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Objective To understand the epidemiological characteristics of scrub typhus and influencing factors in Yunnan province,and provide further information for the prevention and control of scrub typhus.Methods Based on the incidence data of scrub typhus reported in Yunnan from 2006 to 2013,the epidemiological characteristics of scrub typhus were analyzed and related environmental factors were identified with panel negative binomial regression model.Results A total of 8 980 scrub typhus cases were reported during 2006-2013 in Yunnan.The average annual incidence was 2.46/100 000,with an uptrend observed.Natural focus expansion was found,affecting 71.3％ of the counties in 2013.The epidemic mainly occurred in summer and autumn with the incidence peak during July-October.The annual incidence was higher in females than in males.More cases occurred in children and farmers,the proportions of cases in farmers and pre-school aged children showed an obvious increase.Panel negative binomial regression model indicated that the transmission risk of scrub typhus was positive associated with monthly temperature and monthly relative humidity.Furthermore,an "U" pattern between the risk and the increased coverage of cropland and grassland as well as an "inverted-U" pattern between the risk and increased coverage of shrub were observed.Conclusion It is necessary to strengthen the scrub typhus surveillance in warm and moist areas as well as the areas with high coverage of cropland and grassland in Yunnan,and the health education in children and farmers who are at high risk.
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For the past several decades, the infectious disease profile in China has been shifting with rapid developments in social and economic aspects, environment, quality of food, water, housing, and public health infrastructure. Notably, 5 notifiable infectious diseases have been almost eradicated, and the incidence of 18 additional notifiable infectious diseases has been significantly reduced. Unexpectedly, the incidence of over 10 notifiable infectious diseases, including HIV, brucellosis, syphilis, and dengue fever, has been increasing. Nevertheless, frequent infectious disease outbreaks/events have been reported almost every year, and imported infectious diseases have increased since 2015. New pathogens and over 100 new genotypes or serotypes of known pathogens have been identified. Some infectious diseases seem to be exacerbated by various factors, including rapid urbanization, large numbers of migrant workers, changes in climate, ecology, and policies, such as returning farmland to forests. This review summarizes the current experiences and lessons from China in managing emerging and re-emerging infectious diseases, especially the effects of ecology, climate, and behavior, which should have merits in helping other countries to control and prevent infectious diseases.
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Humans , Behavior , China , Epidemiology , Climate , Communicable Diseases , Classification , Epidemiology , Communicable Diseases, Emerging , Epidemiology , Disease Outbreaks , Ecology , Forecasting , IncidenceABSTRACT
Objective To understand the epidemiological characteristics of scrub typhus and influencing factors in Yunnan province,and provide further information for the prevention and control of scrub typhus.Methods Based on the incidence data of scrub typhus reported in Yunnan from 2006 to 2013,the epidemiological characteristics of scrub typhus were analyzed and related environmental factors were identified with panel negative binomial regression model.Results A total of 8 980 scrub typhus cases were reported during 2006-2013 in Yunnan.The average annual incidence was 2.46/100 000,with an uptrend observed.Natural focus expansion was found,affecting 71.3％ of the counties in 2013.The epidemic mainly occurred in summer and autumn with the incidence peak during July-October.The annual incidence was higher in females than in males.More cases occurred in children and farmers,the proportions of cases in farmers and pre-school aged children showed an obvious increase.Panel negative binomial regression model indicated that the transmission risk of scrub typhus was positive associated with monthly temperature and monthly relative humidity.Furthermore,an "U" pattern between the risk and the increased coverage of cropland and grassland as well as an "inverted-U" pattern between the risk and increased coverage of shrub were observed.Conclusion It is necessary to strengthen the scrub typhus surveillance in warm and moist areas as well as the areas with high coverage of cropland and grassland in Yunnan,and the health education in children and farmers who are at high risk.
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Infectious disease surveillance have played an important role in the national diseases prevention and control strategies.In line with the reporting system,infectious disease surveillance has been greatly improved and played pivotal role in preventing epidemics since 1949 in China.To date,surveillance remains an effective approach to infectious disease control and prevention because of the global serious situation.In this column "infectious disease surveillance",we have involved articles as systematic analysis of surveillance data and solid evidence related to the development of strategies and measures for infectious diseases control and prevention.
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Infectious disease surveillance have played an important role in the national diseases prevention and control strategies.In line with the reporting system,infectious disease surveillance has been greatly improved and played pivotal role in preventing epidemics since 1949 in China.To date,surveillance remains an effective approach to infectious disease control and prevention because of the global serious situation.In this column "infectious disease surveillance",we have involved articles as systematic analysis of surveillance data and solid evidence related to the development of strategies and measures for infectious diseases control and prevention.
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Objective To investigate the spatiotemporal expansion and risk factors of scrub typhus (ST) in Shandong,Jiangsu and Anhui provinces.Methods Based on the reported cases in Shandong and Jiangsu from 2006 to 2013,and Anhui from 2008 to 2013 epidemiological characteristics of ST and associated environmental factors were analyzed,using the panel negative binomial regression model.Results A total of 2 968,2 331 and 3 447 ST cases were respectively reported in Shandong,Jiangsu and Anhui during 2006-2013,with the average annual incidence rates as 0.39,0.38 and 0.94 per 100 000 population.Uptrend in Shandong and Jiangsu,but a slight rollback seen in Anhui were observed.Expansion of natural foci was found in the 3 provinces,with affected counties accounted for 38.0％,48.2％ and 46.5％ in Shandong,Jiangsu and Anhui,respectively in 2013.Cases were clustered in autumn but with a peak of single epidemic appeared in October or November,in all the 3 provinces.More female and elderly patients were seen,than in the other age groups,in all the 3 provinces.Majority of the cases were farmers,with an increasing trend in incidence,in all these provinces,followed by housekeepers in Shandong and preschool children in Anhui.The risk factors of transmission in all the 3 provinces were negatively associated with the monthly precipitation,and showing an "inverted-U" pattern in association with monthly temperature.A positive relationship between the risk of transmission and monthly relative humidity was found in Shandong and Jiangsu provinces.However,an "inverted-U" pattern between the risk of transmission and the monthly sunshine hour,appeared in Shandong and Anhui provinces.The incidence of Scrub typhus in Shandong was also positively related to the coverage of forest.Conclusion Surveillance programs and health education measures should focus on the warm and moist areas in all the 3 provinces,and also on forestry areas in Shandong.Health education and prevention on mite-bite should be targeted,especially on high-risk populations as the elderly and farmers,in the 3 provinces.Housekeepers in Shandong and children in Anhui should also be under special concern.
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Objective To investigate the spatiotemporal expansion and risk factors of scrub typhus (ST) in Shandong,Jiangsu and Anhui provinces.Methods Based on the reported cases in Shandong and Jiangsu from 2006 to 2013,and Anhui from 2008 to 2013 epidemiological characteristics of ST and associated environmental factors were analyzed,using the panel negative binomial regression model.Results A total of 2 968,2 331 and 3 447 ST cases were respectively reported in Shandong,Jiangsu and Anhui during 2006-2013,with the average annual incidence rates as 0.39,0.38 and 0.94 per 100 000 population.Uptrend in Shandong and Jiangsu,but a slight rollback seen in Anhui were observed.Expansion of natural foci was found in the 3 provinces,with affected counties accounted for 38.0％,48.2％ and 46.5％ in Shandong,Jiangsu and Anhui,respectively in 2013.Cases were clustered in autumn but with a peak of single epidemic appeared in October or November,in all the 3 provinces.More female and elderly patients were seen,than in the other age groups,in all the 3 provinces.Majority of the cases were farmers,with an increasing trend in incidence,in all these provinces,followed by housekeepers in Shandong and preschool children in Anhui.The risk factors of transmission in all the 3 provinces were negatively associated with the monthly precipitation,and showing an "inverted-U" pattern in association with monthly temperature.A positive relationship between the risk of transmission and monthly relative humidity was found in Shandong and Jiangsu provinces.However,an "inverted-U" pattern between the risk of transmission and the monthly sunshine hour,appeared in Shandong and Anhui provinces.The incidence of Scrub typhus in Shandong was also positively related to the coverage of forest.Conclusion Surveillance programs and health education measures should focus on the warm and moist areas in all the 3 provinces,and also on forestry areas in Shandong.Health education and prevention on mite-bite should be targeted,especially on high-risk populations as the elderly and farmers,in the 3 provinces.Housekeepers in Shandong and children in Anhui should also be under special concern.
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Objective To understand the impact of meteorological factors on the incidence of hand,foot and mouth disease (HFMD) and the epidemiological characteristics of HFMD in China.Methods Bayesian hierarchical model[Besag,York,and Mollie' (BYM) model] was used to fit the data.The fitting effects of uncorrelated heterogeneity (UH) model,correlated heterogeneity (CH) model and spatial and temporal interaction model were compared and the best model was selected to analyze the meteorological factors influencing the incidence of HFMD.Results The UH +CH model with spatial and temporal interaction had best fitting effect (DIC=35 507.2).Rainfall(RR=1.051 7,95％ CI:1.050 4-1.052 5),average temperature (RR=1.089 6,95％ CI:1.078 1-1.106 9),average relative humidity (RR=l.089 0,95％CI:1.082 1-1.091 2),average air pressure (RR=l.076 4,95％ CI:1.074 8-1.077 9) and hours of sunshine (RR=1.0851,95％ CI:1.0798-1.0875) were the meteorological factors influencing the incidence of HFMD.Conclusion The incidence of HFMD had spatial and temporal clustering characteristics.The meteorological factors were closely related with the incidence of HFMD.
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objective To identify the three strains of pink-pigmented bacteria isolated from ticks.Methads 16S rDNA sequence analysis,16S rDNA similarity searching,bacterial morphological,physiological and biochemical tests and fatty acids analysis were used.Results The bacterial strains were pinkpigment,gram negative,strictly aerobic coccobacillus.They grow optimally at 37℃,while not in the presence of≥5% NaCl.The tests showed positive result for urease,D-glucose,citrate,UV absorption,and catalase.The predominant fatty acids were C16:0,C17:0,C18:1 ωgc and C19:0 cyc.Comparative 16S rDNA sequences analysis revealed that the strains were closely related to Roseomonas cervicalis and could reach up to 99.1% identity.Conclusion Based on phenotypic,biochemical and phylogenetic data,we propose these three isolates represent distinct species in genus Roseomonas,of which ticks may serve as a potential vector.
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We report a complete genomic sequence of rare isolates (minor genotype) of the SARS-CoV from SARS patients in Guangdong, China, where the first few cases emerged. The most striking discovery from the isolate is an extra 29-nucleotide sequence located at the nucleotide positions between 27,863 and 27,864 (referred to the complete sequence of BJ01) within an overlapped region composed of BGI-PUP5 (BGI-postulated uncharacterized protein 5) and BGI-PUP6 upstream of the N (nucleocapsid) protein. The discovery of this minor genotype, GD-Ins29, suggests a significant genetic event and differentiates it from the previously reported genotype, the dominant form among all sequenced SARS-CoV isolates. A 17-nt segment of this extra sequence is identical to a segment of the same size in two human mRNA sequences that may interfere with viral replication and transcription in the cytosol of the infected cells. It provides a new avenue for the exploration of the virus-host interaction in viral evolution, host pathogenesis, and vaccine development.
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Base Sequence , China , Cluster Analysis , Gene Components , Genetic Variation , Genome, Viral , Genotype , Molecular Sequence Data , Phylogeny , Reverse Transcriptase Polymerase Chain Reaction , Severe acute respiratory syndrome-related coronavirus , Genetics , Sequence Analysis, DNA , Severe Acute Respiratory Syndrome , GeneticsABSTRACT
Beijing has been one of the epicenters attacked most severely by the SARS-CoV (severe acute respiratory syndrome-associated coronavirus) since the first patient was diagnosed in one of the city's hospitals. We now report complete genome sequences of the BJ Group, including four isolates (Isolates BJ01, BJ02, BJ03, and BJ04) of the SARS-CoV. It is remarkable that all members of the BJ Group share a common haplotype, consisting of seven loci that differentiate the group from other isolates published to date. Among 42 substitutions uniquely identified from the BJ group, 32 are non-synonymous changes at the amino acid level. Rooted phylogenetic trees, proposed on the basis of haplotypes and other sequence variations of SARS-CoV isolates from Canada, USA, Singapore, and China, gave rise to different paradigms but positioned the BJ Group, together with the newly discovered GD01 (GD-Ins29) in the same clade, followed by the H-U Group (from Hong Kong to USA) and the H-T Group (from Hong Kong to Toronto), leaving the SP Group (Singapore) more distant. This result appears to suggest a possible transmission path from Guangdong to Beijing/Hong Kong, then to other countries and regions.
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Humans , Genome, Viral , Haplotypes , Mutation , Open Reading Frames , Phylogeny , Severe acute respiratory syndrome-related coronavirus , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To provide further pathogenic evidence of Granulocytic ehrlichia infection in China.</p><p><b>METHODS</b>Specific primers derived from 444-Epank gene were used to amplify Granulocytic ehrlichia DNA from specimens of ticks, animals and human blood. PCR products of ticks were cloned and sequenced.</p><p><b>RESULTS</b>444 bp specific DNA fragments were amplified from 2 of 62 pools of Ixodes persulcatus collected from Heilongjiang province and 1 of 129 blood specimens from forest workers in Inner Mongolia. Eight animal specimens were negative. PCR products from ticks were then cloned and sequenced. It differed at 23 positions in comparison to American strain (AF047897) with 94.9% homology. The homology of deduced ammonia was 88.44%.</p><p><b>CONCLUSION</b>Our findings further confirmed that Granulocytic ehrlichia infection did exist in China.</p>
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Humans , DNA, Bacterial , Ehrlichia , Classification , Genetics , Ehrlichiosis , Microbiology , Genes, Bacterial , Phylogeny , Polymerase Chain Reaction , Sequence Analysis, DNAABSTRACT
<p><b>OBJECTIVE</b>To learn the existence of natural focus of Lyme disease and its distribution.</p><p><b>METHODS</b>A semi-nested polymerase chain reaction (PCR) method was developed for detection and genotyping of Borrelia burgdorferi on basis of outer surface protein A (OspA) gene. Ticks and mice collected from 6 forest areas in Beijing were detected with above methods. The positive PCR products were cloned and sequenced. The sequences were compared with published sequences for homology. IFA as used to detect IgG antibody on Borrelia burgdorferi. Lyme disease spirochete were isolated from H. longicornis were also attempted.</p><p><b>RESULTS</b>B. Burgdorferi sensu lato were detected from 939 ticks and 250 mice specimens collected from above 6 study sites using primer pairs OA(1)/OA(4) and SL/OA(4). Only the specimens collected from Dongling mountain showed positive amplification. One in three adult Ixodes persulcatus with one of 57 nymph Ixodes persulcatus showed positive while 9 of 119 (7.56%) mice specimens showed positive, of which 8 were B. grinii and one B. afzelii. In this study, we attempted to isolate B. burgdorferi sensu lato strains from 160 H. longicornis ticks (20/group) but failed. Serological survey showed a 9.1% (5/55) infection rate with B. burgdorferi sensu lato in the mice of Dongling mountain forest areas.</p><p><b>CONCLUSIONS</b>The natural focus of Lyme disease including B. garinii and B. afzelii might have existed in Dongling mountain of Mentougou district, Beijing. Ixodes persulcatu and mice may serve as vectors and reservoirs, respectively.</p>
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Animals , Humans , Mice , Antigens, Surface , Genetics , Bacterial Outer Membrane Proteins , Genetics , Bacterial Vaccines , Borrelia burgdorferi , Genetics , Borrelia burgdorferi Group , Classification , Genetics , Ixodes , Microbiology , Lipoproteins , Lyme Disease , Microbiology , Phylogeny , Polymerase Chain Reaction , MethodsABSTRACT
Objective To review the progresses in epidemiology worldwide,and to summarize the achievements in military epidemiology in recent five years,so as to provide an orientation of development of epidemiology in the future. Methods Research articles in the field of epidemiology published were retrieved by information research method. The progress in basic theory,research methods and field application of epidemiology were summarized and the developmental tendency of the subject was analyzed. Results As a basic subject of preventive medicine,epidemiology had made rapid progress in principles and study methods in recent years,and played an important role in diseases prevention and control. The advances in epidemiology mainly encompassed three aspects. Firstly,the study field had extended from only focusing on human diseases to human health and all health-related public health events. Secondly,several branches of epidemiology developed quickly,including field epidemiology,macroepidemiology,fundamental epidemiology and human genome epidemiology. The related study methods had been used for investigating the risk factors of diseases,controlling disease epidemics,decreasing impact of health events,and evaluating the effects of intervention. Thirdly,many new methods and technologies,such as molecular biological technologies and spatial information technologies,had been applied in epidemiological researches. Military epidemiology had obtained remarkable achievements in surveillance of diseases as well as epidemiological studies and prevention of common infectious diseases,natural focus diseases,injury and mental diseases in the armed forces. Conclusions In future,infectious disease epidemiology is still the most important subject in military epidemiology. More attention should be given to noninfectious diseases,especially traumas and mental health problems of the servicemen. Also,introduction of advanced technologies and methods will be helpful for prevention and control of related diseases.
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Objective To select an optimal vaccination approach and provide basis for decision-making on the control of hepatitis B infection in PLA. Methods Decision trees were constructed. The yearly new infection rate in susceptible cohort, using a catalytic model, was estimated. Disability-adjusted life year (DALY) was used to assess the effectiveness. Incremental cost-effectiveness ratio (CER) was then calculated. Results Compared with no vaccination, DALY of immediate vaccination and vaccination after screening were 61.89 and 57.18 with CER 392.70 and 251.90 respectively. After weighting with actual age construction of PLA population, the CERs of vaccination after screening and immediate vaccination were 251.90 and 392.70 respectively. Conclusion The results indicated that screening followed by vaccination was superior to immediate vaccination approach. The younger the vaccination was carried out, the more cost-effective was shown by vaccination.
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Objective To select an optimal vaccination approach and provide basis for decision-making on the control of hepatitis B infection in PLA. Methods Decision trees were constructed. The yearly new infection rate in susceptible cohort, using a catalytic model, was estimated. Disability-adjusted life year (DALY) was used to assess the effectiveness. Incremental cost-effectiveness ratio (CER) was then calculated. Results Compared with no vaccination, DALY of immediate vaccination and vaccination after screening were 61.89 and 57.18 with CER 392.70 and 251.90 respectively. After weighting with actual age construction of PLA population, the CERs of vaccination after screening and immediate vaccination were 251.90 and 392.70 respectively. Conclusion The results indicated that screening followed by vaccination was superior to immediate vaccination approach. The younger the vaccination was carried out, the more cost-effective was shown by vaccination.