Human Coronavirus 22E – Credit CDC PHIL
Until SARS emerged in 2003, coronaviruses were thought only capable of producing mild `cold-like’ illnesses in humans. Six coronaviruses capable of infecting humans have now been identified, but only two of them (MERS & SARS) are routinely linked to severe illnesses.
The remaining four are Alpha coronaviruses 229E and NL63, and Beta coronaviruses OC43 & HKU1.
These four `milder’ coronaviruses are probably responsible for 15%-30% of the `common colds’ around the world, and only rarely migrate to the lower respiratory tract (cite)
Now that two `serious’ coronavirus threats have emerged in less than a decade, researchers are taking a harder look at the coronavirus family, including those that produce mild illness. This becomes even more important as additional, potentially zoonotic, coronaviruses are identified in the wild.
Last month, in IDWeek: Persistence Of MERS-CoV On Hospital Environmental Surfaces, we looked at early data coming of of South Korea’s MERS outbreak, that found extensive and persistent environmental contamination by the MERS virus in, and even adjacent to, isolation rooms, highlighting the need for strict environmental infection control.
Today the open access journal mBio has a report on the persistence of the less severe, but far more common human coronavirus 229E on common surfaces. It finds, as did the Korean MERS study, that the virus can live quite happily on environmental surfaces for up to 5 days.
They did determine that copper and brass surfaces quickly inactivated the virus. Follow the link to read:
The evolution of new and reemerging historic virulent strains of respiratory viruses from animal reservoirs is a significant threat to human health. Inefficient human-to-human transmission of zoonotic strains may initially limit the spread of transmission, but an infection may be contracted by touching contaminated surfaces. Enveloped viruses are often susceptible to environmental stresses, but the human coronaviruses responsible for severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) have recently caused increasing concern of contact transmission during outbreaks.
We report here that pathogenic human coronavirus 229E remained infectious in a human lung cell culture model following at least 5 days of persistence on a range of common nonbiocidal surface materials, including polytetrafluoroethylene (Teflon; PTFE), polyvinyl chloride (PVC), ceramic tiles, glass, silicone rubber, and stainless steel.
We have shown previously that noroviruses are destroyed on copper alloy surfaces. In this new study, human coronavirus 229E was rapidly inactivated on a range of copper alloys (within a few minutes for simulated fingertip contamination) and Cu/Zn brasses were very effective at lower copper concentration.
Exposure to copper destroyed the viral genomes and irreversibly affected virus morphology, including disintegration of envelope and dispersal of surface spikes. Cu(I) and Cu(II) moieties were responsible for the inactivation, which was enhanced by reactive oxygen species generation on alloy surfaces, resulting in even faster inactivation than was seen with nonenveloped viruses on copper. Consequently, copper alloy surfaces could be employed in communal areas and at any mass gatherings to help reduce transmission of respiratory viruses from contaminated surfaces and protect the public health.
Some earlier studies on the persistence and environmental spread of coronaviruses include: