Objective To investigate the influence of host animals on epidemics of hemorrhagic fever with renal syndrome (HFRS) so as to provide a basis for effective control of HFRS.Methods From the national infectious disease network direct reporting system,the incidence of HFRS cases diagnosed by direct diagnosis of medical institutions in Qingdao was collected from 2011-2015.We captured rats indoor and outdoor by night trapping method quarterly and calculated the capture rates from 2011-2015 in Qingdao areas.The incidence of HFRS in different regions and the change of seasonal growth,the distribution of host animals,the characteristics and distribution of animals,and the seasonal variation of dominant species were analyzed and a database was set up and statistic analysis was conducted by SPSS 13.0.Results The peak incidence rate of HFRS in Qingdao areas occurred in 2012 (3.54/100 000) and presented a decrease trend year by year (x2 =64.15,P ＜ 0.05),but there were different characteristics among the epidemic areas,and lowest in 2015 (1.68/100 000).And the peak presented a two-peak pattern which was mainly an autumn peak and a gentle peak in late spring and early summer.The epidemics were gradually decreased from the rural areas to the urban fringes and then the urban areas.The seasonal variation was disappeared gradually.There was a heavy epidemic intensity in areas with a high capture rate and a complex type of host animals.The epidemic peak was in consistence with the distribution of rats.Capture rates were different among the epidemic areas.The capture rate in Jiaonan was the highest [5.32％(2 886/54 287)] and lowest in Pingdu [1.77％ (258/14 584)].The mean (x2 =820.39,P ＜ 0.05) and annual capture rates (x22011-2015 =32.61,356.24,233.07,129.33,33.42,all P ＜ 0.05) among epidemic areas were different.In the third quarter the accumulated capture rate was the highest [4.69％ (1 187/25 301)].In total 8 kinds of host animals were captured and the dominant species were brown rat [30.27％ (1 235/4 080)],house mouse[29.75％ (1 214/4 080)] and striped field mouse [16.25％ (663/4 080)].Conclusions The epidemic intensity of HFRS is related to the densities and the types of host animals.The gradually decreased epidemic pattern from the rural areas to the urban fringes and then the urban areas may be related to urbanization and improved health behaviors.

Teaching of Critical Care Medicine faces several challenging issues includingcomprehensive intensive or specialist intensive, approach of curriculum, tralning of team working ability, building of teaching platform and teaching staff. Critical care medical education requires the concept of viewing the discipline as a whole. Under its guidance and with the opportunity of critical care medical subspecialties building, critical care medical education should focus on bothcompre-hensive critical care and specialist critical care, and have rational planning of Critical Care Medicine course. Through the construction and integration of ICU, we should create a comprehen-sive clinical practice platform of critical care medicine to carry out clinical practice and team work tralning. Meanwhile, construction of quality critical care medicine faculty should be based on its pro-fessional features.

Objective To understand the ecological developmental characteristics of rats in the epidemic areas of hemorrhagic fever with renal syndrome (HFRS) so as to provide a basis for effective control of HFRS.Methods Based on the China National Disease Surveillance Reporting and Management System,data of HFRS cases from 2010 to 2014 were collected and analyzed by retrospective analysis.Meanwhile surveillance data of rats were collected and the capture rates in different seasons,genders and districts were also analyzed.Results Totally 51,92,129,85 and 71 cases of HFRS were reported from 2010 to 2014.Most HFRS cases occurred from October to November which were 43,59,78,37 and 37,respectively.Totally 2902 rats were captured from 2010 to 2014.The five-year average capture rate was 4.87％ (2902/59610).The highest capture rate was 6.94％ (910/13107) in the third quarter and the outdoor capture rate (5.80％,1681/28987) was higher than that of indoor(3.99％,1221/30623,x2 =324.35,P ＜ 0.05).More male rats were captured than female rats and the overall proportion was 62.82％ (348/554) and 37.18％ (206/554),respectively.The outdoor rats were mainly Apodemus agrarius (556),Cricetulus triton (432),Rattus noruegicus (217),Mus musculus (211) and Sorex araneus (139),and the indoor rats were mainly Mus musculus (514),Rattus noruegicus (469) and Sorex araneus (181).The black rat disappeared and White-bellied rat appeared.Conclusions The rat density keeps higher all year round and the type of rats has become increasingly complex.Mixed living of indoor and outdoor rats increased the infection probability of different types of Hantavirus,which has an immediate impact on the spreading pattern of HFRS.

Objective:To analyze the epidemiological characteristics and co-infections of pathogens in children with pneumonia in autumn and winter of 2019 in Qingdao.Methods:From August to November in 2019, 77 children with pneumonia in three hospitals in Qingdao were selected as the research subjects. Throat swabs were collected, nucleic acid was extracted, and 20 common respiratory pathogens were detected by single tube multiplex PCR.Results:Among the 77 cases, the incidence of pneumonia in boys (53.2%) was slightly higher than that in girls (46.7%). Children aged 1-2 years accounted for 10.3% of the total cases, children aged 3-6 years accounted for 61%, and children aged 7-13 years accounted for 20.7%. Twenty-nine cases (38.10%) had high white blood cells; 16 cases (20.77%) had high neutrophil count; 30 cases (38.96%) had high lymphocyte count; the pathogen detection rate was 77.92% of cases, among whom Mycoplasma pneumoniae (MP) was 59.74%, Bocavirus was 10.39%(8/77), adenovirus was 7.79% (6/77), rhinovirus was 3.89% (3/77), parainfluenza virus type 4 was 3.89% (3/77), Bordetella pertussis was 3.89% (3/77), parainfluenza virus type 2 was 2 2.59% (2/77), coronavirus nl63/hku1 was 2.59% (2/77), coronavirus OC43 was 2.59% (2/77), human metapneumovirus was 1.29% (1/77), Parainfluenza virus type 3 was 1.29%(1/77). The 24 cases of virus infection accounted for 31.16% (24/77). The co-infection with two pathogens accounted for 18.18%.Conclusions:Many kinds of pathogens were detected in children with pneumonia in autumn and winter of 2019, in Qingdao. The prevalence of Mycoplasma pneumoniae infection was the highest. Many common viral infections were found in the cases. A high proportion of co-infection was detected in these pneumonia cases.

Objective To investigate the influence of the variations of an epidemic focus on hemorrhagic fever with renal syndrome (HFRS) so as to provide a basis for effective control of HFRS.Methods HFRS epidemic data from the rapid development of urbanization of Huangdao District and the general development of Jiaonan City were collected and analyzed retrospectively from 1979 to 2014.And the HFRS cases,incidences,host animals and Hantavirus surveillances were compared.Results The three epidemic peaks occurred from 1979 to 2014 in Huangdao District and Jiaonan City,they were in the mid-1980s (1983-1987),the late 1990s (1995-1999) and around 2012 (2010-2014),and 954,80,37 and 2 506,614,432 cases were reported,respectively,in Huangdao District and Jiaonan City.The three peak years were 1986,1999 and 2012.And the annual incidences of Huangdao District were 385.73/100 000,15.64/100 000 and 2.51/100 000,respectively.The annual incidences of Jiaonan City were 67.07/100 000,28.68/100 000 and 14.68/100 000,respectively.The three peaks obviously appeared double peaks [the autumn and winter (from Oct.to Dec.) and the spring (from Jan.to Feb.)] in Jiaonan City.And the first peaks in Huangdao District was in the autumn and winter (from Oct.to Dec.) and the spring (from Jan.to Feb.),the second and the third were only in the autumn and winter (from Oct.to Dec.).Eight kinds of host animals were detected in Jiaonan City from 2005 to 2014.They were house mouse [27.53％ (1 108/4 024)],brown rat [25.50％ (1 026/ 4 024)],striped field mouse [14.84％ (597/4 024)],black rat [10.74％ (432/4 024)],hamsters [11.01％ (443/4 024)],shrew [8.72％ (351/4 024)],back grain hamster [1.02％ (41/4 024)] and club rat [0.65％ (26/4 024)].Two kinds of host animals were detected in Huangdao District.They were house mouse [57.14％ (16/28)] and brown rat [42.86％ (12/28)].The capture rates in Jiaonan City were higher than those of Huangdao District.The capture rate in 2012 was 8.04％ (855/10 638) and the capture rates in Huangdao District were all lower than 0.84％.The total detection rate in Jiaonan City was 2.81％ (113/4 024).And there was no positive detection for ten years in Huangdao District.Conclusions HFRS epidemic intensities have receded gradually in Huangdao District and Jiaonan City.The epidemic in Huangdao District obviously presents a low epidemic condition after the first peak.The few kinds and low densities of host animals are resulting in the sustainable condition.The evolution of epidemic patterns of HFRS is related to the change of epidemic sources by the differences in urbanization between the two places.

Objective:To analyze the epidemiological characteristics and genotypes of human rhinovirus (HRV) in patients with upper respiratory tract infection in Qingdao in the winter of 2020.Methods:Throat swab samples were collected from 101 patients with upper respiratory tract infection in Qingdao from November 2020 to January 2021. Quantitative PCR was used to detect 15 common respiratory viruses in the samples. HRV-positive samples were further analyzed with RT-PCR to amplify and sequence HRV VP4/VP2 gene. A phylogenetic tree was constructed based on the sequencing results and homology analysis was conducted.Results:Six common respiratory viruses were detected in the 101 patients. Thirty-four cases (34/101, 33.66%) were single pathogen infection and two cases were multiple infection (2/101, 1.98%). The positive rate of HRV was the highest (21.78%, 22/101). Twenty HRV VP4/VP2 sequences were successfully amplified. Phylogenetic analysis showed that there were 16 strains of HRV-A subtype and four strains of HRV-C subtype and 14 serotypes were involved.Conclusions:HRV was one of the leading viral pathogens causing upper respiratory tract infection in Qingdao in the winter of 2020 and the predominant subtype was HRV-A.

Objective:To investigate the contamination status of SARS-CoV-2 in imported frozen seafood from a Russia cargo ship in Qingdao and to analyze the risk factors for infection in local stevedores.Methods:The method of "two-stage, full coverage and mixed sampling" was used to collect the seafood packaging samples for the nucleic acid detection of SARS-CoV-2 by real-time fluorescent quantitative RT-PCR. A unified questionnaire was designed to investigate 71 stevedores in two shifts through telephone interview. The stevedores were divided into two groups, with 23 in the shit with two infections was group A and 48 in the shift without infection was group B. Software Epi Info7.2 was used to identify the risk factors for SARS-CoV-2 infections in the stevedores.Results:In the frozen seafood from a Russia cargo ship, the total positive rate of SARS-CoV-2 nucleic acid in the frozen seafood was 11.53% (106/919). The positive rate of SARS-CoV-2 nucleic acid in the frozen seafood unloaded by group A (14.29%,70/490) was significantly higher than that in the frozen seafood unloaded by group B (8.39%,36/429)( χ2=7.79, P=0.01) and the viral loads detected in the frozen seafood unloaded by group A were higher than those detected in the frozen seafood unloaded by group B. The scores of personal protection and behaviors in the stevedores in group A were significantly lower than those in group B ( P<0.05), and toilet use, smoking and improper hand washing before meals were the risk factors for the infection. Conclusions:The imported frozen seafood was contaminated by SARS-CoV-2 and the contamination distribution was uneven. Supervision and management of personal occupational protection and behaviors of workers engaged in imported frozen food transportation should be strengthened. It is suggested that a closed-loop monitoring and management system for the whole process of "fishing-transport- loading/unloading" should be established by marine fishery authority.

Objective:To understand the prevalence of coxsackievirus A6 (CV-A6) in hospitalized patients with hand, foot and mouth disease in autumn and winter of 2019, and the genetic characteristics of VP1 region and the relation-ship between germline evolution.Methods:A total of 104 throat swabs from hospitalized patients with hand, foot and mouth disease in Qingdao in autumn and winter of 2019, and screen positive specimens were collected using enterovirus universal real-time PCR technology. Then the universal typing primers in the VP1 region were used to amplify the positive samples, the amplified segments were sequenced and BLAST comparison was performed. CV-A6 VP1 full-length primers were used to amplify the BLAST comparison of CV-A6 positive samples, sequence the ampli-fied products, analyze the homology of nucleotides and amino acids through DNAstar and MEGA software, and construct a phylogenetic tree.Results:Among 104 throat swab samples, 60 were positive for enterovirus, and the overall positive rate was 57.7%, of which the positive rate of CV-A6 was 26.9% (28/104), and the rate of coxsackievirus A16 (CV-A6) was 30.8% (32/104). Twenty-eight CV-A6 positive samples were subjected to full-length amplification, sequencing, comparison and homology analysis of the VP1 region, and 22 positive sequences were obtained. The nucleotide homology was 93.6% to 99.9%, and the amino acid homology was 98.0%-100%. Phylogenetic analysis showed that 22 CV-A6 strains belonged to the D3 subtype in the D genotype.Conclusions:The pathogens causing hospitalized hand, foot and mouth disease in Qingdao in autumn and winter of 2019 were CV-A6 and CV-A16. The prevalent strains of CV-A6 were mainly D3 subtypes.

Objective:To Isolate and identify human rhinovirus (HRV) in hospitalized children with pneumonia in Qingdao in 2020.Methods:A total of 98 throat swab samples were collected from hospitalized children with pneumonia in 2020. Common respiratory viruses were screened through RT-qPCR. The HRV positive samples were inoculated into H1-HeLa cells. Viruses with typical cytopathic effect (CPE) were identified by HRV specific RT-PCR. Subsequently, sequences of HRV-VP4/VP2 gene were used to construct phylogenetic trees and analyze homology with sequences of reference strains through MEGA software.Results:Among 98 hospitalized children with pneumonia, 11 samples were HRV positive in 98 throat swab samples. After the typical CPE appeared in HeLa cells, two strains of HRV were identified by specific RT-PCR. The HRV-A28 and HRV-A58 were confirmed by comparison and analysis of VP4/VP2 sequence. Phylogenetic tree found that the isolated HRV-A28 strain was genetically close to strains of Singapore in 2011, of Tunisia in 2017, and Kenya in 2017. The isolated HRV-A58 strain was genetically close to the strains of Australia in 2009, Venezuela in 2011, Mongolia in 2011, and the United States in 2014.Conclusions:The HRV-A28 and HRV-A58 strains were isolated from the throat swabs of children patients with pneumonia in Qingdao.

Objective To explore the influence of agricultural mechanization progress on epidemic intensity of hemorrhagic fever with renal syndrome (HFRS) so as to provide reference for prevention and control of HFRS in rural areas.Methods Data of HFRS epidemics and agricultural mechanization progress of Qingdao City and five main epidemic areas of HFRS were collected by retrospective analysis methods.Agricultural mechanization progress,time distribution,incidence rate of HFRS and capture rate of rats were compared,respectively.Risk factors were analyzed by case-control study using simple random sampling method.Cases of case group were selected from HFRS cases of Jiaonan County recovered between 2012 and 2013.The control group was healthy residents with a equal number of the case group.Residential locations,work ways,rodent infestation at work locations and in residential areas and skin injury conditions were surveyed by a household questionnaire survey.Results Agricultural machinery gross power of Qingdao City was developed from 174.76 megawatts of electricity (mwe) in 1985 to 854.00 mwe in 2015.The comprehensive mechanization degree marched from 60.0％ in 1994 to 90.2％ in 2015.HFRS incidence in Qingdao City declined from the first epidemic peak (1986) of 32.97/100 000 to the third peak (2012) of 3.54/100 000.HFRS incidence in Jiaonan,Jiaozhou,Pingdu,Laixi,Jimo cities reduced from the first epidemic peak (1985 or 1986) of 101.25/100 000,86.37/100 000,35.80/100 000,11.55/100 000,8.13/100 000 to the third peak(2012) of 14.68/100 000,4.43/100 000,2.33/100 000,6.02/100 000,3.26/100 000.The platform stage of epidemic peak in autumn and winter shortened from 4 or 5 months to 2 months.The capture rate of rats fluctuated around 2％.The infection risk of small farm implements or handwork was greater than huge mechanization (OR =0.01,P ＜ 0.01).Conclusions Agricultural mechanization changes the agricultural activity patterns to a large extent and lowers the HFRS epidemic by minimizing the risk of infection and shortening the platform stage of epidemic peak.The higher the degree of mechanization,the lower the epidemic intensity.