Lockdown reduces cases of flu, colds and bronchitis in England
Lockdown and physical distancing measures have helped reduce the incidence of flu, colds, bronchitis and a host of viruses other than Covid-19 in England, monitoring suggests.
The low incidence of these and other viral infections, including laryngitis and tonsillitis, has helped relieve pressure on the NHS when resources have been dedicated to fighting the coronavirus pandemic. The flipside, however, is that as lockdown eases it is not just cases of Covid-19 that may increase.
Prof Martin Marshall, the chair of the Royal College of GPs, said: “We would expect to see a drop in influenza-like illness during the warmer months but the latest figures from our research and surveillance centre (RSC), which collects data from more than 500 GP practices in England, shows that it’s lower than the five-year average for this time of year.
“The social distancing measures we have seen over the last few months and an increased public emphasis on maintaining good hygiene have probably played their part, but we also know that some patients have been reluctant to use the NHS during Covid-19 because they haven’t wanted to overburden services at a time of crisis or are afraid of catching the virus.”
He added that, as lockdown measures eased, “the number of people seeking medical assistance from their GP is returning to normal, and we have started to see rates of illnesses such as the common cold increasing”. This highlighted the importance of maintaining good hygiene measures to protect not only against Covid-19 but also other common winter illnesses with preparations under way for a second wave, he said.
The RSC data shows infection rates for many viruses plummeted at around the time the government introduced lockdown measures in March. Chickenpox and measles fell off sharply when schools and nurseries closed.
Keith Neal, an emeritus professor in the epidemiology of infectious diseases at the University of Nottingham, said there were reasons to be optimistic about this winter.
“Even if we reduce social distancing by only 10% and we have done a lot more than that, then you would expect 10% less transmission of coughs and colds,” he said. “It’s impossible to say exactly what is going to happen. If people don’t mix as much you will expect less of these coughs and cold type of minor illnesses. We’re already seeing in Australia, which is in their winter, that they are having very little flu compared to previous years.”
Neal said the push to get more people vaccinated should also help suppress the flu virus. “I would be surprised if we get a worse winter for flu. It means social distancing has failed,” he said. “The only caveat to that is if a brand new flu virus appears, which is not in the vaccine. There’s no signs of that happening at the moment and with less flu viruses circulating in the southern hemisphere, there’s less chance of a mutation occurring because there’s less viruses to mutate.”
The RSC data shows infection rates for most viruses had been running below the respective five-year average anyway but a drop in cases related to lockdown meant an ever bigger fall.
Some virus infection rates, however, had crept above the respective five-year average. The infection rate for flu was above the average in the week beginning 9 March – full lockdown began on March 23 – and measles was above the average in the week beginning 23 March, just as schools were closed.