Continuous evolution and emerging lineage of seasonal human coronaviruses: A multicenter surveillance study.

The seasonal human coronaviruses (HCoVs) have zoonotic origins, repeated infections, and global transmission. The objectives of this study are to elaborate the epidemiological and evolutionary characteristics of HCoVs from patients with acute respiratory illness. We conducted a multicenter surveillance at 36 sentinel hospitals of Beijing Metropolis, China, during 2016-2019. Patients with influenza-like illness (ILI) and severe acute respiratory infection (SARI) were included, and submitted respiratory samples for screening HCoVs by multiplex real-time reverse transcription-polymerase chain reaction assays. All the positive samples were used for metatranscriptomic sequencing to get whole genomes of HCoVs for genetical and evolutionary analyses. Totally, 321 of 15 677 patients with ILI or SARI were found to be positive for HCoVs, with an infection rate of 2.0% (95% confidence interval, 1.8%-2.3%). HCoV-229E, HCoV-NL63, HCoV-OC43, and HCoV-HKU1 infections accounted for 18.7%, 38.3%, 40.5%, and 2.5%, respectively. In comparison to ILI cases, SARI cases were significantly older, more likely caused by HCoV-229E and HCoV-OC43, and more often co-infected with other respiratory pathogens. A total of 179 full genome sequences of HCoVs were obtained from 321 positive patients. The phylogenetical analyses revealed that HCoV-229E, HCoV-NL63 and HCoV-OC43 continuously yielded novel lineages, respectively. The nonsynonymous to synonymous ratio of all key genes in each HCoV was less than one, indicating that all four HCoVs were under negative selection pressure. Multiple substitution modes were observed in spike glycoprotein among the four HCoVs. Our findings highlight the importance of enhancing surveillance on HCoVs, and imply that more variants might occur in the future.

Study on age-dependent pre-existing 2009 pandemic influenza virus T and B cell responses from Chinese population.

BACKGROUND: The outbreak of the 2009 H1N1 influenza pandemic (H1N1pdm) affected thousands of people in Mexico and the United States, and spread rapidly throughout the world from April 2009 to July 2010. To explore the age-specific prevalence of seroprotection against H1N1pdm infection, we estimated pre-existing humoral and cellular immunities of residents in Northern China against H1N1pdm and seasonal H1N1 virus in an age-dependent manner. METHODS: Anonymous serum samples were collected from 1425 to 1434 adult healthy individuals before and after the pandemic outbreak, and then grouped by birth year 1913-1990. The antibody titers of H1N1pdm and seasonal H1N1 were determined using microneutralization (MN) assays, and the proportion of seropositive was estimated based on the year of birth. Separately, another 63 blood samples were collected in 2006 and prepared for analysis of virus specific memory B and IFN-γ+ T cells using the ELISpot assays. RESULTS: The prevalence of pre-existing H1N1pdm-specific sero-antibodies in the elderly population (>60 years old) was 7.8%. The younger group, aged 19 to 60 years, exhibited a significant increase in seropositivity for H1N1pdm after the pandemic (4.9% before pandemic and 18.9% after pandemic, p < 0.05). The prevalence of H1N1pdm specific MBCs before the pandemic in the elderly (>60 years) and younger populations (<60 years) was 38% (8/21) and 48% (20/42), respectively (p = 0.6). The IFN-γ+ T cell responses to the pandemic and seasonal viruses were significantly lower in the elder group than those in the younger group (<60 years) (p < 0.05). CONCLUSIONS: Pre-existing serum antibodies and memory B cells against H1N1pdm were low in all age group, whereas diminished memory T cell responses to this virus were observed in the elderly population both before and after the pandemic.

[Studies on prevalence and control of several common chronic diseases among Beijing adults in 2005].

OBJECTIVE: To understand the prevalence and control of several common chronic disease in Beijing adults. METHODS: 16,658 adult residents were randomly selected with stratified multi-stage cluster sampling method. Each participant was invited to receive a set of standardized questionnaire, physical examinations and laboratory tests. RESULTS: Data showed that the prevalence, awareness, treatment and the rate of control on hypertension among the adults in Beijing were 29.1%, 49.3%, 42.3% and 10.6% respectively. The counterparts of diabetes mellitus were 8.8%, 56.7%, 50.0% and 15.0%. The four corresponding figures for dyslipidemia were 33.2%, 31.1%, 13.0% and 4.3%, respectively. 22.9% of the Beijing adults had metabolic syndrome including 8.1 per thousand suffering from myocardial infarction and 18.4 per thousand from stroke. Except for diabetes, all the chronic diseases had higher prevalence rate in rural area than in urban area, according to the findings under our study. Postmenopausal women were more susceptible to chronic disease than men. CONCLUSION: The prevalence rate of chronic disease in Beijing was still high. The prevalence rate in rural area had exceeded the level in urban area. Adjustment and attention should be made according to the prevalence features and weakness existed in present chronic disease control strategy.

[Nutrition and health status of the Beijing residents].

OBJECTIVE: To investigate the constitution and health status of the Beijing residents, and the primary influencing factors on nutrition and health, as to finding out the epidemiological characters and the changing trend of chronic diseases and to establish scientific basis for the establishment of public health and disease prevention policies of Beijing. METHODS: A stratified multi-stage cluster randomly sampling method was used. In total, 18 districts were surveyed, and among them, 9 were conducted dietary survey. The investigation was based on household, and all family members were surveyed at their home. After having got the compliance from the family members, question asking, medical examination, laboratory test and dietary investigation were carried out in these people. RESULTS: The incidence rate of hypertension was 25.0% for the resident > or = 15 year-old, and over 50% for middle-aged and elderly people (> or = 45 years old). The incidence of diabetes for those not younger than 15 years old was 7.7%. The over-weight rate and the obesity rate for adults were 35.1% and 20.6%, respectively. CONCLUSION: The following risk factors of chronic disease, such as unreasonable diet pattern, deficient intake of some micronutrients, over-weight and obesity, lack of physical examination, smoking and over-drinking, should be the important factors influencing the health of Beijing residents severely.

[Re-survey on epidemiological history of 1 091 probable cases with severe acute respiratory syndrome in Beijing].

OBJECTIVE: To know their real epidemiological histories in 1,091 probale cases of severe acute respiratory syndrome (SARS) without definite history of contact with SARS patients in the first survey. METHODS: All the probable SARS cases until June 9, 2003 without definite history of contact with SARS patients in the first epidemiological survey were included in a re-survey with questionnaire. The second survey was carried out during June 9 to 30, 2003. RESULTS: The results showed that history of contact with other SARS patients was obtained in 15.9% of 1 091 probale SRAS cases in the second survey, transmission of SARS to others was found in 10.5% of them, and source of infection in hospital was found in 46.5%. Comprehensive judgement based on epidemiological history showed that probale history of contact with SARS patients could be found in 72.9% of 1,091 probale cases of SARS in the second survey. CONCLUSION: Source of infection could be found through additional survey in part of probale cases of SARS without it in initial epidemiological survey.