Rachael Almond, Laboratory Director, Circular1 Health writes:
We’ve observed that lifting of both behavioural and physical restrictions has resulted in a surge of positive (COVID-19) cases across our customers as people mix more freely. This is also likely to facilitate the spread of other seasonal respiratory viruses in the colder months such as Influenzae and Respiratory Syncytial Virus (RSV).
Sir Patrick Vallance commissioned a report recently for those of you interested in a light read, ‘COVID-19: Preparing for the future: looking ahead to winter 2021/22 and beyond’ (https://acmedsci.ac.uk/file-download/4747802) which aims to forecast the greatest risks to health over the winter.
Experts are predicting an autumn/winter surge in respiratory viruses and this is real concern, not only to health professionals due to the pressure this will have on our NHS, but also in the business community with higher absenteeism expected as a result.
What are the respiratory viruses everyone’s concerned about?
- Influenza (Flu) A and B
- There are two main types of influenza (flu) virus: Types A and B. There is a third type, but this is much less common.
- Influenza A and influenza B are responsible for most clinical illness. It’s highly infectious with a usual incubation period of one to three days.
- Infection is transmitted by droplets, aerosol, or through direct contact with respiratory secretions of someone with the infection, spreading rapidly in closed communities/areas similar to Sars CoV -2.
- Infection is characterised by the sudden onset of fever, chills, headache, myalgia and extreme fatigue. Other common symptoms include a dry cough, sore throat and stuffy nose.
- For otherwise healthy individuals, influenza is an unpleasant but usually self-limiting disease with recovery usually within two to seven days.
- However, illlness may be complicated by (and may present as) bronchitis, secondary bacterial pneumonia or, in children, otitis media or further complicated by other infections such as meningitis, encephalitis or meningoencephalitis.
- The risk of serious illness from influenza is higher amongst children under six months of age, older people and those with underlying health conditions such as respiratory or cardiac disease, chronic neurological conditions, or immunosuppression and pregnant women.
- Most cases in the UK tend to occur during an eight- to ten-week period during the winter. The timing, extent and severity of this ‘seasonal’ influenza varies. Influenza A viruses cause outbreaks most years and it is these viruses that are the usual cause of epidemics. Large epidemics occur intermittently. Influenza B tends to cause less severe disease and smaller outbreaks overall. The burden of influenza B disease is mostly in children when the severity of illness can be similar to that associated with influenza A.
- These occurred as influenza changes periodically, resulting in either minor or major changes and the emergence of a new ‘subtype’ (similar to the variants we’ve observed with COVID-19) with a different surface protein called ‘haemagglutinin protein’. Because immunity from the previous virus may not protect completely against the new subtype, the population may have little or no immunity, and this can lead to epidemics or even a pandemic. This is why the flu vaccine changes annually and it’s success varies from year to year.
- There have been 3 influenza pandemics in the last century (in 1918, 1957 and 1968).
- Figure above demonstrates the low flu levels last season (2020/2021) almost a flatline. (Credit/source, opens PDF)
https://vk.ovg.ox.ac.uk/vk/rsv (Source for image above)
- In infants, RSV is the main cause of bronchiolitis. Most are mild and can be managed at home, but about 3% of cases result in hospitalisation. Worldwide, RSV is the second largest cause of death in children under one year of age (second only to malaria).
- In healthy adults RSV causes symptoms similar to those of a common cold. However, it can develop into severe disease in adults with a weakened immune system and in elderly people.
- RSV is passed from person to person by close contact. The virus can survive for several hours on surfaces.
- There is currently no vaccine available.
Why should we be concerned?
- Lifting of both behavioural and physical measures implemented to reduce Sars CoV-2 (SCV2) infections leaves us open to other respiratory infections.
- Last year we observed the lowest levels of flu and other respiratory infections recorded in over a decade as a result. This means we’ve had limited recent exposure and population immunity will have diminished (both acquired immunity and antibody wanes over time)
- This year’s Flu vaccination programme is even more complex than usual, as predicting what Flu strains will be in circulation this autumn/ winter is a challenge due to lower levels of Flu last year. This increases the likelihood of a vaccine ‘mismatch’ this year (i.e. a vaccine that is ineffective against the flu strain in circulation)
- Although we have an annual Flu vaccination programme in the UK, in comparison to other vaccines, Flu vaccination is considered to be less effective with efficacy of 70% and 50% for healthy adults and the elderly respectively.
- Modelling is predicting 15 to 60k people could die from Flu this year, although the impact of the flu vaccination programme, if effective will reduce this.
- Potentially another wave of COVID-19 or multiple outbreaks over the Autumn/Winter months.
- Higher hospitalisation, increased paediatric ICU burden and mortality in the young due to a loss of population immunity to RSV. This might create a larger susceptible population likely to have an outbreak over winter
- The recent easing of social contact restrictions has also led to a summer surge in some of the respiratory infections that are only typically observed in Winter e.g. RSV, Rhinoviruses (common cold), Bronchiolitis etc.
Why is testing for respiratory Viruses important?
- Circular 1 Health is adding a multiplex respiratory virus test to our testing portfolio ahead of the winter surge.
- This will be critical for managing COVID-19, Flu and RSV over the winter months.
- For our business customers, this will help them make an informed risk managed decision for their business. If offered to family members of employees it could also reduce absenteeism from parental leave to look after children.
- For other customers, it might mean they can get the right treatment pathway or that they can continue with their plans.