7.What about scarlet fever? 

Scarlet fever is caused by a bacterium called Group A Streptococcus, which causes a range of other illnesses, too. Most worryingly Group A Streptococcal infection can cause (albeit rarely) “invasive Group A Strep” (iGAS), which is life-threatening.  Large numbers of children died from scarlet fever before penicillin became available in the UK in 1946. 

In England, reported cases of scarlet fever increased gradually between 2014 and 2019. This appears to be due to mutations in the bacterium. Note that scarlet fever is not a notifiable disease in Scotland, though it is in England and Wales. Hence there is little Scottish data. 

The number of scarlet fever cases reported in England and Wales during November and December 2022 is far beyond what would have been normal pre-Covid. Wales, for example, reported 35 times more scarlet fever during the second week of December compared to the same week in 2019. Unusually high rates of scarlet fever and iGAS have also been reported in France, Ireland, the Netherlands, and Sweden. 

Could those bacterial diseases be spreading more because we had Covid lockdowns and mitigations in the past – or might people be more at risk because they’ve been previously infected with Covid?

Some proponents of “immunity debt” argue that the unusual Group A Streptococcal outbreak is caused by lower immunity in children who were not infected with the bacterium in 2020/21 and/or by unusually high rates of  respiratory viruses which make secondary bacterial infections more likely. 

The idea of children having missed out on Group A Streptococcal infections during Covid mitigations makes little sense, given that there is no immunity to scarlet fever, – having had it once does not protect children from getting it again. 

It’s possible that the apparent current surge of respiratory virus infections in communities could explain the simultaneous surge in scarlet fever. But it’s also possible that mass Covid infections are a significant causal factor. There hasn’t yet been enough research on which to base an answer to these two questions. 

It’s well known that viral infections make bacterial infections more likely, either because they happen at the same time or because they develop afterwards when the immune system is less able to fight off bacterial infections, especially in young children and elderly people. Thus, the vast majority of deaths from flu are actually deaths from secondary bacterial infections. Interestingly, a common non-SARS coronavirus has been linked to pneumonia caused by streptococcal infection. 

Researching a possible link between Covid infections and scarlet fever (as well as other streptococcal infections) should be a priority.