Author: Anuhya Banerjee
Dust has been considered an enemy to many households for years, however, new research puts these tiny particles as a concern amidst the pandemic. Made of many particles of shed skin, bugs, and microscopic creatures, dust is considered an irritant and may cause immune reactions. Depending on the individual, these can be minor or major but in the past, little has been known about the effect of airborne viruses and transmission through dust. This has recently changed as UC Davis researchers have discovered that dust can be considered as a fomite (an object that can carry infection such as door handles, tissues, etc.) which leads to a new perception in many viruses.
For years we have witnessed season flu outbreaks that come with thousands of annual deaths from all over the world. Original assumptions have mainly concluded that respiratory droplets from people’s breathing, coughing, talking, and sneezing are the most traditional routes of airborne transmission. Now, these findings are refined as experimentation with “aerosolized fomites” has shown that the influenza virus can remain viable on objects such as guinea pigs and tissues long enough to then be transmitted through dust particles.
UC Davis Graduates along with virologists at Icahn School of Medicine teamed up to carry out this study. Professor William Ristenpart of the UC Davis Department of Chemical Engineering stated, “It’s really shocking to most virologists and epidemiologists that airborne dust, rather than expiratory droplets, can carry influenza virus capable of infecting animals.”
A device called aerodynamic particle sizer was used to sample the air inside cages of guinea pigs, and they discovered that uninfected guinea pigs who moved around more gave off 1,000 particles per second within their cages. In comparison to respiratory droplets, anesthetized healthy guinea pigs gave off 0.10 to 0.18 particles per second through breathing, and anesthetized guinea pigs who were infected with influenza gave off 0.5 particles per second through breathing. This suggested that dust with virus particles from the environment poses great risk in infectious transmission. With further studies, researchers concluded “airborne particulate matter from a non-respiratory source can transmit influenza virus through the air to a susceptible host”.
The testing of tissues was the final stage of the experiment where they contaminated the fomite with infectious virus particles. By crumpling the tissue in front of the aerodynamic particle sizer, the device recorded 900 particles per second being released in a range that could be inhaled by humans. The particles carrying the virus that could have been inhaled were found in the lab to be capable of infecting cell cultures.
Is This Worrisome?
Researchers in this study emphasized further studies are needed to see the effect of airborne fomites in human transmission and with other trials. Social distancing and caution for health has been able to curb many concerns, and for individuals heading guidelines, these precautions help prevent the spread of the coronavirus and may even help with the upcoming flu season. However, their studies give healthcare professionals new worries in the field. In China, rooms where healthcare providers took off their PPE proved to have the highest levels of airborne viral RNA. As we discover new highlights about the virus, it is important to keep on wearing masks to protect yourself and others from viruses that can spread from surprising fomites.