A new bug has sparked the rising cases of scarlet fever in children all over the world, scientists warned. The resurgence of the disease that caused high death rates for many centuries has been likened to the coronavirus or COVID-19 pandemic. The numbers that were brought down in England have risen up to sevenfold in the last six years. As in COVID-19, a vaccine will soon be required. The supercharged 'clones' of the bacteria named Streptococcus pyogenes that cause the disease are needed to be blamed, a new study showed.

The lead author Dr. Stephan Brouwer of the University of Queensland, stated that it has taken the global health authorities by surprise. An epidemic of the illness, identified by a bright red rash and a sore throat, infected people in Asia in 2011.

"The disease had mostly dissipated by the 1940s. Like the virus that causes Covid-19, Streptococcus pyogenes bacteria are usually spread by people coughing or sneezing. Symptoms include a sore throat, fever, headaches, swollen neck glands, and a characteristic scarlet-colored, red rash. Scarlet fever commonly affects children, typically aged between two and 10 years," Brouwer mentioned.

Scarlet Fever Outbreaks

Daycare
Kids at Daycare Wikimedia commons

"After 2011, the global reach of the pandemic became evident with reports of a second outbreak in the UK, beginning in 2014. This global re-emergence of scarlet fever has caused a more than five-fold increase in disease rate and more than 600,000 cases around the world," the author added.

The team found a type of Streptococcus pyogenes bacteria that acquired bacterial toxins named 'superantigens', forming new clones. The co-author professor Mark Walker stated, "The toxins would have been transferred into the bacterium when it was infected by viruses that carried the toxin genes."

Walker said that the team has shown that the acquired toxins allow Streptococcus pyogenes to better colonizing the host, which likely gives permission to out-complete other strains. The supercharged clones of bacteria have been causing the modern scarlet fever outbreaks. When the scientists removed the toxin genes from the clones they were less able for causing scarlet fever in experiments on mice. Currently, outbreaks have got dampened, largely because of public health measures introduced for controlling coronavirus.

"This year social distancing has kept scarlet fever in check for now. And the disease's main target - children - have been at school less and also spending far less time in other large groups. But when social distancing eventually is relaxed, scarlet fever is likely to come back. We need to continue this research to improve diagnosis and to better manage these epidemics," Walker said.

The researcher added that like coronavirus, ultimately a vaccine is going to be critical for tackling scarlet fever, which is one history's most deadly childhood diseases. After 2014, between 15,000 and 30,000 cases have got diagnosed in England annually, compared to 4,366 in 2013.

In Victorian England, it was one of the main causes of death in children. The infected people develop a white coating on the tongue that peels away a few days later. The disease is caused by close contact with a person already carrying the bacteria. It can take around five days to develop symptoms.