Genetic and phenotypic analysis of 225 Chinese children with developmental delay and/or intellectual disability using whole-exome sequencing.

Developmental delay (DD), or intellectual disability (ID) is a very large group of early onset disorders that affects 1-2% of children worldwide, which have diverse genetic causes that should be identified. Genetic studies can elucidate the pathogenesis underlying DD/ID. In this study, whole-exome sequencing (WES) was performed on 225 Chinese DD/ID children (208 cases were sequenced as proband-parent trio) who were classified into seven phenotype subgroups. The phenotype and genomic data of patients with DD/ID were further retrospectively analyzed. There were 96/225 (42.67%; 95% confidence interval [CI] 36.15-49.18%) patients were found to have causative single nucleotide variants (SNVs) and small insertions/deletions (Indels) associated with DD/ID based on WES data. The diagnostic yields among the seven subgroups ranged from 31.25 to 71.43%. Three specific clinical features, hearing loss, visual loss, and facial dysmorphism, can significantly increase the diagnostic yield of WES in patients with DD/ID (P = 0.005, P = 0.005, and P = 0.039, respectively). Of note, hearing loss (odds ratio [OR] = 1.86%; 95% CI = 1.00-3.46, P = 0.046) or abnormal brainstem auditory evoked potential (BAEP) (OR = 1.91, 95% CI = 1.02-3.50, P = 0.042) was independently associated with causative genetic variants in DD/ID children. Our findings enrich the variation spectrums of SNVs/Indels associated with DD/ID, highlight the value genetic testing for DD/ID children, stress the importance of BAEP screen in DD/ID children, and help to facilitate early diagnose, clinical management and reproductive decisions, improve therapeutic response to medical treatment.

A Joint Extraction Model for Entity Relationships Based on Span and Cascaded Dual Decoding.

The entity-relationship joint extraction model plays a significant role in entity relationship extraction. The existing entity-relationship joint extraction model cannot effectively identify entity-relationship triples in overlapping relationships. This paper proposes a new joint entity-relationship extraction model based on the span and a cascaded dual decoding. The model includes a Bidirectional Encoder Representations from Transformers (BERT) encoding layer, a relational decoding layer, and an entity decoding layer. The model first converts the text input into the BERT pretrained language model into word vectors. Then, it divides the word vectors based on the span to form a span sequence and decodes the relationship between the span sequence to obtain the relationship type in the span sequence. Finally, the entity decoding layer fuses the span sequences and the relationship type obtained by relation decoding and uses a bi-directional long short-term memory (Bi-LSTM) neural network to obtain the head entity and tail entity in the span sequence. Using the combination of span division and cascaded double decoding, the overlapping relations existing in the text can be effectively identified. Experiments show that compared with other baseline models, the F1 value of the model is effectively improved on the NYT dataset and WebNLG dataset.

Nested Named Entity Recognition Based on Dual Stream Feature Complementation.

Named entity recognition is a basic task in natural language processing, and there is a large number of nested structures in named entities. Nested named entities become the basis for solving many tasks in NLP. A nested named entity recognition model based on dual-flow features complementary is proposed for obtaining efficient feature information after text coding. Firstly, sentences are embedded at both the word level and the character level of the words, then sentence context information is obtained separately via the neural network Bi-LSTM; Afterward, two vectors perform low-level feature complementary to reinforce low-level semantic information; Sentence-local information is captured with the multi-head attention mechanism, then the feature vector is sent to the high-level feature complementary module to obtain deep semantic information; Finally, the entity word recognition module and the fine-grained division module are entered to obtain the internal entity. The experimental results show that the model has a great improvement in feature extraction compared to the classical model.

Distributed Reliable and Efficient Transmission Task Assignment for WSNs.

Task assignment is a crucial problem in wireless sensor networks (WSNs) that may affect the completion quality of sensing tasks. From the perspective of global optimization, a transmission-oriented reliable and energy-efficient task allocation (TRETA) is proposed, which is based on a comprehensive multi-level view of the network and an evaluation model for transmission in WSNs. To deliver better fault tolerance, TRETA dynamically adjusts in event-driven mode. Aiming to solve the reliable and efficient distributed task allocation problem in WSNs, two distributed task assignments for WSNs based on TRETA are proposed. In the former, the sink assigns reliability to all cluster heads according to the reliability requirements, so the cluster head performs local task allocation according to the assigned phase target reliability constraints. Simulation results show the reduction of the communication cost and latency of task allocation compared to centralized task assignments. Like the latter, the global view is obtained by fetching local views from multiple sink nodes, as well as multiple sinks having a consistent comprehensive view for global optimization. The way to respond to local task allocation requirements without the need to communicate with remote nodes overcomes the disadvantages of centralized task allocation in large-scale sensor networks with significant communication overheads and considerable delay, and has better scalability.

[The analyses of HIV-1 quasispecies in HIV-infected subjects by the application of single genome amplification assay].

OBJECTIVE: To establish the single genome amplification (SGA) method and analyze the quasispecies in HIV-infected patients. METHODS: All 6 sample RNA acquired in 2010 in Shenzhen and genetic sequenced as overlap peaks were extracted and diluted to a single copy, nest-PCR after one step RT-PCR was employed to amplify HIV-1 genome, and then PCR products was purified and sequenced. Mega 4.02 software was used to analyze the genetic distance among HIV-1 quasispecies, and phylogenetic tree was constructed. RESULTS: Our data showed that viral sequences derived from different patients were grouped into different clusters. Subcluster was also observed in several clusters, indicating these existed competition and preferential replication of certain viral strains. The genetic distance within one cluster of 6 samples were between 0.008 and 0.06, it was likely to associate with the duration since infection and viral load. CONCLUSION: SGA is a useful approach to gain information on quasispecies, the genetic distance within one cluster may help to determine the infection time and immune escaping. The analysis of related affecting factors need more samples.

Epidemiological dynamics and phylogeography of influenza virus in southern China.

BACKGROUND: Understanding the epidemiological dynamics of influenza virus is central to surveillance and vaccine strain selection. It has been suggested that tropical and subtropical regions represent the global source of influenza epidemics. However, our understanding of the epidemiological dynamics of influenza virus in these regions is limited by a relative lack of long-term data. METHODS: We analyzed epidemiological and virological data on influenza recorded over a period of 15 years from the metropolitan city of Shenzhen in subtropical southern China. We used wavelet analysis to determine the periodicity of influenza epidemics and molecular phylogeographic analysis to investigate the role of Shenzhen and southern China in the global evolution of influenza virus. RESULTS: We show that southern China is unlikely to represent an epicenter of global influenza activity, because activity in Shenzhen is characterized by significant annual cycles, multiple viral introductions every year, limited persistence across epidemic seasons, and viruses that generally are not positioned on the trunk of the global influenza virus phylogeny. CONCLUSIONS: We propose that novel influenza viruses emerge and evolve in multiple geographic localities and that the global evolution of influenza virus is complex and does not simply originate from a southern Chinese epicenter.

A structured sentiment analysis dataset based on public comments from various domains.

A structured sentiment analysis dataset, derived from social media comments, is introduced in this paper. The dataset spans 22 diverse domains and comprises over 200,000 reviews, providing a rich resource for sentiment analysis tasks in the Chinese language context. Each comment within the dataset has been manually annotated with a sentiment label, either positive, negative, or neutral, and grouped by topic. This meticulous annotation process ensures the dataset's reliability for training, validating, and testing sentiment analysis models. The construction of the dataset involved a three-step process. Initially, data was collected from the topics that garnered high attention and discussion rates, thereby reflecting the authentic opinions of users. Following data collection, preprocessing was undertaken to remove extraneous elements, while preserving emoticons that are crucial for sentiment analysis. The final step involved manual annotation by researchers, who assigned sentiment labels to each comment based on various factors. The dataset stands as a valuable contribution to the field of natural language processing, particularly for sentiment analysis tasks in the Chinese language context.

Direct economic burden of hepatitis B virus related diseases: evidence from Shandong, China.

BACKGROUND: Although the expenses of liver cirrhosis are covered by a critical illness fund under the current health insurance program in China, the economic burden associated with hepatitis B virus (HBV) related diseases is not well addressed. In order to provide evidence to address the economic disease burden of HBV, we conducted a survey to investigate the direct economic burden of acute and chronic hepatitis B, cirrhosis and liver cancer caused by HBV-related disease. METHODS: From April 2010 to November 2010, we conducted a survey of inpatients with HBV-related diseases and who were hospitalized for seven or more days in one of the seven tertiary and six secondary hospitals in Shandong, China. Patients were recorded consecutively within a three-to-five month time period from each sampled hospital; an in-person survey was conducted to collect demographic and socio-economic information, as well as direct medical and nonmedical expenses during the last month and last year prior to the current hospitalization. Direct medical costs included total outpatient, inpatient, and self-treatment expenditures; direct nonmedical costs included spending on nutritional supplements, transportation, and nursing. Direct medical costs during the current hospitalization were also obtained from the hospital financial database. The direct economic cost was calculated as the sum of direct medical and nonmedical costs. Our results call for the importance of implementing clinical guideline, improving system accountability, and helping secondary and smaller hospitals to improve efficiency. This has important policy implication for the on-going hospital reform in China. RESULTS: Our data based on inpatients with HBV-related diseases suggested that the direct cost in US dollars for acute hepatitis B, severe hepatitis B, chronic hepatitis B, compensated cirrhosis, decompensated cirrhosis and primary liver cancer was $2954, $10834, $4552, $7400.28, $6936 and $10635, respectively. These costs ranged from 30.72% (for acute hepatitis B) to 297.85% (for primary liver cancer) of the average annual household income in our sample. Even for patients with health insurance, direct out-of-pocket cost of all HBV-related diseases except acute hepatitis B exceeded 40.00% of the patient's disposable household income, making it a catastrophic expenditure for the household. CONCLUSION: Hepatitis B imposes considerable economic burden on a family. Our findings will help health policy makers' understanding of the magnitude of the economic burden of HBV-related diseases in China. Evidence from our study also contributes to our understanding of potential benefits to society from allocating more resources to preventing and treating HBV infection, as well as increasing insurance coverage in China. These findings have important policy implications for health care reform efforts currently underway in China focusing on how to reduce the burden of catastrophic disease for its citizens.

Real-world 10-year retrospective study of the guidelines for diagnosis and treatment of primary liver cancer in China.

BACKGROUND: Hepatocellular carcinoma (HCC) is a common malignant tumor worldwide. Many regions across the world have issued various HCC diagnosis and treatment protocols to improve the diagnosis and targeted treatment of patients with HCC. However, real-world studies analysing the practice, application value, and existing problems of the China Liver Cancer (CNLC) staging system are scarce. AIM: To analyze the current situation and problems associated with the Guidelines for Diagnosis and Treatment of Primary Liver Cancer in China. METHODS: We collected the medical records of all patients with HCC admitted to the First Affiliated Hospital of Zhengzhou University from January 1, 2011 to December 31, 2019, and recorded the hospitalization information of those patients until December 31, 2020. All information on the diagnosis and treatment of the target patients was recorded, and their demographic and sociological characteristics, CNLC stages, screening situations, and treatment methods and effects were analyzed. The survival status of the patients was obtained from follow-up data. RESULTS: This study included the medical records of 3022 patients with HCC. Among these cases, 304 patients were screened before HCC diagnosis; their early-stage diagnosis rate was 69.08%, which was significantly higher than that of patients with HCC who were diagnosed without screening and early detection (33.74%). Herein, patients with no clinical outcome at discharge were followed up, and the survival information of 1128 patients was obtained. A Cox model was used to analyse independent risk factors affecting overall survival, which were revealed as age > 50 years, no screening, alpha-fetoprotein > 400 ng/mL, Child-Pugh grade B, and middle and late CNLC stages. Based on the Cox model survival analysis, in our study, patients with HCC identified via screening had significant advantages in overall and tumor-free survival after hepatectomy. CONCLUSION: Early diagnosis and treatment can be achieved by screening groups at high risk for HCC based on the guidelines; however, real-world compliance is poor.

Assessing health-related quality of life and health utilities in patients with chronic hepatitis B-related diseases in China: a cross-sectional study.

OBJECTIVES: The health-related quality of life (HRQoL) and utilities of patients with chronic hepatitis B (CHB) virus infection, including compensated cirrhosis (CC), decompensated cirrhosis (DC) and different stages of hepatocellular carcinoma (HCC), have not been well described in China. This study aimed to evaluate HRQoL and utilities and provide parameters for the economic evaluation of CHB-related diseases. METHODS: We conducted a multicentre cross-sectional and study to measure the HRQoL of patients with CHB, CC, DC and HCC using the Chinese short form (SF) 36 health survey V.2. The utilities were extracted based on the SF-six dimension scoring model. Multivariable regression analyses identified the effects on HRQoL. RESULTS: A total of 1071 patients (639 with CHB, 125 with CC, 85 with DC and 222 with HCC) were invited to complete the questionnaire. Physical HRQoL was not impaired in the CHB stage, while mental HRQoL was significantly impaired. Physical composite summary scores have a more significant decrease than mental composite summary scores at the advanced stages (CC, DC and HCC). The utility scores of CHB only, CC, DC and HCC were 0.773, 0.750, 0.683 and 0.640, respectively. The utility scores in the early, middle and terminal stages of HCC were 0.656, 0.635 and 0.615, respectively. CONCLUSION: Slowing the progress of CHB-related diseases and providing psychological support early are the key points to improving the quality of life with the diseases. The utility values estimated in this study can provide a vital instrument for cost-effectiveness studies on CHB-related diseases.

Knowledge, attitudes and practices (KAP) relating to avian influenza in urban and rural areas of China.

BACKGROUND: Studies have revealed that visiting poultry markets and direct contact with sick or dead poultry are significant risk factors for H5N1 infection, the practices of which could possibly be influenced by people's knowledge, attitudes and practices (KAPs) associated with avian influenza (AI). To determine the KAPs associated with AI among the Chinese general population, a cross-sectional survey was conducted in China. METHODS: We used standardized, structured questionnaires distributed in both an urban area (Shenzhen, Guangdong Province; n = 1,826) and a rural area (Xiuning, Anhui Province; n = 2,572) using the probability proportional to size (PPS) sampling technique. RESULTS: Approximately three-quarters of participants in both groups requested more information about AI. The preferred source of information for both groups was television. Almost three-quarters of all participants were aware of AI as an infectious disease; the urban group was more aware that it could be transmitted through poultry, that it could be prevented, and was more familiar with the relationship between AI and human infection. The villagers in Xiuning were more concerned than Shenzhen residents about human AI viral infection. Regarding preventative measures, a higher percentage of the urban group used soap for hand washing whereas the rural group preferred water only. Almost half of the participants in both groups had continued to eat poultry after being informed about the disease. CONCLUSIONS: Our study shows a high degree of awareness of human AI in both urban and rural populations, and could provide scientific support to assist the Chinese government in developing strategies and health-education campaigns to prevent AI infection among the general population.

Incidence of novel coronavirus (2019-nCoV) infection among people under home quarantine in Shenzhen, China.

BACKGROUND: Since the outbreak of 2019-nCoV in December, Chinese government has implemented various measures including travel bans, centralized treatments, and home quarantines to slowing the transmission across the country. In this study, we aimed to estimate the incidence of 2019-nCoV infection among people under home quarantine in Shenzhen, China. METHODS: We used a stratified multistage random sampling method to recruit participants and collected demographic information and laboratory results of people under home quarantine. We conducted descriptive analysis to estimate the basic characteristics and to calculate the incidence in out study population. RESULTS: A total of 2004 people under home quarantine participated in this study, of which 1637 participants finished the questionnaire with a response rate of 81.7%. Mean age of the participants was 33.7 years, ranging from 0.3 to 80.2 years. Of people who provided clear travel history, 129 people have traveled to Wuhan city and 1,046 people have traveled to other cities in Hubei province within 14 days before the home quarantine. Few (less than 1%) participants reported contact history with confirmed or suspected cases during their trip and most of these arrived at Shenzhen between Jan 24, 2020 to Jan 27, 2020. The incidence of COVID-19 in the sample was 1.5‰ (95% CI: 0.31‰-4.37‰). CONCLUSION: Home quarantine has been effective in preventing the early transmission of COVID-19, but that more needs to be done to improve early detection of COVID-19 infection.

[Epidemiological and molecular characterization of seasonal influenza A/H3N2 viruses circulating in Shenzhen, 2005 - 2007].

OBJECTIVE: To determine the epidemiological characteristics of seasonal influenza in Shenzhen from 2005 to 2007 and the molecular variation of HA1 domain of influenza H3N2 viruses. METHODS: The consultation rate for influenza-like illness (ILI) were calculated weekly for indicating the influenza activities (the Shenzhen Influenza Surveillance System mainly consisted of 16 institutions with 9 hospitals, 6 districts and one municipal centers of disease control and prevention). Pharyngeal swabs from the cases of ILI, which were collected during 2005 to 2007 from the city-wide and quality-controlled surveillance network, were used to propagate the viruses. The HA1 region of the influenza A/H3N2 viruses were detected by RT-PCR and sequenced subsequently. The analyses of pairwise amino acid variations, genetic clustering and phylogenetics was performed. RESULTS: The activity levels of influenza showed certain changes during each year from 2005 to 2007, and there were summer peaks from May to July in 2006 and 2007. The positive rates of influenza virus were 4.78% (114/2385), 5.77% (212/3674) and 12.12% (343/2831) from 2005 to 2007 respectively. The weekly isolating rates changed accordingly with the trend of the percentages of ILI. The proportions of influenza H3N2 virus were 25.46% (28/114) and 2.83% (6/212) in 2005 and in 2006 respectively, but the proportion increased to 62.68% (215/343), which indicated that H3N2 virus became the predominant strain in 2007. Phylogenetic clustering analysis of influenza H3N2 virus revealed that there were 5 clades. The viruses which were isolated in 2005 contained in the clade I and II, the viruses in 2006 were comprised in clade III, and clade IV and V included the viruses isolated in 2007. Although the stem of cladogram developed with one accord of the time isolated viruses, the viruses which were similar to vaccine strains had circulated in Shenzhen before a given strain was determined as vaccine strain by WHO. It was also noticed that more amino acid changes at antigenic sites, especially at sites A and B in the H3N2 viruses, were found in 2007 than that in 2005 and in 2006. But the sequences at the receptor-binding sites and disulphide bond sites were conserved and no new circulating strain for genetic reassortment had been found in the period. CONCLUSION: Shenzhen might be one of areas where the ongoing genetic drift of influenza H3N2 viruses appeared earlier in China. The changes of influenza H3N2 virus showed the active status in the population. The results suggested that monitoring seasonal influenza viruses by sequence analysis could provide important and timely information on the appearance of strains with epidemiologic significance.

[Analysis of pulsed-field gel electrophoresis molecular subtyping of Shigella strains in Shenzhen].

OBJECTIVE: To analyze the genetic relations of Shigella isolated from Shenzhen in 2001-2006 and develop primary molecular subtyping surveillance network of Shigella. METHODS: Chromosomal DNAs from 55 isolated in agarose were digested with the restriction enzyme Xba I, and then were analyzed by pulsed-field gel electrophoresis. Pulsed-field gel electrophoresis (PFGE) patterns were clustered using BioNumerics software. RESULTS: All 41 distinctive PFGE patterns were identified among 55 strains. 32 strains belonged to one cluster. Differences were observed in other strains. CONCLUSION: Both genetic-related clones and non-related clones of Shigella existed in Shenzhen. The development of PFGE molecular subtyping surveillance network would contribute to the active surveillance, outbreak investigation and source tracking for Shigellosis.

[Study on the molecular characteristic of natural infection of rodents with Hantaviruses in Shenzhen city].

OBJECTIVE: In order to investigate Hantavirus (HV) infection of captured rodents and to understand the genotypes and the molecular characteristic of Hantaviruses in Shenzhen. METHODS: The captured rodents were classified and the density of distribution was calculated. A total of 472 animals were captured, among which Rattus norvegicus was the dominant group. The total viral RNA was extracted from the lung tissues positive with HV antigens by immunofluorescent assay and gene sequence of M fragment was amplified with RT-nested-PCR by using the Hantavirus genotype specific primers. The amplified genes were then sequenced, and subjected to genotyping and homology analysis. RESULTS: The results of genotype analysis showed that the Hantaviruses taken from twenty-one lung specimens in Rattus norvegicus in Shenzhen city belonged to the Hantavirus type II (SEOV). Results in homology analysis suggested that the homology among twenty-one samples should be rather high with 95.4% of nucleotide sequence identity and they belonged to the same subtype. Phylogenetic tree analysis showed that they were branched into at least six different lineages, and were highly homologized with SZ2083. We also found that these virus strains had not shown more highly homology of nucleotide sequence in nearest district, whereas revealed consistency in farther district. CONCLUSION: The major hosts of Hantaviruses in Shenzhen city were Rattus norvegicus and the epidemic strains were genotyped as SEO-type. Nucleotide sequence and deduced amino acid sequence from different rodents were highly homologous, while nucleotide mutation had also been observed. Further studies are required to explore the possible viruses' sequence mutation.

Effect of monospecific and mixed sea-buckthorn (Hippophae rhamnoides) plantations on the structure and activity of soil microbial communities.

This study aims to evaluate the effect of different afforestation models on soil microbial composition in the Loess Plateau in China. In particular, we determined soil physicochemical properties, enzyme activities, and microbial community structures in the top 0 cm to 10 cm soil underneath a pure Hippophae rhamnoides (SS) stand and three mixed stands, namely, H. rhamnoides and Robinia pseucdoacacia (SC), H. rhamnoides and Pinus tabulaeformis (SY), and H. rhamnoides and Platycladus orientalis (SB). Results showed that total organic carbon (TOC), total nitrogen, and ammonium (NH4(+)) contents were higher in SY and SB than in SS. The total microbial biomass, bacterial biomass, and Gram+ biomass of the three mixed stands were significantly higher than those of the pure stand. However, no significant difference was found in fungal biomass. Correlation analysis suggested that soil microbial communities are significantly and positively correlated with some chemical parameters of soil, such as TOC, total phosphorus, total potassium, available phosphorus, NH4(+) content, nitrate content (NH3(-)), and the enzyme activities of urease, peroxidase, and phosphatase. Principal component analysis showed that the microbial community structures of SB and SS could clearly be discriminated from each other and from the others, whereas SY and SC were similar. In conclusion, tree species indirectly but significantly affect soil microbial communities and enzyme activities through soil physicochemical properties. In addition, mixing P. tabulaeformis or P. orientalis in H. rhamnoides plantations is a suitable afforestation model in the Loess Plateau, because of significant positive effects on soil nutrient conditions, microbial community, and enzyme activities over pure plantations.

[Effect of afforestation modes on soil microbial community and nitrogen functional genes in Hippophae rhamnoides plantation].

The study aimed to assess the effect of different afforestation modes on microbial composition and nitrogen functional genes in soil. Soil samples from a pure Hippophae rhamnoides stand (SS) and three mixed stands, namely, H. rhamnoides and Pinus tabuliformis (SY), H. rhamnoides and Platycladus orientalis (SB), H. rhamnoides and Robinia pseucdoacacia (SC) were selected. The results showed that the total PLFA (TPLFA), bacterial PLFA, gram positive bacterial PLFA (G⁺PLFA) were significantly higher in soil samples from other three stands than those of the pure one. However, no significant difference was found for fungal PLFA among them. The abundance of nifH, amoA, nirK and narG genes were higher in SY and SC than in SS. The TPLFA, G⁺PLFA, gram negative bacterial PLFA (G⁻PLFA), and all of the detected gene abundance were significantly and positively correlated with soil pH, total organic carbon, total nitrogen, ammonium nitrogen and available potassium. Afforestation modes affected indirectly soil microbial composition and functional genes through soil properties. Mixing P. tabuliformis or P. orientalis with H. rhamnoides might be suitable afforestation modes, which might improve soil quality.

Epidemiological investigation of a norovirus GII.4 Sydney outbreak in a China elder care facility.

An outbreak of norovirus GII.4/Sydney_2012 affected a China elder care facility in December 2012. A total of 39 elderly people and staff met the outbreak case definition. The attack rates in the elderly and the staff were 15.9% (31/195) and 23.2% (19/82), respectively, including 13 asymptomatic cases in the staff. The result of gene sequencing revealed that the outbreak was caused by norovirus GII.4 Sydney. The mode of transmission of this outbreak was proven to be person-to-person. The first case (a self-cared elder) was affected outside the elder care facility and was not isolated after returning. Norovirus was transmitted via close contact among the self-cared elderly. Then, through service-related close contact, the attendants promoted the cross-transmission between the self-cared elderly and the nursed elderly. The virus was also spread among the staff via daily contact. In the elder care facility, the asymptomatic cases in the attendants played an important role in the transmission of norovirus, which deserves high attention.

Rural villagers and urban residents exposure to poultry in China.

Patterns of poultry exposure in rural and urban areas in China have not been systematically evaluated and compared. The objective of our study is to investigate patterns in human exposure to poultry in rural and urban China. We conducted a two-stage household-based clustered survey on population exposure to live/sick/dead poultry in Xiuning and Shenzhen. Half of the rural households (51%) in Xiuning raised poultry, mostly (78%) free-range. Around half of those households (40%) allowed poultry to stay in their living areas. One quarter of villagers reported having contact with sick or dead poultry. In Shenzhen, 37% urban residents visited live poultry markets. Among these, 40% purchased live poultry and 16% touched the poultry or cages during purchase. Our findings indicated that human exposure to poultry was different in rural and urban areas in China. This discrepancy could contribute to the observed differences in epidemiologic characteristics between urban and rural cases of influenza A(H7N9) and A(H5N1) virus infection.

[Decision tree and cost-benefit analysis on strategies related to preventing maternal-infantile transmission of hepatitis B virus infection].

OBJECTIVE: To synthesize relevant data and to analyze the benefit-cost ratio on strategies related to preventing the maternal-infantile transmission of hepatitis B virus infection and to explore the optimal strategy. METHODS: A decision tree model was constructed according to the strategies of hepatitis B immunization and a Markov model was conducted to simulate the complex disease progress after HBV infection. Parameters in the models were drawn from meta-analysis and information was collected from field study and review of literature. Economic evaluation was performed to calculate costs, benefit, and the benefit-cost ratio. Sensitivity analysis was also conducted and a tornado graph was drawn. RESULTS: In view of the current six possible strategies in preventing maternal-infantile transmission of hepatitis B virus infection, a multi-stage decision tree model was constructed to screen hepatitis B surface antigen (HBsAg) or screen for HBsAg then hepatitis B e antigen (HBeAg). Dose and the number of injections of HBIG and hepatitis B vaccine were taken into consideration in the model. All the strategies were considered to be cost-saving, while the strategy of screening for HBsAg and then offering hepatitis B vaccine of 10 µg×3 for all neonates with hepatitis B immunoglobulin (HBIG) of 100 IU×1 for the neonates born to mothers who tested positive for HBsAg appeared with most cost-saving. In the strategies, the benefit-cost ratio of using 100 IU HBIG was similar to 200 IU HBIG, and one shot of HBIG was superior to two shots. RESULTS: from sensitivity analysis suggested that the rates of immunization and the efficacy of the strategy in preventing maternal-infantile transmission were the main sensitive variables in the model. CONCLUSION: The passive-active immune-prophylaxis strategy that using 10 µg hepatitis B vaccine combined with 100 IU HBIG seemed to be the optimal strategy in preventing maternal-infantile transmission, while the rates of immunization and the efficacy of the strategy played the key roles in choosing the ideal strategy.