The Underlying Structure of Preventive Behaviors and Related Factors During the COVID-19 Pandemic: A Comprehensive Network Analysis.

BACKGROUND: Various strategies against COVID-19 have been adopted in different countries, with vaccination and mask-wearing being widely used as self-preventive interventions. However, the underlying structure of these behaviors and related factors remain unclear. PURPOSE: In this study, we aimed to explore the network structure of preventive behaviors during the COVID-19 pandemic and their underlying factors, incorporating age and sex in the network. METHODS: We used a multi-center sample of 20,863 adults who were vaccinated against COVID-19 in China between April 1, 2021, and June 1, 2021. Networks were estimated using unregularized partial correlation models. We also estimated the accuracy and stability of the network. RESULTS: The preventive behaviors related to network factors revealed that self-initiated vaccination was more connected with cognition factors, and mask-wearing was more connected with personal profiles. The two clusters were linked through information-seeking and political beliefs. Moreover, self-initiated vaccination was negatively connected with vaccine hesitancy and concerns about COVID-19 vaccines and positively connected with trust in the vaccines, pandemic-related altruism, political beliefs, and being married. Mask-wearing was negatively connected with being a professional/white collar worker and higher education level and positively connected with regular physical examination, self-rated health, migration, being married, and better family relationships. Incorporation of age and sex into the network revealed relevant associations between age and mask-wearing and age and self-initiated vaccination. The network was highly accurately estimated. The subset bootstrap showed that the order of node strength centrality, betweenness, and closeness were all stable. The correlation stability coefficient (CS-coefficient) also showed the stability of this estimate, with 0.75 for node strength, 0.75 for betweenness, and 0.67 for closeness. CONCLUSIONS: The internal structures of vaccination and mask-wearing behaviors were quite different, the latter of which were mainly affected by socioeconomic status and health-related behaviors and the former by knowledge about vaccines and political beliefs. Information-seeking and family relationships were the bridge factors connecting these two self-preventive behavior clusters, suggesting the direction of future efforts.

Does a GP service package matter in addressing the absence of health management by the occupational population? A modelling study.

OBJECTIVE: To assess the influence of supply and demand factors on the contract behavior of occupational populations with general practitioner (GP) teams. METHODS: We employed a system dynamics approach to assess and predict the effect of the general practitioner service package (GPSP) and complementary incentive policies on the contract rate for 2015-2030. First, the GPSP is designed to address the unique needs of occupational populations, enhancing the attractiveness of GP contracting services, including three personalized service contents tailored to demand-side considerations: work-related disease prevention (WDP), health education & counseling (HEC), and health-care service (HCS). Second, the complementary incentive policies on the supply-side included income incentives (II), job title promotion (JTP), and education & training (ET). Considering the team collaboration, the income distribution ratio (IDR) was also incorporated into supply-side factors. FINDINGS: The contract rate is predicted to increase to 57.8% by 2030 after the GPSP intervention, representing a 15.4% increase on the non-intervention scenario. WDP and HEC have a slightly higher (by 2%) impact on the contract rate than that from HCS. Regarding the supply-side policies, II have a more significant impact on the contract rate than JTP and ET by 3-5%. The maximum predicted contract rate of 75.2% is expected by 2030 when the IDR is 0.5, i.e., the GP receives 50% of the contract income and other members share 50%. CONCLUSION: The GP service package favorably increased the contract rate among occupational population, particularly after integrating the incentive policies. Specifically, for a given demand level, the targeted content of the package enhanced the attractiveness of contract services. On the supply side, the incentive policies boost GPs' motivation, and the income distribution motivated other team members.

A multiplex fluorescence-based loop-mediated isothermal amplification assay for identifying chicken parvovirus, chicken infectious anaemia virus, and fowl aviadenovirus serotype 4.

Chicken parvovirus (ChPV), chicken infectious anaemia virus (CIAV) and fowl adenovirus serotype 4 (FAdV-4) are avian viruses that have emerged in recent years and have endangered the global poultry industry, causing great economic loss. In this study, a multiplex fluorescence-based loop-mediated isothermal amplification (mLAMP) assay for detecting ChPV, CIAV and FAdV-4 was developed to simultaneously diagnose single and mixed infections in chickens. Three primer sets and composite probes were designed according to the conserved regions of the NS gene of ChPV, VP1 gene of CIAV and hexon gene of FAdV-4. Each composite probe was labelled with a different fluorophore, which was detached to release the fluorescence signal after amplification. The target viruses were distinguished based on the colour of the mLAMP products. The mLAMP assay was shown to be sensitive, with detection limits of 307 copies of recombinant plasmids containing the ChPV target genes, 749 copies of CIAV and 648 copies of FAdV-4. The assay exhibited good specificity and no cross-reactivity with other symptomatically related avian viruses. When used on field materials, the results of the mLAMP assay were in 100% agreement with those of the previously published PCR assay. The mLAMP assay is rapid, economical, sensitive and specific, and the results of amplification are directly observable by eye. Therefore, the mLAMP assay is a useful tool for the clinical detection of ChPV, CIAV and FAdV-4 and can be applied in rural areas.

Accelerate the process of getting vaccinated: factors associated with consideration of and accessibility to COVID-19 vaccination in metropolises of China.

BACKGROUND: Rapid mutation of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus is sweeping the world and delaying the full reopening of society. Acceleration of the vaccination process may be the key element in winning the race against this virus. We examine factors associated with personal considerations of and accessibility to the corona virus disease 2019 (COVID-19) vaccination in metropolises of China. METHODS: This multi-center, cross-sectional research was conducted using online questionnaires from April 1 to June 1, 2021, in community health service centers of Shanghai, Chengdu and Fuzhou. 9,047 vaccinated participants were included and data for 8,990 individuals were eligible for analysis. Chi-square test was conducted to find potential predictors, which were included in the logistic regressions. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the influence of region, socio-economic status (SES), and attitudes on vaccination process. RESULTS: In consideration phase, participants in Fuzhou (OR:2.26, 95%CI: 1.90 to 2.68) and Chengdu (OR: 2.48, 95%CI: 2.17 to 2.83) were more likely than those in Shanghai to consider longer than one month. These odds increased for participants with master or above degree (reference: illiteracy and primary school), higher monthly household income (reference: < ¥5000), and greater vaccination hesitancy (reference: low hesitancy). Unemployed and household-based participants (OR: 3.37, 95%CI: 1.69 to 6.75, reference: farmer) and participants without brand preference (OR:1.13, 95%CI:1.02 to 1.26) may take longer time of consideration. In the accessibility phase, participants in Fuzhou (OR: 8.82, 95%CI: 7.28 to 10.68) and Chengdu (OR: 2.28, 95%CI: 1.98 to 2.63) were more likely to wait longer than one week. These odds decreased for participants with master or above degree (reference: illiteracy and primary school), monthly household income from ¥5000 to ¥10,000 (reference: < ¥5000), and teacher or student (reference: farmer). Participants without brand preference (OR: 0.86, 95%CI: 0.77 to 0.95) were likely to wait shorter after appointment, while participants with higher risk awareness of domestic epidemic (medium, OR: 1.24, 95%CI: 1.12 to 1.37, reference: low) may wait longer. CONCLUSIONS: The influential factors changed over two phases of vaccination process. Regional disparity affected both consideration and accessibility phases. Expect that, SES, and hesitancy were major factors of the consideration phase, but had limited impact on accessibility phase.

Can family doctor contracted services facilitate orderly visits in the referral system? A frontier policy study from Shanghai, China.

BACKGROUND: China committed to establishing a family doctor (FD)-based referral system following the medical reform in 2009. This paper explored the effect of FD on establishing the anticipated system. METHODS: Two waves of survey were conducted in Shanghai, China. 2754 and 1995 individuals were sampled in 2013 and 2016 respectively. We compared orderly visiting behaviour between contracted and non-contracted residents. Logistic regression models were performed to further test the effect of FD on orderly visits. RESULTS: More contracted residents first-contacted community health service centres (CHSCs; 45.48%) than non-contracted residents (28.93%). Contracted residents were also more likely to refer to specialists via CHSCs than the non-contracted (9.84% vs. 2.60%). The odds ratio (OR) for first-contact at CHSCs by contract status was 1.569 in 2013, but increased to 1.675 in 2016. Being contracted with a FD was associated with referral behaviour, but the OR declined from 2.692 to 2.487 over years. CONCLUSION: The survey from Shanghai showed that FD had a significant effect on attracting first-contact at CHSCs and referral via CHSCs; however, the effect on the latter decreased. The effectiveness of the FD role on referral behaviour requires a well-established referral system, which has not yet been completely achieved in China.

Influencing mechanisms of lifestyle and dietary factors on chronic diseases among community residents: updated evidence in Shanghai, China.

OBJECTIVES: This study aimed to determine the risk factors for chronic diseases and to identify the potential influencing mechanisms from the perspectives of lifestyle and dietary factors. The findings could provide updated and innovative evidence for the prevention and control of chronic diseases. DESIGN: A cross-sectional study. SETTING: Shanghai, China. PARTICIPANTS: 1005 adults from Yangpu district of Shanghai participated in the study, and responded to questions on dietary habits, lifestyle and health status. RESULTS: Residents suffering from chronic diseases accounted for about 34·99 % of the respondents. Logistic regression analysis showed that age, diet quality, amount of exercise and tea drinking were related to chronic diseases. Age > 60 and overeating (Diet Balance Index total score > 0) had negative additive interaction on the occurrence of chronic disease, while overexercise (Physical Activity Index > 17·1) and tea drinking had negative multiplicative interaction and negative additive interaction on the occurrence of chronic disease. Diet quality, physical activity and tea drinking were incomplete mediators of the relationship between types of medical insurance residents participating in and chronic diseases. CONCLUSIONS: The residents in Yangpu District of Shanghai have a high prevalence of chronic diseases. Strengthening access of residents to health education and interventions to prevent chronic diseases and cultivating healthy eating and exercise habits of residents are crucial. The nutritional environment of the elderly population should be considered, and the reimbursement level of different types of medical insurance should be designed reasonably to improve the accessibility of medical and health services and reduce the risk of chronic diseases.

The developing family doctor system: evidence from the progress of the family doctor signing service from a longitudinal survey (2013-2016) in Pudong New Area, Shanghai.

BACKGROUND: The family doctor system is a vital part of China's national medical and health system reform. Evidence of the degree of implementation of the family doctor system is required to assist managers and policy makers in Pudong with resource allocation planning. This study analyzed changes in indicators (family doctor team construction, contracted medical services, health management services and so on) over time to evaluate the progress of the family doctor system in Pudong. METHODS: We used a cross-sectional design with an online questionnaire survey to collect 3-year (2013-2016) consecutive data. The online questionnaires were completed by the doctors responsible for information reporting in each community health service center of Pudong. The data were sorted, and the indices calculated and analyzed using descriptive statistics and statistical tests. RESULTS: The proportion of registered general practitioners increased each year, from 50.8% in 2013 to 66.5% in 2016; this difference was statistically significant (P = 0.000). The number of family doctors per 10,000 permanent residents rose each year, from 1.7 in 2013 to 2.1 in 2016. The rate of contracted household residents was 55.7% in 2013 and increased to 71.7% in 2016, with the difference being significant in different years (P = 0.012). Analysis of referral services showed the people times of contracted residents transferring to higher-level hospitals from family doctors increased each year, from 172,734 in 2013 to 341,615 in 2016; differences among different regions were statistically significant for 2013-2016. The rate of health screening for contracted residents also increased each year, with statistically significant differences in different years (P = 0.000). The rate of health assessment interventions for contracted residents rose each year, with statistically significant differences in different years (P = 0.003). CONCLUSIONS: The family doctor signing service in Pudong made headway in general practitioner availability, contract service rate of household residents, and providing health management services. However, problems included family doctor shortages and limited supporting policies, especially in rural and suburban areas compared with urban divisions. Increasing the enrollment rate of family doctors and speeding up the implementation of "contract service fees" are key tasks for the sustainable development of the family doctor system in Pudong.

Impact of air pollutants on pediatric admissions for Mycoplasma pneumonia: a cross-sectional study in Shanghai, China.

BACKGROUND: Children are especially vulnerable to pneumonia and the effects of air pollution. However, little is known about the impacts of air pollutants on pediatric admissions for Mycoplasma pneumonia. This study was conducted to investigate the impacts of air pollutants on pediatric hospital admissions for Mycoplasma pneumonia in Shanghai, China. METHODS: A cross-sectional design was applied to explore the association between pediatric hospital admissions and levels of air pollutants (fine particulate matter, particulate matter, ozone, sulfur dioxide, nitrogen dioxide, and carbon monoxide). Data on hospital admissions for pneumonia and levels of ambient air pollutants were obtained for the period of 2015 to 2018. Associations between pediatric admissions for Mycoplasma pneumonia and ambient air pollutants were calculated using logistic regression and described by the odds ratio and relevant 95% confidence interval. The hysteresis effects of air pollutants from the day of hospital admission to the previous 7 days were evaluated in single-pollutant models and multi-pollutant models with adjustments for weather variables and seasonality. Lag 0 was defined as the day of hospital admission, lag 1 was defined as the day before hospital admission, and so forth. RESULTS: In the single-pollutant models (without adjustment for other pollutants), pediatric hospital admissions for pneumonia were positively associated with elevated concentrations of nitrogen dioxide and fine particulate matter. A 0.5% increase in daily admissions per 10-µg/m3 increase in the nitrogen dioxide level occurred at lag 1 and lag 2, and a 0.3% increase in daily admissions per 10-µg/m3 increase in fine particulate matter occurred at lag 1. In the multi-pollutant models, nitrogen dioxide and fine particulate matter remained significant after inclusion of particulate matter, ozone, sulfur dioxide, and carbon monoxide. CONCLUSIONS: This study illustrated that higher levels of nitrogen dioxide and fine particulate matter increase the risk of pediatric hospitalization for Mycoplasma pneumonia in Shanghai, China. These findings imply that the high incidence of Mycoplasma pneumonia in children in Asia might be attributed to the high concentration of specific air pollutants in Asia.

The effect of family doctor policy practice on primary health-care workers' health in Hongkou District of Shanghai, China: varied by occupational divisions?

BACKGROUND: A key component of the 2009 medical reform in China was the change to family doctor (FD) policy practice. However, this led to an increased workload for primary health-care workers (PHCWs) at community health service centres. Their increasing workload may play a significant role in affecting PHCWs' health. METHODS: A questionnaire survey was conducted in Hongkou district of Shanghai amongst PHCWs including family doctors (FDs), family nurses (FNs), public health doctors (PHDs), and other PHCWs in early 2019. Ordered logistic regression models (Models 1 to 3) were performed to explore the differing health status amongst PHCWs, and their respective influential factors were also tested (Models 4 to 7). RESULTS: Five hundred sixty-two valid questionnaires were collected with a response rate of 96.4%. Other PHCWs' (OR = 2.03; 95% CI: 1.163-3.560) and FNs' (OR = 1.98; 95% CI: 1.136-3.452) self-rated health (SRH) were significantly better than that of FDs. In terms of FNs, the OR of SRH for those who strongly perceived the extra workload brought by FD-contracted services was only 12.0% (95% CI: 0.018-0.815) of that of the no-pressure group. Similarly, FNs with stronger work pressure had worse SRH, i.e., compared with "no" pressure, the SRH ORs for "neutral," "strong," and "very strong" evaluations of work pressure were 0.002 (95% CI: 0.000-0.055), 0.001 (95% CI: 0.000-0.033), and 0.000 (95% CI: 0.000-0.006), respectively. Information technology (IT) systems and performance incentives were suggested to improve SRH for FNs, while the former was found to be negatively correlated with other PHCWs. After one unit increase in the PHDs' team/department support, their OR was 10.7 times (95% CI: 1.700-67.352) higher. In addition, policy support had a negative effect on SRH for PHDs. The OR of "good" assessments of cultural environments was 25.98 times (95% CI: 1.391-485.186) higher than that of "very poor" for Other PHCWs. CONCLUSIONS: The influences of FD policy practice on FNs' SRH were the most significant amongst PHCWs, rather than FDs' as expected. The significant factors of SRH were varied over different occupational categories, that is team/department support and policy support (though negative) for PHDs, IT system and incentive for FNs, facility and equipment for FDs, and culture environment for other PHCWs respectively.

Examining health disparities and characteristics in general practice utilization: based on outpatient data from 2014 - 2018 in Shanghai.

BACKGROUND: Since 2000, China has been developing primary care institutions to serve as the gateway to the healthcare system. However, the investment of resources in primary care institutions is not based on the actual medical demands of the public. This study analysed primary care utilization to provide targeted guidance for the improvement of primary healthcare delivery in China. METHODS: We extracted outpatient visit data from all community healthcare centres in Shanghai from 2014 to 2018. Diseases were then classified according to ICD-10 codes. The disease spectrum (frequency, proportion, rank) was stratified by sex, age, and region. RESULTS: Most primary care outpatients were female (58.20%), 60-79 years old (57.91%), and in suburban regions (62.18%). Chronic diseases accounted for the majority (91.41%). Hypertension, chronic ischaemic heart disease, diabetes, and acute upper respiratory tract infections were the top four disorders for primary care visits regardless of sex. In the group aged 0-18 years, symptoms, signs and abnormal clinical and laboratory findings not elsewhere classified accounted for 37.96% of the top 20 reasons. Acute upper respiratory tract infections were the most common diseases in the groups aged 0-18 (11.20%) and 19-39 (11.14%) years. However, hypertension was the most common disease in the group aged > 39 years old (> 20%). There were more outpatients with respiratory and digestive diseases in suburban areas than in urban areas. In addition, problems associated with medical equipment and other healthcare deficiencies were relatively more common in suburban areas (suburban: 4.13%, rank 5; urban: 2.29%, rank 10). CONCLUSIONS: To meet the patients' needs and to develop the primary care system, the Shanghai government should focus on diseases with regionally high proportions. Disease diagnosis and treatment should be improved in the younger and suburban populations.

Altered gene expression profiles of the MDA5 signaling pathway in peripheral blood lymphocytes of chickens infected with avian reovirus.

Avian reovirus (ARV) is a member of the genus Orthoreovirus in the family Reoviridae and causes a severe syndrome including viral arthritis that leads to considerable losses in the poultry industry. Innate immunity plays a significant role in host defense against ARV. Here, we explored the interaction between ARV and the host innate immune system by measuring mRNA expression levels of several genes associated with the MDA5 signaling pathway. The results showed that expression peaks for MDA5, MAVS, TRAF3, TRAF6, IRF7, IKKɛ, TBK1 and NF-κB occurred at 3 days postinfection (dpi). Moreover, type I IFN (IFN-α, IFN-ß) and IL-12 expression levels peaked at 3 dpi, while type II IFN (IFN-γ), IL-6, IL-17 and IL-18 expression reached a maximum level at 1 dpi. IL-8 changed at 5 dpi, and IL-1ß and TNF-α changed at 7 dpi. Interestingly, several key IFN-stimulated genes (ISGs), including IFITM1, IFITM2, IFITM5, Mx1 and OASL, were simultaneously upregulated and reached maximum values at 3 dpi. These data indicate that the MDA5 signaling pathway and innate immune cytokines were induced after ARV infection, which would contribute to the ARV-host interaction, especially at the early infection stage.

A preliminary effect analysis of family doctor and medical insurance payment coordination reform in Changning District of Shanghai, China.

BACKGROUND: Changning District of Shanghai pioneered in implementing Family Doctor and Medical Insurance Payment Coordination Reform. The survey aimed to assess the effect of the reform to provide a decision-making basis for ensuring the "gatekeeper" role of the family doctor. METHODS: A cross-sectional survey was conducted using a self-designed questionnaire in Changning District of Shanghai during January and February in 2014. Multi-stage random cluster was applied and 3040 residents were selected. Comparisons were made with statistically test between the contracted and non-contracted residents in four policy targeted dimensions, doctor-visiting behavior, health management and status, medical cost control and satisfaction. RESULTS: Compared with the non-contracted residents, the contracted residents (72.9%) presented a higher prevalence rate of chronic diseases (32.6%), a higher proportion (51.9%) in first-contact in the community health service center and a higher proportion to refer to specialists as well (P < 0.001).The result showed that the average annual medical expense were significantly higher than non-contracted residents (P < 0.001), however, the difference disappeared after age, medical insurance and other socio-demographic variables were controlled. In terms of self-management of non-communicable diseases and complication prevention, the blood pressure control rate and blood glucose control rate for the contracted group were also higher than the counterparts, reaching up to 85.6 and 72.7% respectively. CONCLUSION: The preliminary analysis indicated that the contracted residents performed better in orderly doctor visiting behavior, health management behavior, health status and satisfaction. Follow up survey is necessary to further analyze the policy effect.

Fluctuating operation development index of community health service centres in the Pudong new area of Shanghai: A continuous investigation.

BACKGROUND: Previous performance evaluations among community health service centres (CHSCs) have been mainly based on absolute indicators, while the operation index, a more comprehensive evaluation method, has been rarely used in evaluation. This study aimed to develop a set of operation index suitable for the evaluation of CHSCs in Pudong. METHODS: The operation index system, developed based on a literature review, focus group, and factor analysis, was applied to all 45 CHSCs in Pudong. The data were mainly derived from the Pudong Health Statistics Information System from 2010 to 2014. The analysis included a descriptive analysis, t tests, variance analysis, and repeated measures analysis of variance. RESULTS: Different aspects of the operation index showed different developing trends during 2010 to 2014. The overall operation, service operation, management condition, and comprehensive satisfaction index were significantly different in different years (P < 0.05). However, the differences in the development foundation index were not obvious (P > 0.05). Moreover, the regional factor and medical association influenced the performance of service operation index, and the informatization level affected the performance of overall operation and management condition index (P < 0.05), with different family GP programmes level affecting management condition index (P < 0.05). CONCLUSION: Changes in the management condition index led to fluctuations in overall operation in the CHSCs. Since regional factors, family GP programmes, and medical associations promoted the operation of CHSCs, we advocate a multi-dimensional evaluation combining horizontal performance appraisal and vertical index evaluation to focus on these factors.

The effect of family doctor-contracted services on noncommunicable disease self-management in Shanghai, China.

BACKGROUND: Noncommunicable diseases (NCDs) are a major threat to population health worldwide. In Shanghai, China, a new pattern of NCD management-self-management-has been developed in community health service centres (CHSCs). OBJECTIVE: To clarify how contracting with CHSC-based family doctors (FDs) influences the engagement in and effectiveness of self-management behaviour among NCD patients. METHOD: We conducted two waves of a questionnaire survey (in 2013 and 2016) to collect data on patients with NCDs. Separate logistic regression models and longitudinal analysis were performed to examine the effect of contracting with an FD on NCD self-management and the effectiveness of this self-management. RESULTS: Nearly all contracted patients (80.79%) had implemented NCD self-management, while only 55.57% of non-contracted patients did so. The self-management effectiveness rate was also higher among contracted patients than among non-contracted ones (86.66% vs. 54.79%). In the population-averaged models, contracted patients had 2.25 and 2.91 times greater odds of implementing self-management and reporting that the self-management was effective, respectively, after controlling for all related variables. Additionally, awareness of FD-contracted services, satisfaction with CHSCs, and experiencing first contact at CHSCs had positive impacts on the implementation and effectiveness of self-management. CONCLUSIONS: FDs were important for ensuring that NCD patients engaged in self-management behaviour, the most common form of which was focus group. Participation in NCD focus groups may be key for attaining the effects of self-management, including improved health knowledge, greater health awareness, more frequent engagement in health behaviour, and, most importantly, greater practice of self-monitoring. Self-management might help to achieve greater NCD control.

Longitudinal Evaluation on the Operation Index Applied to Public Hospitals in Pudong New District of Shanghai, China.

The public hospital reform has lasted 5 years in China; however, the operation development status and trends of public hospitals have not been systematically evaluated in Pudong New District. We first applied the technology of longitudinal index to assess the development of public hospitals there. The quantitative data were mainly gathered by taking health statistics database from 2009 to 2014. The results showed that overall operating index presented a down-up trend, with the highest point in 2014 and the lowest point in 2012. Overall operating index, development foundation index, and management condition index were found to be statistically different ( P = .010, P = .016, P = .031) in different years, whereas the service operation index and financial risk index were not so ( P = .543, P = .228). Moreover, the results demonstrated that no obvious difference was observed in the overall operating index between the general and specialized hospitals ( P = .327), which was the same in the 4 first-class indexes. However, there were statistical differences in the overall operating index and development foundation index among these 5 years ( P = .018, P = .036), but none in the service operation index, management condition index, and financial risk index ( P = .503, P = .062, P = .177). No interaction effects were discovered between year and hospital categories in the current study ( P = .673, P = .375, P = .885, P = .152, P = .288).

An attempt to develop a detection method specific for virulent duck plague virus strains based on the UL2 gene B fragment.

A comparison of the unique long region 2 (UL2) gene sequences between 10 virulent and 11 attenuated duck plague virus (DPV) strains (including all DPV UL2 gene sequences registered in GenBank) showed that the UL2 genes in the attenuated DPV strains had a 528 bp deletion in the B fragment. Primers were designed based on the B fragment sequence of the UL2 gene in an attempt to establish a fluorescence quantitative polymerase chain reaction (PCR) and a conventional PCR detection method that could specifically detect virulent DPV strains (i.e. positive detection for virulent DPV strains and negative detection for attenuated DPV strains). Additionally, PCR products were cloned for sequence analysis. These two methods detected five attenuated DPV strains in addition to the virulent DPV strains. Sequence analysis of the PCR products showed that the amplified products were the B fragments of the UL2 gene. These results indicated that detection methods specific for virulent DPV strains could not be established using primers designed based on the UL2 gene B fragment.

Avian reovirus σA and σNS proteins activate the phosphatidylinositol 3-kinase-dependent Akt signalling pathway.

The present study was conducted to identify avian reovirus (ARV) proteins that can activate the phosphatidylinositol 3-kinase (PI3K)-dependent Akt pathway. Based on ARV protein amino acid sequence analysis, σA, σNS, µA, µB and µNS were identified as putative proteins capable of mediating PI3K/Akt pathway activation. The recombinant plasmids σA-pcAGEN, σNS-pcAGEN, µA-pcAGEN, µB-pcAGEN and µNS-pcAGEN were constructed and used to transfect Vero cells, and the expression levels of the corresponding genes were quantified by immunofluorescence and Western blot analysis. Phosphorylated Akt (P-Akt) levels in the transfected cells were measured by flow cytometry and Western blot analysis. The results showed that the σA, σNS, µA, µB and µNS genes were expressed in Vero cells. σA-expressing and σNS-expressing cells had higher P-Akt levels than negative control cells, pcAGEN-expressing cells and cells designed to express other proteins (i.e., µA, µB and µNS). Pre-treatment with the PI3K inhibitor LY294002 inhibited Akt phosphorylation in σA- and σNS-expressing cells. These results indicate that the σA and σNS proteins can activate the PI3K/Akt pathway.

Genetic and phylogenetic analysis of a novel parvovirus isolated from chickens in Guangxi, China.

A previously unidentified chicken parvovirus (ChPV) strain, associated with runting-stunting syndrome (RSS), is now endemic among chickens in China. To explore the genetic diversity of ChPV strains, we determined the first complete genome sequence of a novel ChPV isolate (GX-CH-PV-7) identified in chickens in Guang Xi, China, and showed moderate genome sequence similarity to reference strains. Analysis showed that the viral genome sequence is 86.4 %-93.9 % identical to those of other ChPVs. Genetic and phylogenetic analyses showed that this newly emergent GX-CH-PV-7 is closely related to Gallus gallus enteric parvovirus isolate ChPV 798 from the USA, indicating that they may share a common ancestor. The complete DNA sequence is 4612 bp long with an A+T content of 56.66 %. We determined the first complete genome sequence of a previously unidentified ChPV strain to elucidate its origin and evolutionary status.

GeXP analyzer-based multiplex reverse-transcription PCR assay for the simultaneous detection and differentiation of eleven duck viruses.

BACKGROUND: Duck viral pathogens primarily include the avian influenza virus (AIV) subtypes H5, H7, and H9; duck hepatitis virus (DHV); duck tembusu virus (DTMUV); egg drop syndrome virus (EDSV); duck enteritis virus (DEV); Newcastle disease virus (NDV); duck circovirus (DuCV); muscovy duck reovirus (MDRV); and muscovy duck parvovirus (MDPV). These pathogens cause great economic losses to China's duck breeding industry. RESULT: A rapid, specific, sensitive and high-throughput GeXP-based multiplex PCR assay consisting of chimeric primer-based PCR amplification with fluorescent labeling and capillary electrophoresis separation was developed and optimized to simultaneously detect these eleven viral pathogens. Single and mixed pathogen cDNA/DNA templates were used to evaluate the specificity of the GeXP-multiplex assay. Corresponding specific DNA products were amplified from each pathogen. Other pathogens, including duck Escherichia coli, duck Salmonella, duck Staphylococcus aureus, Pasteurella multocida, infectious bronchitis virus, and Mycoplasma gallisepticum, did not result in amplification products. The detection limit of GeXP was 10(3)copies when all twelve pre-mixed plasmids containing the target genes of eleven types of duck viruses were present. To further evaluate the reliability of GeXP, 150 clinical field samples were evaluated. Comparison with the results of conventional PCR methods for the field samples, the GeXP-multiplex PCR method was more sensitive and accurate. CONCLUSION: This GeXP-based multiplex PCR method can be utilized for the rapid differential diagnosis of clinical samples as an effective tool to prevent and control duck viruses with similar clinical symptoms.

A duplex real-time PCR assay for the detection and quantification of avian reovirus and Mycoplasma synoviae.

BACKGROUND: Infectious arthritis in broilers represents an economic and health problem, resulting in severe losses due to retarded growth and downgrading at the slaughterhouse. The most common agents associated with cases of infectious arthritis in poultry are avian reovirus (ARV) and Mycoplasma synoviae (MS). The accurate differentiation and rapid diagnosis of ARV and MS are essential prerequisites for the effective control and prevention of these avian pathogens in poultry flocks. This study thus aimed to develop and validate a duplex real-time PCR assay for the simultaneous detection and quantification of ARV and MS. METHODS: Specific primers and probes for each pathogen were designed to target the special sequence of the ARV σC gene or the MS phase-variable surface lipoprotein hemagglutinin (vlhA) gene. A duplex real-time PCR assay was developed, and the reaction conditions were optimized for the rapid detection and quantification of ARV and MS. RESULTS: The duplex real-time PCR assay was capable of ARV- and MS-specific detection without cross-reaction with other non-targeted avian pathogens. The sensitivity of this assay was 2 × 10(1) copies for a recombinant plasmid containing ARV σC or MS vlhA gene, and 100 times higher than that of conventional PCR. This newly developed PCR assay was also reproducible and stable. All tested field samples of ARV and/or MS were detectable with this duplex real-time PCR assay compared with pathogen isolation and identification as well as serological tests. CONCLUSION: This duplex real-time PCR assay is highly specific, sensitive and reproducible and thus could provide a rapid, specific and sensitive diagnostic tool for the simultaneous detection of ARV and MS in poultry flocks. The assay will be useful not only for clinical diagnostics and disease surveillance but also for the efficient control and prevention of ARV and MS infections.