The Common Cold
The implication of the name “common cold” is that it is caused by one virus. In fact, there are over 200 types of viruses that have been associated with colds1. The most frequent causes of colds are rhinoviruses but even they are made up of over 100 different subtypes. Other viruses that are responsible for the common cold include adenoviruses, parainfluenza viruses, respiratory syncytial virus (RSV), metapneumovirus, and several non-SARS coronaviruses. The vast array of potential viral infections that can result in the common cold is part of the reason why we never acquire complete immunity from disease.
The impact of lockdown restrictions
All the measures designed to reduce the spread of SARS-CoV-2 including social distancing, mask-wearing, and the increased focus on personal hygiene have inevitability led to a decrease in the circulation of other communicable diseases. The 2020-21 influenza season resulted in a record low number of viral isolations2. In addition to this, one subtype of influenza has not been detected since April 2020 leading to suggestions it may have become extinct3. This trend is not just restricted to influenza. A study from New Zealand suggested a drop in several cold-causing viruses such as RSV, rhinovirus, and adenovirus4.
Post-Lockdown
As COVID lockdown rules have eased in the UK health experts were warning of potential spikes in the rates of infectious diseases other than coronavirus5. This was because it was believed that social distancing measures that had been in place in some form or another for 18 months would have resulted in a reduction in population immunity to these viruses. These warnings have been borne out as RSV has caused a rapid rise in A&E visits6. Additionally, upper respiratory tract infection consultations with GPs have been above baseline levels since restrictions began to ease in the UK7. These increases in non-COVID-related infections led some media outlets to report on “the worst cold ever” circulating8.
What can we do about it?
For the most part, colds and flu-like illnesses are more common and more easily spread as we enter Autumn and move into Winter. SARS-CoV-2 is still very much present in our communities, so if you are displaying cold and flu-like symptoms the first step should always be to rule out COVID-19 via a PCR test and isolate whilst you wait for the result. Assuming you do not have COVID-19, following the guidelines recommended for the prevention of the spread of SARS-CoV-2 will similarly help to reduce the spread of colds and flu. Regular hand washing and the use of an effective anti-viral hand sanitiser when soap and water are not available, are essential. Keeping your home and working environment clean and tidy, and using a residual multi-purpose cleaner that protects against bacteria and viruses in-between cleans is an advantage. Social distancing and wearing masks in crowded areas and remaining at home when unwell will also go a long way to reducing the spread of all communicable diseases.