Rising global incidence of invasive group A streptococcus infection and scarlet fever in the COVID-19 era - our knowledge thus far.

Dear Editor, Group A streptococci (Strep A) (GAS) infections range from mild symptoms to fatal disease1. Recently (as of 8 December 2022), five European Region member states have informed the WHO about numerous instances of invasive group A streptococcal (iGAS) sickness and, in certain cases, scarlet fever-related fatalities in kids under 10 years of age2. Scarlet fever and iGAS cases have increased during 2022 (notably in the second half) in France, the Netherlands, Ireland, the UK, and Sweden, mostly affecting young children. Mild symptoms like tonsillitis, pharyngitis, impetigo, cellulitis, and scarlet fever are frequently brought on by GAS infection, while it could also occasionally result in an invasive infection (iGAS) that is life-threatening3. Winter and the beginning of spring are often the seasons when GAS pharyngitis is most common, with frequent outbreaks among school and kindergarten children, although it could also affect younger ones. The observed rise in critical cases might be due to an earlier onset of GAS infection than its usual season, combined with an increasing spread of viral coinfections (including respiratory viruses) that could have raised the risk of iGAS infection. This is in light of the fact that there is more mixing among the population now that social distancing (owing to the COVID-19 pandemic) has been lifted. Skin lesions due to trauma, surgery, or skin disorders, heart ailments, diabetes, and cancer are the other risk factors. Injection drug users have shown a higher risk of iGAS infection owing to their immunocompromised status and low living standards. The risk of iGAS infections is considered minimal in general as of now due to the mild increase in cases, GAS endemicity, the low spread of the novel emm gene sequence, and no evidence of antibiotic resistance. Rapid antigen testing (Rapid Strep) or examining bacterial cultures are the common diagnostic tools for identifying GAS pharyngitis; the positive cases are then treated with antibiotics and supportive care. Data from March to July 2022 show an increase in iGAS instances brought on by several recognized emm gene sequence types (the gene encoding the M virulence protein found in many Streptococcus pyogenes serotypes). This trend is still intact with no decrement sign. There have been reports of co-infection with respiratory viruses and Varicella zoster. Routine laboratory investigation in the UK for antimicrobial susceptibility has not exhibited alarming results. Further, laboratory surveillance has not detected any novel emm gene sequence types. Usually referred to as Group A streptococci, the Gram-positive Streptococcus pyogenes is a natural member of the human microflora that could reside externally (on human skin) or internally (in the throat). However, as an aggressive opportunistic pathogen it causes more than 500 000 fatalities worldwide. Close contact with an infected individual facilitates transmission, which could happen through sneezing, coughing, or touching a wound. Supportive clinical management of severe iGAS cases includes intravenous administration of fluids and electrolytes and measures to ameliorate or neutralize the effects of the bacterial toxin produced. Antibiotics such as cloxacillin, clindamycin, vancomycin, penicillin, and others are used to treat GAS infections and associated complications and could check localized transmission within 24 h of treatment4–6. Administering intravenous immunoglobulins and opting for secondary prophylaxis as adjunctive therapies have been found beneficial in managing iGAS infections6. Culture and antibiotic sensitivity testing are recommended for guiding effective antibiotic treatment options in emerging antimicrobial resistance situations. When GAS infection progresses to invasive GAS, it could result in postimmune-mediated illnesses like rheumatic heart disease, acute rheumatic fever, and poststreptococcal glomerulonephritis, as well as life-threatening situations like streptococcal toxic shock syndrome, necrotizing fasciitis, and other severe infections. Personal cleanliness in general and good hand sanitization could help reduce transmission. In order to improve early recognition, reporting, and timely treatment initiation of GAS cases, improved monitoring systems and public healthcare messages addressing the general public and doctors have been initiated in countries that have reported increased cases of iGAS. The WHO has warned other nations to keep an eye on similar spikes in iGAS cases. In light of the moderate rise in iGAS cases, GAS endemicity, lack of identification of novel or emerging emm gene sequence types, and absence of observed increases in antibiotic resistance, the WHO currently considers the risk posed by the reported increase in iGAS infections for the general public in some European countries as low. It will be routinely evaluated using the shared and readily accessible data. In the prevailing situation, continued close examination of the epidemiological situation is highly recommended especially in countries with reported cases, as it will be necessary to evaluate the existing risk level and promptly alter risk management strategies. Given the potential for severe cases, it is crucial that GAS-related infections like streptococcal toxic shock syndrome and scarlet fever are identified and treated quickly to reduce the risk of complications like iGAS as well as onward transmissions. For correct clinical assessment, early diagnosis of symptomatic patients with consistent GAS infection and prompt treatment of patients, and engaging the public health communication activities is advised4,5. Also, healthcare professionals may be informed that rapid identification and initiating specific and supportive therapies timely in patients with iGAS infection can save life. Individuals with a history of viral illness like chickenpox, and those in close contact with scarlet fever or iGAS cases may be evaluated precisely with a high GAS infection suspicion. If hospitalized, droplet safety measures may be installed. Healthcare professionals should take recommended precautions and examine the potential need for further safeguarding of health. Increased risk of critical (scarlet fever and iGAS) illnesses in household contacts should also be emphasized to healthcare professionals7. Close family members of the cases may be treated in accordance with national regulations. Further, emphasizing the importance of good hand and respiratory hygiene and good interior ventilation throughout this winter is crucial to continue with. Ethical approval This article does not require any human/animal subjects to acquire such approval. Sources of funding None. Author contribution R.K.M.: conceptualized, writing – review and editing. L.V.S.K., L.S.T.: made the initial draft. K.D., S.M.: updated, writing – review and editing. All authors have critically reviewed and approved the final draft and are responsible for the content and similarity index of the manuscript. Conflicts of interest disclosure No conflicts to declare. Research registration unique identifying number (UIN) 1. Name of the registry: NA. 2. Unique identifying number or registration ID: NA. 3. Hyperlink to your specific registration (must be publicly accessible and will be checked): NA. Guarantor All authors Data statement Data not available/not applicable.