Are respiratory diseases spread through items?

The answer is that there is a theoretical and practical possibility of transmission, but it is not a mainstream transmission route for respiratory diseases, and the risk of infection in ordinary scenarios is extremely low.

When I was doing infectious disease control at the grassroots level in the past two years, I specifically followed up on related environmental sampling studies. On the surfaces of common office building elevator buttons, shared desks, supermarket trolleys, and other high-touch items that everyone considers "dirty", less than 1 out of 100 samples could detect live viruses. Even if the remaining samples tested positive, most of them were viral nucleic acid fragments that had lost their infectivity. Even if they were touched, it would be difficult to get the viral load to cause infection, and they would basically not cause illness.

However, the academic community has always had different views on the actual clinical impact of this transmission route. A research team with a virology focus believes that as long as it is not in a high virus-loaded environment such as a hospital fever clinic or an enclosed indoor playground, the probability of items transmitting respiratory diseases in ordinary scenarios is less than 0.5% and can almost be ignored.； However, some clinicians in the Department of Pediatric Infectious Diseases have come up with supporting cases. In a kindergarten in their area during the peak influenza season last year, three children in the same class were infected with influenza A. The possibility of simultaneous airborne droplet exposure was ruled out during the influenza investigation. Finally, live influenza A virus was detected on the building blocks that the children had touched before. It is highly suspected that the transmission was caused by contact with objects.

For example, when the COVID-19 epidemic hit a few years ago, everyone was always worried about the virus being carried by express delivery. We also sampled thousands of cross-provincial express delivery, and not one positive case of live virus was found. Ordinary express delivery bumps on the road for several days, and the temperature and lighting conditions are not suitable for the virus to survive. The probability of bringing live virus to consumers is lower than winning the lottery. At that time, many people sprayed disinfectant three times inside and outside after receiving the express delivery. In fact, it was a bit over-protective.

Of course, that doesn’t mean you don’t need to worry about it at all. If you are in the same space with someone who has a cold or fever, and you take the cup or mouse that he just touched, and you touch your mouth and rub your eyes without washing your hands, you may still be infected. To put it bluntly, to prevent this transmission route, there is no need to bother disinfecting everything. Just remember to wash your hands before touching public items, going out and returning home, and don’t touch your face without washing your hands. On the contrary, excessive spraying of disinfectant into the air can easily irritate the respiratory mucosa, making it easier for pathogens to take advantage of it.