Scientists at North Carolina (NC) State University have developed a vomiting machine to study norovirus, which is said to affect 20 million people each year in the US.
Norovirus is a group of more than 30 related viruses that can cause vomiting and diarrhoea.
Caused by consuming contaminated foods or water, the ‘noro’ infections can lead to hospitalisation and sometimes death, especially in the elderly.
NC State University PhD graduate Grace Thompson said: "Epidemiological studies have suggested that norovirus can be aerosolised through vomiting, meaning that small particles containing norovirus can become airborne when someone throws up."
"If aerosolised particles land on a countertop, you could also touch the counter with your hand, then touch your hand to your mouth, leading to infection."
To validate the claims, NS State’s researchers and a Wake Forest University gastroenterologist developed a machine that represents a scaled-down version of the mouth, oesophagus and stomach.
The machine is made of tubes and a pressure chamber that passes through a clay face to give it the correct vomiting angle, and has been designed to allow researchers to control the pressure and volume of the vomit, in order to mimic a range of natural vomiting behaviours.
Scientists conducted the research using liquid solutions of different viscosities or thicknesses as ‘artificial vomitus’ to reflect different stages of digestion, and substituted norovirus with a bacteriophage called MS2, which is a common stand-in for noro.
The team found the virus was aerosolised and vomit from infected people contains millions of particles, even though the amount as a percent of total virus vomited was relatively low.
US Department of Agriculture-National Institute of Food and Agriculture Food Virology Collaborative scientific director Lee-Ann Jaykus said: "This machine may seem odd, but it’s helping us understand a disease that affects millions of people.
"This is work that can help us prevent or contain the spread of norovirus, and there’s nothing odd about that."
The machine underwent extensive testing in 2012 and 2013, and was used for formal experiments in 2014.
Image: The clay mask of the vomiting device weighs down the end of the tubing to direct the spray of the vomit. Photo: courtesy of Grace Tung-Thompson.