Epidemiological characteristics of 45 norovirus clusters in Baoshan District / 预防医学

Objective@#To investigate the epidemiological characteristics of 45 norovirus clusters in Baoshan District, Shanghai Municipality from 2019 to 2021, so as to provide the evidence for improving the management of norovirus clusters. @*Methods@#The epidemiological characteristics and laboratory testing of 45 norovirus clusters were collected in Baoshan District from 2019 to 2021, and the temporal distribution, population distribution, distribution of places of norovirus clusters, clinical manifestations, laboratory testing results, origin of norovirus infection and transmission routes of norovirus clusters were analyzed using a descriptive epidemiological method. @*Results@#A total of 45 norovirus clusters involving 29 379 individuals were reported in Baoshan District from 2019 to 2021, and 435 cases with norovirus infections were identified, with an average attack rate of 1.48%. Norovirus infection most often occurred from November to April of the following year, and the infection predominantly occurred among students (408 cases, 93.79%). There were 25 norovirus clusters in kindergartens (55.56%), 18 clusters in primary and middle schools (40.00%), one cluster in a social care facility and one cluster in a geriatric ward. Vomiting was the predominant clinical symptom (416 cases, 95.63%). The positive rate of norovirus was 37.35% in 597 samples. There were 40 norovirus clusters caused by the norovirus GⅡ genotype (88.89%), and the median duration of the norovirus cluster was 6 days (interquartile range, 1 day). In addition, 82.22% of the norovirus clusters reported to centers for disease control and prevention within 1 day,and 88.89% of the clusters were transmitted through human to human transmission or vomitus of cases.@*Conclusion@#The norovirus clusters predominantly occur in winter/spring and among students in Baoshan District from 2019 to 2021. Kindergartens and primary and middle schools are main places of norovirus infections, and the norovirus GⅡ genotype is the main type of pathogens. Human-to-human transmission and exposure to patients' vomitus are the main routes of transmission.

An outbreak of school influenza complicated with mycoplasma pneumoniae infection / 中国学校卫生

Objective@#To describe the clinical features, causal agent and transmission mode of a fever outbreak in a school in Shanghai.@*Methods@#Field epidemiological approaches including case definition development, searching for contacts, distribution of diseases description, environmental sampling and laboratory testing.@*Results@#A total of 16 influenza like cases were included, all concentrated in the one class of grade two, including 15 students and 1 teacher. Among student cases, the incidence rate was 36.59% (15/41), the average age was 7.4 years, the incidence rate was 36.84%(7/19) for boys, 36.36%(8/22) for girls. The clinical course was 5-15 days, with the median of 9 days, and 18.75%(3/16) of the cases stayed studying while sick. The nasopharyngeal swab specimens in 16 cases all tested positive for influenza B, of which 11 tested positive for mycoplasma pneumoniae and 1 case also tested positive for coronavirus OC43. Body temperature, number of mononuclear cells, and treatment time of patients infected with Influenza B and mycoplasma pneumoniae were higher than those of patients infected with influenza B alone( P <0.05). The outbreak lasted for 12 days, all sick students were treated and discharged from hospital, with no severe cases or death, and the outbreak was effectively controlled.@*Conclusion@#This campus cluster outbreak caused by influenza B and mycoplasma pneumoniae. Patients with influenza B with mycoplasma pneumoniae have severe symptoms and a long course of illness, suggesting the importance of early management of the epidemic.

Three infection clusters related with potential pre-symptomatic transmission of coronavirus disease (COVID-19), Shanghai, China, January to February 2020.

We report three clusters related with potential pre-symptomatic transmission of coronavirus disease (COVID-19) between January and February 2020 in Shanghai, China. Investigators interviewed suspected COVID-19 cases to collect epidemiological information, including demographic characteristics, illness onset, hospital visits, close contacts, activities' trajectories between 14 days before illness onset and isolation, and exposure histories. Respiratory specimens of suspected cases were collected and tested for SARS-CoV-2 by real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) assay. The interval between the onset of illness in the primary case and the last contact of the secondary case with the primary case in our report was 1 to 7 days. In Cluster 1 (five cases), illness onset in the five secondary cases was 2 to 5 days after the last contact with the primary case. In Cluster 2 (five cases) and Cluster 3 (four cases), the illness onset in secondary cases occurred prior to or on the same day as the onset in the primary cases. The study provides empirical evidence for transmission of COVID-19 during the incubation period and indicates that pre-symptomatic person-to-person transmission can occur following sufficient exposure to confirmed COVID-19 cases. The potential pre-symptomatic person-to-person transmission puts forward higher requirements for prevention and control measures.

Nontyphoidal Salmonella Gastroenteritis in Baoshan, Shanghai, China, 2010 to 2014: An Etiological Surveillance and Case-Control Study.

Nontyphoidal Salmonella (NTS) gastroenteritis is a widespread global foodborne disease. To identify the epidemiologic characteristics, sources of food contamination, and risk factors of NTS gastroenteritis, epidemiologic data and stool specimens of diarrheal patients were collected from sentinel hospitals in Baoshan, Shanghai, People's Republic of China, between 2010 and 2014. Food products from nearby farmers' markets and animal feces from live poultry markets and livestock farms were sampled to identify the pathogen; a case-control study was conducted to characterize risk factors of NTS gastroenteritis. Of 3,906 diarrheal patients examined, 266 (6.8%) were positive for Salmonella. The positive rates were higher in summer than in the other seasons. Salmonella Typhimurium (36.1%) and Salmonella Enteritidis (30.8%) were the dominant serovars in the patients. Salmonella was detected in 26.2% pork samples, 7.1 to 7.8% poultry meats, and 3.3 to 8.9% poultry feces. Salmonella Typhimurium was the major serovar in contaminated food and animal feces. Multivariate conditional logistic regression analysis indicated that consumption of pork and quickly cooked eggs increased, whereas separating kitchen knives for cooked and raw food decreased the risk of NTS gastroenteritis, independently. We believe that NTS in poultry feces contaminated the meat products in the same markets and then infected humans if these foods were not sufficiently cooked. To prevent NTS gastroenteritis, it is necessary to survey Salmonella in meats and poultry feces, to cook eggs and pork sufficiently, to separate kitchen knives for cooked and raw food, and to prohibit live poultry trade in fresh meat markets.

Risk Factors for Influenza A(H7N9) Disease in China, a Matched Case Control Study, October 2014 to April 2015.

Background. Human infections with avian influenza A(H7N9) virus have been associated with exposure to poultry and live poultry markets (LPMs). We conducted a case-control study to identify additional and more specific risk factors. Methods. Cases were laboratory-confirmed A(H7N9) infections in persons in China reported from October 1, 2014 to April 30, 2015. Poultry workers, those with insufficient data, and those refusing participation were excluded. We matched up to 4 controls per case by sex, age, and residential community. Using conditional logistic regression, we examined associations between A(H7N9) infection and potential risk factors. Results. Eighty-five cases and 334 controls were enrolled with similar demographic characteristics. Increased risk of A(H7N9) infection was associated with the following: visiting LPMs (adjusted odds ratio [aOR], 6.3; 95% confidence interval [CI], 2.6-15.3), direct contact with live poultry in LPMs (aOR, 4.1; 95% CI, 1.1-15.6), stopping at a live poultry stall when visiting LPMs (aOR, 2.7; 95% CI, 1.1-6.9), raising backyard poultry at home (aOR, 7.7; 95% CI, 2.0-30.5), direct contact with backyard poultry (aOR, 4.9; 95% CI, 1.1-22.1), and having ≥1 chronic disease (aOR, 3.1; 95% CI, 1.5-6.5). Conclusions. Our study identified raising backyard poultry at home as a risk factor for illness with A(H7N9), suggesting the need for enhanced avian influenza surveillance in rural areas.

Economic burden and its associated factors of hospitalized patients infected with A (H7N9) virus: a retrospective study in Eastern China, 2013-2014.

BACKGROUND: H7N9 continues to cause human infections and remains a pandemic concern. Understanding the economic impacts of this novel disease is important for making decisions on health resource allocation, including infectious disease prevention and control investment. However, there are limited data on such impacts. METHODS: Hospitalized laboratory-confirmed H7N9 patients or their families in Jiangsu Province of China were interviewed. Patients' direct medical costs of hospitalization were derived from their hospital bills. A generalized linear model was employed to estimate the mean direct medical costs of patients with different characteristics. RESULTS: The mean direct cost of hospitalization for H7N9 was estimated to be ¥ 71 060 (95 % CI, 48 180-104 820), i.e., US$ 10 996 (95 % CI, 7 455-16 220), and was ¥12 060 (US$ 1 861), ¥136 120 (US$ 21 001) and ¥218 610 (US$ 33 728) for those who had mild or severe symptoms or who died, respectively. The principal components of the total fees differed among patients with different disease severity, although medication fees were always the largest contributors. Disease severity, proportion of reimbursement and family member monthly average income were identified as the key factors that contributed to a patient's direct medical cost of hospitalization. CONCLUSIONS: The direct medical costs of hospitalized patients with H7N9 are significant, and far surpass the annual per capita income of Jiangsu Province, China. The influencing factors identified should be taken into account when developing related health insurance policies and making health resource allocation. TRIAL REGISTRATION: Not applicable. This is a survey study with no health care intervention implemented on human participants.

[An outbreak of brucellosis in a village in Jiangsu province].

OBJECTIVE: To investigate the cause and related risk factors of an outbreak caused by Brucellosis. METHODS: Epidemiological investigation and laboratory test were carried out among occupationally invloved population including sheep slaughters and sellers in the village. RESULTS: 18 people were serology positive among the 129 occupationally involved persons under survey. Seven of them were confirmed cases, 11 were latent infection, to make the overall attack rate as 14%. 90% of the sheep were from high-risk areas of Brucella. Among the occupationally involved persons, 89% of them never wore face masks, 84% never wear overalls and 70% never wear gloves. Factors as:work but wearing no gloves (RR = 7.4, 95%CI:1.1-53.0), with hand wound (RR = 3.4, 95%CI:1.1-11.0) could increase the risk of Brucella infection. CONCLUSION: The cause of this outbreak was due to the plentiful influx of unchecked sheep from the northern part of China and the employees in the process of sheep slaughtering or trading were lack of effective prevention programs.

Comparison of extracts and toxicities of organic compounds in drinking water concentrated by single and composite XAD resins.

We compared extracts and toxicities of organic compounds (OCs) in drinking water concentrated by composite XAD-2/8 resin (mixed with an equal volume of XAD-2 and XAD-8 resins) with those extracted by single XAD-2 (non-polar) and XAD-8 (polar) resins. Drinking water was processed from raw water of the Han River and the Yangtze River in Wuhan section, China. The extraction efficiency of all resins was controlled at 30%. The types of extracted OCs were detected by gas chromatography-mass spectrometry, and the cytotoxicity and genotoxicity were assessed by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and comet assays, respectively, in human hepatoma HepG2 cells. Our results showed that XAD-2/8 extracted a larger variety of OCs, compared with XAD-8 and XAD-2. The cytotoxicity and genotoxicity of extracted OCs were in the order of XAD-8> XAD-2/8> XAD-2 at almost all tested concentrations after 24 h treatment (P < 0.05). Our findings suggest that single XAD resin selectively extracts either polar or non-polar OCs, which would lead to over- or under-estimation of the toxicity of drinking water. Nevertheless, composite resin extracts both polar and non-polar OCs, and could be utilized as a useful extraction technique to evaluate the level and toxicity of OCs in drinking water.