Influenza imposes a significant disease burden on society and individuals annually, and influenza vaccination is considered a significant public health measure to prevent influenza and reduce influenza-related severe disease and death. The low influenza vaccination rate in China is partly due to certain factors affecting the willingness and behavior of individuals to receive them. Scientific research and targeted interventions on these factors can effectively improve the vaccination situation. Commonly used individual-level theoretical models for influenza vaccination behavior include the health belief model, protection motivation theory, and theory of planned behavior. This study reviews theoretical models commonly employed in researching influenza vaccination willingness and behavior. An overview of these practical applications and challenges models is presented to provide references for relevant research and intervention programs in China.

Objective:To analyze the epidemiological characteristics of indigenous 2019-nCoV infection in population under 18 years old in 31 provinces of China, and provide evidence for the prevention and control of COVID-19.Method:Demographic and epidemiologic information of children and adolescents with 2019-nCoV infection reported in China between April 29, 2020 and May 31, 2022 were collected from China's Disease Prevention and Control Information System. We analyzed the epidemiological characteristics of the 2019-nCoV infection in children and adolescents and compared the epidemiological characteristics of the cases at different epidemic stages.Result:A total of 63 916 indigenous 2019-nCoV infection cases in children and adolescents were reported in China from April 29, 2020 to May 31, 2022, in which 14 777 (23.12%) were confirmed cases and 49 139 (76.88%) were asymptomatic cases. An obvious incidence peak (40 864 cases) was observed in April, 2022, and two sub-peaks were observed in January, 2020 and January, 2021, respectively. The 2019-nCoV infection cases occurred in 187 cities above prefecture level in 30 provinces, the cases reported in Shanghai (41 562 cases), Changchun (5 753 cases) and Jilin (3 888 cases) accounted for 80.11% of the total cases (51 203/63 916). The proportion of the cases in males was 54.34%. The age of the cases, M ( Q1, Q3) was 10 (5, 14) years, and 57.73% of the cases were 6 - 15 years old. The cases in students accounted for the highest proportion (56.14%). The interval between illness onset and diagnosis of confirmed cases, M ( Q1, Q3) was 1 (0, 2) days. Among the 2019-nCoV infection cases in children and adolescents, 76.88% were asymptomatic, 21.78% were mild ones, 1.32% were moderately severe ones, 0.02% were severe ones, and there were no critical cases and deaths. Compared with other age groups, the proportion of severe or critical cases was higher in children aged <1 year (0.12%). The proportion of asymptomatic infections was highest in Omicron variant epidemic (78.43%). Conclusion:The 2019-nCoV infection cases in children and adolescents aged <18 years in 31 provinces in China were mainly primary and secondary school students aged 6-15 years. Most cases were asymptomatic and mild ones with low clinical severity. It is still necessary to strengthen the surveillance for 2019-nCoV infection in children and adolescents to improve the prevention and control of COVID-19 in school age children.

Objective:To assess plasma microfibrillar associated protein 5(MFAP5) level in patients with polycystic ovary syndrome(PCOS), and to explore its relationship with glucose and lipid metabolism as well as sex hormones.Methods:Fifty PCOS patients and 65 healthy female subjects were selected as PCOS group and control group, respectively. Clinical data and plasma MFAP5 levels between the two groups were compared.Results:The plasma MFAP5 level in PCOS group was significantly higher than that in control group( P<0.01), and the plasma MFAP5 level in PCOS overweight subgroup was higher than that in control subgroup( P<0.01). No difference was observed in plasma MFAP5 level between the two non-overweight subgroups( P>0.05). Correlation analysis showed that plasma MFAP5 level was positively correlated with waist circumference, low density lipoprotein-cholesterol, fasting insulin, homoeostasis model assessment of insulin resistance index(HOMA-IR), HbA 1C, testosterone, LH/FSH ratio, and leukocyte( P<0.05 or P<0.01). There was no significant correlation of MFAP5 with body weight, body mass index(BMI), hip circumference, waist hip ratio, high density lipoprotein-cholesterol(HDL-C), triglyceride, total cholesterol, and blood glucose( P>0.05). In PCOS group, plasma MFAP5 level was positively correlated with body weight, BMI, waist circumference, hip circumference, total cholesterol, and leukocyte( P<0.05 or P<0.01). There was no significant correlation of MFAP5 with waist hip ratio, HDL-C, triglyceride, blood glucose, fasting insulin, HOMA-IR, leukocyte, and sex hormones( P>0.05). Multivariate logistic regression analysis showed that MFAP5 was an independent risk factor for PCOS( P<0.05). Conclusion:Plasma MFAP5 level is increased in PCOS patients and is closely related to BMI, waist circumference, hip circumference, and total cholesterol. Plasma MFAP5 is an independent risk factor for PCOS, which may be involved in the pathogenesis of PCOS.

Objective: To observe the incidence of unreasonable use of high beam at nighttime among motor vehicle drivers, so as to provide the evidence for the prevention and control of road traffic injury. Methods: Four roads into city and five urban roads were selected in Yongkang of Zhejiang Province. An automatic recording system was used to collect the unreasonable use of high beam among motor vehicle drivers on the selected roads from 19:00 to 5:00 on Monday, Wednesday, Friday and Sunday during a week in July 2020. The regression tree model was used to analyze the relationship of the unreasonable use of high beam with road, time and traffic flow. Results: A total of 89 989 motor vehicles were observed, and 2 419 motor vehicle drivers had unreasonable use of high beam, with an incidence rate of 2.69%. The incidence rate of the unreasonable use of high beam was 3.14% in the roads into city, which was higher than 2.30% in the urban roads ( P<0.05 ). The incidence rates of the unreasonable use of high beam in the roads into city and in the urban roads were 5.15% and 2.90% on Wednesday, which were higher than those on Monday ( 2.89% and 2.34% ), Friday ( 2.90% and 1.92% ) and Sunday (2.06% and 2.12%). The highest incidence rate of the unreasonable use of high beam in the roads into city was 6.07% between 4:00 and 5:00, and in the urban roads was 4.50% between 2:00 and 3:00. The results of regression tree classification analysis showed that the highest incidence rate was 8.13% on the roads into city in the east, west and south directions, and on the urban roads in the east and north directions with less than 317 vehicles per hour on Wednesday. Conclusion It is more likely for motor vehicle drivers to use high beams unreasonably at nighttime on the roads into city with less traffic flow.

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.
Antibodies, Neutralizing ; Antibodies, Viral ; COVID-19 ; Humans ; Immunoglobulin M ; SARS-CoV-2

COVID-19 is an emerging infectious disease caused by SARS-CoV-2. After the infection of the virus, the host immune system is stimulated to produce multifarious specific antibodies to decrease or eliminate effects of the pathogen. Study of the specific antibodies dynamic characteristics in patients with COVID-19 is very important for the understanding and diagnosis of the disease, research and development of vaccine, and planning of prevention and control strategy. This paper reviews and summarizes the domestic and oversea research on dynamic characteristics of specific antibodies of COVID-19 patients, including the antibody producing, duration and level, and its possible influencing factors in order to improve the understanding of the immunological characteristics of COVID-19.

As the progress of population aging in China, the proportion of elderly population is increasing. Both chronic diseases and infectious diseases can threaten the health of the elderly. There are many kinds of infectious diseases, including vaccine preventable infectious diseases affecting the health of adults, such as influenza, pneumococcal diseases and herpes zoster. In addition, the newly emerged COVID-19 has caused a pandemic in the world, resulting the highest proportion of deaths occurred in the elderly and posing a serious threat to the health of the elderly. This paper mainly summarizes the prevention and control of vaccine preventable diseases and COVID-19 to which the elderly are susceptible, analyzes the infectious disease problems affecting the health of elderly population, and recommends countermeasures for the prevention and control of these diseases in elderly population.

The studies on infectiousness of person infected with SARS-CoV-2 at different stages of illness are an important basis for making effective prevention and control measures such as investigating the infectious source, determining the scope of close contacts and the timing of case isolation. This review discusses the infectiousness of cases infected with SARS-CoV-2 in the incubation period, symptomatic period and convalescent period by reviewing national and international literatures, technical and professional guidelines. Existing researches suggest that the infectious viruses could be isolated at the end of the incubation period as well as since illness onset, and viral load in upper respiratory tract swabs reached the peak on day 4-6 after illness onset and thereafter began to decline, implying the infectiousness was relatively strong at the end of incubation period and within one week after illness onset. Although there were a few cases who tested positive for SARS-CoV-2 after recovery, no evidence was found to indicate these cases can cause the transmission.

Objective:To analyze the incidence of acute respiratory infection (ARI) and related healthcare seeking behaviors in population in the period of COVID-19 epidemic in China.Methods:According to the province specific cumulative incidence rates of COVID-19 reported as of March 31, 2020, the low, medium and high-risk areas were classified. In these areas, a stratified two stage cluster random sampling method was used to select participants for face-to-face questionnaire surveys. Data on the incidence of ARI and related healthcare seeking behaviors in community residents during COVID-19 epidemic period were collected to calculate the attack rate of ARI and related healthcare seeking rate. Logistic regression method was used to explore the influencing factors for ARI incidence and healthcare seeking behavior.Results:A total of 34 857 community residents were surveyed, in whom 647 (1.9%) reported that they had ARI symptoms during the COVID-19 epidemic period, and 241 (37.2%) had healthcare seeking behaviors. In terms of the incidence of COVID-19-related ARI, in high-risk area, the risk of COVID-19-related ARI was 1.36 times (95% CI: 1.12-1.65) than that in low-risk area; among different age groups, the risk of COVID-19-related ARI in age groups 20-39 years, ≥60 years was 1.80 times (95% CI: 1.29-2.59) and 1.63 times (95% CI: 1.14-2.40) than that in age group 1-9 years; the risk of COVID-19-related ARI in people with underlying diseases was 1.53 times (95% CI: 1.23-1.89) than that in those without underlying diseases; the risk of COVID-19-related ARI in people with contacts with confirmed cases of COVID-19 and people with fever or respiratory symptoms was 1.53 times (95% CI: 1.01-2.27) and 6.60 times (95% CI: 5.05-8.53) than those in people without these contacts. The healthcare seeking rate in COVID-19-related ARI patients with exposures to those with fever or respiratory symptoms was 1.68 times (95% CI: 1.05-2.70) than that in such patients without the exposures. Conclusions:The attack rate of COVID-19-related ARI was affected by the local epidemic level of COVID-19, and in high-risk area, the attack rate of COVID-19-related ARI was also high. The healthcare seeking rate in patients with COVID-19-related ARI was low. Therefore, it is necessary to encourage the healthcare seeking in people with ARI in COVID-19 pandemic period.