Ranked among the top10 infectious causes of death worldwide, group A Streptococcus (GAS) causes small- and large-scale outbreaks, depending on the trigger as transmission of a GAS strain or expansion of predominant clones. In China, GAS infections other than scarlet fever are not notifiable. In Shanghai, an epidemiological investigation was initiated after two successive severe pneumonia cases with one death in a digital factory, from where outbreaks are less widely reported. The investigation was performed using emm typing, pulsed-field gel electrophoresis (PFGE) typing, superantigen profiling, and genome analysis. This enabled characterization of relatedness among the outbreak isolates and identification of the mobile genetic elements present. Among 57 patients with respiratory symptoms investigated in the factory, emm5 GAS strains were isolated from 8 patients. The eight GAS infection cases comprising one fatal severe pneumonia case, six influenza-like illness cases, and one pharyngitis case. Two risk factors were identified: adult with an age of 18-20 years and close contact with a GAS patient or carrier. GAS attack rate was 14.0% (8/57), and GAS carriage rate was probably around 2.7% (14/521) based on surveys in two nearby districts. All the 10 outbreak associated isolates were assigned to emm5 and sequence type ST-99 (emm5/ST-99), harbored superantigen genes speC, speG and smeZ, and were assigned to two similar PFGE patterns (clones). Among the outbreak associated isolates, all carried ermA with resistance to erythromycin and inducible resistance to clindamycin, and eight (80%) carried a tetM gene with resistance to tetracycline. Among the 14 carriage isolates, 12 were emm12/ST-36, and 2 were emm1/ST-28, all with superantigen genes speC, speG, ssa and smeZ. All the carriage isolates harbored ermB and tetM with resistance to erythromycin, clindamycin, and tetracycline. Genome analysis showed the two outbreak clones were closely related and possessed new prophages carrying virulence gene sdc and antibiotic resistance genes of ermA and tetM, which were not found in the emm5 reference strain Manfredo. This is the first report of a GAS outbreak in this type of workplace. The outbreak was caused by two closely-related emm5 clones that differed from the predominant emm types circulating in China.

The novel avian influenza H7N9 virus has caused severe diseases in humans in eastern China since the spring of 2013. On January 18th 2014, a doctor working in the emergency department of a hospital in Shanghai died of H7N9 virus infection. To understand possible reasons to explain this world’s first fatal H7N9 case of a health care worker (HCW), we summarize the clinical presentation, epidemiological investigations, laboratory results, and prevention and control policies and make important recommendations to hospital-related workers. The patient was a 31-year-old male Chinese surgeon who was obese and had a five-year history of hypertension and suspected diabetes. On January 11th 2014, he showed symptoms of an influenza-like illness. Four days later, his illness rapidly progressed with bilateral pulmonary infiltration, hypoxia and lymphopenia. On January 17th, the case had a high fever, productive cough, chest tightness and shortness of breath, so that he was administered with oseltamivir, glucocorticoid, immunoglobulin, and broad-spectrum antibiotic therapy. The case died in the early morning of next day after invasive ventilation. He had no contact with poultry nor had he visited live-poultry markets (LPMs), where positive rates of H7N9 were 14.6 % and 18.5 %. Before his illness, he cared for three febrile patients and had indirect contact with one severe pneumonia patient. Follow-up with 35 close contacts identified two HCWs who had worked also in emergency department but had not worn masks were anti-H7N9-positive. Viral sequence identity percentages between the patient and two LPM-H7N9 isolates were fewer than between the patient and another human case in shanghai in January of 2014. Important reasons for the patient’s death might include late treatment with oseltamivir, and the infected H7N9 virus carrying both mammalian-adapted signature (HA-Q226L) and aerosol transmissibility (PB2-D701N). The LPM he passed every day was an unlikely source of his infection, but a contaminated environment, or an unidentified mild/asymptomatic H7N9 carrier were more probable. We advocate rigorous standard operating procedures for infection control practices in hospital settings and evaluations thereafter.

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) poses a significant threat to human health in hospital settings. These environments could serve as a reservoir for CRAB, since Acinetobacter baumannii (AB) exhibits strong survival capabilities outside the human body. Therefore, it is necessary to investigate the distribution of CRAB in the environment and identify the risk factors associated with its positive detection rate.Methods: From 2018 to 2023, long-term environmental monitoring of surfaces around CRAB patients was conducted across 16 hospitals in Shanghai. During each quarter, 48 environmental samples, along with information about the samples, were collected. Bacterial isolates were collected, and antimicrobial susceptibility testing (AST) was performed in accordance with the Clinical and Laboratory Standards Institute (CLSI) guidelines (2019–2021 edition). The CRAB detection rate in the environmental samples was compared across different variables. For nominal categorical variables, intergroup differences were analyzed using Pearson’s chi-squared (χ²) test. In addition, logistic regression analysis was employed to identify risk factors associated with CRAB-positive environmental samples.Results: A total of 10,268 samples were included in this study, among which 391 tested positive for CRAB. The overall CRAB positivity rate on environmental surfaces was 3.81%. Significant differences in positivity rates were observed across hospital levels, departments, sampling locations, and exposure frequencies (p < 0.05). Compared to Class B secondary hospitals, the following hospital classes showed significantly higher risks of CRAB detection: Class A secondary hospitals (OR = 13.34, 95%CI: 3.25–54.79, p < 0.001), Class B tertiary hospitals (OR = 20.63, 95%CI: 5.10–83.49, p < 0.001), and Class A tertiary hospitals (OR = 8.77, 95%CI: 2.14–35.87, p = 0.003). Compared to internal medicine departments, environmental surfaces in the following high-risk departments demonstrated higher rates of CRAB detection: surgical departments (OR = 1.93, 95%CI: 1.23–3.05, p = 0.005) and intensive care units (ICUs) (OR = 3.10, 95%CI: 2.19–4.39, p < 0.001). Additionally, surfaces located inside wards (OR = 1.834, 95%CI: 1.230 ~ 2.736, p = 0.003) and those with high-touch frequency (OR = 1.467, 95%CI: 1.134 ~ 1.898, p = 0.003) were identified as risk factors for the positive detection rate of CRAB in the environment.Conclusion: Class A secondary hospitals and Class B tertiary hospitals should prioritize infection control measures to prevent the dissemination of CRAB. Special attention should be given to high-risk areas, such as the surgical department and ICU, with enhanced disinfection of high-touch surfaces within patient wards.

Group A Streptococcus (GAS) imposes a significant global health burden across all age groups, annually causing over 600 million cases of pharyngitis and more than 18 million severe invasive infections or sequelae. The resurgence of scarlet fever globally and streptococcal toxic shock syndrome (STSS) outbreaks in Japan have brought GAS infections back into the spotlight as a pressing global health concern. Unfortunately, no licensed vaccine against GAS is yet available for clinical use. Our comprehensive review examines the developmental history of GAS vaccines, outlining the research trajectory from early inactivated vaccines to contemporary multivalent, conjugate, multi-antigen, and mRNA-based vaccine platforms. It systematically analyzes clinical trial outcomes of GAS vaccines, highlighting recent advances in both M protein-based and non-M protein vaccine candidates while summarizing promising target antigens. The review concludes with critical strategies to accelerate vaccine commercialization, including enhanced investment in research and development, expanded collaborations, leveraging advanced vaccine technologies, streamlined clinical trials, and strengthened public health advocacy. This review critically evaluates the current evidence and future prospects in GAS vaccine development, emphasizing innovative strategies and engaging broader stakeholders to accelerate GAS vaccine development.

Substantial achievements have been made in preventing and treating human parasitic diseases in China over the past six decades. However, with the recent progression of economic globalization and food diversification, foodborne parasitic diseases have become a significant public health challenge. Here, we investigated and analyzed the characteristics of foodborne parasitic infections arising from market-sold aquatic food products and in key populations. Freshwater, seawater, and pickled products were randomly obtained from agricultural trade markets, restaurants, supermarkets, and retail stores in four districts of Shanghai from 2022 to 2024. Parasite metacercariae or larvae were subsequently detected in these aquatic products via artificial digestion or dissection methods. Fecal samples from 698 diarrhea outpatients from the intestinal clinics of hospitals were analyzed via molecular methods. Of the 1,914 aquatic samples, 163 (8.52%) tested positive for parasites. Nine out of 1,086 freshwater products tested positive for parasites, including Clonorchis sinensis (7; 0.64%) and Gnathosotoma spinigerum (2; 0.18%). Anisakis was detected only in 7 of 27 seawater fish species, with contamination rates ranging from 6.00 to 100.00%. Echinostoma metacercariae was found only in marinated mud snails (20.43%). The prevalence of Clonorchis sinensis metacercariae in freshwater fish was highest in the second quarter (April–June), and catering samples presented the highest contamination rate, at 12.96%. In the sequence analysis, only one outpatient sample tested positive for parasitic infection, identified as Cryptosporidium meleagridis. No Giardia lamblia was found in the participants. Foodborne parasite contamination occurs in market-sold aquatic food products in Shanghai Municipality, although the incidence of parasite infection was low in the key populations tested. Further studies are needed to establish more comprehensive information that could improve public health and human food safety awareness.

As COVID-19 transitions from pandemic to endemic, our prevention and control policies have shifted from broad, strict community interventions to focusing on the prevention of cluster outbreaks. Currently, information on the characteristics of cluster outbreaks remains limited. This study describes the features of COVID-19 clusters in Shanghai. It aims to provide valuable insights for managing localized outbreaks. We conducted a retrospective analysis of clusters of confirmed COVID-19 cases. Epidemiological descriptions, the transmission characteristics of clusters, and individual risk factors for contagiousness were analyzed. A total of 381 cases of COVID-19 were confirmed and 67 clusters were identified. Most clusters (58.21%, 39/67) only had two cases, with a declining proportion held by clusters of more cases. Familial transmission was predominant, accounting for 79.10% (53/67) of clusters. Although other types of cluster outbreaks, such as those in workplaces (1.49%, 1/67), occur less frequently compared to household clusters, they tend to involve larger scales and more cases. Workplaces and similar venues are more likely to experience large-scale cluster outbreaks. Contagiousness was higher among cases with runny nose (risk ratio [RR]: 4.8, 95% CI: 1.40–16.44, p-value = 0.01) and those with diabetes (RR: 3.8, 95% CI: 1.01–14.60, p-value = 0.05). In conclusion, household cluster outbreaks, in particular, are both a key priority and a foundational issue. Establishing an indicator system based on the transmissibility of cases holds significant practical value for infectious disease prevention and control. By enhancing household hygiene and developing a case classification and management system based on transmissibility, it is possible to better prevent and control regional COVID-19 outbreaks.