Coronaviruses and influenza virusi are sensitive to acidity of aerosol. pH-mediated rapid inactivation of coronaviruses is possible by enriching the indoor air with non-hazardous levels of nitric acid. Conversely, indoor air filter may unintentionally remove volatile acids thus prolonging persistence of airborne virusi. This new understanding can be very helpful in controlling airborne transmission especially in indoor environment such as hospital settings.
Respiratory infections caused by ushawishi na corona viruses are significant persistent problems for human health. Influenza alone is responsible over 400,000 deaths per year worldwide. The ongoing COVID-19 pandemic attributed to riwaya coronavirus SARS CoV-2 has caused over 6 million deaths so far plus immense human suffering and unthinkable economic damages to world economy. Therefore, minimising transmission of these virusi is an extremely important priority.
It is known that their dominant mode of transmission is airborne. These infections are contracted by breathing in contaminated air. The expiratory aerosol particles act as vehicles for the transmission of influenza virusi and novel coronavirus SARS-CoV-2. Hence the importance of wearing face coverings. It is hypothesized that the virusi can remain in the air for about 3 hours with a half-life of 1.1 hours.
Needless to say, that rapid inactivation of these virusi would greatly contribute to limiting their transmission.
It is known that the enveloped virusi like influenza and corona virusi are inactivated in acidic conditions however level of acidity of expiratory aerosol particles and its role on inactivation of the virusi was unknown.
In a recent study published in the preprint medRxiv, the researchers examined this aspect for influenza and coronaviruses. They found that the aerosol particles exhaled into indoor air become mildly acidic (pH ≈ 4). This acidic condition rapidly inactivated influenza-A virusi within minutes but the novel coronavirus SARS-CoV-2 required days for inactivation. Further, if the indoor air were enriched with non-hazardous levels of nitric acid, the acidity of the aerosol dropped by up to 2 units which in turn reduced the inactivation times for both virusi to below 30 seconds. This pH-mediated 99%- reduction in inactivation time could be of great significance in rapid inactivation of these virusi in indoor settings thus helping reduce community spread considerably.
In light the above finding, use of indoor air filters should be carefully considered because any unintentional removal of volatile acids from the indoor air may reduce acidity of expiratory aerosol and prolong airborne virusi kuendelea.
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Marejeo:
- COVID-19: What Does Confirmation of the Airborne Transmission of SARS-CoV-2 virusi Mean? Scientific European. Posted 17 April 2021. Available at http://scientificeuropean.co.uk/covid-19/covid-19-what-does-confirmation-of-the-airborne-transmission-of-sars-cov-2-virus-mean/
- Luo B., et al 2022. Acidity of expiratory aerosols controls the infectivity of airborne influenza virusi and SARS-CoV-2. Pre-print medRxiv. Posted March 14, 2022. DOI: https://doi.org/10.1101/2022.03.14.22272134
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