Cold chain food has frequently tested positive for the covid recently. After the outbreak in Qingdao, the live new corona virus was isolated for the first time in cold chain food. Recently, 3 imported ice creams in Tianjin tested positive for the new corona virus.
There is no doubt that the virus can indeed be transmitted through cold chain food contact. Hearing this news, many people may wonder, how long does the virus have a lifespan on the surface of the item, or that the virus will not die and can only be killed with disinfectants?
How long is the lifespan of a virus attached to an object? Or will it never die and must be disinfected?
How long is the lifespan of a virus attached to an object?
The stability of a virus on the surface of the object can directly affect its ability to spread. Viruses with pandemic potential, such as Ebola virus and influenza virus, can survive on the surface of the object for a period of time and there is a risk of transmission.
The survival of the virus on the surface of the object is affected by a series of factors, including the type of virus, the load, the temperature, humidity, material of the object, ultraviolet rays, pH value, etc. As early as February last year, experts from the National Health Commission said that if the temperature and humidity are suitable, the new corona virus may survive in the environment for several days. Scientists have studied the survival time of the new coronavirus [. There are mainly the following:
1) Environmental materials
Some researchers have studied the survival time of the new coronavirus on aerosols and common materials in life, including aerosols, plastics (polypropylene), alloy stainless steel, copper and cardboard. When the ambient temperature is 21-23°C and the relative humidity is 65%, the new coronavirus can survive in the aerosol after nebulization for 3 hours. The new coronavirus is relatively stable on plastic and stainless steel surfaces and can survive for up to 72 hours. The specific survival time of the new coronavirus on the surface of the four materials is: copper (3.4 hours) < cardboard (8.45 hours) < stainless steel (13.1 hours) < plastic (15.9 hours). And British experts have also reported that the new coronavirus survives longer on non-permeable (waterproof) surfaces, such as stainless steel or plastic surfaces; and relatively short on permeable materials such as fabrics or paper towels.
2) Temperature and humidity
Different temperatures and humidity are also key to the survival of the virus. Some studies have found that when the average temperature is 8.72 ℃, it is most suitable for the spread of the new coronavirus. Studies have found that the new coronavirus can survive for up to a month in a super-saturated environment with a low temperature below zero and a relative humidity of 100%. Therefore, in winter, the weather is cold, and the epidemic is more likely to recur.
How long is the lifespan of a virus attached to an object? Or will it never die and must be disinfected?
Summarize
We don’t need to panic too much about a positive nucleic acid test such as cold chain food, because a positive nucleic acid test can only prove that there was a virus in the sampling place. means to test. However, under the background of the current global epidemic outbreak, for the sake of epidemic prevention, the disease control department will prioritize the storage and destruction of this batch of ingredients and notify the public. In fact, after the cold chain food has been imported for a long time, the virus on it has often been reduced in number and activity, and the infectivity is no longer high.
In short, we say that the new coronavirus can survive for a long time under the influence of the environment, but it will not exist forever, and the virulence and transmission of the virus will gradually weaken over time. For imported items, it is still necessary to sterilize some high-touch surfaces, wash hands frequently, and ventilate frequently.