Mild and asymptomatic influenza B virus infection among unvaccinated pregnant persons: Implication for effectiveness of non-pharmaceutical intervention and vaccination to prevent influenza.

BACKGROUND: We estimated symptomatic and asymptomatic influenza infection frequency in community-dwelling unvaccinated pregnant persons to inform risk communication. METHODS: We collected residue sera from multiple antenatal-care blood draws during October 2016-April 2017. We determined influenza infection as seroconversion with ≥ 4-fold rise in antibody titers between any two serum samples by improved hemagglutinin-inhibition assay including ether-treated B antigens. The serology data were linked to the results of nuclei acid testing (rRT-PCR) based on acute respiratory illness (ARI) surveillance. RESULTS: Among all participants, 43 %(602/1384) demonstrated serology and/or rRT-PCR evidenced infection, and 44 %(265/602) of all infections were asymptomatic. ARI-associated rRT-PCR testing identified only 10 %(61/602) of total infections. Only 1 %(5/420) of the B Victoria cases reported ARI and had a rRT-PCR positive result, compared with 33 %(54/165) of the H3N2 cases. Among influenza ARI cases with multiple serum samples, 19 %(11/58) had seroconversion to a different subtype prior to the illness. CONCLUSIONS: The incidence of influenza B infection in unvaccinated pregnant persons is under-estimated substantially. Non-pharmaceutical intervention may have suboptimal effectiveness in preventing influenza B transmission due to the less clinical manifestation compared to influenza A. The findings support maternal influenza vaccination to protect pregnant persons and reduce consequent household transmission.

Incidence rates of influenza illness during pregnancy in Suzhou, China, 2015-2018.

BACKGROUND: Data on influenza incidence during pregnancy in China are limited. METHODS: From October 2015 to September 2018, we conducted active surveillance for acute respiratory illness (ARI) among women during pregnancy. Nurses conducted twice weekly phone and text message follow-up upon enrollment until delivery to identify new episodes of ARI. Nasal and throat swabs were collected ≤10 days from illness onset to detect influenza. RESULTS: In total, we enrolled 18 724 pregnant women median aged 28 years old, 37% in first trimester, 48% in second trimester, and 15% in third trimester, with seven self-reported influenza vaccination during pregnancy. In the 18-week epidemic period during October 2015 to September 2016, influenza incidence was 0.7/100 person-months (95% CI: 0.5-0.9). In the cumulative 29-week-long epidemic during October 2016 to September 2017, influenza incidence was 1.0/100 person-months (95% CI: 0.8-1.2). In the 11-week epidemic period during October 2017 to September 2018, influenza incidence was 2.1/100 person-months (95% CI: 1.9-2.4). Influenza incidence was similar by trimester. More than half of the total influenza illnesses had no elevated temperature and cough. Most influenza-associated ARIs were mild, and <5.1% required hospitalization. CONCLUSIONS: Influenza illness in all trimesters of pregnancy was common. These data may help inform decisions regarding the use of influenza vaccine to prevent influenza during pregnancy.

Antiviral Activity of 3D, a Butene Lactone Derivative Against Influenza A Virus In Vitro and In Vivo.

Influenza A virus is a highly variable and contagious respiratory pathogen that can cause annual epidemics and it poses an enormous threat to public health. Therefore, there is an urgent need for a new generation of antiviral drugs to combat the emergence of drug-resistant strains of the influenza virus. A novel series of butene lactone derivatives were screened and the compound 3D was selected, as it exhibited in vitro potential antiviral activity against A/Weiss/43 H1N1 virus with low toxicity. In addition, 3D dose-dependently inhibited the viral replication, expression of viral mRNA and viral proteins. 3D exerted a suppressive effect on A/Virginia/ATCC2/2009 H1N1 and A/California/2/2014 H3N2 in vitro. The time-of-addition analysis indicated that 3D suppressed H1N1 in the early stage of its life cycle. A/Weiss/43 H1N1-induced apoptosis in A549 cells was reduced by 3D via the mitochondrial apoptosis pathway. 3D could decrease the production of H1N1-induced pro-inflammatory cytokines that are induced by H1N1 in vitro and in vivo. The administration of 3D reduced lung lesions and virus load in vivo. These results suggest that 3D, which is a butene lactone derivative, is a promising agent for the treatment of influenza A virus infection.

Screening and pharmacodynamic evaluation of the antirespiratory syncytial virus activity of steroidal pyridine compounds in vitro and in vivo.

Respiratory syncytial virus (RSV) causes serious lower respiratory tract infections and there are currently no safer or more effective drugs available. It is important to find novel medications for RSV infection. A series of steroidal pyridines were synthesized for screening and evaluation of their antiviral activity and investigation of their antiviral mechanism of action. Compound 3l had the highest antiviral activity, with a half-maximal effective concentration (EC50 ) of 3.13 µM. Compound 3l was explored for its effects in vitro on RSV 2 h before infection (pretreatment), at the time of infection (competition), and 2 h after infection (postinfection). Toll-like receptor (TLR)-3, retinoic acid-inducible gene (RIG)-I, interleukin (IL)-6, and interferon (IFN)-ß were suppressed at the cellular level. Mouse lung tissue was subjected to hematoxylin and eosin (HE) staining and immunohistochemistry, which showed that RSV antigen and M gene expression could be reduced by compound 3l. Decreased expression of TLR-3, RIG-I, IL-6, IFN-ß, and IL-10 was also found in vivo. The results indicated that compound 3l exerted its antiviral effects mainly through inhibition of viral replication and downregulation of inflammatory factors.

Screening and pharmacodynamic evaluation of the anti-respiratory syncytial virus activity of butene lactones in vitro and in vivo.

A series of butene lactones were synthesized and these compounds were tested for anti-respiratory syncytial virus (RSV) activity in vitro. Three compounds exhibited an antiviral effect, the highest of which was compound 6b3 with an effective concentration 50% of 6.35 µM. The effects of 6b3 were then evaluated in vivo and a significant reduction in the lung index caused by RSV was detected. Reduced inflammatory infiltration and necrosis of the lungs were revealed by histopathology and gross pathology. Activation of an early immune response by 6b3 was also observed by cytokine analysis via a real-time polymerase chain reaction. These results indicated that 6b3 has an anti-RSV effect both in vitro and in vivo, and is a possible candidate compound for the development of an anti-RSV drug in the future.

Discovery and SAR Research for Antivirus Activity of Novel Butenolide on Influenza A Virus H1N1 In Vitro and In Vivo.

Influenza viruses (IV) cause substantial morbidity and mortality through routine seasonal spread and epidemics. A novel series of butenolides were discovered to be able to inhibit influenza H1N1 activity in vitro, and the SAR for anti-influenza activity was investigated. By optimization of the hit compound, compound 37 was obtained with an EC50 of 6.7 µM against influenza A virus H1N1 as an inhibitor of NA and with low cytotoxicity on MDCK cells. Also, it can inhibit the expression of the influenza A virus gene in the lung of SPF KM mice to show antivirus activity in vivo. These results suggested that compound 37 could inhibit the influenza A virus H1N1 via targeting NA.

An Internet-Based Survey of Influenza Vaccination Coverage in Healthcare Workers in China, 2018/2019 Season.

Influenza vaccination coverage was low among healthcare workers (HCWs) in China. In October 2018, the National Health Commission of China began to require all hospitals to provide free influenza vaccination for HCWs to increase vaccine uptake, and no study on vaccine coverage among HCWs at the national level after the announcement of new policy. This evaluation aims to investigate self-reported influenza vaccination coverage among HCWs and factors that may affect vaccine receipt during the 2018/2019 influenza season. We delivered an opt-in internet panel survey among registered HCWs of DXY forum (the biggest online forum for HCWs in China). The survey was self-administered using a standard questionnaire to collect information on demographics, occupational characteristics, policy implementation, influenza vaccination and influence factors. We conducted multivariate logistic regression analysis to assess factors associated with receipt of influenza vaccine. The response rate of this online survey was 3.6%. The seasonal influenza vaccine coverage reported among HCWs surveyed during the 2018/2019 season was 11.6% (472/4078). Only 19.0% (774/4078) of HCWs surveyed reported free policy in their workplace. Combing free policy and workplace requirement proved to be effective to improve influenza vaccination coverage in HCWs (PR = 6.90, 95% CI: 6.03-7.65). The influenza vaccination coverage among surveyed HCWs in China was low during the 2018/2019 season. To increase future vaccination uptake, we recommend a multi-faceted strategy that include free policy, workplace requirement and promotion, on-site vaccination, and monitoring.

Cohort profile: China respiratory illness surveillance among pregnant women (CRISP), 2015-2018.

PURPOSE: We established the China Respiratory Illness Surveillance among Pregnant women (CRISP) to conduct active surveillance for influenza-associated respiratory illness during pregnancy in China from 2015 to 2018. Among annual cohorts of pregnant women, we assess the incidence of acute respiratory illness (ARI), influenza-like illness (ILI), laboratory-confirmed influenza virus infection and the seroconversion proportion during the winter influenza season. We also plan to examine the effect of influenza virus infection on adverse pregnancy, delivery and infant health outcomes with cumulative data from the three annual cohorts. PARTICIPANTS: Cohort nurses enrol pregnant women in different trimesters of pregnancy from prenatal care facilities in Suzhou, Jiangsu Province, eastern China. Pregnant women who plan to deliver in the study facilities are eligible. Pregnant women who are seeking care for anything other than routine prenatal care, such as confirmation of low progesterone and threatened miscarriage, are excluded. At enrolment, study nurses collect baseline information on demographics, education-level attained, underlying medical conditions, seasonal influenza vaccination receipt, risk factors for influenza infection, gravidity and parity and contact information. For each participant, cohort nurses conduct twice weekly follow-up contacts, one phone call and one WeChat message (free instant messaging), from the time of enrolment until delivery or termination of pregnancy. During follow-up, study nurses ask about symptoms, timing and characteristics of ARI, healthcare-seeking behaviour and medications taken for participants reporting respiratory illness since the last contact. In addition, we collect combined nasal and throat swabs for identified ARI to test for influenza viruses. We collect paired sera before and after the influenza season. Active respiratory illness surveillance and seroinfection data during pregnancy of participants are linked to their medical record and the Suzhou Maternal Child Information System for detailed information on clinical treatment for respiratory illness, pregnancy, delivery and infant health outcomes. FINDINGS TO DATE: In 2015-2016, of 4915 pregnant women approached, 192 (4%) refused to participate, 91 (2%) were ineligible because they did not plan to deliver in one of the study hospitals or because their visit was for anything other than routine prenatal care and 4632 (94%) were enrolled, 46% during their first trimester of pregnancy (range 5-12 weeks), 48% during the second trimester (range 13-27 weeks) and 6% during the third trimester (range 28-37 weeks). The median age of the enrollees was 27 years (range 16-45) and two (0.04%, 95% CI 0.01% to 0.17%) reported influenza vaccination in the previous 12 months before pregnancy, while zero reported influenza vaccination in the previous 12 months during pregnancy. During the observation time of 648 518 person-days, 1355 ARI episodes were identified. Among 1127 swabs collected (for 83% of all ARIs), 68 (6%) tested positive for influenza virus, for a laboratory-confirmed influenza incidence of 0.31 (95% CI 0.25 to 0.40) per 100 person-months during pregnancy in the study cohort. FUTURE PLANS: Results will be used to describe influenza disease burden in this population to model potential numbers of influenza illnesses averted if influenza vaccination coverage were increased and to support enhanced influenza prevention and control strategies among pregnant women in China. We also plan to enrol and follow three cohorts of pregnant women over three influenza seasons during 2015-2018 which will allow an analysis of the effect of influenza virus infection during pregnancy on adverse pregnancy, delivery and infant outcomes.

Influenza A(H7N9) Virus Antibody Responses in Survivors 1 Year after Infection, China, 2017.

Avian influenza A(H7N9) virus has caused 5 epidemic waves in China since its emergence in 2013. We investigated the dynamic changes of antibody response to this virus over 1 year postinfection in 25 patients in Suzhou City, Jiangsu Province, China, who had laboratory-confirmed infections during the fifth epidemic wave, October 1, 2016-February 14, 2017. Most survivors had relatively robust antibody responses that decreased but remained detectable at 1 year. Antibody response was variable; several survivors had low or undetectable antibody titers. Hemagglutination inhibition titer was >1:40 for <40% of the survivors. Measured in vitro in infected mice, hemagglutination inhibition titer predicted serum protective ability. Our findings provide a helpful serologic guideline for identifying subclinical infections and for developing effective vaccines and therapeutics to counter H7N9 virus infections.

City Level of Income and Urbanization and Availability of Food Stores and Food Service Places in China.

OBJECTIVE: The contribution of unhealthy dietary patterns to the epidemic of obesity has been well recognized. Differences in availability of foods may have an important influence on individual eating behaviors and health disparities. This study examined the availability of food stores and food service places by city characteristics on city level of income and urbanization. METHODS: The cross-sectional survey was comprised of two parts: (1) an on-site observation to measure availability of food stores and food service places in 12 cities of China; (2) an in-store survey to determine the presence of fresh/frozen vegetables or fruits in all food stores. Trained investigators walked all the streets/roads within study tracts to identify all the food outlets. An observational survey questionnaire was used in all food stores to determine the presence of fresh/frozen vegetables or fruits. Urbanization index was determined for each city using a principal components factor analysis. City level of income and urbanization and numbers of each type of food stores and food service places were examined using negative binomial regression models. RESULTS: Large-sized supermarkets and specialty retailers had higher number of fresh/frozen vegetables or fruits sold compared to small/medium-sized markets. High-income versus low-income, high urbanized versus low urbanized areas had significantly more large-sized supermarkets and fewer small/medium-sized markets. In terms of restaurants, high urbanized cities had more western fast food restaurants and no statistically significant difference in the relative availability of any type of restaurants was found between high- and low-income areas. CONCLUSIONS: The findings suggested food environment disparities did exist in different cities of China.

[A survey on the condition of bike lanes in 12 cities, China].

OBJECTIVE: To explore the condition on bike lanes and the relationship with GDP of the related cities, residential of regions and prosperity of streets in 12 selected cities in China. METHODS: Eexistence and maintenance of bike lanes were examinedin in all the streets under survey in 333 blocks of 12 cities (Beijing, Tianjin, Shanghai, Qingdao, Hangzhou, Shaoxing, Suzhou, Nantong, Zhenjiang, Chengdu, Xining and Harbin). Data were collected on GDP of the related cities, together with the sizes of population and proportion of the 333 blocksand the numbers of stores and restaurants in those streets. RESULTS: A total of 4 202 streets were included in the study. In the 12 cities, 32.6% of the streets were equipped with bike lanes. Bike-lane-equipmentsseemed better in Nantong (46.5%), Tianjin (39.6%) and Shanghai (39.4%), but the scores were lower in Xining (2.0%), Qingdao (5.4%), and Harbin (27.1%). The higher GDP was, the better bike lanes were equipped. In the meantime, the isolation of bike lanes were worse and the streets more crowded. Density of the residential area was negatively correlated with the score on bike lane-equipments. CONCLUSION: Differences of the condition of bike lanes in the 12 cities indicated that improvement should be made on bike lanes. More attention should be paid to those cities with high GDPs and crowded residential regions on setting up the isolated bike lanes and reasonable equipments.

Gender, Age, and Education Level Modify the Association between Body Mass Index and Physical Activity: A Cross-Sectional Study in Hangzhou, China.

INTRODUCTION: Numerous studies have reported a strong inverse association between BMI and physical activity in western populations. Recently, the association between BMI and physical activity has been considered bidirectional. This study aimed to examine the associations of body mass index (BMI) with physical activity and sedentary behavior and to explore whether those associations were modified by socio-demographic characteristics. MATERIALS AND METHODS: We conducted a multistage random sampling survey in three districts of Hangzhou, China, in 2012. The International Physical Activity Questionnaire long form was used to collect data regarding physical activity and sedentary behavior. A multilevel mixed-effects regression model was used to assess the associations of BMI with physical activity and sedentary behavior. RESULTS: A total of 1362 eligible people (624 men and 738 women, ages 23-59 years) completed the survey. People who are young or middle-aged and have the highest education level are the most inactive. Significant differences in the associations between physical activity and BMI across socio-demographic groups were identified (sex*BMI, P=0.018; age*BMI, P<0.001; education level*BMI, P=0.030). Women or individuals older than 50 had a higher level of physical activity with increasing BMI. There was no statistically significant association between BMI and sedentary behavior (P=0.450). CONCLUSIONS: The associations between BMI and physical activity were modified by sex, age, and education level in Hangzhou, China.

Association between perceived urban built environment attributes and leisure-time physical activity among adults in Hangzhou, China.

BACKGROUND: Neighborhood built environment may influence residents' physical activity, which in turn, affects their health. This study aimed to determine the associations between perceived built environment and leisure-time physical activity in Hangzhou, China. METHODS: 1440 participants aged 25-59 were randomly selected from 30 neighborhoods in three types of administrative planning units in Hangzhou. International Physical Activity Questionnaire long form and NEWS-A were used to obtain individual-level data. The China Urban Built Environment Scan Tool was used to objectively assess the neighborhood-level built environment. Multi-level regression was used to explore the relationship between perceived built environment variables and leisure-time physical activities. Data was collected in Hangzhou from June to December in 2012, and was analyzed in May 2013. RESULTS: Significant difference between neighborhood random variations in physical activity was identified (P=0.0134); neighborhood-level differences accounted for 3.0% of the variability in leisure-time physical activity. Male residents who perceived higher scores on access to physical activity destinations reported more involvement in leisure-time physical activity. Higher scores on perception of esthetic quality, and lower on residential density were associated with more time in leisure-time walking in women. CONCLUSIONS: The present study demonstrated that perceived urban built environment attributes significantly correlate with leisure-time physical activity in Hangzhou, China.

Proteomic insight into the effect of ethanol on citrinin biosynthesis pathway in Monascus purpureus NTU 568.

Monascus species produce several potent bioactive metabolites through polyketide secondary metabolic pathways; however, little is known of the regulation of metabolic processes in this organism. Therefore, we investigated the effect of extreme growth conditions on the production of secondary metabolites by Monascus purpureus strain NTU 568 and identified pathways that plausibly regulate the polyketide pathways by using proteomic analysis. Citrinin, a type of antibiotic, is synthesized through the polyketide pathway in M. purpureus NTU 568. We hypothesized that production of citrinin might be inhibited by ethanol. When M. purpureus NTU 568 was cultured in the medium containing 4% ethanol, the secretion of secondary metabolites was inhibited, but the dry cell weight was increased. We also found that branched chain amino acid degradation and the expression level of aldehyde dehydrogenase (ALDH) were downregulated, but proteins related to the heat shock response were induced. Furthermore, polyketide synthesis-related proteins, fatty acid synthase, epoxide hydrolase, and proteins involved in the shikimate secondary metabolic pathway were inhibited by ethanol treatment. These results suggested that reduced production of polyketide metabolites resulted not only from the expression levels of proteins in the polyketide synthesis pathway but also from reduction in the concentration of primary metabolism-generated molecules (e.g., acetyl-CoA, fatty acids) that are used as substrates for polyketide syntheses. This study provides insights into the polyketide secondary metabolism of Monascus as well as into improvement of the production of bioactive secondary metabolites in Monascus species.

[Setting of logos on tobacco control information at outlets for retails and restaurants in 12 cities of China].

OBJECTIVE: To explore the setting of logos on tobacco control information at outlets for retails and restaurants in 12 selected cities of China. METHODS: For all the shops for retail of tobacco, alcohol, food and restaurants under survey in 333 blocks of 12 cities(Beijing, Tianjin, Shanghai, Qingdao, Hangzhou, Shaoxing, Suzhou, Nantong, Zhenjiang, Chengdu, Xining and Harbin), setting and contents of logos on tobacco control information, inside and outside them were examined. RESULTS: 45 700 objectives were included in the study. Among all types of retail shops, the identification rate of tobacco control information at the entrance and inside were 3.6% and 4.4%, with an overall identification rate as 7.0%. The overall rate at the entrance of all the restaurants was 4.6% which was larger than the ones at the retail shops. Our result showed that there were differences between cities and types of establishments and higher rates seen in the larger ones. Of all the places that having had placement of information on tobacco control, only 18.5% of them had put them both inside and outside. Slogans or images on "No Smoking" were the main forms of information but less than 10% of them would show signs as 'exclusive non-smoking'. CONCLUSION: Data from our survey showed that the identification rate of tobacco control information was at a low level in 12 cities, and differences were seen between cities, size of establishment, that called for improvement of the existing tobacco control policies in China.