Emergency Response for a Laboratory Biosafety Incident / 生物医学与环境科学（英文）

On December 14, 2017, a faculty member of a university in Hunan Province reported that an anthrax vaccine strain might have recovered virulence during an undergraduate experiment and potential exposure could not be ruled out for the students involved. Upon receiving the case report, the CDC, health bureaus, and local governments at the county, prefectural, and provincial levels promptly organized experts in different fields (including epidemiologists, biosafety experts, and laboratory testing experts) for case investigation, evaluation, and response. As the investigation results showed, no virulence recovery was identified in the involved anthrax vaccine strain; and no contamination of Bacillus anthracis was detected at the involved areas. Thus, the university returned to normal functioning.

The influence of familial factors on post rabies exposure vaccination in rural habitants / 中华流行病学杂志

Objective To understand the current situation of potential exposure to rabies among the rural habitants in Hunan province,and to study the impact related to familial factors on post rabies exposure vaccination.Methods In total,40 villages from 20 townships of 4 counties were selected by multistage sampling method.Study samples were selected from these villagers and familial basic information and vaccination post rabies exposures were recorded through questionnaires.Data were statistically analyzed by SPSS 17.0.Results Among 3042 villagers from 864 households being surveyed,124 person-time exposures were found from January,2009 to October,2010,with a total exposure rate as 4.08％,and the annual average exposure rate as 2.33％.Data from univariante analysis showed that the rates on post rabies exposure vaccination were statistically correlated with the following four factors:knowledge on the score of rabies prevention (x2 =8.260,P =0.042),whether being involved in the new type of rural cooperative medical care (P =0.035),family disposable cash income in the year of 2009 (x2 =10.831,P =0.031),distance between the households and the health facilities in towns and townships (x2 =9.071,P=0.033).Results from logistic regression analysis indicated that the score of knowledge on rabies prevention (OR=1.420,95％CI:1.055-1.905) and the annual disposable cash income of the family in 2009 (OR=1.480,95％ CI:1.044-2.098) were independent factors that influencing the rabies vaccination.Conclusion Strengthening the education programs on rabies prevention in rural habitants and increasing family income were feasible way to increase the rate of rabies vaccination in rural areas of Hunan province.

Virological surveillance of pandemic (H1N1) 2009 virus and its genetic characteristics in Hunan Province, 2009-2011 / 病毒学报

To understand and master the dynamic variation of the pandemic influenza A (H1N1) 2009 in Hunan province from 2009 to 2011, and to know the genetic characteristics and drug resistance of the pandemic (H1N1) 2009 viruses. Throat swab specimens of influenza-like illness patients were collected from sentinel hospitals and tested for influenza by fluorescent PCR or virus isolation methods. Partial isolates were selected for sequencing. The sequences were used for phylogenetic analysis by MEGA 5. 05 software. From the 20th week of 2009 to the 52nd week of 2011, 17 773 specimens were tested. 3 831 specimens were influenza-positive with a positive rate of 21. 6%, of which 1 794 were positive specimens of pandemic (H1N1) 2009, accounting for 46. 8%00 of the influenza-positives. There were 2 epidemic peaks of pandemic (H1N1) 2009, which were in the 41st-53rd week of 2009 and the 1st-12nd week of 2011, respectively. The HA genes of 23 strains that were selected for sequencing had close relationship; the distribution of strains in the phylogenetic tree was basically in chronological order. The complete genome sequence analysis showed that all of 8 gene segments of 7 strains were homologous to the vaccine strain, and there was no gene reassortment. The HA amino acid sites of the 23 strains were highly similar to the vaccine strain (98. 2% - 100. 0% in homology), but all 23 strains had P83S, S203T and 1321V mutations. The 222 site mutation that may lead to enhanced virulence was found in the A/Hunan/YQ30/2009 strain. The mutation was D222E. There was no oseltamivir resistance mutation found in all strains. The pandemic (H1N1) 2009 in Hunan province from 2009 to 2011 had a bimodal distribution. There was no large-scale variation of virus genes. The clinical use of oseltamivir was still effective. Key words: Pandemic (H1N1) 2009; Surveillance; Genetic characteristics

Study on the influence of landscape elements regarding on the transmission of hemorrhagic fever with renal syndrome in Changsha / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the influence of landscape elements on the transmission of hemorrhagic fever with renal syndrome (HFRS) in Changsha.</p><p><b>METHODS</b>A total of 327 cases of HFRS diagnosed between year 2005 - 2009 were recruited in the study. Based on the demographic data, meteorological data and the data of second national land survey during the same period, a GIS landscape elements database of HFRS at the township scale of Changsha was established. Spatial-temporal cluster analysis methods were adopted to explore the influence of landscape elements on the spatial-temporal distribution of HFRS in Changsha during the year of 2005 - 2009.</p><p><b>RESULTS</b>The annual incidences of HFRS in Changsha between year 2005 - 2009 were 1.16/100 000 (70 cases), 0.95/100 000 (58 cases), 1.40/100 000(87 cases), 0.75/100 000(47 cases) and 1.02/100 000(65 cases) respectively. The results of poisson regression model analysis of principal component showed that the incidence of HFRS was positively correlated with farmland area (M = 29.00 km2) and urban and rural area (M = 6.12 km2; incidence rate ratios (IRR) = 1.34, 95% CI: 1.27 - 1.41); but negatively correlated with forestland area (M = 39.00 km2; IRR = 0.67, 95% CI: 0.55 - 0.81) and garden plot area (M = 0.99 km2; IRR = 0.74, 95% CI: 0.63 - 0.86). A significant cluster of the spatial-temporal distribution of HFRS cases was found in the study. The primary cluster (28.9 N, 113.37 E, radius at 22.22 km, RR = 5.23, log likelihood ratio (LLR) = 51.61, P <0.01, 67 cases of HFRS and incidence at 4.4/100 000) was found between year 2006 and 2007; and the secondary cluster (28.2 N, 113.6 E, RR = 10.77, LLR = 16.01, P < 0.01, 11 cases of HFRS and the incidence at 10.6/100 000) was found between year 2008 and 2009.</p><p><b>CONCLUSION</b>The landscape elements were found to be closely related to the prevalence and transmission of HFRS.</p>

Analysis of genetic features of influenza B virus in Hunan province from 2007 to 2010 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the gene variations of influenza B virus isolated in Hunan province from 2007 to 2010.</p><p><b>METHODS</b>A total of 42 strains of influenza B virus,which were isolated in the Influenza Surveillance Network Laboratories in Hunan province between year 2007 and 2010, were selected for the study. The hemagglutinin 1 (HA1) and neuraminidase (NA) genes of the selected strains were amplified by RT-PCR, and the sequence of the purified product were detected and homologically compared with the sequence of influenza vaccine strains isolated from Northern Hemisphere by WHO during the same period. In addition, the phylogenetic trees were constructed to characterize the molecular features.</p><p><b>RESULTS</b>In the Victoria branch of the HA1 gene phylogenetic tree, the strains isolated from year 2007 to 2009 were included in the V1 sub-branch, as well as the vaccine strain Malaysia/2506/2004; the strains isolated in year 2010 were involved in the V2 sub-branch, similar to the vaccine strains Brisbane/60/2008. In the Yamagata branch,the strains isolated in year 2007 were in the Y1 sub-branch,different from the strains isolated between year 2008 and 2010, which were in the Y2 sub-branch, instead. All virus in NA gene phylogenetic tree were included in the Yamagata branch, indicated their Yamagata origin. The genetic sequence analysis of the 7 strains isolated in year 2010 revealed that the viruses were classified as genotype 2 and genotype 15. The results of homological comparison between HA1 molecule and the influenza vaccine strains recommended by WHO were as below: Victoria lineage, 98.6% - 99.1% in 2007, 98.6% - 99.1% in 2008, 98.1% - 99.1% in 2009, and 97.6% - 99.1% in 2010; and Yamagata lineage, 97.9% - 98.5% in 2007, 97.9% - 98.5% in 2009 and 97.9% - 98.2% in 2010. The major mutations of the strains isolated in year 2007 were found in sites R48K, K88R, P108A, D197N and S230G. While the major mutations of the strains isolated between year 2009 and 2010 were sited in K88R, S150I, N166Y, D197N and S230G.</p><p><b>CONCLUSION</b>The prevalent influenza B virus isolated in Hunan province from 2007 to 2010 has mutated and evolved continuously.</p>

Study on sensitivity of climatic factors on influenza A (H1N1) based on classification and regression tree and wavelet analysis / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analyze the periodicity of pandemic influenza A (H1N1) in Changsha in year 2009 and its correlation with sensitive climatic factors.</p><p><b>METHODS</b>The information of 5439 cases of influenza A (H1N1) and synchronous meteorological data during the period between May 22th and December 31st in year 2009 (223 days in total) in Changsha city were collected. The classification and regression tree (CART) was employed to screen the sensitive climatic factors on influenza A (H1N1); meanwhile, cross wavelet transform and wavelet coherence analysis were applied to assess and compare the periodicity of the pandemic disease and its association with the time-lag phase features of the sensitive climatic factors.</p><p><b>RESULTS</b>The results of CART indicated that the daily minimum temperature and daily absolute humidity were the sensitive climatic factors for the popularity of influenza A (H1N1) in Changsha. The peak of the incidence of influenza A (H1N1) was in the period between October and December (Median (M) = 44.00 cases per day), simultaneously the daily minimum temperature (M = 13°C) and daily absolute humidity (M = 6.69 g/m(3)) were relatively low. The results of wavelet analysis demonstrated that a period of 16 days was found in the epidemic threshold in Changsha, while the daily minimum temperature and daily absolute humidity were the relatively sensitive climatic factors. The number of daily reported patients was statistically relevant to the daily minimum temperature and daily absolute humidity. The frequency domain was mostly in the period of (16 ± 2) days. In the initial stage of the disease (from August 9th and September 8th), a 6-day lag was found between the incidence and the daily minimum temperature. In the peak period of the disease, the daily minimum temperature and daily absolute humidity were negatively relevant to the incidence of the disease.</p><p><b>CONCLUSION</b>In the pandemic period, the incidence of influenza A (H1N1) showed periodic features; and the sensitive climatic factors did have a "driving effect" on the incidence of influenza A (H1N1).</p>

Surveillance on the etiology and genetic characteristics of rabies in Hunan province, from 2008 to 2009 / 中华流行病学杂志

Objective To analyze the etiology of rabies in Hunan province and the genetic characteristics of rabies N gene isolated from 2008 to 2009.Methods Direct immunofluorescence assay (DFA) and nested PCR were employed to detect the monitoring samples including brain tissues of dogs and saliva,serum or urine which were collected in 2008 to 2009,from the rabies patients.Positive samples were sequenced by ABI3730 gene analyzer for the full length of the N gene target.The homology and hpylogeography of the rabies virus were analyzed after the phylogenetic tree was constructed by Blast,Clustal W and Mega 4.0 software.Results Of the 1451 tissue samples from the dogs' brain,31 were positive under DFA and the positive rate was 2.14％.The DFA positive samples were redeteeted by RT-PCR and the positive rate was 1.17％.56 samples of saliva,serum and urine samples were detected by RT-PCR from the rabies patients,with 3 positives and the positive rate was 5.36％.The length of nest PCR products were 255 bp.The rates of homology to the nucleotide and the amino acid of rabies N gene were 87.2％-87.9％ after compared to the pasture strain.The phylogenetic tree was successfully built and 20 strains isolated lately belonged to the rabies gene type Ⅰ.Conclusion The epidemic situation of human and dogs rabies in Human were relatively stable,with all the isolated rabies virus belonging to genotype Ⅰ,without any variation.

Risk factors of death cases of hand-foot-and-mouth disease in Hunan province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study risk factors of death cases of hand foot and mouth diseases (HFMD) in Hunan province, so as to provide scientific evidence for further prevention and control.</p><p><b>METHODS</b>The 105 death cases of HFMD between January and October, 2010 in Hunan Province were selected as case group; and the 210 survival cases of serious HFMD, which were matched by gender and resident places with a ratio at 2:1 in the same period in Hunan were selected as control group. The basic information, hospitalized experience and previous medical history had been surveyed and the relevant risk factors were analyzed by single factor and multi-factor logistic regression.</p><p><b>RESULTS</b>In case group, 79.05% (83/105) of the cases lived in rural area and 9.52% (10/105) of the cases lived in urban-rural midst area. In control group, 87.62% (184/210) of the cases lived in rural area and 11.43% (24/210) of the cases lived in urban-rural midst area. In case group, 59.05% (62/105) of the patients first visited rural (private) clinics and 20.00% (21/105) first visited community hospitals in villages and towns; while in control group, 43.81% (92/210) and 13.33% (28/210) chose rural (private) clinics and community hospitals in villages and towns as the first choice respectively.22.86% (24/105) of the case group and 39.05% (82/210) of the control group were diagnosed as HFMD in their first visit to hospital.27.62% (29/105) of the case group and 7.14% (15/210) in control group were provided pyrazolone in the treatment. For glucocorticoid, 80.95% (85/105) and 5.71% (6/105) of the case group were given as treatment by rural (private) clinics and community hospitals in villages and towns separately; while the proportions in the control group were 41.43% (87/210) and 0.48% (1/210) respectively. For antibiotics, 35.24% (37/105) and 23.81% (25/105) of the case group were prescribed by rural (private) clinics and community hospitals in villages and towns separately; while the percentages in the control group were 15.71% (33/210) and 7.14% (15/210). 3.81% (4/105) of the case group and 11.90% (25/210) of the control group were vaccinated in one month before the onset. The results of single-factor logistic regression indicated that living in rural areas (OR = 0.075, 95%CI: 0.016 - 0.343) and in rural-urban midst areas (OR = 0.069, 95%CI: 0.013 - 0.368), diagnosis of HFMD in the first visit to hospital (OR = 0.463, 95%CI: 0.271 - 0.788) and vaccination one month before the onset (OR = 0.293, 95%CI: 0.099 - 0.866) were four protective factors; while rural (private) clinics as the first choice (OR = 4.717, 95%CI: 1.891 - 11.767), community hospital in villages and towns as the first choice (OR = 5.250, 95%CI: 1.883 - 14.641), medication of pyrazolone (OR = 4.961, 95%CI: 2.520 - 9.766), medication of glucocorticoid in rural (private) clinics (OR = 6.009, 95%CI: 3.435 - 10.510) and in community hospital in villages and towns (OR = 12.667, 95%CI: 1.505 - 106.638), medication of antibiotics in rural (private) clinics (OR = 2.918, 95%CI: 1.690 - 5.040) and in community hospital in villages and towns (OR = 4.062, 95%CI: 2.036 - 8.108) were seven risk factors. The results of multi-factors logistic regression showed that medication of pyrazolone (OR = 2.311, 95%CI: 1.062 - 5.030), medication of glucocorticoid in rural (private) clinics (OR = 5.480, 95%CI: 3.039 - 9.880), medication of antibiotics in rural (private) clinics (OR = 2.430, 95%CI: 1.301 - 4.538) and medication of antibiotics in community hospitals in villages and towns (OR = 3.344, 95%CI: 1.477 - 7.569) were the risk factors of death of HFMD.</p><p><b>CONCLUSION</b>The risk factors of HFMD deaths include the medication of pyrazolone, glucocorticoid and antibiotics by rural (private) clinics and medical institutions in villages and towns. The department concerned should revise the technical manual to standardize the medication of the above drugs.</p>

Molecular characterization of highly pathogenic avian influenza A(H5N1)viruses isolated from humans in Hunan province,2006-2009 / 中华流行病学杂志

Objective To understand the possible origins,genetic re-assortment and molecular characterization of 4 highly pathogenic avian influenza A(H5N1)viruses isolated from humans in Hunan province,between 2006 and 2009,Methods H5N1 PCR test-positive specimens were inoculated in embryonated eggs while H5N1 virus was isolated and genomes sequenced.Genome homology and genetic molecular characterization were analyzed by BLAST and MEGA 4.0.Results All gene segments of the 4 viruses were avian in origin.No re-assortment was found between avian influenza A(H5N1)viruses and human seasonal influenza viruses.Virnses that isolated from domestic poultry shared high similarity with the 4 human viruses in gene homology.Data from the whole genome phylogenetic analysis showed that the 4 viruses were in clade 2.3.4,while 2 viruses belonged to genotype V,and another 2 were new genotypes.Results from molecular characterization showed that amino acid sequences of HA cleavage site of the 4 viruses were PLRERRKR/G.All 4 viruses had A160T mutation in HA,a 20 amino acid deletion in the neuraminidase(NA)stalk at position 49-68,and a 5 amino acid deletion in the non-structural protein 1(NS1).Most sites in the HA molecules showed that the viruses preferentially bound to avian influenza virus receptor.However,T192I mutation that might enhance the α2,6-linked sialic acid human influenza receptor binding had emerged in HN/1/09 and HN/2/09.D701N mutation of PB2 that increased the virulence in mice was found in HN/1/08.Analysis on drug resistance gene amino acid showed that all 4 viruses were sensitive to amantadine and oseltamivir.Conclusion Highly pathogenic avian influenza A(H5N1)viruses isolated from humans in Hunan province from 2006 to 2009 were avian in origin,and the 4 viruses belonged to different genotypes.Some mutations that related to virulence and receptor binding positions had emerged in some of the strains.

Laboratory diagnosis and molecular characterization of highly pathogenic avian influenza virus (H5N1) in human in Hunan Province in 2005-2006 / 病毒学报

To determine the etiologic agents of two atypical pneumonia human cases in Hunan Province in 2005-2006 and to study their pathogenic potential, the patients' respiratory tract samples and sera were collected. The respiratory tract samples were tested by real-time RT-PCR and RT-PCR methods, and the sera by hemagglutination-inhibition assay. Virus was isolated from case 2 and its genome was sequenced and analyzed. Results showed the H5 nucleic acid tests of two cases were positive. The H5-specific antibody titer of the convalescence serum of case 1 showed a 4-fold greater rise than that of the acute phase. And case 2's antibody titer of acute phase was negative. The two atypical pneumonia cases were confirmed as the avian influenza A (H5N1) infection cases. Viral strain A/Hunan/1/2006 was isolated from case 2. Phylogenetic and molecular analysis suggested that 8 gene segments of A/Hunan/1/2006 originated from avian viruses. And A/Hunan/1/2006 was similar with viruses isolated from avian in Hunan Province. The isolated virus did not recombine with human influenza viruses and no obvious variation was observed.

Virological surveillance on hemorrhagic fever with renal syndrome in Hunan province in 2006 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the rate of viral carrying status among rodents as well as genotypes and distribution of Hantaviruses (HV) isolated in Hunan province.</p><p><b>METHODS</b>With DFA, the HV antigen in lung tissues of rodents was detected. The total viral RNA was extracted from the lung tissues of the HV infected rats and amplified with reverse transcrition-polymerase chain reaction (RT-PCR), using the HV genotype specific primers. The amplified genes were then sequenced and subjected to genotyping and homologic analysis.</p><p><b>RESULTS</b>The average density of rodents was 3.15% and the virus carrying rate among rodents was 1.31%. Data from genotype analysis showed that the HV isolated from seven lung specimens taken from Rattus norvgicus, Apodemus agraius, Mus musculus, Rattus flavipectus among indoor rodents in Shaodong and Liuyang belonged to HV type II (SEOV), and one isolated from Apodemus agraius in Shaungfen belonged to HV type I (HTNV) among outdoor rodents. Six strains were sequenced successfully and the homology between six srains was 88.3%-100%. The homology of HN1, HN2, HN4, HN6 came from Liuyang and the HN7 and HN8 from Shaodong were both 100% while the homology between L99 and the strains from Liuyang and Shaodong were 94.4% and 88.3% respectively.</p><p><b>CONCLUSION</b>HV type II (SEOV) and the HV type I (HTNV) were all existed in Hunan province while SEOV was the main genotype.</p>

Analysis on the factors related to rabies epidemic in China, in 2005 / 中华流行病学杂志

<p><b>OBJECTIVE</b>To analyse the related epidemic factors of rabies and to provide basic evidence for developing rabies control and prevention programs in China.</p><p><b>METHODS</b>Possible factors that causing rabies epidemics in the southern part of China were obtained through collecting both epidemic and surveillance data of rabies in 2005, and to analyse every factor by software of Excel 2002.</p><p><b>RESULTS</b>The number of rabies cases was 2548 in 2005. Among 885 cases being investigated, 60.56%, 49.04%, 96.16% had not had any chance to receive treatment, vaccine or immunoglobulin. Among the exposed persons, 89.95% received treatment on wounds and 94.93% were immunized, and 8.56% received immunoglobulin. 94.86% of them accomplished the full rabies post-exposure prophylaxis course, but 8.56% of them did not accomplish it. 88.50% of the cases and 92% of the persons under exposure were bitten by dogs. The density of dogs was 3.20-13.37 per 100 persons. The vaccination coverage rates among dogs were 5.31% -75.11% with a positive rate of 2.93 % -6.40%.</p><p><b>CONCLUSION</b>Factors as: low rate of post-exposure prophylaxis and failed to have finished the necessary post-exposure treatment (PET) of the cases, nonstandard PET in hospital or local clinic, low rabies vaccination coverage and high infectivity of rabies virus in animal host (mainly for dog) might be responsible for rabies epidemics in China, in 2005.</p>

The first confirmed human case of avian influenza A (H5N1) in mainland, China / 中华流行病学杂志

<p><b>OBJECTIVE</b>To ascertain the causation of a family cluster involving two undefined pneumonia cases, a 12-year-old girl and her brother, reported October, 2005 in Xiangtan county, Hunan province.</p><p><b>METHODS</b>Information on epidemiology and clinical manifestation of the cases was collected from interviewing the keyman and referring to related medical records. The environment exposure of the cases to their households and the timeline of the illness were reproduced, using this information. Medical check-up was undergone among the close contacts of the cases and on sick/dead poultry. Throat swab of the cases were collected and tested by both RT-PCR and real-time PCR to detect viral nucleic acids of A/H5N1, and were then inoculated into special pathogen free (SPF) embryonated hens' eggs. Serum of the cases including acute and convalescent phases were also collected and tested by microneutralization and haemagglutination-inhibition (HI) assays to detect H5-specific antibodies.</p><p><b>RESULTS</b>Both the girl and her brother developed fever 2 and 4 days after sudden deaths of chickens being raised in the same house. Both of them had developed pneumonia and the girl died from acute respiratory distress syndrome (ARDS) complicated with multi-organ failure. The boy survived and subsequently discharged from hospital. An eighth-day serum from the girl tested H5 antibody negative, while 4-fold and greater increased in antibody titers were detected in serum from the boy using microneutralization and HI assays in sequential acute and convalescent sera. Of 192 cases, only one doctor who cared for the girl during hospitalization had upper respiratory symptoms but tested negative for H5N1 by microneutralization assay.</p><p><b>CONCLUSION</b>The boy was the first confirmed human case of avian influenza A (H5N1) in the mainland of China and his sister was diagnosed clinically. The most probable explanation of these two cases was that the transmission of H5N1 virus from infected poultry within the same household environment. No evidence of human-to-human transmission was noted in the family cluster.</p>

Effectiveness of personal protective measures in prevention of nosocomial transmission of severe acute respiratory syndrome / 中华流行病学杂志

<p><b>OBJECTIVE</b>To evaluate the effectiveness of personal protective measures of health care workers (HCWs) against severe acute respiratory syndrome (SARS).</p><p><b>METHODS</b>A case-control study from ten hospitals in Guangdong, with 180 non-infected and 77 infected staff members that accessed the isolation unit every day, and participated in direct first aid for severe SARS patients. All participants were surveyed about how they were using personal protective equipment (PPE), protective drugs and hygiene habits when caring for patients with SARS. Statistical analysis was done with either chi(2) or Fisher's exact test for univariate analysis, whereas we used forward stepwise selection (Waldesian) for logistic regression.</p><p><b>RESULTS</b>Univariate analysis showed that mask, gown, gloves, goggles, footwear, "hand-washing and disinfecting", gargle, "membrane protection", "taking shower and changing clothing after work", "avoid from eating and drinking in ward", oseltamivir phospha tall had protective effects (P < 0.05), but stepwise logistic regression showed significant differences for mask (OR = 0.78, 95% CI: 0.60 - 0.99), goggles (OR = 0.20, 95% CI: 0.10 - 0.41) and footwear (OR = 0.58, 95% CI: 0.39 - 0.86). Analysis for linear trend in proportions showed that dose response relationship existed in mask, gown, gloves, goggles, footwear, gargle, "membrane protection" and "taking shower and changing dree after work" (P < 0.01). The attack rate of HCWs who were rescuing severe SARS patients without any PPE was 61.5% (16/26). It seemed that the more the protective measures were used, the higher the protective effect was (P < 0.001), and could reach 100% if mask, gown, gloves, goggles, footwear, "hand-washing and disinfecting" were all used at the same time.</p><p><b>CONCLUSIONS</b>Nosocomial infection of SARS can be prevented effectively by precautions against droplets and personal contact. HCWs must take strict protection according to the guidance of WHO or Chinese MOH and pay attention to personal hygiene.</p>

An investigation on nosocomial infection with severe acute respiratory syndrome in health-care workers at 13 key hospitals in Guangdong Province / 中华预防医学杂志

<p><b>OBJECTIVE</b>To analysis the risk factors influencing nosocomial infection of severe acute respiratory syndrome (SARS) in health-care workers and to evaluate effectiveness of its control and preventive measures in 13 key hospitals caring for SARS patients.</p><p><b>METHODS</b>Number of SARS patients, clinical conditions of them, its attack rate in health-care workers, and characteristics of hospitals, including their environment, isolating measures, etc. were investigated at the 13 hospital in Guangzhou to analyze the risk factors influencing nosocomial infection of SARS and its attack rates in health-care workers before and after implementation of preventive measures and to evaluate their effectiveness.</p><p><b>RESULTS</b>Totally, 841 patients with SARS were treated at the 13 hospitals in Guangzhou and 285 health-care workers caring for them infected nosocomially. Attack rate in health-care workers was higher at general hospitals, hospital accepting more cases in critical conditions and hospitals with poor precautious measures, and lower in hospitals with isolated wards or areas, or department of infection, specially caring for SARS patients, and those with effective intervention measures to prevent secondary infection.</p><p><b>CONCLUSION</b>Nosocomial infection of SARS in health-care workers was affected by clinical condition of SARS patients, characteristics and environment of hospitals and their personal protective measures adopted.</p>