Progress in prevention and control of Nipah virus disease / 中华流行病学杂志

Nipah virus disease (NVD) is a newly emerged zoonosis with a case fatality rate of 40%-75%. NVD is a severe threat to human health and the development of livestock farming. NVD has become one of the emerging infectious diseases with great concern globally during more than 20 years. Nipah virus (NiV) is a pathogen for NVD, the natural host of which is Fruit bats of the Pteropodidae family. The clinical spectrum of NiV infection is broad, including asymptomatic infection, acute respiratory infection, fatal encephalitis, and even death. Since NiV was first identified in Malaysia in 1999, it has been prevalent mainly in Southeast Asia and South Asia. NiV is primarily transmitted to humans through bat-pig-human, contaminated food. Currently, there are no specific therapeutic drugs and vaccines for NVD. Although there are no cases of NVD reported in China, which has close personnel and trade exchanges with major NVD-endemic countries, and NiV antibody has also been detected in relevant bats. There is a potential risk of importing NVD and domestic outbreaks in the future in this country. This paper provides a systematic review of the research progress in the prevention and control of NVD etiology, epidemiology, clinical manifestations and laboratory diagnosis to help relevant staff to understand NVD more comprehensively and systematically.

Course of disease and related epidemiological parameters of COVID-19: a prospective study based on contact tracing cohort / 中华预防医学杂志

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.

Analysis on characteristics and influencing factors of COVID-19 confirmed cases with viral nucleic acid re-positive after discharge in Guangdong Province / 中华预防医学杂志

Objective: To analyze the epidemiological characteristics and influencing factors of COVID-19 confirmed cases with viral nucleic acid re-positive in anal and/or throat swabs after discharge during the domestic imported epidemic stage in Guangdong Province in early 2020. Methods: The COVID-19 confirmed cases with the onset time before March 1, 2020 in Guangdong Province were collected to analyze the demographic data, epidemiological characteristics, and specimen collection and testing data after discharge. Logistic regression model was used for influencing factors analysis of re-positive cases. Results: A total of 1 286 COVID-19 confirmed cases were included, the M(Q1,Q3) of age was 44(32,58)years, 617 cases were male, 224 cases were re-positive in anal and/or throat swabs with the re-positive rate 17.42%. The M(Q1,Q3) of age of re-positive cases was 35(23, 50) years, which was younger than that of re-negative cases age was those 46(33, 59) years (P<0.001). With the increase of age, re-positive rate decreased (χ2trend=52.73, P<0.001). 85.27% (191/224) of re-positive cases were found in 14 d after discharge, the duration time of re-positive status was 13(7, 24) d, and 81.69% (183/224) of re-positive cases were re-tested negative in 28 d after re-positive date. No fever and other symptoms had been observed among re-positive cases during the whole follow-up. No secondary infectious cases had been found among close contacts after 14 d of centralized isolation and sampling screening. Univariate logistic regression model analysis revealed that the influencing factors of the re-positive cases included age, occupation, clusters, clinical types, and admission time. Multivariate logistic regression model analysis revealed that age was an independent risk factor. Conclusions: SARS-CoV-2 viral nucleic acid re-positive is found in COVID-19 confirmed cases after discharge in Guangdong Province. Most re-positive cases are confirmed among 14 d after discharge and re-test to negative among 28 d after re-positive date. Age is an risk factor for re-positive cases after discharge.

Cooperative work and mechanism in the COVID-19 containment action by the support-to-Hebei epidemiological investigation group formed by five provinces / 上海预防医学

ObjectiveTo understand the cooperative work and mechanism in the corona virus disease 2019 containment action by the support-to-Hebei epidemiological investigation group formed by five provinces， summarize the existing challenges， and discuss the relevant mechanism， so as to provide evidence for future support actions. MethodsA questionnaire survey was used to investigate the members from five provinces of the support-to-Hebei epidemiological investigation team. The content included basic information， work situation， problems in cooperative work， and suggestions in support mechanisms. ResultsA total of 104 questionnaires were issued， of which 101 valid questionnaires were collected with an effective response rate of 97.12%. The proportions of respondents who participated in the epidemic-related data preparation， case investigation， technical training， supervision of key venues， and specimen collection was 93.07%， 85.15%， 81.19%， 65.35%， and 44.55%， respectively. The respondents believed that information sharing channel of local epidemic situation was blocked （95.05%）， coordination mechanism among local departments was insufficient （84.16%）， communication and coordination mechanism among the dispatch institutions， support team， and local departments was unperfect （84.16%）， management of the dispatch institutions to the support team was relatively loose （79.21%）， dispatch institutions failed to make full use of professional advantages of the support team （72.28%）， and majority of the support team members engaged in a single profession （59.41%）. The respondents suggested that local departments should improve the information sharing mechanism （95.05%）， strengthen communication and coordination among the dispatch institutions， support team， and local departments （92.08%）， and dispatch institutions should clarify the tasks and responsibilities of the support team （91.09%）， formulate cross-regional emergency support plans （87.13%） and evaluation plans of support action （72.28%）. ConclusionIn order to ensure the efficiency and accuracy of future support actions， it is necessary to improve the mechanism of emergency coordination， communication and matching， response procedures， team management， and support evaluation.

Identification and genetic analysis of new mutations in EYA1 gene of BOS syndrome / 中华耳鼻咽喉头颈外科杂志

Objective: To analyze the clinical manifestations of a patient with branchiootic syndrome(BOS) and her families and to carry out genetic testing in order to specify the biological pathogenesis. Methods: Clinical data of the patient and her families were collected. Genomic DNA in the peripheral blood of the proband and her family members was extracted. All exons of 406 deafness-related susceptible genes as well as their flanking regions were sequenced by high-throughput sequencing, and the mutation sites of the proband and her parents were validated by Sanger sequencing. Results: There were nine members in three generations, of whom four presented with hearing loss, preauricular fistula and branchial fistula which met the diagnostic criteria of BOS. Proband and her mother presented with auricle malformation and inner ear malformation. And no one had abnormalities in the kidneys of all the patients. Pedigree analysis revealed that the mode of inheritance in the family was consistent with the autosomal dominant pattern. Mutational analysis showed that all the affected patients detected a heterozygous frameshift variation c.1255delT in the EYA1 gene, which had not been reported. Genotype and phenotype were co-isolated in this family. Such a frameshift variation produced a premature termination codon, thereby causing premature termination of translation (p.C419VFS*12). ACMG identified that the mutation was pathogenic. This mutation was novel and not detected in controls. A heterozygous missense variation mutation c.403G>A(p.G135S) in EYA1 gene was also detected in three members of this family. ACMG identified that the mutation clinical significance was uncertain. However, two of whom were normal, which seemed the disease was not caused by this mutation in this family. Conclusions: A novel frameshift mutation in EYA1(c.1255delT) is the main molecular etiology of BOS in the Chinese family. This study expands the mutational spectrum of EYA1 gene. The clinical manifestations are heterogeneous among patients in this family. The diagnosis of BOS should combine gene tests with clinical phenotypes analysis.

Analysis of genetic characteristics in two Chinese children of type Ⅱ Waardenburg syndrome / 中华耳鼻咽喉头颈外科杂志

Objective: To screen and analyze the mutations of MITF gene in two children of type Ⅱ Waardenburg syndrome (WS2) from different families in Yunnan,China,and to explore the possible molecular pathogenesis. Methods: With informed consent, medical history collection, physical examinations, audiological evaluation, and high resolution computer tomography (HRCT) scan of temporal bone were performed on the two WS2 probands and their family members. Genomic DNA was extracted from peripheral blood of all individuals. The coding regions including all exons, part of introns and promoters of MITF, PAX3, SOX10, SNAI2, END3, ENDRB, and KITLG genes were sequenced by high-throughput sequencing. According to the results of high-throughput sequencing, pathogenic mutations detected in the probands and their parents were verified by Sanger sequencing. Results: The proband 1 carried c.641_643delGAA mutation in the 7th exon of MITF gene, which was a frame-shift mutation resulting in an amino acid change of p.214delR. It was a de novo mutation as the parents of proband 1 showed no variation on this site. The proband 2 carried heterozygous loss of the large fragment ranging from exon 1 to exon 9 of MITF gene, which defected the function of MITF protein. Conclusion: Genetic examinations provide important evidence for diagnosis of Waardenburg syndrome. Heterozygous mutation c.641_643delGAA and heterozygous loss of the large fragment ranging from exon 1 to exon 9 of MITF gene might be the molecular pathogenesis of the two WS2 probands in this study.

Risk assessment and early warning of imported COVID-19 in 21 cities, Guangdong province / 中华流行病学杂志

Objective To assess the imported risk of COVID-19 in Guangdong province and its cities, and conduct early warning. Methods Data of reported COVID-19 cases and Baidu Migration Index of 21 cities in Guangdong province and other provinces of China as of February 25, 2020 were collected. The imported risk index of each city in Guangdong province were calculated, and then correlation analysis was performed between reported cases and the imported risk index to identify lag time. Finally, we classified the early warming levels of epidemic by imported risk index. Results A total of 1 347 confirmed cases were reported in Guangdong province, and 90.0% of the cases were clustered in the Pearl River Delta region. The average daily imported risk index of Guangdong was 44.03. Among the imported risk sources of each city, the highest risk of almost all cities came from Hubei province, except for Zhanjiang from Hainan province. In addition, the neighboring provinces of Guangdong province also had a greater impact. The correlation between the imported risk index with a lag of 4 days and the daily reported cases was the strongest (correlation coefficient: 0.73). The early warning base on cumulative 4-day risk of each city showed that Dongguan, Shenzhen, Zhongshan, Guangzhou, Foshan and Huizhou have high imported risks in the next 4 days, with imported risk indexes of 38.85, 21.59, 11.67, 11.25, 6.19 and 5.92, and the highest risk still comes from Hubei province. Conclusions Cities with a large number of migrants in Guangdong province have a higher risk of import. Hubei province and neighboring provinces in Guangdong province are the main source of the imported risk. Each city must strengthen the health management of migrants in high-risk provinces and reduce the imported risk of Guangdong province.

Clinical outcomes of COVID-19 cases and influencing factors in Guangdong province / 中华流行病学杂志

Objective To analyze the clinical courses and outcomes of COVID-19 cases and the influencing factors in Guangdong province and provide basis for the formulation or adjustment of medical care and epidemic control strategy for COVID-19. Methods We collected demographic data, medical histories, clinical courses and outcomes of 1 350 COVID-19 patients reported in Guangdong as of 4 March 2020 via epidemiological investigation and process tracking. Disease severity and clinical course characteristics of the patients and influencing factors of severe illness were analyzed in our study. Results Among 1 350 cases of COVID-19 cases in Guangdong, 72 (5.3%) and 1049 (77.7%) were mild and ordinary cases, 164 (12.1%) were severe cases, 58 (4.3%) were critical cases and 7 (0.5%) were fatal. The median duration of illness were 23 days ( P 25 - P 75 : 18-31 days) and the median length of hospitalization were 20 days ( P 25 - P 75 : 15-27 days). For severe cases, the median time of showing severe manifestations was on the 12th day after onset ( P 25 - P 75 : 9th to 15th days), and the median time of severe manifestation lasted for 8 days P 25 - P 75 : 4-14 days). Among 1 066 discharged/fetal cases, 36.4% (36/99) and 1.0% (1/99) of the mild cases developed to ordinary cases and severe cases respectively after admission; and 5.2% (50/968) and 0.6% (6/968) of the ordinary cases developed to severe cases, and critical cases respectively after admission. In severe cases, 11.4% developed to critical cases (10/88). The influencing factors for severe illness or worse included male (a HR =1.87, 95% CI : 1.43-2.46), older age (a HR =1.67, 95% CI : 1.51-1.85), seeking medical care on day 2-3 after onset (a HR =1.73, 95% CI : 1.20-2.50) pre-existing diabetes (a HR =1.75, 95% CI : 1.12-2.73) and hypertension (a HR =1.49, 95% CI : 1.06-2.09). Conclusions The course of illness and length of hospitalization of COVID-19 cases were generally long and associated with severity of disease clinical outcomes. The severe cases were mainly occurred in populations at high risk. In the epidemic period, classified management of COVID-19 cases should be promoted according to needs for control and prevention of isolation and treatment for the purpose of rational allocation of medical resources.

Comparison of two epidemic patterns of COVID-19 and evaluation of prevention and control effectiveness: an analysis based on Guangzhou and Wenzhou / 中华流行病学杂志

Objective To compare the epidemiological characteristics of COVID-19 in Guangzhou and Wenzhou, and evaluate the effectiveness of their prevention and control measures. Methods Data of COVID-19 cases reported in Guangzhou and Wenzhou as of 29 February, 2020 were collected. The incidence curves of COVID-19 in two cities were constructed. The real time reproduction number ( R t ) of COVID-19 in two cities was calculated respectively. Results A total of 346 and 465 confirmed COVID-19 cases were analysed in Guangzhou and Wenzhou, respectively. In two cities, most cases were aged 30-59 years (Guangzhou: 54.9%; Wenzhou: 70.3%). The incidence curve peaked on 27 January, 2020 in Guangzhou and on 26 January, 2020 in Wenzhou, then began to decline in both cities. The peaks of imported COVID-19 cases from Hubei occurred earlier than the peak of COVID-19 incidences in two cities, and the peak of imported cases from Hubei occurred earlier in Wenzhou than in Guangzhou. In early epidemic phase, imported cases were predominant in both cities, then the number of local cases increased and gradually took the dominance in Wenzhou. In Guangzhou, the imported cases was still predominant. Despite the different epidemic pattern, the R t and the number of COVID-19 cases declined after strict prevention and control measures were taken in Guangzhou and in Wenzhou. Conclusion The time and scale specific differences of imported COVID-19 resulted in different epidemic patterns in two cities, but the spread of the disease were effectively controlled after taking strict prevention and control measures.

Chemical constituents from Achyrocline satureioides (I) / 中草药

Objective To study the chemical constituents from Achyrocline satureioides. Methods Chemical constituents from A. satureioides were separated and purified by a variety of chromatographic techniques, and their structures were identified by various spectroscopic methods. Results Twenty-one compounds were isolated from ethyl acetate fraction of the plant, which were α-amyrin (1), ergosta-4,6,8,22-tetraene-3-one (2), (R)-24-ethylcholest-4-en-3,6-dione (3), clovandiol (4), caryolane-1,9β-diol (5), lepidissipyrone (6), 5,7-dihydroxy-3,6-dimethoxyflavone (7), quercetin-7-O-β-D-glucoside (8), pinocembrin (9), (2R,3R)-taxifolin (10), quercetin-4’-O-β-D-glucoside (11), helichrysetin (12), 3-[5,7-dihydroxy-2,2-dimethyl-8-(2-(S)-methyl-butanoyl)-2H-chromen-6- yl-methyl]-6-ethyl-4-hydroxy-5-methyl-pyran-2-one (13), quercetin (14), protocatechuic acid (15), (+)-(3R)-3-hydroxyl-4,4- dimethyl-4-butyrolactone (16), (4S,5R)-5-(4’-methyl-3’-pentenyl)-4-hydroxy-5-methyldihydrofuran-2-one (17), genkwanin (18), quercetin-3-methyl ether (19), galangin (20), and neosakuranin (21). Conclusion Compounds 1, 4, 5, 16, 17, and 21 are obtained from the genus for the first time, and compounds 1-12, 16-18, and 21 are obtained from the plant for the first time.

Strategy for prevention and control of imported infectious disease / 中华流行病学杂志

The process of globalization increases the risk of global transmission of infectious diseases,resulting in pressure for country's prevention and control of imported infectious disease.Based on the risk assessment of disease importation and local transmission,a strategy that conducting importation prevention and routine prevention and control before the importation of disease and taking emergency control measures after the importation of disease was developed.In addition,it is important to take part in global infectious disease response action,aid the countries with outbreak or epidemic to actively decrease the risk of disease importation.

Epidemiological characteristics of influenza in Guangdong province, during winter of 2017-2018 / 中华流行病学杂志

Objective To understand the epidemiological characteristics of influenza in Guangdong province,during the winter of 2017-2018,to provide evidence for response to the diversity of influenza,in different seasonal patterns.Methods Data on weekly influenza surveillance from January 2016 to April 2018,were collected in Guangdong.Information on patients with Influenza-like illness (ILI),on influenza virus positive rates and on outbreaks during the winter of 2017 to 2018,was analyzed and compared with those in spring of 2016 and summer of 2017.x2 test and Fisher exact test were used.Results In the above said winter,the average percentage of visits for ILI in 28 hospitals where sentinel surveillance program had been set,was 4.99％ (157 235/3 149 656),which was above the level of the same period in the previous five years.The positive rates of influenza virus among samples collected from ILI outpatients and hospitalized cases under severe acute respiratory infection (SARI) were 28.33％ (2 137/7 543) and 14.93％ (256/1 715),with the proportions of B (Yamagata) as 70.43％ (1 505/2 137) and 73.05％ (187/256) respectively.A total of 257 influenza outbreaks were reported in the winter period,with 82.49％ (212/257) occurred in elementary schools.Cases aged 6-14 years occurred in winter and spring appeared of having higher positive rate than those seen in summer (P＜0.05) whereas elderly cases aged 60 and above showed higher positive rate in summer than those in winter and spring two seasons (P＜0.05).Conclusions Epidemiological characteristics of influenza appeared in Guangdong province,during the winter from 2017 to 2018,were correlated to Influenza B (Yamagata).Capacity on the implementation of surveillance programs and on the coverage of vaccination should be improved and increased in order to control influenza in different epidemic seasons,in Guangzhou.

Strategy for prevention and control of imported infectious disease / 中华流行病学杂志

The process of globalization increases the risk of global transmission of infectious diseases,resulting in pressure for country's prevention and control of imported infectious disease.Based on the risk assessment of disease importation and local transmission,a strategy that conducting importation prevention and routine prevention and control before the importation of disease and taking emergency control measures after the importation of disease was developed.In addition,it is important to take part in global infectious disease response action,aid the countries with outbreak or epidemic to actively decrease the risk of disease importation.

Epidemiological characteristics of influenza in Guangdong province, during winter of 2017-2018 / 中华流行病学杂志

Objective To understand the epidemiological characteristics of influenza in Guangdong province,during the winter of 2017-2018,to provide evidence for response to the diversity of influenza,in different seasonal patterns.Methods Data on weekly influenza surveillance from January 2016 to April 2018,were collected in Guangdong.Information on patients with Influenza-like illness (ILI),on influenza virus positive rates and on outbreaks during the winter of 2017 to 2018,was analyzed and compared with those in spring of 2016 and summer of 2017.x2 test and Fisher exact test were used.Results In the above said winter,the average percentage of visits for ILI in 28 hospitals where sentinel surveillance program had been set,was 4.99％ (157 235/3 149 656),which was above the level of the same period in the previous five years.The positive rates of influenza virus among samples collected from ILI outpatients and hospitalized cases under severe acute respiratory infection (SARI) were 28.33％ (2 137/7 543) and 14.93％ (256/1 715),with the proportions of B (Yamagata) as 70.43％ (1 505/2 137) and 73.05％ (187/256) respectively.A total of 257 influenza outbreaks were reported in the winter period,with 82.49％ (212/257) occurred in elementary schools.Cases aged 6-14 years occurred in winter and spring appeared of having higher positive rate than those seen in summer (P＜0.05) whereas elderly cases aged 60 and above showed higher positive rate in summer than those in winter and spring two seasons (P＜0.05).Conclusions Epidemiological characteristics of influenza appeared in Guangdong province,during the winter from 2017 to 2018,were correlated to Influenza B (Yamagata).Capacity on the implementation of surveillance programs and on the coverage of vaccination should be improved and increased in order to control influenza in different epidemic seasons,in Guangzhou.

Bergapten attenuates D-galactose-induced immunosenescence in BALB/c mice / 中国药理学与毒理学杂志

OBJECTIVE Bergapten (BG), is a furanocoumarin derived from herbal and citrus extracts can act as antioxidant and selective anticancer agents.The current study aimed to investigate whether bergapten would attenuate immunosenescence and to exploreits immunomodulatory effects on immune responses in D-galactose-induced aging BALB/c mice.METHODS Firstly,mice were given D-galactose(180 mg·kg-1)subcutaneous injections for 30 d.To evaluate the establishment of the aging-related effect in mice, serum samples of BALB/c mice were collected from tail vein. Aging BALB/c mice were freely divided into three groups: negative control group received 1% Tween 80 solution only, named D-gal group. Positive groups were received BG administration at the dose of 20 and 100 mg·kg-1, named D-gal+BG(20)group and D-gal+BG(100)group,respectively.Effects of bergapten on T lympho-cyte proliferation and flow cytometry were assessed by using the splenic cell suspension. Enzyme linked immunospot kits were used to quantitatively determine interferon-γ(IFN-γ)and interleukin-4(IL-4) levels of the isolated serum. Immunophenotype was determined by using mixture of antibodies includ-ing anti-CD3,anti-CD4,and anti-CD8.RESULTS Bergapten(20 mg·kg-1)therapy can modulate immu-nity against viral epidemics and attenuate aging-induced immune deficiency(P<0.01),which was correlat-ed with the decline in the activation of the Th and Tc responses in D-galactose induced aging BALB/c mice.According to the in vivo results,bergapten exposure up-regulated the secretion of IFN-γ and IL-4 in T-helper 1(Th1)and T helper 2(Th2)cells(P<0.05,P<0.01).Additionally,BG(20 mg·kg-1)restored antigen-specific CD4+and CD8+T cells in aging models (P<0.05, P<0.01), which may help to curing chronic infections. CONCLUSION The beneficial effect of bergapten in D-galactose induced aging BALB/c mice may be due to the Th and Tc responses activation.

Research progress on iridoid compounds in plants from Rubiaceae / 中草药

Iridoid compounds have wild variety, including ordinary, split ring, dipolymer, and other types, which are found in various genus of the Rubiaceae widely. It has the functions of antitumor, antidepression, anti-inflammation and cell protection, etc. This paper reviews the research progress of iridoid compounds in plants from Rubiaceae, which provides theoretical supports for the application breakthrough of chemical constituents.

The effects of closure to live poultry markets on Avian influenza A (H7N9) epidemics in China / 中华流行病学杂志

Since March 2013,China had experienced five seasonal epidemics related to Avian influenza A (H7N9).An unprecedented outbreak of H7N9 epidemic started from September 2016,with 730 cases reported till June 30th 2017,in mainland China that caused profound influences on both social development and health of the people.As an emerging infectious disease,information on pathogenic characteristics,transmission patterns and other epidemiological features of H7N9 virus somehow remained unclear.Data from previous studies suggested that the live poultry market (LPM) seemed to have served as main places where H7N9 virus got originated,mutated,spread and thus infected the human beings.Hence,closure of LPMs was suggested a major measure to control and prevent H7N9 epidemics in China.However,the effectiveness of different ways of LPM closures on H7N9 epidemics had been controversial.This study systemically summarized the effects of different ways of LPM closures on H7N epidemics from previous studies,aiming to provide references for developing a better program on H7N9 control and prevention in the country.

The effects of closure to live poultry markets on Avian influenza A (H7N9) epidemics in China / 中华流行病学杂志

Since March 2013,China had experienced five seasonal epidemics related to Avian influenza A (H7N9).An unprecedented outbreak of H7N9 epidemic started from September 2016,with 730 cases reported till June 30th 2017,in mainland China that caused profound influences on both social development and health of the people.As an emerging infectious disease,information on pathogenic characteristics,transmission patterns and other epidemiological features of H7N9 virus somehow remained unclear.Data from previous studies suggested that the live poultry market (LPM) seemed to have served as main places where H7N9 virus got originated,mutated,spread and thus infected the human beings.Hence,closure of LPMs was suggested a major measure to control and prevent H7N9 epidemics in China.However,the effectiveness of different ways of LPM closures on H7N9 epidemics had been controversial.This study systemically summarized the effects of different ways of LPM closures on H7N epidemics from previous studies,aiming to provide references for developing a better program on H7N9 control and prevention in the country.

Serological Study of An Imported Case of Middle East Respiratory Syndrome and His Close Contacts in China, 2015 / 生物医学与环境科学（英文）

The first imported Middle East respiratory syndrome (MERS) case in China was identified in May 2015. We determined the kinetics of antibody (IgG and IgM) and neutralizing antibodies against MERS-coronavirus (MERS-CoV) in this case before discharge. Moreover, no seroconversion was found among 53 close contacts by anti-MERS IgG antibody enzyme-linked immunosorbent assay (ELISA) of paired serum samples. These findings suggest that neither community nor nosocomial transmission of MERS-CoV occurred in China.

Establishment of an inactivated viral particle-based ELISA for the detection of anti-MERS-CoV anti-bodies / 中华微生物学和免疫学杂志

Objective To establish an inactivated viral particle-based ELISA for the detection of antibodies against Middle East respiratory syndrome coronavirus (MERS-CoV) in serum samples collected from a MERS-CoV associated case. Methods Serum samples were collected from 10 newborns and 40 healthy adults. A viral particle-based ELISA was established by using the inactivated MERS-CoV virions as antigen. The levels of IgM and IgG antibodies in the serum samples were detected by the established ELISA and the cut-off values for positive detection were determined. Then the inactivated MERS-CoV virion-based ELISA was used to detect the antibodies against MERS-CoV in 5 serum samples collected from the first im-ported MERS case in China. Results The cut-off values of IgM and IgG antibodies in serum samples for ELISA were determined to be A450 readings of 0. 32 and 0. 42, respectively. The titers of IgM and IgG anti-bodies in serum samples collected at early admission to hospital from the first imported MERS case in China were both 1 ︰ 40. Seroconversion occurred 2 weeks after his admission to hospital with the titers of IgM and IgG reaching to 1 ︰ 320. Conclusion The inactivated MERS-CoV virion-based ELISA was established successfully and could be used for the detection of serum antibodies (IgG and IgM) in MERS associated cases.