The stuff of Victorian nightmares is marching through the country once again: cases of scarlet fever have hit a 50-year high.
After barely 2,000 annual cases of the highly contagious illness in recent years, there were 17,586 in England and Wales in 2015. Particularly bad outbreaks have hit London, Yorkshire and the Midlands, and a “peak season” is expected over the next few weeks. Near my home in Norfolk, school classrooms have been disinfected after outbreaks, which most commonly affect two- to eight-year-olds.
The reason for its return is baffling scientists, but the fever has taken an interesting journey since the 19th century.
“The scarlet fever that would have been around in the Victorian era is a completely different beast to what we see now,” says Dr Theresa Lamagni, Public Health England (PHE)’s head of streptococcal infection surveillance. “It was a very severe infection that led to a lot of childhood deaths, but over the course of the last century its virulence diminished hugely.”
The theory is that a bacterial pathogen evolves to become weaker over time because it will not be passed on if it rapidly kills its host, and scarlet fever was diminishing in force before the advent of the modern antibiotics that treat it today. There have been no recorded fatalities during the current outbreak.
PHE’s analysis of the data has found that every four years or so there is a higher-than-average year for scarlet fever, but this “natural cycle” does not explain the current outbreak, according to Lamagni.
Outbreaks of scarlet fever most commonly affect two- to eight-year-olds.
There is no sign that the fever has developed an increased resistance to antibiotics, nor is it a virulent new strain. Scientists have analysed more than 400 “isolates” of the disease recorded by hospitals during the latest outbreak and found that they are the same as in previous years, and quite diverse (in other words, there is no dominant strain).
“That was a bit of a surprise for us,” says Lamagni. “It doesn’t seem that the bugs themselves are giving us any clues as to what is happening.”
So, is it us? Could the spread of scarlet fever be down to us forgetting about this infection and failing to diagnose it quickly enough to stop to spreading? Lamagni thinks this is unlikely, because most parents wouldn’t ignore its distinctive sandpapery, red rash, which usually first appears on the chest and stomach, alongside a fever and a swollen tongue.
The current outbreak remains a mystery, but it has left me convinced of one thing: that my children will catch it just in time for the Easter holidays.
This article was written by Patrick Barkham from The Guardian and was legally licensed through the NewsCred publisher network.
