OBJECTIVEAn epidemic of severe acute respiratory syndrome (SARS) hit Beijing, China, between March and July 2003 with an attack rate of 1.9 per 10 thousand. (2,521 cases). To control the epidemic of SARS, a total of 30,173 residents were quarantined either in their residence or in quarantine sites. In order to understand the personal need of being quarantined and to estimate the risk of developing SARS during the quarantine period, a survey on the quarantined residents of Haidian District, Beijing, China was carried out.

METHODS33 precincts in Haidian District divided into five groups (7 in north, 6 in south, 7 in west, 6 in east and 7 in central of Haidian District) according to the location of the precincts were involved. The director of Center of Disease Control and Prevention of Haidian District was asked to select 1 precinct from each group according to the workload of the precinct quarantine officers. From those 5 precincts we obtained lists of all quarantined persons from the precinct quarantine officers. All quarantinees were asked to complete a self-administered questionnaire. The SARS patients were diagnosed and verified according to the diagnosis criteria released by Chinese Ministry of Health which was equivalent to the SARS 'probable case' definition of WHO. All SARS cases had been reported to the relative authorities.

RESULTSBy May 23, 2003, 5,186 persons had been quarantined in Haidian district, accounting for 0.23% of all residents. 1,028 of sampled quarantined residents completed the questionnaire. Of those who completed the questionnaire, 2.3% (95% CI: 1.5% - 3.5%) developed SARS while under quarantine. The median quarantine period was 14 days (range 1 day to 28 days). 61% of the quarantinees had a direct contact history with SARS patients, and all secondary SARS patients developed through contact to these quarantinees. The remaining 39% quarantinees who did not have a direct contact history with SARS patients had not developed SARS during the period under quarantine. 37% of the quarantees had direct contact during original patients' symptomatic period with an AR of 6.3%. Persons who looked after the illed SARS patient(s) during their symptomatic period, had an highest attack rate of 31% (95% CI: 20% - 44%). 63% (95% CI: 60% - 66%) of the total quarantined persons did not have direct contact with a SARS patient during his/her symptomatic period, with an attack rate of 0% (95% CI: 0% - 0.73%).

CONCLUSIONOnly those persons having direct contact with ill SARS patients need to be under quarantine. The overall cost for quarantine on SARS prevention could be reduced by as much as 63% if the quarantine program was limited to this group. No evidence was found that SARS patient was infective during the incubation period.

Adolescent ; Adult ; Aged ; Child ; Child, Preschool ; China ; epidemiology ; Disease Outbreaks ; prevention & control ; Female ; Humans ; Infant ; Male ; Middle Aged ; Quarantine ; methods ; organization & administration ; psychology ; Risk Factors ; Severe Acute Respiratory Syndrome ; epidemiology ; prevention & control ; psychology ; Time Factors

OBJECTIVETo analyze the spatial distribution of hemorrhagic fever with renal syndrome (HFRS) in Haidian district, Beijing and to explore the geographical characteristics of HFRS in highly endemic areas.

METHODSAdministration boundary layer was established under the background of 1:100,000 map in the ArcInfo 8.1 software. The HFRS cases from 1997 to 2002 were positioned on the map. Highly endemic areas were identified by spatial cluster analysis using SaTScan 3.0 software. Distribution of HFRS cases was shown in different colors and contours by spatial analysis of geographic information system (GIS).

RESULTSSpatial Cluster Analysis of confirmed cases of HFRS identified in 1997 - 2002 in Haidian district showed that HFRS patients were not randomly distributed. The highly endemic areas were founded in Sujiatuo township, Yongfeng township, Shangzhuang township, Wenquan town and Bei'anhe township (relative risk = 4.43, P = 0.001). A thematic map of HFRS in haidian district was set up.

CONCLUSIONHFRS infections were not randomly distributed, since the distribution was related to geographic-environmental factors.

China ; epidemiology ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; Humans ; Urban Health ; statistics & numerical data ; Urbanization

OBJECTIVETo analyze epidemiological features of severe acute respiratory syndrome (SARS) in Haidian district, Beijing.

METHODSEach SARS case was interviewed by trained investigator using standardized questionnaire followed a descriptive analysis.

RESULTSFour hundred and three SARS cases were identified and 27 of them died from March 18 and May 31, 2003. The incidence rate of SARS was 18.0/100,000 with case fatality rate as 6.7% in Haidian district, Beijing. Seventy-four percent of patients were adults with higher risk in age group of 20 - 29 year. SARS patients were scattered around in 32 out of 33 streets and villages in this district. The disease appeared to be sporadic but the case of outbreaks in family or university only seen in three streets. The course of SARS epidemic in this district could be divided into three phases: initial-which last for days, peak-21 days and then rapid decline-for 26 days. Number of patients having had a history of close contact to other SARS were gradually decreasing along with the process of the epidemics (trend chi(2) = 8.800, P = 0.003). Seventy-two point seven percent of the SARS cases had been exposed to the injection in the hospital settings. When the epidemics came to a rapid decline, 85.7% of the patients diagnosed during that period could be traced down to have had the history of contacting SARS cases within their own families. The distribution of occupation was also showed significantly different in the three respective stages (chi(2) = 36.41, P < 0.01). Among the patients who could not be identified as having confirmed contact history, 26.6% having had outward activities and 47.6% of them visited hospitals, especially during the peak stage.

CONCLUSIONThe intensity of SARS epidemic among the residents of Haidian district was recognized as similar to the other parts of Beijing. Nosocomial infection in hospital settings was most important cause responsible for the transmission of SARS in this district.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; China ; epidemiology ; Contact Tracing ; Cross Infection ; transmission ; Family Health ; Female ; Humans ; Incidence ; Male ; Middle Aged ; Severe Acute Respiratory Syndrome ; epidemiology ; mortality ; transmission ; Surveys and Questionnaires

OBJECTIVETo study the prevalence of hepatitis C virus (HCV) infection and characteristics on molecular biology related to HCV among patients who were enrolled in a Methadone maintenance clinic in Wuhan.

METHODSSerum samples from 332 injection drug users (IDUs) were obtained and anti-HCV IgG was detected by enzyme linked immunosorbrent assay(ELISA), together with 86 anti-HCV positive specimens genotyped. A reverse transcriptase-polymerase chain reaction (RT-nPCR) assay using conserved primers deduced from the core-envelopel (C-E1) region of the HCV genome was employed to amplify a 474 bp fragment. Phylogenetic analysis of the C-E1 sequences was conducted by direct sequencing of the RT-nPCR products and alignment with determined by nucleotide sequencing followed by composition of a phylogenetic tree.

RESULTSThere were 313 cases (94.3%) appeared positive anti-HCV IgG in the 332 patients from a Methadone maintenance clinic in Wuhan. It was demonstrated that there were four different subtypes of HCV in that clinic in Wuhan, including 6a--71 cases (82.5%), 3b--7 cases (8.2%), 1a--5 cases (5.8%) and 1b--3 cases (3.5%).

CONCLUSIONInfection of 6a genotype HCV was predominant in patients from the Methadone maintenance clinic in Wuhan, followed by HCV 3b, 1a and 1b.

Adult ; Antibodies, Viral ; analysis ; China ; Enzyme-Linked Immunosorbent Assay ; Female ; Genotype ; Hepacivirus ; classification ; genetics ; Humans ; Male ; Methadone ; therapeutic use ; Middle Aged ; Phylogeny ; Reverse Transcriptase Polymerase Chain Reaction ; Substance Abuse Treatment Centers ; Substance-Related Disorders ; drug therapy ; rehabilitation ; Young Adult

OBJECTIVETo investigate hantanvirus infection of captured rodents in Haidian district and Changping district of Beijing and to type hantavirus using molecular technique.

METHODSThe captured mice were classified and the density of distribution was calculated. Reverse transcription-polymerase chain reaction (RT-PCR) technique was used to amplify the partial M fragnments of hantaviruse. Several representative positive samples were sequenced and analysed by ClustalX (5.0) and DNAClub software.

RESULTSA total of 414 animals were captured, among which Battus norvegicus was the dominant group. In Haidian district, the median infection rates with hantavirus were 13.14% in Battus norvegicus and 0 in Mus musculus Linnaeus. In Changping district, the average infection rates were 17.46% in Battus norvegicus and 3.57% in Mus musculus Linnaeus. Nucleotide sequences analysis showed that the virus detected all belonged to SEO-type. They clustered with Z37 virus and could be branched into 2 different subclades.

CONCLUSIONThe major hosts of hantavirus in Haidian and Changping district were Battus norvegicus and the epidemic strains in the two districts of Beijing were genotyped as SEO-type. Nucleotide sequence and deduced amino acid sequence from different rodents were highly homologous, while nucleotide mutation had also been observed. Further studies are required to explore the possible virus sequence mutation.

Animals ; China ; epidemiology ; DNA, Viral ; genetics ; Disease Reservoirs ; Fluorescent Antibody Technique ; Hantavirus ; classification ; genetics ; isolation & purification ; Hantavirus Infections ; epidemiology ; veterinary ; virology ; Hemorrhagic Fever with Renal Syndrome ; epidemiology ; veterinary ; virology ; Mice ; Molecular Epidemiology ; Phylogeny ; Rats ; Reverse Transcriptase Polymerase Chain Reaction ; Rodent Diseases ; epidemiology ; virology

OBJECTIVETo further understand the association of hantavirus (HV) harbored and transmitted in wild brown rats.

METHODSRattus norvegicus (n = 570) were trapped in 10 sites in Beijing. RT-PCR was used to test rodent lung samples for hantavirus infection. Unconditional multivariate logistic regression analysis was performed, with PCR positive as the dependent variable and the characteristics of Rattus norvegicus population as independent variables.

RESULTSThe overall HV prevalence in Rattus norvegicus was 9.1% (52/570). Significant association between HV infection in Rattus norvegicus and some biological characteristics of host population was observed. Adult Rattus norvegicus had a higher HV prevalence than juveniles. Males in the reproduction periods and rats with wounds were more likely to be infected with HV than others.

CONCLUSIONIt was further confirmed that there existed parallel transmission of HV in Rattus norvegicus hosts. Aggression might be the primary mode of HV transmission among male Rattus norvegicus.

Aggression ; Animals ; Animals, Wild ; injuries ; virology ; China ; epidemiology ; Female ; Hantavirus ; isolation & purification ; Hantavirus Infections ; epidemiology ; transmission ; veterinary ; virology ; Logistic Models ; Lung ; virology ; Male ; Prevalence ; Rats ; injuries ; virology ; Reproduction ; Reverse Transcriptase Polymerase Chain Reaction ; Risk Factors ; Rodent Diseases ; epidemiology ; transmission

OBJECTIVES: To analyze the relationship among electrical conductivity （EC）, total volatile basic nitrogen （TVB-N）, which is an index of decomposition rate for meat production, and postmortem interval （PMI）. To explore the feasibility of EC as an index of cadaveric skeletal muscle decomposition rate and lay the foundation for PMI estimation. METHODS: Healthy Sprague-Dawley rats were sacrificed by cervical vertebrae dislocation and kept at 28 ℃. Muscle of rear limbs was removed at different PMI, homogenized in deionized water and then skeletal extraction liquid of mass concentration 0.1 g/mL was prepared. EC and TVB-N of extraction liquid were separately determined. The correlation between EC (x₁) and TVB-N (x₂) was analyzed, and their regression function was established. The relationship between PMI (y) and these two parameters were studied, and their regression functions were separately established. RESULTS: The change trends of EC and TVB-N of skeletal extraction liquid at different PMI were almost the same, and there was a linear positive correlation between them. The regression equation was x₂=0.14x₁-164.91(R²=0.982). EC and TVB-N of skeletal muscle changed significantly with PMI, and the regression functions were y=19.38x₁³-370.68x₁²+2 526.03 x₁-717.06(R²=0.994), and y=2.56x₂³-48.39x₂²+330.60x₂-255.04(R²=0.997), respectively. CONCLUSIONS EC and TVB-N of rat postmortem skeletal muscle show similar change trends, which can be used as an index for decomposition rate of cadaveric skeletal muscle and provide a method for further study of late PMI estimation.
Animals ; Autopsy ; Electric Conductivity ; Forensic Pathology ; Muscle, Skeletal/pathology* ; Nitrogen ; Postmortem Changes ; Rats ; Rats, Sprague-Dawley ; Time Factors

OBJECTIVES: To determine the electrical conductivity （EC） of the liver, spleen and kidney of rats at different postmortem intervals （PMIs） within 24 hours for investigating the relationship between EC of different organs and early PMI. METHODS: Totally 45 SD rats were sacrificed by cervical dislocation and kept at a constant temperature of 25 ℃. Tissues were taken from the liver, spleen, and kidney of rats at 0, 3, 6, 9, 12, 15, 18, 21 and 24 h. Impregnating solution with a mass concentration 0.1 g/mL was prepared using deionized water. The EC value of impregnating solution with different organs was separately determined. The regression equations of EC and PMI for different organs were established, respectively. The relationship between EC of different organs and early PMI was analysed in deceased rats. RESULTS: The relationship between PMI and EC of the liver and spleen was well fitted with the linear equation. The liver showed the best fitting degree followed by the spleen, while the EC of the kidney showed no significant changes within 24 h. There was a good linear relationship between early PMI and the EC of the liver and spleen. CONCLUSIONS A good linear relationship between early PMI and the EC of the liver and spleen can be found in rats after death, which can be used for the early PMI estimation.
Animals ; Electric Conductivity ; Forensic Pathology ; Liver ; Postmortem Changes ; Rats ; Rats, Sprague-Dawley ; Spleen ; Time Factors

Objective To assess the feasibility of using 28S ribosomal RNA （28S rRNA） and mitochondrial cytochrome c oxidase subunit Ⅰ （COⅠ） gene sequences of nine necrophagous Calliphorid flies for the identification of common necrophagous Calliphorid flies, and to provide technical support for postmortem interval （PMI） estimation. Methods Twenty-three Calliphorid flies were collected and identified morphologically, and DNA were extracted from legs. The gene fragments of 28S rRNA and COⅠ were amplified and sequenced, then the sequence alignment was performed with BLAST. The composition of obtained sequences was analyzed and evolutionary divergence rate between species and intraspecies were established. The phylogeny tree was constructed with neighbor-joining method. Results The 23 necrophagous Calliphorid flies were identified to 9 species of 5 genera. The 715 bp from 28S rRNA and 637 bp from COⅠ gene were obtained and the online BLAST result showed more than 99% of similarity. The phylogeny tree showed that the necrophagous flies could cluster well into 9 groups, which was consistent with morphological identification results. The intraspecific difference in 28S rRNA was 0 and the interspecific difference was 0.001-0.033. The intraspecific difference in COⅠ was 0-0.008 and the interspecific difference was 0.006-0.101. Conclusion Combined use of 28S rRNA and COⅠ gene sequence fragments can effectively identify the nine Calliphorid flies in this study. However, for closely related blowfly species, more genetic markers should be explored and used in combination in future.
Animals ; DNA, Mitochondrial/genetics* ; Diptera/genetics* ; Phylogeny ; RNA, Ribosomal, 28S/genetics* ; Sequence Analysis, DNA ; Species Specificity

Objective To study the mechanism of change of the electrical conductivity （EC） of rat skeletal muscle impregnating solution that occurs with the change of postmortem interval （PMI）. Methods Healthy Sprague-Dawley rats were killed and kept at about 25 ℃. Skeletal muscles were extracted at different PMI--immediate （0 d）, 1 d, 2 d, 3 d, 4 d, 5 d, 6 d, and 7 d, then mixed with deionized water to make impregnating solution with a mass concentration of 0.1 g/mL. The solution's EC and nine common chemicals in it, such as potassium ion, calcium ion, and chloride ion, were determined. Results EC increased gradually with the extending of PMI （P=0.024） during the 7 days after the rats' death. The content of uric acid （P=0.032）, urea nitrogen （P=0.013） and phosphorus （P=0.022） also increased during the extension. However, the content of magnesium ions decreased with extending of PMI （P=0.047）. The correlation between potassium ion, sodium ion, chlorine ion, calcium ion, creatinine and PMI were weak （P>0.05）. Conclusion The molecular basis of skeletal muscle EC change in rats after their death is the changes of uric acid, urea nitrogen, inorganic phosphorus and other chemical components. Furthermore, combine use of various indicators can improve the accuracy of the EC method to infer PMI.
Animals ; Electric Conductivity ; Forensic Pathology ; Muscle, Skeletal ; Postmortem Changes ; Rats ; Rats, Sprague-Dawley ; Time Factors