COVID-19, a disease caused by a new strain of coronavirus, SARS-CoV-2, has infected very large numbers of people in a short period of time (since it was first recognised on 01/12/2019). It appears to be highly infectious with a significant mortality rate. Current estimates suggest it would be around 2%, much less than the fatality rate of other human Coronaviruses, such as SARS (9.5%) and MERS (37.1%), but greater than that of the seasonal influenza virus (0.04 – 0.088%).
The likelihood of a virus being directly or indirectly transmitted between humans can increase when it has a low mortality rate. Influenza virus is a good example of a virus that normally has a low mortality rate but is a recurrent burden on human health (291,000 – 646,000 deaths annually) and the economy ($11.2 billion in USA alone). This is because a live, infected human is mobile and can spread the virus by sneezing or coughing and as such, uninfected individuals and uncontaminated surfaces/spaces can be exposed to and contaminated by the virus.
SARS-CoV-2 is believed to have originated from bats and then been transmitted to humans via an intermediate host – as seen with other human Coronaviruses. However, SARS-CoV-2 differs from other human Coronaviruses in that it appears to be more transmissible. MERS infections are ongoing, but the total number of MERS cases reported since its emergence in 2012 are already dwarfed by that of SARS-CoV2. Similarly, the 2002-2003 SARS epidemic caused fewer cases (8096) and has been contained with no naturally occurring cases reported since 2003. The increased transmissibility of SARS-CoV-2 could mean it remains a human pathogen for longer whilst causing more cases than other human Coronaviruses that have previously caused outbreaks.
Symptomatic patients and severely hit regions have been quarantined to try to control the spread of SARS-CoV-2. However, the daily increases seen in case numbers and fatalities shows that these quarantines are not yet containing the virus, as well as disrupting lives and in some cases, having deadly consequences. Possible reasons why quarantining has failed to contain the outbreak include the delayed onset of symptoms for SARS-CoV-2 (2-14 days) and the similarity of these symptoms to other respiratory tract diseases, which delays the diagnosis and isolation of a patient. Also, the lack of a virus-targeting cure means patients remain infectious for longer, with most treatment regimens designed around symptom relief rather than virus clearance. Further investigations into the SARS-CoV-2 may show some other factors are hampering its containment including long term persistence in the air and on surfaces or resistance to disinfectants used to eliminate the virus.
Prevention of transmission and contamination is the most effective control measure when faced with an untreatable virus spreading through a population. Health authorities have issued guidelines on actions we can take to minimise the spread of SARS-CoV-2, but successful containment requires strict adherence to these guidelines. A vaccine could also provide effective protection, but as seen with the influenza virus vaccine, it may not be 100% effective, and the time required to develop and test a vaccine means it could be months or years before it is administered in a medical setting.
Prevention of transmission can also be achieved by deploying antimicrobial technologies designed to sterilise the air we breathe and the surfaces we touch, but are these effective against Coronaviruses? Testing of air purifiers, facemasks, detergents/biocides, antimicrobial devices and antimicrobial surfaces/textiles is required to measure their ability to inactivate or filter out the Coronavirus. These tests should be performed by suitably trained personnel and they should mimic real-life situations. The virology department at airmid healthgroup possesses the necessary expertise and equipment to perform a range of antiviral tests using Human Coronavirus 229E and OC43 as surrogates for the SARS-CoV-2 virus. We can follow international standards or develop custom assays to assess the antiviral activity of your product. Here is an overview of the tests we can provide:
- Aerosolization of virus in controlled environments using 28.5 and 30 m3 chambers.
- Antiviral effectiveness of textile products (ISO 18184:2019).
- Viricidal activity of disinfectants/biocides (EN 14476:2013+A1:2015)
- Antiviral activity of photocatalytic materials (ISO 18061:2014)
- Antiviral activity of plastics/non-porous surfaces (ISO 21702:2019)
- Viral barrier testing including clothes, facemasks and PPE (ASTM F1671 / F1671M – 13)
- Custom designed tests optimised for your product
For more information on how airmid healthgroup can verify the effectiveness of your product against Human Coronavirus please contact Graeme Tarbox on +353 1 633 6820 or via email, gtarbox@airmidhealthgroup.com