How long does it take until the coronavirus loses its infectivity?

Health Article and healthographics by HKUMed

During this pandemic, we have been advised to stay vigilant when it comes to disinfecting apparel and personal belongings upon returning home. However, without understanding how long it takes until the coronavirus loses its infectivity under different conditions, lingering fears remain that traces would stay on surfaces even after cleaning.

Research team led by Professor Leo Poon, Division Head of the Public Health Laboratory Sciences at the School of Public Health, published findings on factors affecting the duration of infectivity of the coronavirus at the Lancet Microbe.

Q1. Are higher temperatures more likely to cause loss of infectivity in viruses?

Common knowledge says higher temperature are generally not ideal for viruses; the study further examines how different temperatures can have varying effects on the amount of time it takes for the virus to lose its infectivity. To test this hypothesis, the team incubated the virus and observed how long it would take for it to lose infectivity at different temperatures.

Q2. Do different surfaces have an effect on the amount of time it takes for viruses to lose infectivity?

In addition to testing the impact of temperature on the infectivity of the virus, the team also tested how long it would take for the virus to lose infectivity on different surfaces. In summary, it seems the virus took a longer period of time to lose infectivity while on smoother surfaces, and less time on coarser ones:

Q3. Are disinfectants effective in causing viruses to lose infectivity?

Although the coronavirus may take longer to lose infectivity when under room temperature, disinfectants may be used to shorten this duration, thereby reducing chances of transmission and infection. The team tested a wide variety of different disinfectants and found that all the following were effective in causing viruses to lose infectivity after five minutes of use:

In conclusion, the key to protecting oneself against the coronavirus is proper disinfection with the right disinfecting agents at a strong enough concentration and for enough time. As long as we remain vigilant, there is no need to worry.