Group A streptococcal infections increase in the UK in 2022

In a recent study published in the journal European surveillanceTo understand the clinical presentations of iGAS, as well as the incidence of co-infection with respiratory viruses, the researchers investigated the recent increase in cases of invasive group A streptococcal (iGAS) infection among children under 15 years of age in the UK.

Studies: Increase in reports of invasive group A streptococcal infection, England, 2022. Image Credit: ART-ur / Shutterstock

Background

2022 saw an increase streptococcus Infections such as scarlet fever and iGAS among children in the UK. In addition, coinfections of iGAS and other respiratory viruses were reported among children under 15 years of age in the second half of 2022. Invasive group A streptococcal infections are diagnosed using throat cultures or rapid strep antigen tests, and positive cases must be reported to the UK’s Health Safety Organization’s Second Generation Surveillance System (SGSS) for contact tracing.

iGAS incidence

During the 2022–2023 season, which ran from mid-September one year to mid-September the following year, the number of iGAS lab notifications increased each week at unusual levels than expected in the UK at that time of year. For example, 37-48. There were 772 iGAS cases at weeks 48, and 110 cases at week 48 alone.

Compared to the previous five seasons, the median age of iGAS patients had decreased from 53-57 to 46. However, there was a marked increase in the number of iGAS cases among children in the 2022-2023 season; The percentage of pediatric iGAS cases increased from 6.4% to 13.3% in previous seasons and to 26.1% in the most recent season. In addition, infection rates in various age groups were higher than in previous seasons; The incidence in children under one year of age was 2.5 cases per 100,000 compared to previous incidence rates of 0.1-1.3 per 100,000 cases. There were also higher cases of iGAS in children aged one to four and five to nine years in 2022-2023 compared to previous seasons.

Weeks 37 to 48 also reported a higher incidence of death among children, and 14 of the 61 iGAS-related deaths were children. In comparison, the previous five seasons had 4-27 deaths over the entire season. In addition, pediatric iGAS patients also showed an increase in streptococcal samples detected in pleural and lower respiratory tract samples. However, no similar increase in pleural or lower respiratory tract streptococcal specimens was observed in older patients.

Viral respiratory coinfections

Data from SGSS and DataMart, the sentinel surveillance on respiratory viruses, also suggested an increase in iGAS and respiratory virus coinfection reports during the October-November 2022 period. In November 2022, about a quarter of pediatric iGAS patients had co-infections with a respiratory virus; the most common respiratory virus was respiratory syncytial virus (12.4% of iGAS cases among children under 15 years of age), followed by human metapneumovirus and rhinovirus at 11.3% and 7.2%, respectively. Five out of ten deaths among pediatric iGAS patients had viral respiratory co-infections.

Samples from iGAS patients of all age groups did not show any unusual M protein genes (um) types. This um Gene codes for a virulence protein on its surface Streptococcus pyogenesand 57% of iGAS cases in children under 15 years of age um 1 type. When declaring that data is not new um types have been identified, um 1 M1UK clone detected in 2010, most seen in pediatric iGAS um 1 isolate is known to upregulate an expression. Streptococcus pyogenes disease-causing factor.

In addition, GPs in the UK have reported a marked increase in the number of cases of scarlet fever and sore throat between the ages of 37 and 37.^pearl and 48^pearl week of 2022. There were 8,688 reports of scarlet fever during this period, compared to previous seasons from 2017 to 2021, which received between 333 and 2,536 notifications.

concerns about similar increases streptococcus infections are on the rise in other European countries such as France, Ireland and the Netherlands. This trend can be attributed to reduced immunity due to lower group A streptococcal exposure due to the 2019 coronavirus disease (COVID-19) outbreak and related mitigation measures such as wearing masks and social distancing.

solution

Overall, the results compared to previous seasons, streptococcus Infections such as scarlet fever and iGAS saw a marked increase, especially among children under 15 years of age. The number of iGAS-related deaths among children also increased. Immediate reporting of iGAS cases, contact tracing, and treatment with prophylactics are essential to halt future transmission of iGAS. Streptococcus and limits respiratory complications.