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Domestic and foreign literatures related to the persistence of SARS-CoV-2 and the re-positive cases infected with SARS-CoV-2 were reviewed, and the characteristics and infectivity of the re-positive cases were analyzed to provide scientific evidence for the improvement of case management and the development of measures to stop the spread of SARS-CoV-2. Existing studies have shown that re-positive rate of SARS-CoV-2 ranged from 2.4% to 19.8%, the median of interval between re-positive detection and discharge was 4-15 days. Following the second course of the disease, the anti-SARS-CoV-2 IgM, IgG and IgA positive rates of the cases were 11.11%-86.08%, 52.00%-100.00% and 61.54%-100.00% respectively, the total antibody and neutralizing antibody positive rates were 98.72% and 88.46%. The viral load of the re-positive cases was lower than that in the initial infection. At least 3 380 re-positive cases have been reported globally. SARS-CoV-2 strains were isolated from the samples of 3 re-positive cases (1 immunodeficiency case and 2 cases with abnormal pulmonary imaging). There were close contacts that were infected by an asymptomatic case taking immunosuppressive agents. In conclusion, the infectivity of re-positive cases infected with SARS-CoV-2 is generally very low. Rare re-positive cases infected with SARS-CoV-2 might cause further transmission. The management approach for the re-positive cases can be based on the assessment of the individual transmission risk according to the pathogen detection results.
Subject(s)
Humans , Antibodies, Neutralizing , Antibodies, Viral , COVID-19 , Immunoglobulin M , SARS-CoV-2ABSTRACT
@#In December 2019, novel coronavirus pneumonia epidemic occurred in Wuhan, Hubei Province, and spread rapidly across the country. In the early stages of the epidemic, China adopted the containment strategy and implemented a series of core measures around this strategic point, including social mobilization, strengthening case isolation and close contacts tracking management, blocking epidemic areas and traffic control to reduce personnel movements and increase social distance, environmental measures and personal protection, with a view to controlling the epidemic as soon as possible in limited areas such as Wuhan. This article summarizes the background, key points and core measures in the country and provinces. It sent prospects for future prevention and control strategies.
ABSTRACT
In December 2019, novel coronavirus pneumonia epidemic occurred in Wuhan, Hubei Province, and spread rapidly across the country. In the early stages of the epidemic, China adopted the containment strategy and implemented a series of core measures around this strategic point, including social mobilization, strengthening case isolation and close contacts tracking management, blocking epidemic areas and traffic control to reduce personnel movements and increase social distance, environmental measures and personal protection, with a view to controlling the epidemic as soon as possible in limited areas such as Wuhan. This article summarizes the background, key points and core measures in the country and provinces. It sent prospects for future prevention and control strategies.
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Objective@#To evaluate the current status and related factors of influenza vaccination among health care workers (HCWs) in tertiary hospitals of Xining city after the implementation of the free influenza vaccination policy.@*Methods@#In August 2018, the cluster sampling method was used to select four medical institutions in Xining that had previously conducted investigations and interventions. All HCWs(excluding logistic staff) in each medical institution were included in the study. A total of 3 260 valid respondents were included. Questionnaires were used to collect the demographic characteristics, influenza and influenza vaccination awareness, implementation of free policy in the influenza epidemic season from 2017 to 2018, influenza vaccination status, awareness of influenza vaccination schedule and free policy. The multivariate logistic regression model was used to analyze related factors of influenza vaccination.@*Results@#The age of respondents was (31.41±5.00) years. The influenza vaccination rate was 6.80% (226/3 260) in 2017-2018 influenza epidemic season. After controlling for related factors, the awareness of the influenza vaccination schedule (OR=17.05, 95%CI: 5.86-49.59), vaccination frequency (OR=8.22, 95%CI: 2.98-22.61) and the free policy (OR=3.15, 95%CI: 1.49-6.67) had higher vaccination rate.@*Conclusion@#The influenza vaccination rate of HCWs in tertiary hospitals of Xining city was low. Increasing the awareness of the vaccination schedule, frequency and free policy may promote the influenza vaccination rate of HCWs.
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Objective@#We planned to evaluate the effectiveness of moving epidemic method (MEM) in calculating influenza epidemic threshold of 7 climatic zones in China mainland.@*Methods@#The positive rate of influenza virus was obtained from the National Influenza Surveillance Network System from 2010/2011 to 2017/2018. We divided the 31 provinces into 7 climatic zones according to previous literatures and applied MEM to calculate the influenza epidemic threshold of 2018/2019 influenza season for these climatic zones. Sensitivity, specificity, positive predictive value and negative predictive value were calculated to evaluate the effectiveness of MEM.@*Results@#Pre-epidemic threshold (the positive rate of influenza virus) varied from 9.66% (temperate zone) to 16.36% (subtropical zone) for 2018/2019 influenza season. The gap between pre-epidemic and post-epidemic thresholds was less than 5% except for plateau zone. The sensitivity was 86.16% (95CI:66.81%-98.23%), the specificity was 94.92% (95CI: 91.13%-98.41%), the positive predictive value was 89.87% (95%CI: 84.39%-94.38%), the negative predictive value was 92.96% (95%CI: 84.46%-99.17%).@*Conclusion@#Overall, moving epidemic Method performs well in calculating influenza epidemic threshold in China, much better than the previous study.
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Health care workers have higher risk of influenza infection because of their occupational exposure to infected patients. Infection of the health care workers may not only result in the increasing risk of the nosocomial infection and family transmission, but also disrupt the health services due to absence from work. Health care workers were recommended as a priority group of influenza vaccinationin more than 40 countries and regions in the world. In recent years, domestic surveys show that the influenza vaccine coverage among health care workers was low. This paper outlines the current status and related policies of influenza vaccination among health care workers in China and global. Additionally, we analyzed and discussed the proper immunization strategy of influenza vaccine for medical staff in China.
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The annual deaths associated with influenza is estimated to be between 290 000 and 650 000,which caused substantial burden to the society.Children have the highest incidence of influenza among all age groups,which can cause overloaded medical visits and a significant increase of hospitalization risk.The severe economic burden includes not only the direct medical costs due to outpatients and hospitalization,but also the indirect burden of school absence of children and work absence of their family members.Annual vaccination is the best measure to prevent influenza,however,influenza vaccination coverage among children in China is very low,and influenza vaccination has not yet been included in the National Immunization Program.Now,the disease burden of influenza and the vaccine usage in children in China were reviewed,and in order to provide evidence for influenza control and prevention.
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Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and its complications.Currently,China has licensed trivalent (IIV3) and quadrivalent inactivated influenza vaccine (IIV4),including split-virus influenza vaccine and subunit vaccine.In most parts of China,influenza vaccine is a category Ⅱ vaccine,which means influenza vaccination is voluntary,and recipients need to pay for it.To strengthen the technical guidance for prevention and control of influenza and the operational research on influenza vaccination in China,the National Immunization Advisory Committee (NIAC),Influenza Vaccine Technical Working Group (TWG),updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)",based on most recent existing scientific evidences.The main updates include:epidemiology and disease burden of influenza,types of influenza vaccines,northern hemisphere influenza vaccination composition for the 2018-2019 season,and,IIV3 and IIV4 vaccines' major immune responses,durability of immunity,immunogenicity,vaccine efficacy,effectiveness,safety,cost-effectiveness and cost-benefit.The recommendations include:Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications.No preferential recommendation is made for any influenza vaccine product for persons who can accept ≥ 1 licensed,recommended,and appropriate products.To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups,the recommendations prioritize seasonal influenza vaccination for children aged 6-60 months,adults ≥60 years of age,persons with specific chronic diseases,healthcare workers,the family members and caregivers of infants ＜6 months of age,and pregnant women or women who plan to pregnant during the influenza season.Children aged 6 months to 8 years old require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection.If they were vaccinated in previous influenza season,1 dose is recommended.People ≥ 9 years old require 1 dose of influenza vaccine.It is recommended that people receive their influenza vaccination by the end of October.Influenza vaccination should be offered as soon as the vaccination is available.Influenza vaccination should continue to be available for those unable to be vaccinated before the end of October during the whole season.Influenza vaccine is also recommended for use in pregnant women during any trimester.These guidelines are intended for CDC members who are working on influenza control and prevention,PoVs members,healthcare workers from the departments of pediatrics,internal medicine,and infectious diseases,and members of materuity and child care institutions at all levels.
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Influenza can be prevented through annual appropriate vaccination against the virus concerned.In China,influenza vaccine is categorized as "Class Ⅱ " infectious diseases which the cost is paid out of the user's pockets.The annual coverage of influenza vaccination had been 2％-3％.The main reasons for the low coverage would include the following factors:lacking awareness on both the disease and vaccine,poor accessibility of vaccination service,and the cost of vaccination.To reduce the health and economic burden associated with influenza,comprehensive policies should be improved,targeting the coverage of seasonal influenza vaccination.These items would include:① Different financing reimbursement schemes and mechanisms to improve the aspiration on vaccination and on the vaccine coverage in high-risk groups,as young children,elderly,people with underlying medical conditions;② to ameliorate equality of vaccination services;③ to improve knowledge of the health care workers (HCWs) and the public on influenza and related vaccines;④ to improve clinical and preventive medical practice and vaccination among HCWs through revising clinical guidelines,pathway and consensus of experts;⑤ to provide more convenient,accessible and normative vaccination service system;⑥ to strengthen research and development as well as marketing on novel influenza vaccines;⑦ to revise items regarding the contraindication for influenza vaccine on pregnancy women,stated in the Chinese Pharmacopoeia.
ABSTRACT
In China,the control and prevention programs on any disease has always been based on comprehensive strategies.Take influenza as an example,related contents would include:strengthening the surveillance,recommendation and promotion of vaccination,rational use of antiviral drugs,conducting outbreak investigation and control,and publicizing individual protective measures,etc.In terms of the response to challenges,specific proposals would include:adjustment of case reports,optimization of surveillance systems,reinforcement of vaccination recommendation by health care workers,improvement of access to vaccination,development of rapid diagnostic reagents,and rational use of antiviral drugs,etc.
ABSTRACT
Five influenza pandemics had occurred during the past century (1918 "Spanish flu",1957 "Asian flu",1968 "Hong Kong flu",1977 "Russian flu" and 2009 H1N1 Pandemic),accounting for hundreds of millions of people infected and tens of millions dead.China was influenced by all the five pandemics,and three of them (1957 "Asian flu",1968 "Hong Kong flu" and 1977 "Russian flu") were originated from China.The pandemics triggered the establishment of public health agencies and influenza surveillance capacities.In addition,more resources were allocated to influenza-related research,prevention and control.As a leader in the field of influenza,China should further strengthen its pandemic preparedness and response to contribute to global health.
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Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and complications from infection. Currently, China has licensed trivalent inactivated influenza vaccine (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. Except for a few major cities, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients must pay for it. To strengthen the technical guidance for prevention and control of influenza and operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC) Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" . The main updates in this version include: epidemiology, disease burden, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, IIV3 and IIV4 immune response, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The influenza vaccine TWG provided the recommendations for influenza vaccination for the 2018-2019 influenza season based on existing scientific evidence. The recommendations described in this report include the following: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended, and appropriate product is available. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-59 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to become pregnant during the influenza season. Children aged 6 months through 8 years require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in 2017-2018 influenza season or a prior season, 1 dose is recommended. People more than 8 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. For the people unable to be vaccinated before the end of October, influenza vaccination will continue to be offered for the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for use by staff members of the Centers for Disease Control and Prevention at all levels who work on influenza control and prevention, PoVs staff members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and staff members of maternity and child care institutions at all levels.
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Objective@#To understand characteristics of demographic, seasonal and spatial distribution of H5N1 cases in major countries of Asia (Indonesia, Cambodia, Vietnam, China) and Africa (Egypt).@*Methods@#Through searching public data resource and published papers, we collected cases information in five countries from May 1st, 1997 to November 6th, 2017, including general characteristics, diagnosis, onset and exposure history, etc. Different characteristics of survived and death cases in different countries were described and χ2 test was used to compare the differences among death cases and odds ratio (OR) and 95%CI value was used to compare death risk in different countries.@*Results@#A total of 856 cases were reported in five countries with Egypt had the most cases (44.3%). The highest number of cases were reported in 2015 (18.3%). 53% cases were reported from January to March, and 96.1% of cases had the history of poultry exposure. 64.2% (43 cases) cases in China had live poultry market exposure, but the sick/dead poultry exposure was the major exposure for cases in other four countries. 452 death cases were reported in five countries, and the fatality rate was 52.8%. With Egypt as the reference group, the highest death risk was seen in Indonesia (OR (95%CI): 11.52 (7.46-17.77)), followed by Cambodia (OR (95%CI): 4.27(2.37-7.69)) and China (OR (95%CI): 2.87 (1.73-4.74)). The age distribution of death cases among 5 countries was statistically significant, and the highest fatality rate was in 15-54 years group in Egypt (83.6%, 102 cases), while in Cambodia the highest fatality rate was in 0-14 years group (76.9%, 30 cases). The highest number of deaths were reported in 2006, and 48.3% were reported from January to March. There was difference in exposure routes among 5 countries (χ2=43.85, P=0.001), 63.2% (24 cases) of the death cases in China had live poultry market exposure. 92.9% (79 cases), 83.3% (40 cases) and 100.0% (38 cases) death cases in Indonesia, Vietnam and Camodia had sick/dead poultry exposure, respectively;and 81.6% (31 cases) of the death cases in Egypt had backyard poultry exposure.@*Conclusion@#The geographical distribution, seasonal age, gender, exposure matter and outcome of H5N1 cases in five countries were different.
ABSTRACT
Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and its complications.Currently,China has licensed trivalent (IIV3) and quadrivalent inactivated influenza vaccine (IIV4),including split-virus influenza vaccine and subunit vaccine.In most parts of China,influenza vaccine is a category Ⅱ vaccine,which means influenza vaccination is voluntary,and recipients need to pay for it.To strengthen the technical guidance for prevention and control of influenza and the operational research on influenza vaccination in China,the National Immunization Advisory Committee (NIAC),Influenza Vaccine Technical Working Group (TWG),updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)",based on most recent existing scientific evidences.The main updates include:epidemiology and disease burden of influenza,types of influenza vaccines,northern hemisphere influenza vaccination composition for the 2018-2019 season,and,IIV3 and IIV4 vaccines' major immune responses,durability of immunity,immunogenicity,vaccine efficacy,effectiveness,safety,cost-effectiveness and cost-benefit.The recommendations include:Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications.No preferential recommendation is made for any influenza vaccine product for persons who can accept ≥ 1 licensed,recommended,and appropriate products.To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups,the recommendations prioritize seasonal influenza vaccination for children aged 6-60 months,adults ≥60 years of age,persons with specific chronic diseases,healthcare workers,the family members and caregivers of infants ＜6 months of age,and pregnant women or women who plan to pregnant during the influenza season.Children aged 6 months to 8 years old require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection.If they were vaccinated in previous influenza season,1 dose is recommended.People ≥ 9 years old require 1 dose of influenza vaccine.It is recommended that people receive their influenza vaccination by the end of October.Influenza vaccination should be offered as soon as the vaccination is available.Influenza vaccination should continue to be available for those unable to be vaccinated before the end of October during the whole season.Influenza vaccine is also recommended for use in pregnant women during any trimester.These guidelines are intended for CDC members who are working on influenza control and prevention,PoVs members,healthcare workers from the departments of pediatrics,internal medicine,and infectious diseases,and members of materuity and child care institutions at all levels.
ABSTRACT
Influenza can be prevented through annual appropriate vaccination against the virus concerned.In China,influenza vaccine is categorized as "Class Ⅱ " infectious diseases which the cost is paid out of the user's pockets.The annual coverage of influenza vaccination had been 2％-3％.The main reasons for the low coverage would include the following factors:lacking awareness on both the disease and vaccine,poor accessibility of vaccination service,and the cost of vaccination.To reduce the health and economic burden associated with influenza,comprehensive policies should be improved,targeting the coverage of seasonal influenza vaccination.These items would include:① Different financing reimbursement schemes and mechanisms to improve the aspiration on vaccination and on the vaccine coverage in high-risk groups,as young children,elderly,people with underlying medical conditions;② to ameliorate equality of vaccination services;③ to improve knowledge of the health care workers (HCWs) and the public on influenza and related vaccines;④ to improve clinical and preventive medical practice and vaccination among HCWs through revising clinical guidelines,pathway and consensus of experts;⑤ to provide more convenient,accessible and normative vaccination service system;⑥ to strengthen research and development as well as marketing on novel influenza vaccines;⑦ to revise items regarding the contraindication for influenza vaccine on pregnancy women,stated in the Chinese Pharmacopoeia.
ABSTRACT
In China,the control and prevention programs on any disease has always been based on comprehensive strategies.Take influenza as an example,related contents would include:strengthening the surveillance,recommendation and promotion of vaccination,rational use of antiviral drugs,conducting outbreak investigation and control,and publicizing individual protective measures,etc.In terms of the response to challenges,specific proposals would include:adjustment of case reports,optimization of surveillance systems,reinforcement of vaccination recommendation by health care workers,improvement of access to vaccination,development of rapid diagnostic reagents,and rational use of antiviral drugs,etc.
ABSTRACT
Five influenza pandemics had occurred during the past century (1918 "Spanish flu",1957 "Asian flu",1968 "Hong Kong flu",1977 "Russian flu" and 2009 H1N1 Pandemic),accounting for hundreds of millions of people infected and tens of millions dead.China was influenced by all the five pandemics,and three of them (1957 "Asian flu",1968 "Hong Kong flu" and 1977 "Russian flu") were originated from China.The pandemics triggered the establishment of public health agencies and influenza surveillance capacities.In addition,more resources were allocated to influenza-related research,prevention and control.As a leader in the field of influenza,China should further strengthen its pandemic preparedness and response to contribute to global health.
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[Abstract ] Objective At present, the majority of injectable tissue engineering bones or carrier stents are gel , whose surface area , intensity, and hardness cannot satisfy the requirements of the repair of complex and varied bone and cartilage defects .This paper evaluated the new injectable microspherical porous chitosan/biological properties of the hydroxyapatite ceramic scaffold . Methods Injectable porous chitosan /hydroxyapatite composite microspheres with mass fractions of 30%, 50%, and 70% were prepared respectively . The hydroxyapatite ceramic ball was obtained by sintering with liquid nitrogen freezing ( liquid nitrogen group ) or without liquid nitrogen pro-cessing ( non-liquid nitrogen group ) as a new carrier of bone tissue engineering scaffold material .The microstructure of the scaffold was observed and the porosity measured under the scanning electron microscope .The mechanical properties were determined through biome-chanical experiments.Human umbilical vein endothelial cells (HUVECs) were grown in the porous chitosan/hydroxyapatite ceramic scaf-fold followed by observation of the growth of the cells and validation of the biological fusion of the scaffold . Results No difference was observed with the naked eye in the ceramic scaffold of different mass fractions in the liquid nitrogen and non -liquid nitrogen groups . Scanning electron microscopy exhibited spherical shape , uniform size, and regular morphology of the ceramic scaffolds in both groups .A large number of irregular pores were seen in the surface of the microspherical ceramic scaffolds treated with liquid nitrogen but not in the surface of those not treated .With increased mass percentage of chitosan/hydroxyapatite , the internal pores were reduced and the interior structure compacted.In the liquid nitrogen group, the scaffold of 50%mass fraction had a significantly larger diameter ([0.48 ±0.11] mm), higher compression intensity ([1.75 ±0.14] MPa), and lower porosity ([79 ±2]%) than that of 30%mass fraction ([0.40 ± 0.08] mm, [1.21 ±0.12] MPa, and [87 ±1]%) (all P<0.05).Electron microscope scanning revealed well -grown HUVECs with multiple synapses in the porous tricalcium phosphate scaffold. C onclusion The porous chitosan /hydroxyapatite ceramic scaffold of 50%mass fraction treated with liquid nitrogen , with its strong mechanical intensity and high biological fusibility , can be used as a new carrier of bone tissue engineering scaffolds .
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<p><b>OBJECTIVE</b>To investigate clinical and epidemiological characteristics of hospitalized severe acute respiratory illnesses (SARI) patients under 15 years old registered by sentinel hospitals at 10 cities and risk factors analysis of severe illness.</p><p><b>METHODS</b>The objects of this study were 2 937 SARI patients under 15 years old registered by sentinel surveillance in internal wards, pediatrics wards and intensive care units (ICU) of 10 sentinel hospitals in 10 cities during the period from December 2009 to June 2014. We also collected case report form (CRF) of them and their throat swabs for influenza testing. The inclusion criteria was hospitalized patients who were admitted by surveillance departments, registered by SARI surveillance system, under 15 years old, meeting SARI case definition and with complete CRF. Rank-sum test was used to compare the difference of age, the duration including from onset to admission, hospital stay and from onset to discharging/death between mild illness and severe illness. Chi-square test was used to compare the difference of demographic characteristics, influenza psoitive rate, vaccination rate of influenza, chronic medical conditions and clinical characteristics between mild illness and severe illness. Logistic regression was used to analysis risk factors associated with severe illness by two stratifications from SARI surveillance protocol (< 2 years old and ≥ 2 years old).</p><p><b>RESULTS</b>Among 2 937 SARI patients under 15 years old, 97.7% (2 872/2 937) was mild illnesses, and 2.3% (65/2 937) was severe illnesses. 78.8% (2 315/2 937) was under 5 years old. The median ages of severe illness and mild illness were 0.4 and 2.0 years old (U = -6.23, P < 0.001). The proportions of severe illness and mild illness with at least one chronic medical condition were 32.3% (21/65) and 8.4% (240/2 872) (χ² = 45.03, P < 0.001). The positive rate of influenza virus was 6.5% (190/2 937), which was 6.5% (186/2 858) for mild illness and 6.2% (4/65) for severe illness (χ² = 0.08, P = 0.961). The proportion of seasonal influenza vaccination was 1.5% (42/2 853), which was 1.5% (42/2 788) for mild illness and higher than that for severe illness (0) (χ² = 6.09, P = 0.048). For under 2 years old patients, age < 11 months and with at least one chronic medical condition were risk factors for severe SARI illness, and the risk for SARI patients who was 12-23 months and without medical condition was 14.71 (5.35-40.44) and 5.61 (2.96-10.63). For ≥ 2 years old patients, age, with at least one chronic medical condition and seasonal influenza vaccination history have no association with severe illness, OR (95% CI) was 0.92 (0.80-1.05), 0.67 (0.09-5.05) and 0.85 (0.31-2.35), respectively.</p><p><b>CONCLUSION</b>Most of SARI patients registered by 10 urban sentinel hospitals were patients under 5 years old. Age < 11 months and with at least chronic medical conditions were possible risk factors of severe illness of SARI patients.</p>
Subject(s)
Adolescent , Child , Child, Preschool , Humans , Infant , China , Chronic Disease , Cities , Hospitalization , Hospitals , Influenza, Human , Orthomyxoviridae , Respiratory Tract Diseases , Risk Factors , Sentinel Surveillance , VaccinationABSTRACT
Objective To understand the epidemiological characteristics of influenza outbreaks in China from 2005 to 2013. Methods The data of influenza-like illness outbreaks involving 10 or more cases were collected through Public Health Emergency Management Information System and National Influenza Surveillance Information System in China,and the influenza outbreaks were identified according to the laboratory detection results. Descriptive epidemiological analysis was conducted to understand the type/subtype of influenza virus and outbreak time,area,place and extent. Results From 2005 to 2013,a total of 3 252 influenza-like illness outbreaks were reported in the mainland of China,in which 2 915 influenza outbreaks were laboratory confirmed,and influenza A(H1N1) pdm09 virus and influenza B virus were predominant. More influenza outbreaks were reported in the influenza A(H1N1)pandemic during 2009-2010. Influenza outbreaks mainly occurred during winter-spring,and less influenza outbreaks occurred in winter and summer vocations of schools. More influenza outbreaks were reported in southern provinces,accounting for 79% of the total. Influenza outbreaks mainly occurred in primary and middle schools,where 2 763 outbreaks were reported,accounting for 85% of the total. Averagely 30-99 people were involved in an outbreak. Conclusion A large number of influenza outbreaks occur during influenza season every year in China,the predominant virus type or subtype varies with season. Primary and middle schools are mainly affected by influenza outbreaks.