The red rash is a typical symptom of scarlet fever. (Image: Valentyna / stock.adobe.com)
Scarlet fever is back: the return of childhood illnesses
Scarlet fever, an infectious disease, has been almost eradicated by antibiotics and penicillin. However, in recent years, cases have more than quintupled worldwide. A research team has now found the reason for the return of childhood illness and found that the bacterial pathogen is more aggressive than ever.
Researchers at the University of Queensland in Australia studied the scarlet fever pathogen Streptococcus pyrogenes from current outbreaks of the disease. The task force found that the bacteria had taken over the genes of some viruses, making the pathogen more toxic, more infectious and more resistant to some common antibiotics. The team recently presented the results of their study in the renowned journal “Nature Communications”.
Scarlet fever bacteria with viral genes
Scarlet fever is on the rise again around the world after the infectious disease was nearly eliminated in the 1940s. An international team of researchers have shown that a strain of the bacteria Streptococcus pyogenes has acquired so-called prophages. This is viral DNA that has been incorporated into the genetic material of bacteria. This new tribe is responsible for the resurgence of the disease.
Scarlet fever cases are on the rise again since 2011
Health authorities around the world were surprised when some Asian countries again reported an increase in scarlet fever cases in 2011. “The disease had largely resolved by the 1940s,” reports research director Dr. Stephan. Brouwer. A major outbreak in the UK followed in 2014. The pathogens have also been discovered in Australia for some time.
Sharp increase in cases of scarlet fever
“This worldwide recurrence of scarlet fever has resulted in a more than five-fold increase in the incidence rate and more than 600,000 cases worldwide,” says Brouwer. Researchers have now been able to find the cause of the recurrence of the centuries-old childhood disease.
When bacteria are infected with viruses
As the research team explains, a population of scarlet fever bacteria has been infected with viruses carrying toxin genes. As a result, parts of the DNA of the virus integrated into the genome of Streptococcus pyogenes and formed a new strain of the pathogen called Streptococcus pyogenes serotype M12 (emm12) from Northeast Asia. These offshoots contain what are called “superantigenic toxins”, which make the pathogen more dangerous.
“We have shown that these acquired toxins allow Streptococcus pyogenes to better colonize its host,” explains study co-author Professor Mark Walker. This is also suggested by the results of animal models. The researchers removed the pathogen’s toxin genes, after which it was no longer able to reproduce as efficiently in test animals.
COVID-19 pandemic slows the spread of scarlet fever
“Much like the SARS-CoV-2 coronavirus that causes COVID-19, the bacteria Streptococcus pyogenes is usually spread by coughing or sneezing, with symptoms such as sore throat, fever, headache, swollen lymph nodes and a characteristic scarlet rash, ”says study leader Brouwer. . Most children between the ages of two and ten are affected by scarlet fever.
As part of the health policy measures to fight COVID-19, we can also expect a sharp drop in cases of scarlet fever. “This year, social distancing due to COVID-19 has so far kept scarlet fever outbreaks at bay,” added Professor Walker. If measures against COVID-19 are completed, however, a further increase in scarlet fever cases is likely. “We must continue this research to improve the diagnosis and better control these epidemics”, summarizes Walker. (v)
Author and source information
This text complies with the requirements of specialized medical literature, medical directives and ongoing studies and has been verified by healthcare professionals.
Graduate Editor (FH) Volker Blasek
University of Queensland: Supercharged “ clones ” Spark Scarlet Fever’s Re-Emergence (published: 07.10.2020), uq.edu.auStephan Brouwer, Timothy C. Barnett, Diane Ly, Katherine J. Streptococcus pyogenes causing epidemic scarlet fever; in: Nature Communications, 2020, nature.com
This article is provided for informational purposes only and should not be used for self-diagnosis or self-treatment. It cannot replace a visit to the doctor.