into examining how long a virus particle can stay airborne and how far it is capable of traveling in the air.
The norovirus is a group made up of over 30 viruses responsible for diarrhea and vomiting, affecting around 20 million people in the United States each year. Infections can be commonly acquired by consuming contaminated water and food, but they can also be easily spread when people are in close contact with each other.
Jaykus and colleagues' work were supported by the U.S. Department of Agriculture's National Institute of Food and Agriculture. Other authors include Kenneth Koch, Dominic Libera and Grace Tung-Thompson.
