OBJECTIVETo investigate the epidemiological characteristics of influenza B viruses and explore the genetic evolution characteristics of the hemagglutinin(HA) and neuraminidase(NA) genes of local isolated strains in Ningbo, Southeast China, during 2010 to 2012.

METHODSRespiratory specimens from 3440 cases of patients with influenza-like illness(ILI) during 2010 to 2012 were collected in for virus isolation. And the 628 sera samples were collected in 2010 from the healthy community population to detect the HI antibody level against the local isolated virus.For phylogenetic analysis, the fragments of HA and NA genes were amplified and sequenced from strains isolated in different years. The association between evolution of HA and epidemiological characteristics were analyzed.

RESULTSA total of 109 strains of influenza B virus were isolated, including 102 (93.6%) Victoria-lineage strains and 7 (6.4%) Yamagata-lineage strains. Positive rates of HI antibody against Victoria-lineage strains and Yamagata-lineage strains were 51.1% (321) and 47.8% (300), respectively (χ(2) = 1.405, P > 0.05) among the 628 sera samples. The phylogenetic analysis showed that all HA fragments of isolated strains clustered the same branch with Malaysia/2506/2004 while the NA genes formed different branches. Compared with Brisbane/60/2008 strain, there were 1 to 5 Amino acid mutations in HA domain, and more mutations were detected in NA domain, ranged from 6 to 16 sites. The genetic evolution of NA in Victoria-lineage strains were faster compared with HA.

CONCLUSIONThe genetic evolution rates of NA genes were faster than that of HA genes in the local circulated Victoria-lineage viruses during 2010 to 2012;The comprehensive analysis of HA and NA fragments were more reliable and sensitive on surveillance of genetic evolution of influenza B viruses.

China ; epidemiology ; Genetic Variation ; Hemagglutinin Glycoproteins, Influenza Virus ; genetics ; Humans ; Influenza B virus ; classification ; genetics ; isolation & purification ; Influenza, Human ; epidemiology ; virology ; Neuraminidase ; genetics ; Phylogeny ; RNA, Viral

OBJECTIVETo explore the integrated application of sales of child-specific over-the-counter (OTC) cold related medications in retail pharmacies and healthcare visits of children for influenza-like illness (ILI) in surveillance and early warning of influenza among children.

METHODSAn integrated surveillance system (ISS) was implemented since 2012 in Qianjiang County, a rural area in Hubei Province of China. The daily information from August 1, 2012 to February 28, 2013 of health care visits of children for ILI reported by 80 health facilities and sales of 14 child-specific over-the-counter (OTC) cold related medications reported by 11 pharmacies were extracted from ISS database. Cumulative sums (CUSUM) model was conducted to analyze the degree of fitting and the early warning signal generated; the correlationship was then analyzed further.

RESULTSIn 212 days, 983 visits of children for ILI and 12 819 sales by person of child-specific OTC were reported. Conducting CUSUM model, the fitting degree was in the acceptable range, 31 warning signals were generated from ILI data series with 3 peak periods and 14 from OTC data series with 2 peak periods. A similar time trend of two data series was observed with a correlation(r = 0.497, P < 0.05), but without any spatial clustering. And the optimal correlation(r = 0.505, P < 0.05) appeared at a time offset of 4 days preceded by OTC sales.

CONCLUSIONThe availability of integrated surveillance system for symptoms could be applied for surveillance of influenza among children; while it could explore the possibility of real epidemic in the very early stage.

Child ; China ; epidemiology ; Disease Outbreaks ; prevention & control ; Humans ; Influenza, Human ; epidemiology ; prevention & control ; Nonprescription Drugs ; Population Surveillance

OBJECTIVETo investigate the epidemic characteristics and pathogenic spectrum of community acquired pneumonia (CAP) in Guangzhou from 2009 to 2012.

METHOD14 major comprehensive hospitals were selected from 11 districts as sentinel hospitals for CAP cases surveillance, including 18 982 223 in total during the 4 years. The characteristics of pathogenic spectrum of CAP were stratified and analyzed by year, age and season.

RESULTS18 982 223 cases were included in the surveillance from year 2009 to 2012, in which 56 618 cases were CAP. The number of CAP cases increased from 8677 in year 2009 to 19 947 in year 2012 in Guangzhou; while the percentage of visits for CAP raised from 0.22% (8677/3 893 800) to 0.41% (19 947/4 839 766). The difference showed statistical significance (χ(2) = 2693.00, P < 0.05). Among the hospitalized CAP cases, 66.05% (10 954/16 585) were aged ≤ 5 years old or > 66 years old. The percentage of cases infected by a single pathogen was 88.11% (14 613/16 585), while co-infected cases accounted for 4.17% (691/16 585). Bacteria accounted for the largest proportion of 65.25% (10 821/16 585) as a single pathogen, followed by mycoplasma 13.54% (2245/16 585), virus 9.01% (1494/16 585) and chlamydia 0.32% (53/16 585). The proportion of virus infection was increasing from 4.74% to 11.64%. The difference showed statistical significance (χ(2) = 135.32, P < 0.05). Bacteria infection was the leading causes for CAP cases in all age groups; however the percentage increased with the increasing of ages. The rate of bacterial infection was increased from 48.35% (2993/6191) among children aged ≤ 5 years old to 81.31% (3873/4763) among adults aged over 65 years (χ(2) = 1632.00, P < 0.05). The rate of atypical pathogens (mycoplasma, chlamydia) for children ( ≤ 15 years old) (25.99%, 1805/6945) was higher than that for adults aged ≥ 16 years old (5.12%, 494/9640) (χ(2) = 2.11, P < 0.05). The effect from season on the pathogenic spectrum was not observed.433 hospitalized CAP cases were dead from 2009 to 2012. Case fatality rate was highest among people aged over 65 years old (4.70%, 224/4763) and lowest among children aged between 6 to 15 years old (0.27%, 2/754).

CONCLUSIONThe incidence of community acquired pneumonia was rising in Guangzhou from 2009 to 2012. Bacteria was the dominant pathogen. Children and old people were the high-risk population of community acquired pneumonia; while co-infection was still at low level.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Child, Preschool ; China ; epidemiology ; Community-Acquired Infections ; epidemiology ; microbiology ; Female ; Humans ; Infant ; Male ; Middle Aged ; Pneumonia ; epidemiology ; microbiology ; Sentinel Surveillance ; Young Adult

OBJECTIVETo study the pathogenic ecology characteristics of plague in Qinghai plateau.

METHODSApplied molecular biology techniques, conventional technologies and geographic information system (GIS) to study phenotypic traits, plasmid spectrum, genotype, infected host and media spectrum etc.of 952 Yersinia pestis strains in Qinghai plateau plague foci, which were separated from different host and media in different regions during 1954 to 2012.

RESULTSThe ecotypes of these strains were Qingzang plateau (91.49%, 871/952),Qilian mountain (6.41%, 61/952) and Microtus fuscus (1.26%, 12/952).83.6% (796/952) of these strains contained all the 4 virulence factors (Fr1, Pesticin1,Virulence antigen, and Pigmentation), 93.26% (367/392) were velogenic strains confirmed by virulence test.725 Yersinia pestis strains were separated from Qinghai plateau plague foci carried 9 kinds of plasmid, among which 713 strains from Marmot himalayan plague foci carried 9 kinds of plasmid, the Mr were 6×10(6), 7×10(6), 23×10(6), 27×10(6), 30×10(6), 45×10(6), 52×10(6), 65×10(6) and 92×10(6) respectively. 12 Yersinia pestis strains were separated from Microtus fuscus plague foci carried only 3 kinds of plasmid, the Mr were 6×10(6), 45×10(6), 65×10(6). Meanwhile, the strains carrying large plasmid (52×10(6), 65×10(6) and 92×10(6)) were only distributed in particular geographical location, which had the category property. The research also confirmed that 841 Yersinia pestis strains from two kinds of plague foci in Qinghai plateau had 11 genomovars. The strains of Marmot himalayan plague foci were given priority to genomovar 5 and 8, amounted to 611 strains, genomovar 8 accounted for 56.00% (471/841), genomovar 5 accounted for 23.07% (194/841). Besides, 3 new genomovars, including new 1(62 strains), new 2(52 strains), new 3(48 strains) were newly founded, and 12 strains of Microtus fuscus plague foci were genomovar 14.

CONCLUSIONThe main host and media of Qinghai plateau plague foci directly affected the spatial distribution regularities of plague epidemic and the pathogens characteristics, meanwhile the polymorphism of plague ecological geographic landscape leds to the complexity of Yersinia pestis' genotype.

Animals ; Arvicolinae ; microbiology ; China ; epidemiology ; Disease Reservoirs ; microbiology ; Ecology ; Genotype ; Marmota ; microbiology ; Plague ; epidemiology ; microbiology ; Virulence ; genetics ; Yersinia pestis ; genetics ; pathogenicity

Agricultural Workers' Diseases ; Agriculture ; Humans

Animals ; Disease Reservoirs ; microbiology ; Genome, Bacterial ; Geography ; Marmota ; microbiology ; Plague ; epidemiology ; microbiology ; Polymorphism, Genetic ; Yersinia pestis ; genetics

OBJECTIVETo establish the method of simultaneous determination of methylcarbamate (MC) and ethylcarbamate (EC) in yellow rice wine by gas chromatography-mass spectrometry (GC/MS).

METHODSMC and EC in yellow rice wine were derived by 9-xanthydrol, and then the derivants were detected by GC/MS; and quantitatively analyzed by D5-EC isotope internal standard method.

RESULTSThe linearity of MC and EC ranged from 2.0 µg/L to 400.0 µg/L, with correlation coefficients at 0.998 and 0.999, respectively. The limits of quantitation (LOQ) and detection (LOD) were 0.67 and 2.0 µg/kg. When MC and EC were added in yellow rice wine at the range of 2.0-300.0 µg/kg, the intraday average recovery rate was 78.8%-102.3%, relative standard deviation was 3.2%-11.6%; interday average recovery rate was 75.4%-101.3%, relative standard deviation was 3.8%-13.4%. 20 samples of yellow rice wine from supermarket were detected using this method, the contents of MC were in the range of ND (no detected) to 1.2 µg/kg, the detection rate was 6% (3/20), the contents of EC in the range of 18.6 µg/kg to 432.3 µg/kg, with the average level at 135.2 µg/kg.

CONCLUSIONThe method is simple, rapid and useful for simultaneous determination of MC and EC in yellow rice wine.

Carbamates ; analysis ; Food Contamination ; analysis ; Gas Chromatography-Mass Spectrometry ; methods ; Oryza ; Urethane ; analysis ; Wine ; analysis

OBJECTIVETo compare the concordance in predicting genotype HIV-1 drug resistance between In-house method and TRUGENE(TM) or ViroSeq(TM) method.

METHODS25 international proficiency testing (PT) samples received from 2009 to 2013 were detected by three methods, then pairwise comparison results was analyzed to validate their concordance on drug resistance mutation and drug resistance report. To further confirm the results, another 15 serum specimens were detected by In-house and TRUGENE(TM) methods, then compared their results concordance.

RESULTSThe evaluation of the consistency of resistance-associated mutations showed that for 25 PT samples, the consistency was 99.42% (2933/2950) in testing drug resistance mutation sites among the three methods; all pairwise comparison Kappa values >0.81(P < 0.01). The evaluation of the consistency of drug resistance test showed that inconsistent comparison results mainly concentrated in the four nucleoside reverse transcriptase inhibitors zidovudine (AZT), didanosine (ddI), stavudine (d4T), abacavir (ABC), and the inconsistencies were mainly minor. Where the minor inconsistencies between In-house and ViroSeq(TM) methods were 28% (7/25), 28% (7/25), 16% (4/25) and 20% (5/25), respectively. And the inconsistencies between In-house and TRUGENE(TM) method were separately 44% (11/25), 28% (7/25), 36% (9/25) and 28% (7/25);while the inconsistencies between TRUGENE(TM) and ViroSeq(TM) method were separately 24% (6/25), 8% (2/25), 28% (7/25) and 8% (2/25). AZT in the comparison between In-house and ViroSeq(TM) methods, ddI, d4T, ABC and TDF in the comparison between In-house and TRUGENE(TM) methods were moderately consistent (weighted Kappa values were separately 0.54, 0.44, 0.52, 0.42, 0.59, all the P value <0.01). The other compared results were all highly-consistent (weighted Kappa values were 0.61-0.80) or extremely high-consistent (weighted Kappa values were >0.80). For 15 serum specimens, 99.55% (1762/1770) drug resistance mutation sites could be detected by the two methods, the difference about drug results concentrated in AZT, ddI, d4T and ABC.

CONCLUSIONThe In-house genotyping system had a high concordance with commercial TRUGENE(TM) or ViroSeq(TM) genotyping system.

Drug Resistance, Viral ; genetics ; Genes, Viral ; Genotype ; HIV-1 ; drug effects ; genetics ; isolation & purification ; Humans ; Reagent Kits, Diagnostic

OBJECTIVETo establish the reverse transcription loop-mediated isothermal amplification (RT-LAMP) methods for on-site HIV-1 detection.

METHODSAs for the real-time fluorescent RT-LAMP, we firstly tested the specificity and sensitivity, then explored its quantitative determination, and finally applied the method to the detection of 35 HIV-1 positive samples. For colorimetric judgment, after choosing different ameliorates to modify Hydroxynaphthol blue (HNB), we tested their real effects on coloration, and then picked out the modified dyes with obvious color change to test the sensitivity and the detection of the 35 HIV-1-positive samples.

RESULTSThe real-time fluorescent RT-LAMP showed great specificity of HIV-1, and the sensitivity to detect HIV-1 RNA was between 10 and 100 copies per reaction. On testing 35 HIV-1-positive samples, the method could reach 100 percent detection rate. However, for the quantitative determination, the quantitative relation was not observed regarding the HIV-1 RNA of below 10(3) copies per reaction. Three modified HNB dyes with clear color variation between the reaction tubes of the negative and the positive were got in the study, and their sensitivities equaled to the level of agarose gel electrophoresis. Similarly, 100% (35/35) detection rate was reached when the colorimetric RT-LAMP with the modified dyes was applied to detect 35 HIV-1-positive samples.

CONCLUSIONThe established real-time fluorescence method and the modified color judgment of RT-LAMP could be helpful for truly achieving rapid, accurate, and sensitive on-site detection of HIV-1.

HIV-1 ; genetics ; isolation & purification ; Nucleic Acid Amplification Techniques ; methods ; Reverse Transcriptase Polymerase Chain Reaction

OBJECTIVETo investigate the genetic features of drug resistance to group A streptococcus(GAS) and macrolides antibiotics among pediatric patients in Beijing 2012.

METHODSA total of 199 strains of GAS were collected from 36 hospitals in Beijing between May and July, 2012. All strains were isolated from oropharyngeal swabs. The minimum inhibitory concentrations (MICs) of ten antibiotics (penicillin, ampicillin, erythromycin, clindamycin, tetracycline, levofloxacin, tigecycline, vancomycin, linezolid and streptogramin) were detected by VITEK-2 compact with GPS-67 test kit. The genes encoding macrolides resistance (ermA, ermB and mefA ) were amplified and tested by PCR. The macrolides resistant phenotype of group A streptococcus was detected by double disc test (D-test).

RESULTSAmong 199 strains of GAS collected in this study, 101(50.8%) were from suburbs and the other 98(49.2%) were from urban areas. 111(55.8%) strains were collected from scarlet fever patients while the other 88(44.2%) were from oropharyngeal infection cases. All the strains were sensitive to penicillin and ampicillin, and the percentage of resistance to erythromycin, clindamycin and tetracycline were 96.5% (192/199), 95.5% (190/199) and 92.0% (183/199), respectively. All strains were susceptible to levofloxacin, tigecycline, vancomycin, linezolid and streptogramin. The rates of resistance to erythromycin, clindamycin and tetracycline were different in different districts, however, the difference in it between ages and clinical diagnosis did not show statistical significance (P > 0.05) . The detected rate of drug resistance gene ermB was 98.5% (196/199). The gene ermA was only detected out in 5 strains and the gene mefA was not detected out. 199 strains showed A macrolides resistant phenotype cMLS, while the phenotype iMLS was not found in this study.

CONCLUSIONThis study demonstrates the high level of clindamycin resistance in group A streptococcus collected from children in Beijing, 2012. The macrolides resistance of group A streptococcus was highly prevalent in Beijing, and the dominant phenotype was cMLS mediated by gene ermB.

Anti-Bacterial Agents ; pharmacology ; Bacterial Proteins ; genetics ; Child ; Child, Preschool ; China ; epidemiology ; Drug Resistance, Multiple, Bacterial ; genetics ; Genotype ; Humans ; Macrolides ; pharmacology ; Streptococcal Infections ; epidemiology ; microbiology ; Streptococcus pyogenes ; drug effects ; genetics ; isolation & purification