An emm5 Group A Streptococcal Outbreak Among Workers in a Factory Manufacturing Telephone Accessories

Epidemiological Characteristics and Trends of Scarlet Fever in Zhejiang Province of China: Population-Based Surveillance during 2004-2022

Background

Over the past two decades, scarlet fever has resurged in some countries or areas. Nationwide nonpharmaceutical interventions changed the patterns of other infectious diseases, but its effects on the spread of scarlet fever were rarely studied. This study aimed to evaluate the changes in scarlet fever incidence in Zhejiang Province, China, before and during the COVID-19 pandemic periods and to provide references for scarlet fever prevention and control.

Methods

Scarlet fever surveillance data in Zhejiang, China (2004-2022), were analyzed in three stages. Two-sample z test, ANOVA, and Tukey's test were used to compare and analyze the characteristics of disease spread at different stages. The ARIMA model was used to predict the overall trend. The data were obtained from the National Infectious Disease Reporting Information System.

Results

A total of 28,652 cases of scarlet fever were reported across Zhejiang Province during the study period, with the lowest average monthly incidences in 2020 (0.111/100,000). The predominant areas affected were the northern and central regions of Zhejiang, and all regions of Zhejiang experienced a decrease in incidence in 2020. The steepest decline in incidence in 2020 was found in children aged 0-4 years (67.3% decrease from 23.8/100,000 to 7.8/100,000). The seasonal pattern changed, with peak occurrences in April to June and November to January during 2004-2019 and 2021 and a peak in January in 2020. The median duration from diagnosis to confirmation was highest before COVID-19 (4 days); however, it decreased to 1 day in 2020-2022, matching the other two medians.

Conclusions

In 2020, Zhejiang experienced an unprecedented decrease in scarlet fever, with the lowest incidence in nearly 18 years, but it rebounded in 2021 and 2022. The seasonal epidemiologic characteristics of scarlet fever also changed with the COVID-19 outbreaks. This suggested that nationwide nonpharmaceutical interventions greatly depressed the spread of scarlet fever. With the relaxation of non-pharmaceutical intervention restrictions, scarlet fever may reappear. Government policymakers should prioritize the control of future scarlet fever outbreaks for public health.

Evolution of Sequence Type 4821 Clonal Complex Hyperinvasive and Quinolone-Resistant Meningococci

Expansion of quinolone-resistant Neisseria meningitidis clone China^{CC4821-R1-C/B} from sequence type (ST) 4821 clonal complex (CC4821) caused a serogroup shift from serogroup A to serogroup C invasive meningococcal disease (IMD) in China. To determine the relationship among globally distributed CC4821 meningococci, we analyzed whole-genome sequence data from 173 CC4821 meningococci isolated from 4 continents during 1972–2019. These meningococci clustered into 4 sublineages (1–4); sublineage 1 primarily comprised of IMD isolates (41/50, 82%). Most isolates from outside China (40/49, 81.6%) formed a distinct sublineage, the Europe–USA cluster, with the typical strain designation B:P1.17-6,23:F3-36:ST-3200(CC4821), harboring mutations in penicillin-binding protein 2. These data show that the quinolone-resistant clone China^{CC4821-R1-C/B} has expanded to other countries. The increasing distribution worldwide of serogroup B CC4821 raises the concern that CC4821 has the potential to cause a pandemic that would be challenging to control, despite indirect evidence that the Trumenba vaccine might afford some protection.

A Review of Streptococcus pyogenes: Public Health Risk Factors, Prevention and Control

Streptococcus pyogenes, (colloquially named “group A streptococcus” (GAS)), is a pathogen of public health significance, infecting 18.1 million people worldwide and resulting in 500,000 deaths each year. This review identified published articles on the risk factors and public health prevention and control strategies for mitigating GAS diseases. The pathogen causing GAS diseases is commonly transmitted via respiratory droplets, touching skin sores caused by GAS or through contact with contaminated material or equipment. Foodborne transmission is also possible, although there is need for further research to quantify this route of infection. It was found that GAS diseases are highly prevalent in developing countries, and among indigenous populations and low socioeconomic areas in developed countries. Children, the immunocompromised and the elderly are at the greatest risk of S. pyogenes infections and the associated sequelae, with transmission rates being higher in schools, kindergartens, hospitals and residential care homes. This was attributed to overcrowding and the higher level of social contact in these settings. Prevention and control measures should target the improvement of living conditions, and personal and hand hygiene. Adherence to infection prevention and control practices should be emphasized in high-risk settings. Resource distribution by governments, especially in developed countries, should also be considered.

Global genomic epidemiology of Streptococcus pyogenes

Streptococcus pyogenes is one of the Top 10 human infectious disease killers worldwide causing a range of clinical manifestations in humans. Colonizing a range of ecological niches within its sole host, the human, is key to the ability of this opportunistic pathogen to cause direct and post-infectious manifestations. The expansion of genome sequencing capabilities and data availability over the last decade has led to an improved understanding of the evolutionary dynamics of this pathogen within a global framework where epidemiological relationships and evolutionary mechanisms may not be universal. This review uses the recent publication by Davies et al., 2019 as an updated global framework to address S. pyogenes population genomics, highlighting how genomics is being used to gain new insights into evolutionary processes, transmission pathways, and vaccine design.

Severe community-acquired pneumonia due to Streptococcus pyogenes in the Newcastle area

Background

An apparent increase in the incidence of severe community-acquired pneumonia (CAP) caused by Streptococcus pyogenes (group A Streptococcus - GAS) was observed during 2017 in the Newcastle area. The study was undertaken to establish whether there was a true increase in severe S. pyogenes pneumonia and to explore its epidemiology and clinical features.

Methods

The study was a retrospective descriptive study of S. pyogenes pneumonia set in two tertiary referral hospitals in Newcastle, a large regional city, during the period 2007 to 2018. Subjects were adults identified as having S. pyogenes pneumonia by searching a database of severe CAP (defined as requiring intensive care unit [ICU] admission) for the period 2007-2018. Laboratory records were also searched for sterile site isolates of S. pyogenes to identify patients not requiring ICU admission.

Results

There were 13 cases of S. pyogenes CAP identified during the study period, of whom 12 (92%) required ICU admission. S. pyogenes accounted for 12/728 (1.6%) cases of severe CAP during the study period. The severity of S. pyogenes pneumonia was high despite a mean patient age of 48 years and 7/13 (54%) having no significant past medical history. The mortality rate was 2/13 (15%). Viral co-infection was found in 6/12 (50%) of patients tested. Overall 7/12 (58%) of the patients with severe S. pyogenes CAP during the study period presented in the winter or spring of 2017.

Conclusions

Streptococcus pyogenes is a rare cause of severe CAP in the Newcastle area, but there was a marked increase in frequency observed during the 2017 influenza season. Further study of the epidemiology of invasive GAS (iGAS) disease in Newcastle is warranted to identify emerging trends in this severe infection.

Exposure to air pollution and scarlet fever resurgence in China: a six-year surveillance study

Scarlet fever has resurged in China starting in 2011, and the environment is one of the potential reasons. Nationwide data on 655,039 scarlet fever cases and six air pollutants were retrieved. Exposure risks were evaluated by multivariate distributed lag nonlinear models and a meta-regression model. We show that the average incidence in 2011-2018 was twice that in 2004-2010 [RR = 2.30 (4.40 vs. 1.91), 95% CI: 2.29-2.31; p < 0.001] and generally lower in the summer and winter holiday (p = 0.005). A low to moderate correlation was seen between scarlet fever and monthly NO₂ (r = 0.21) and O₃ (r = 0.11). A 10 μg/m³ increase of NO₂ and O₃ was significantly associated with scarlet fever, with a cumulative RR of 1.06 (95% CI: 1.02-1.10) and 1.04 (95% CI: 1.01-1.07), respectively, at a lag of 0 to 15 months. In conclusion, long-term exposure to ambient NO₂ and O₃ may be associated with an increased risk of scarlet fever incidence, but direct causality is not established.

Epidemiological analysis of Group A Streptococcus infections in a hospital in Beijing, China

Our study aimed to investigate the epidemiological and molecular characteristics of isolates collected from Group A Streptococcus (GAS) infections in children in Beijing China during the year 2019. Emm typing, superantigens, and erythromycin resistance genotypes were determined by PCR. Antimicrobial susceptibility testing was performed as recommended by Clinical Laboratory Standards Institute (CLSI). A total of 271 GAS isolates were collected. Thirteen different emm types, including 31 subtypes, were identified. The most prevalent emm types were emm12 (52.77%), emm1 (36.9%), emm3.1 (2.95%), and emm75.0 (2.95%). Two variant subtypes, STC36.0 and STG840.2, were identified. There was no difference in the portion of emm12 and emm1 isolates in scarlet fever, impetigo, and psoriasis. The majority of superantigens detected were smeZ (94.46%), speC (91.14%), and ssa (74.91%), followed by speH (56.46%), speI (45.76%), speJ (36.9%), and speA (34.32%). More scarlet fever isolates harbored speA (35.6%) and speJ (38.4%), more psoriasis isolates harbored speI (57.9%), and more impetigo isolates harbored ssa (89.7%). Isolates were universally susceptible to penicillin and resistant to erythromycin (94.83%). Moreover, 89.67% erythromycin resistance isolates harbored the ermB gene. The erythromycin resistance rate of the isolates from the three diseases was different. Scarlet fever is the common streptococcal infectious disease in dermatology. Emm12 and emm1 were the most prevalent emm types. The most prevalent superantigens detected were smeZ, spec, and ssa. There is association between diversity of superantigens and disease manifestation. Hence, continuous surveillance of GAS molecular epidemiological characterizations in different diseases is needed.

Identification and Characterization of Fluoroquinolone Non-susceptible Streptococcus pyogenes Clones Harboring Tetracycline and Macrolide Resistance in Shanghai, China

Streptococcus pyogenes, also known as group A Streptococcus (GAS), is one of the top 10 infectious causes of death worldwide. Macrolide and tetracycline resistant GAS has emerged as a major health concern in China coinciding with an ongoing scarlet fever epidemic. Furthermore, increasing rates of fluoroquinolone (FQ) non-susceptibility within GAS from geographical regions outside of China has also been reported. Fluoroquinolones are the third most commonly prescribed antibiotic in China and is an therapeutic alternative for multi-drug resistant GAS. The purpose of this study was to investigate the epidemiological and molecular features of GAS fluoroquinolone (FQ) non-susceptibility in Shanghai, China. GAS (n = 2,258) recovered between 2011 and 2016 from children and adults were tested for FQ-non-susceptibility. Efflux phenotype and mutations in parC, parE, gyrA, and gyrB were investigated and genetic relationships were determined by emm typing, pulsed-field gel electrophoresis and phylogenetic analysis. The frequency of GAS FQ-non-susceptibility was 1.3% (30/2,258), with the phenotype more prevalent in GAS isolated from adults (14.3%) than from children (1.2%). Eighty percent (24/30) of FQ-non-susceptible isolates were also resistant to both macrolides (ermB) and tetracycline (tetM) including the GAS sequence types emm12, emm6, emm11, and emm1. Genomic fingerprinting analysis of the 30 isolates revealed that non-susceptibility may arise in various genetic backgrounds even within a single emm type. No efflux phenotype was observed in FQ non-susceptible isolates, and molecular analysis of the quinolone resistance-determining regions (QRDRs) identified several sequence polymorphisms in ParC and ParE, and none in GyrA and GyrB. Expansion of this analysis to 152 publically available GAS whole genome sequences from Hong Kong predicted 7.9% (12/152) of Hong Kong isolates harbored a S79F ParC mutation, of which 66.7% (8/12) were macrolide and tetracycline resistant. Phylogenetic analysis of the parC QRDR sequences suggested the possibility that FQ resistance may be acquired through inter-species lateral gene transfer. This study reports the emergence of macrolide, tetracycline, and fluoroquinolone multidrug-resistant clones across several GAS emm types including emm1 and emm12, warranting continual surveillance given the extensive use of fluoroquinolones in clinical use.