Scarlet fever, a common cause of childhood death in the 1800s and early 1900s, has seen an increase in England since 2011 after decades of decline, scientists said on Tuesday.
The identification of the cause of the increase in cases was "a public health priority", they warned.
"England is experiencing an unprecedented increase in scarlet fever with the highest incidence for nearly 50 years," said a study published in The Lancet Infectious Diseases a leading medical journal.
In 2014, that amounts to a notification of scarlet fever "for one in 500 children under 10 years old". There were no deaths.
"While the current rates are not close to those observed at the beginning of the 20th century, the magnitude of the recent recrudescence is greater than that documented in the last century," said study leader Theresa Lamagni of Public Health England, Great Brittany. executive health agency.
Scarlet fever is an infection, usually not severe, with symptoms that include sore throat, headache, high fever, and a sandpaper-like rash by which the disease is named.
Caused by streptococcus bacterium pyogenes, it is more common in children younger than 10 years and can be treated with antibiotics.
Killed thousands of people in the Victorian era, but has become much less feared since the advent of antibiotics.
Still, in rare cases it can cause pneumonia, sepsis and liver and kidney damage, the research team
Regarding notifications of scarlet fever in England and Wales from 1911 on, they discovered a seven-fold increase in new cases from 2011 to 2016.
There were 620 outbreaks in 2016 with more than 19,000 cases, mostly in schools and experiences.
From 2013 to 2014, the incidence of scarlet fever tripled from 8.2 infections per 100,000 people to 27.2, the team found.
Hospitalizations almost doubled from 703 in 2013 to 1,300 in 2016.
The reason for "Continuous increase" in cases is not known, "the team said, genetic tests found there was no new strain of easily transmissible bacteria behind the surge.
The search for an answer continues.
Meanwhile, people with scarlet fever symptoms "should see their GP quickly because they will need antibiotics." treatment to reduce the risk of complications, "the team said.
"Treatment with antibiotics also reduces the likelihood of transmission of the infection to others."
Vietnam, China, South Korea and Hong Kong have also reported an escalation in the past five years, researchers said, but no other European country has reported a sudden increase.
Scarlet fever returns