Epidemiological characteristics and serum antibody detection of a COVID-19 aggregated outbreak in vaccinated population / 中华预防医学杂志

An epidemiological investigation was conducted on a cluster epidemic of COVID-19 in the vaccinated population in Beijing in 2022, and serum samples were collected from 21 infected cases and 61 close contacts (including 20 cases with positive nucleic acid in the isolation observation period). The results of antibody detection showed that the IgM antibody of two infected persons was positive, and the IgG antibody positive rates of patients who were converted, not converted to positive and infected persons were 36.84% (7/19), 63.41% (26/41) and 71.43% (15/21), respectively. About 98.78% of patients had been vaccinated with the SARS-CoV-2 inactivated vaccine. The positive rate of IgG antibody in patients immunized with three doses of vaccine was 86.00% (43/50), which was higher than that in patients with one or two doses [16.12% (5/31)]. The antibody level of M (Q1, Q3) in patients immunized with three doses was 4.255 (2.303, 7.0375), which was higher than that in patients with one or two doses [0.500 (0.500, 0.500)] (all P values<0.001). The antibody level of patients who were vaccinated less than three months [7.335 (1.909, 7.858)] was higher than that of patients vaccinated more than three months after the last vaccination [2.125 (0.500, 4.418)] (P=0.007). The positive rate and level of IgG antibody in patients who were converted to positive after three doses were 77.78% (7/9) and 4.207 (2.216, 7.099), respectively, which were higher than those in patients who were converted after one or two doses [0 and 0.500 (0.500, 0.500)] (all P values<0.05).

Analysis on infection sources and transmission chains of three outbreaks caused by 2019-nCoV Omicron variant in Beijing, China / 中华流行病学杂志

Objective: To investigate the infection sources and the transmission chains of three outbreaks caused by 2019-nCoV Omicron variant possibly spread through cross-border logistics in Beijing. Methods: Epidemiological investigation and big data were used to identify the exposure points of the cases. Close contacts were traced from the exposure points, and the cases' and environmental samples were collected for nucleic acid tests. Positive samples were analyzed by gene sequencing. Results: The Omicron variant causing 3 outbreaks in Beijing from January to April, 2022 belonged to BA.1, BA.1.1 and BA.2. The outbreaks lasted for 8, 12 and 8 days respectively, and 6, 42 and 32 cases infected with 2019-nCoV were reported respectively. International mail might be the infection source for 1 outbreak, and imported clothes might be the infection sources for another 2 outbreaks. The interval between the shipment start time of the imported goods and the infection time of the index case was 3-4 days. The mean incubation period (Q1, Q3) was 3 (2,4) days and the mean serial interval (Q1, Q3) was 3 (2,4)days. Conclusions: The 3 outbreaks highlighted the risk of infection by Omicron variant from international logistics-related imported goods at normal temperature. Omicron variant has stronger transmissibility, indicating that rapid epidemiological investigation and strict management are needed.

Studies on prevalence and control of several common chronic diseases among Beijing adults in 2005 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the prevalence and control of several common chronic disease in Beijing adults.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Nutrition and health status of the Beijing residents / 中华预防医学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Re-survey on epidemiological history of 1 091 probable cases with severe acute respiratory syndrome in Beijing / 中华预防医学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>Source of infection could be found through additional survey in part of probale cases of SARS without it in initial epidemiological survey.</p>