[A cost-benefit analysis of the influenza H1N1 vaccination in the primary and junior school in Shanghai].

OBJECTIVE: To evaluate the cost-benefit for the Influenza Type A H1N1 Virus (Influenzae H1N1) vaccination in Shanghai primary and junior schools. METHODS: A semi-experiment study was selected to evaluate the cost-benefit for Influenza H1N1 vaccination in primary and junior schools in 6 districts of Shanghai, including 414 636 students in total. According to the voluntary principle, the students were divided into the vaccinated group (233 445 students) and control group (181 191 students). The information of vaccine cost was collected from CDC in 19 districts in Shanghai by questionnaire; and the information of medical treatment cost was collected from questionnaire and abstracts of retrospective medical records, which included 31 mild cases and 15 severe cases. The cost-benefit analysis was conducted by health economic evaluation. RESULTS: In total, there were 414 636 students enrolled in this study; while 233 445 (56.3%) students were in the vaccinated group and 181 191 in the control group. The attack rate in vaccinated group and control group was 0.61% (1433/233 445) and 1.76% (3166/181 191) respectively. The protection ratio was 65.34% ((1.76 - 0.61)/1.76) in the vaccinated group. The average cost of Influenza H1N1 was 36.81 yuan/person; and the average cost of medical treatment was (358.3 ± 243.6) yuan/mild case and (49 188.4 ± 99 917.3) yuan/severe case. The total benefit of vaccination in schools was 19 155 566.3 yuan, and the net benefit was 10 560 673.7 yuan. Therefore, the benefit-cost ratio was 2.24:1. CONCLUSION: Influenza H1N1 vaccine could protect the students from Influenza H1N1 infection, and the cost-benefit analysis showed that the intervention strategy was worth trying.

Prevalence of 16S rRNA Methylation Enzyme Gene armA in Salmonella From Outpatients and Food.

Salmonella is the primary cause of community-acquired foodborne infections, so its resistance to antimicrobials, such as aminoglycosides, is a public health issue. Of concern, aminoglycoside resistance in Salmonella is increasing rapidly. Here, we performed a retrospective study evaluating the prevalence of Salmonella harboring armA-mediated aminoglycoside resistance in community-acquired infections and in food or environmental sources. The prevalence rates of armA-harboring Salmonella strains were 1.1/1,000 (13/12,095) and 8.7/1,000 (32/3,687) in outpatient and food/environmental isolates, respectively. All the armA-harboring Salmonella strains were resistant to multiple drugs, including fluoroquinolone and/or extended-spectrum cephalosporins, and most (34/45) belonged to serovar Indiana. The armA gene of these strains were all carried on plasmids, which spanned five replicon types with IncHI2 being the dominant plasmid type. All the armA-carrying plasmids were transferable into Escherichia coli and Acinetobacter baumannii recipients. The conjugation experiment results revealed that the armA-harboring S. Indiana strains had a relatively higher ability to acquire armA-carrying plasmids. The low similarity of their pulsed field gel electrophoresis patterns indicates that the armA-harboring Salmonella strains were unlikely to have originated from a single epidemic clone, suggesting broad armA spread. Furthermore, the genetic backgrounds of armA-harboring Salmonella strains isolated from outpatients exhibited higher similarity to those isolated from poultry than to those isolated from swine, suggesting that poultry consumption maybe an infection source. These findings highlight an urgent need to monitor the prevalence and transmission of armA-harboring Salmonella, especially S. Indiana, to better understand the potential public health threat and prevent the further spread of these strains.

[Establishing and applying of autoregressive integrated moving average model to predict the incidence rate of dysentery in Shanghai].

OBJECTIVE: To explore the feasibility of establishing and applying of autoregressive integrated moving average (ARIMA) model to predict the incidence rate of dysentery in Shanghai, so as to provide the theoretical basis for prevention and control of dysentery. METHODS: ARIMA model was established based on the monthly incidence rate of dysentery of Shanghai from 1990 to 2007. The parameters of model were estimated through unconditional least squares method, the structure was determined according to criteria of residual un-correlation and conclusion, and the model goodness-of-fit was determined through Akaike information criterion (AIC) and Schwarz Bayesian criterion (SBC). The constructed optimal model was applied to predict the incidence rate of dysentery of Shanghai in 2008 and evaluate the validity of model through comparing the difference of predicted incidence rate and actual one. The incidence rate of dysentery in 2010 was predicted by ARIMA model based on the incidence rate from January 1990 to June 2009. RESULTS: The model ARIMA (1, 1, 1) (0, 1, 2)(12) had a good fitness to the incidence rate with both autoregressive coefficient (AR1 = 0.443) during the past time series, moving average coefficient (MA1 = 0.806) and seasonal moving average coefficient (SMA1 = 0.543, SMA2 = 0.321) being statistically significant (P < 0.01). AIC and SBC were 2.878 and 16.131 respectively and predicting error was white noise. The mathematic function was (1-0.443B) (1-B) (1-B(12))Z(t) = (1-0.806B) (1-0.543B(12)) (1-0.321B(2) x 12) micro(t). The predicted incidence rate in 2008 was consistent with the actual one, with the relative error of 6.78%. The predicted incidence rate of dysentery in 2010 based on the incidence rate from January 1990 to June 2009 would be 9.390 per 100 thousand. CONCLUSION: ARIMA model can be used to fit the changes of incidence rate of dysentery and to forecast the future incidence rate in Shanghai. It is a predicted model of high precision for short-time forecast.

Epidemiologic and genomic insights on mcr-1-harbouring Salmonella from diarrhoeal outpatients in Shanghai, China, 2006-2016.

BACKGROUND: Colistin resistance mediated by mcr-1-harbouring plasmids is an emerging threat in Enterobacteriaceae, like Salmonella. Based on its major contribution to the diarrhoea burden, the epidemic state and threat of mcr-1-harbouring Salmonella in community-acquired infections should be estimated. METHODS: This retrospective study analysed the mcr-1 gene incidence in Salmonella strains collected from a surveillance on diarrhoeal outpatients in Shanghai Municipality, China, 2006-2016. Molecular characteristics of the mcr-1-positive strains and their plasmids were determined by genome sequencing. The transfer abilities of these plasmids were measured with various conjugation strains, species, and serotypes. FINDINGS: Among the 12,053 Salmonella isolates, 37 mcr-1-harbouring strains, in which 35 were serovar Typhimurium, were detected first in 2012 and with increasing frequency after 2015. Most patients infected with mcr-1-harbouring strains were aged <5 years. All strains, including fluoroquinolone-resistant and/or extended-spectrum ß-lactamase-producing strains, were multi-drug resistant. S. Typhimurium had higher mcr-1 plasmid acquisition ability compared with other common serovars. Phylogeny based on the genomes combined with complete plasmid sequences revealed some clusters, suggesting the presence of mcr-1-harbouring Salmonella outbreaks in the community. Most mcr-1-positive strains were clustered together with the pork strains, strongly suggesting pork consumption as a main infection source. INTERPRETATION: The mcr-1-harbouring Salmonella prevalence in community-acquired diarrhoea displays a rapid increase trend, and the ESBL-mcr-1-harbouring Salmonella poses a threat for children. These findings highlight the necessary and significance of prohibiting colistin use in animals and continuous monitoring of mcr-1-harbouring Salmonella.

Estimation of the direct cost of treating people aged more than 60 years infected by influenza virus in Shanghai.

BACKGROUND: Influenza is a common, vaccine preventable, viral respiratory infection with potentially serious consequences in persons aged 60 years and above. In China, influenza vaccination is recommended but not reimbursed for people. Therefore, we studied management of influenza episode, healthcare resource use and costs associated with influenza infection in people aged over 60 in Shanghai. METHODS: A prospective, observational study was conducted over the 2008-2009 influenza season. Persons aged 60 years and above presenting to a study center with acute onset of influenza-like illness (ILI) were enrolled and tested by PCR for influenza virus. Laboratory confirmed influenza (LCI) patients were visited 2 weeks later for detail information. RESULTS: From January 2009 to December 2009, 1,946 subjects were recruited. Among them 1,777 patients met the inclusion criteria, 395 (22.2%) tested positive. 341 (86%) patients received ambulatory care only while 54 (14%) were hospitalized. Most patients had been prescribed at least one medication (94%), and had had at least one laboratory test (92%). An outpatient cost a mean of USD 47 per case. Once hospitalized, the average length of stay was 17.0 days (SD = 13.82) and the mean total inpatient cost reached USD 1,601. The public health insurance paid 69% and 79% of the mean outpatient and inpatient costs per patient respectively. CONCLUSION: This study described the management of a LCI case in people aged more than 60 years in Shanghai and estimated the economic burden in particular from the public healthcare system perspective, showing expensive consequences among hospitalized patients.

[Study on the epidemiological characteristics and molecular typing of Salmonella enterica subsp. enterica serovar Senftenberg in Shanghai].

OBJECTIVE: To study the molecular epidemiological characteristics of Salmonella enterica subsp. enterica serovar Senftenberg (Salmonella senftenberg) in Shanghai, from 2006 to 2007. METHODS: A retrospective analysis in 2006 and 2007 was performed to explore the source of food-borne Salmonella senftenberg. The isolates from diarrhea patients between 2006 and 2007 were identified, including biochemical test, hilA and invA gene phenotyping, drug susceptibility, Riboprinter((R)) (RP) and pulsed-field gel electrophoresis (PFGE). RESULTS: Of the diarrhea patients isolates in the monitoring program on non-typhi Salmonella infection in the year of 2006 in Shanghai, number of patients caused by Salmonella senftenberg ranked the third. The stock of Salmonella senftenberg food-born isolates were derived from swine and beef products between 2003 and 2005. All of the strains from diarrhea patients were susceptible to antibiotics except tetracylina (75.6%). With RP and PFGE molecular typing, the two groups (with hydrogen sulfide and hilA, invA gene or without) could be divided into two different independent clone cluster in genetics. 34 strains of diarrhea were divided into 16 PFGE typing-pattern, and among them 12 strains including type 4 (4 strains), type 5 (1 strains), type 6 (6 strains), type 7 (1 strains) and 13 strains including type 11 (3 strains), type 17 (5 strains), type 23 (5 strains) were two different dominant clone cluster. CONCLUSION: The epidemic of Salmonella senftenberg within 2006 might have been the result of a long period of case occurrence in Shanghai. This rare outbreak belonged to a cluster of outbreaks caused by two different PFGE clone clusters. Data suggested that the genetic clone of Salmonella senftenberg might have been unstable and the source of contamination were complicated, with the characteristics as the obvious decreasing number of patients, with no food-borne isolates in 2007.