The Effects of Online Homeschooling on Children, Parents, and Teachers of Grades 1-9 During the COVID-19 Pandemic.

BACKGROUND Beginning in the 2020 spring semester, due to the COVID-19 pandemic, all school-age children in China were homeschooled via live/recorded broadcasts, online group communication, and software-based homework submission. This study assessed the effects of and proper preparation for this educational approach. MATERIAL AND METHODS The homeschooling behaviors and feelings of school-age children were assessed with 2010 online surveys obtained separately from students, parents, and teachers of grades 1-9 in 15 Chinese provinces. Answers were compared among low- (grades 1-3), middle- (grades 4-6), and high- (grades 7-9) grade groups. The chi-square test was used to identify significant differences between groups. RESULTS We found that 76% of the respondents thought the homeschooling style was acceptable. However, teachers were concerned that students' interest, focus, and academic performance would decline. Sixty-nine percent of the parents reported their children had more than 3 hours of daily screen time, and 82% of students had less than 2 hours of daily outdoor activity. Ninety-five percent of the parents were concerned about their children's eyesight. Additionally, 17.6% of the students were suspected to have emotional or behavioral problems according to the parent-rated Strengths and Difficulties Questionnaire (SDQ) results. The Self-Rating Anxiety Scale (SAS) results of parents and teachers showed higher levels of anxiety than usual. CONCLUSIONS Students should continue the going-to-school rhythm at home to cope with changes caused by the COVID-19 pandemic. Integrated grade-specific approaches are needed. Because long screen time and insufficient outdoor activities can severely affect children's eyesight, appropriate eye-protection measures should be implemented.

Growth of HIV-uninfected children born to HIV-infected mothers in Guangdong, China: an 18-month longitudinal follow-up study.

BACKGROUND: To evaluate the early growth (weight and length) of HIV-exposed uninfected (HEU) children from the prevention of mother-to-child transmission (PMTCT) of human immunodeficiency virus (HIV) program in Guangdong Province, China. METHODS: A total of 731 HEU children were longitudinally followed up at 7 time points, with anthropometric measurement conducted of weight and length (supine) in the first 18 months. Z scores were calculated, with and without adjustment for gestational age. RESULTS: A total of 708 HEU children were included in the final follow-up cohort, and 105 (14.83%) children completed all 7 follow-up visits. The mean of adjusted weight-for-age Z scores in these children was above zero and showed a decreasing trend in 18 months. The mean of adjusted length-for-age Z scores showed a decreasing trend and was above zero in the first 12 months; this declined to under zero at age 18 months. The proportion of underweight was 0.28-2.19% and that of stunting was 0.71-4.63% at each follow-up month-age. Slower growth in HEU children was associated with no sustained food subside after 6 month, mothers' hemoglobin content less than 100 g/L during pregnancy, preterm birth, and low birth weight (p < 0.05). CONCLUSIONS: HEU children could catch up to WHO growth standards in first 18 months in Guangdong; however, growth declined after 12 months, and these children need sustained nutritional support.

[Long-term effect of cadmium exposure on residents' renal dysfunction: An epidemiologic study].

OBJECTIVE: To study long-term effect on renal function exposed to environmental cadmium. METHODS: Stratified random sampling and cluster sampling method of epidemiological investigations were carried out in northern Guangdong province between April, 2011 and August, 2012. A total of 167 residents who lived in high cadmium exposure area for more than 15 years, aged above 40 were selected in exposed group. Moreover, A total of 145 residents who had similar living and economic conditions and lived in local for more than 15 years, aged above 40 were selected in control group. We used health questionnaires and medical examinations in order to acquire their health status. Home-harvested rice and vegetables were collected using quartering method for detection of cadmium level. Urine specimens of residents were collected for detection of cadmium level and creatinine as well as renal dysfunction biomarkers, namely, N-acetyl-beta-D-glucosamidase (NAG), ß2-microglobulin (ß2-MG), and retinol binding protein(RBP), respectively. The analysis of spearman rank correlation and multiple regression were used to investigate the relationships between age, urinary cadmium levels and renal injury biomarkers. RESULTS: The cadmium levels in rice and vegetables of exposed group were 0.75 and 0.10 mg/kg, both were significantly higher than 0.07 and 0.01 mg/kg in the control group (Z values were -6.32 and -7.84, all P values < 0.001). The urinary cadmium level of exposed group was 8.29 µg/g · cr, which was higher than that of the control group 2.03 µg/g · cr with significant difference (Z value was -11.39, P < 0.001). After stratified the total population by age, the urinary cadmium level in 40-49 years, 50-59 years and ≥ 60 years subgroups were 7.22, 8.71, and 13.10 µg/g · cr, which both were significantly higher than 1.80, 2.04, and 2.05 µg/g · cr in the control group (Z values were -5.22, -7.41, and -7.14, all P values < 0.001). After stratified the total population by gender, the urinary cadmium level of male and female were 5.12 and 12.36 µg/g · cr, which both were significantly higher than 1.79 and 2.16 µg/g · cr in the control group (Z values were -7.68 and -9.03, all P values < 0.001). Comparing the differences of renal dysfunction biomarkers (NAG, ß2-MG, RBP) between two groups. The level of urinary ß2-MG and RBP of exposed group were 0.21 and 0.04 µg/g · cr, which were higher than 0.05 and 0.00 µg/g · cr of the control group with significant difference (Z value was -7.08 and -9.65, all P values < 0.001). Pearson correlation analysis showed that NAG, ß2-MG and RBP were positively correlated with urinary cadmium and age, the correlation coefficients were 0.57, 0.49, 0.21 and 0.22, 0.26, 0.23 respectively (all P values < 0.001). After adjusting the effect of age, it was appeared that urinary cadmium levels contributed most to the alteration of NAG, ß2-MG and RBP, the standardized regression coefficients were 0.57, 0.49 and 0.20 (all P values < 0.001), and suggested that the cadmium body burden was one of the most important factors for renal dysfunction. CONCLUSION: Residents, who had cadmium contaminated rice and vegetables for a long time, would take the risk of increasing body burden of cadmium and urinary early biomarkers of renal tubular injury that referred to occurrence of renal dysfunction.

Identifying early urinary metabolic changes with long-term environmental exposure to cadmium by mass-spectrometry-based metabolomics.

Cadmium (Cd) is a common environmental pollutant, and urinary Cd (UCd) is generally used as a marker of exposure; however, our understanding on the related urinary metabolic changes caused by Cd exposure is still not clear. In this study, we applied a mass-spectrometry-based metabolomic approach to assess the urinary metabolic changes in human with long-term environmental Cd exposure, aimed to identify early biomarkers to assess Cd nephrotoxicity. Urine samples from 94 female never smokers aged 44-70 with UCd in the range of 0.20-68.67 µg/L were analyzed by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-ToF-MS) and gas chromatography-mass spectrometry (GC-MS). It was found that metabolites related to amino acid metabolism (L-glutamine, L-cystine, L-tyrosine, N-methyl-L-histidine, L-histidinol, taurine, phenylacetylglutamine, hippurate, and pyroglutamic acid), galactose metabolism (D-galactose and myo-inositol), purine metabolism (xanthine, urea, and deoxyadenosine monophosphate), creatine pathway (creatine and creatinine), and steroid hormone biosynthesis (17-α-hydroxyprogesterone, tetrahydrocortisone, estrone, and corticosterone) were significantly higher among those with a UCd level higher than 5 µg/L. Moreover, we noticed that the level of N-methyl-L-histidine had already started to elevate among individuals with a UCd concentration of ≥2 µg/L. The overall findings illustrate that metabolomics offer a useful approach for revealing metabolic changes as a result of Cd exposure.

Comparative antigenic proteins and proteomics of pathogenic Yersinia enterocolitica bio-serotypes 1B/O: 8 and 2/O: 9 cultured at 25°C and 37°C.

Yersinia enterocolitica is a Gram-negative enteric pathogen responsible for a number of gastrointestinal disorders; the most pathogenic bio-serotype is 1B/O: 8. In this study, we compared the antigenicity of the outer membrane proteins and proteomics of the whole-cell proteins of a pathogenic bio-serotype 2/O: 9 isolated in China and a bio-serotype 1B/O: 8 strain isolated in Japan. Using two-dimensional gel electrophoresis, we showed that the outer membrane proteins A (OmpA), C (OmpC) and F (OmpF) were the major antigens for both strains, although proteins located on the bacterial cell membrane and enzymes involved in energy metabolism were also identified as antigenic. We compared the whole-cell proteins of the two strains cultured at 25°C and 37°C and found portions of the outer membrane proteins (OmpX, OmpF and OmpA) were downregulated when the bacteria were cultured at 37°C, whereas urease subunit gamma (UreA), urease subunit alpha (UreC) and urease accessory protein (UreE), which are involved in urease synthesis, were upregulated when the bacteria were grown at 37°C. These observations will lay a foundation to selection of diagnostic markers for pathogenic Yersinia enterocolitica, and maybe contribute to choose the vaccine targets.

Adenovirus serotype 7 associated with a severe lower respiratory tract disease outbreak in infants in Shaanxi Province, China.

BACKGROUND: Pneumonia caused by adenovirus infection is usually severe especially with adenovirus serotype 7 commonly associated with lower respiratory tract disease outbreaks. We reported an outbreak of 70 cases of severe pneumonia with one death of infants in Shaanxi Province, China. Sampling showed adenovirus 7 (Ad7) as the primary pathogen with some co-infections. RESULTS: Two strains of adenovirus and two strains of enterovirus were isolated, the 21 pharynx swabs showed 14 positive amplifications for adenovirus; three co-infections with respiratory syncytial virus, two positive for rhinovirus, one positive for parainfluenza 3, and four negative. Adenovirus typing showed nine of the nine adenovirus positive samples were HAdV-7, three were HAdV-3 and two were too weak to perform sequencing. The entire hexon gene of adenovirus was sequenced and analyzed for the two adenovirus serotype 7 isolates, showing the nucleic acid homology was 99.8% between the two strains and 99.5% compared to the reference strain HAdV-7 (GenBank accession number AY769946). For the 21 acute phase serum samples from the 21 patients, six samples had positives results for ELISA detection of HAdV IgA, and the neutralization titers of the convalescent-phase samples were four times higher than those of the acute-phase samples in nine pairs. CONCLUSIONS: We concluded adenovirus was the viral pathogen, primarily HAdV-7, with some co-infections responsible for the outbreak. This is the first report of an infant pneumonia outbreak caused by adenovirus serotype 7 in Shaanxi Province, China.

Pathogenic strains of Yersinia enterocolitica isolated from domestic dogs (Canis familiaris) belonging to farmers are of the same subtype as pathogenic Y. enterocolitica strains isolated from humans and may be a source of human infection in Jiangsu Province, China.

We isolated 326 Yersinia enterocolitica strains from 5,919 specimens from patients with diarrhea at outpatient clinics, livestock, poultry, wild animals, insect vectors, food, and the environment in the cities of Nantong and Xuzhou in Jiangsu Province, China, from 2004 to 2008. The results showed that the 12 pathogenic strains were of the O:3 serotype. Six strains were isolated from domestic dogs (Canis familiaris) belonging to farmers and were found to be the primary carriers of pathogenic Y. enterocolitica strains, especially in Xuzhou. Pulsed-field gel electrophoresis analysis of the pathogenic strains from dogs belonging to farmers showed that they shared the same patterns as strains from diarrhea patients isolated in 1994. This indicates that the strains from domestic dogs have a close correlation with the strains causing human infections.

Possible use of ail and foxA polymorphisms for detecting pathogenic Yersinia enterocolitica.

BACKGROUND: Yersinia enterocolitica is an enteric pathogen that invades the intestinal mucosa and proliferates within the lymphoid follicles (Peyer's patches). The attachment invasion locus (ail) mediates invasion by Y. enterocolitica and confers an invasive phenotype upon non-invasive E. coli; ail is the primary virulence factor of Y. enterocolitica. The ferrioxamine receptor (foxA) located on the Y. enterocolitica chromosome, together with its transport protein, transports a siderophore specific for ferric ion. Currently, ail is the primary target gene for nucleic acid detection of pathogenic Y. enterocolitica. RESULTS: The genes ail and foxA in 271 pathogenic and 27 non-pathogenic Y. enterocolitica strains isolated from China and 10 reference strains were sequenced, aligned, compared to the ail and foxA sequences of Yersinia enterocolitica subsp. enterocolitica 8081 (Genbank: NC_008800), and analyzed for sequence polymorphism. The ail from the 282 strains showed 3 sequence patterns: 277 strains of serotypes O:3, O:9 and O:5, 27 with identical nucleic acid sequences formed pattern A1; 4 strains of serotype 1B/O:8 with identical nucleic acid sequences formed pattern A2; and one Chinese isolate 2/O:9 formed pattern A3. In the primary coding region of the foxA ORF (Genebank: X60447 nt 433-1866; nt 28 to 1,461 in the ORF), the sequences formed 3 groups and were further divided into 8 sequence patterns. CONCLUSION: The ail and foxA loci of pathogenic Y. enterocolitica have been analyzed. The ail sequence was highly conserved among the same serotype strains from different sources; and foxA was highly conserved among the pathogenic strains, although there was some sequence diversity. Fewer strains were used from outside China, which is a limitation of the study.

Retrospective seroepidemiology indicated that human enterovirus 71 and coxsackievirus A16 circulated wildly in central and southern China before large-scale outbreaks from 2008.

BACKGROUND: Large nationwide outbreaks of hand, foot, and mouth disease (HFMD) occurred in China from 2008; most of the cases were in children under 5 years. This study aims to identify the situation of natural human enterovirus 71 (HEV71) and coxsackievirus A16 (CVA16) infections in children before 2008 in China. RESULTS: Retrospective seroepidemiologic studies of HEV71 and CVA16 were performed with 900 serum samples collected from children ≤5 years of age in 2005. The samples were collected from 6 different geographical areas (Anhui, Guangdong, Hunan, Xinjiang, Yunnan, and Heilongjiang provinces) in mainland China. Of the 900 samples, 288 were positive for HEV71; the total positive rate was 32.0% and the geometric mean titer (GMT) was 1:8.5. Guangdong (43.7% and 1:10.8), Xinjiang (45.4% and 1:11.1), and Yunnan (43.4% and 1:12.0) provinces had relatively high rates of infection, while Heilongjiang province (8.1% and 1:4.9) had the lowest rate of infection. On the other hand, 390 samples were positive for CVA16; the total positive rate was 43.4% and the GMT was 1:9.5. Anhui (62.2% and 1:16.0) and Hunan (61.1% and 1:23.1) had relatively high rates, while Heilongjiang (8.0% and 1:4.6) had the lowest rate. Although there is a geographical difference in HEV71 and CVA16 infections, low neutralizing antibody positive rate and titer of both viruses were found in all 6 provinces. CONCLUSIONS: This report confirmed that HEV71 and CVA16 had wildly circulated in a couple provinces in China before the large-scale outbreaks from 2008. This finding also suggests that public health measures to control the spread of HEV71 and CVA16 should be devised according to the different regional characteristics.

Outbreak of acute respiratory disease in China caused by B2 species of adenovirus type 11.

An outbreak of acute respiratory tract infection occurred in Shanxi Province, China, from March to April 2006. Of the 254 patients affected by this outbreak, 247 patients were students of a senior high school; 1 of these patients died during the outbreak. Serological tests and blood culture revealed no evidence of bacterial infection. The results of direct reverse transcription-PCR or PCR performed with clinical specimens collected from the patients, including the sole patient who died, were positive for human adenoviruses (HAdVs) but negative for influenza virus, measles virus, rubella virus, mumps virus, parainfluenza virus, respiratory syncytial virus, and human enteroviruses. These findings were confirmed by enzyme-linked immunosorbent assay for HAdV immunoglobulin A, the conventional neutralization test, and viral isolation and identification. Sequencing of the entire hexon gene revealed that HdAV type 11a (HAdV-11a) belonging to the B2 species of HAdV was the etiological agent responsible for the outbreak. However, both the analysis of the phylogenetic relationship and the similarity plot indicated that the sequence of the 3' end of the hexon gene outside the hypervariable regions the HAdV-11a strain isolated in this outbreak may be a recombinant with the sequence of the HAdV-14 strain of species B2. Although isolates of HAdV species B2 seldom cause respiratory infections, they may pose a new global challenge with regard to acute respiratory diseases; this possibility cannot be overlooked and should be carefully considered. Hence, the need to establish and improve both epidemiological and virological surveillance of HAdV infections in China should be emphasized.

Genomic analyses of recombinant adenovirus type 11a in China.

Whole-genome sequencing of human adenovirus type 11 (HAdV-11) strain QS, isolated in China, was conducted, and its sequence was compared with the sequences of strains within the species of HAdVs. The HAdV-11 QS genome contains 34,755 nucleotides. Similar to the other HAdV subgenus B sequences, the HAdV-11 QS genome coded 37 functional proteins and could be divided into four early, two intermediate, and five late transcription regions. The amino acid sequences of the fiber and the hypervariable regions (HVRs) within the hexon gene of HAdV-11 QS were identical to the corresponding sequences of the HAdV-11a strain; further analyses that compared those amino acid sequences with the amino acid sequences of the HAdV species subgenus B:2 strains revealed that the highest degree of homology (>99.2%) existed between HAdV-11 QS and the prototypical HAdV-14 strain, except for a few coding sequences of HVRs within the hexon gene, DNA polymerase, pVI, and pre-terminal protein. This indicate that HAdV-11 strain QS, isolated in China, is a recombinant adenovirus of HAdV-14, and the recombination analyses also confirmed this finding. It is difficult to clarify the time and manner of the recombination, and further investigations are required to determine whether the emergence of recombination between HAdV-11a and HAdV-14 might increase virulence, thereby posing a new global challenge with regard to acute respiratory diseases in the near future.

Human bocavirus in children suffering from acute lower respiratory tract infection in Beijing Children's Hospital.

BACKGROUND: Human bocavirus (HBoV) is a parvovirus recently found to possibly cause respiratory tract disease in children and adults. This study investigated HBoV infection and its clinical characteristics in children younger than five years of age suffering from acute lower respiratory tract infection in Beijing Children's Hospital. METHODS: Nasopharyngeal aspirates were collected from children suffering from acute lower respiratory tract infection during the winters of 2004 to 2006 (from November through the following February). HBoV was detected by polymerase chain reaction amplification and virus isolation and the amplification products were sequenced for identification. RESULTS: HBoV infection was detected in 16 of 333 study subjects. Coinfections with respiratory syncytial virus were detected in 3 of 16 HBoV positive patients with acute lower respiratory tract infection. The median age for HBoV positive children was 8 months (mean age, 17 months; range, 3 to 57 months). Among the HBoV positive children, 14 were younger than 3 years old, 9 were younger than 1 year old and 7 were younger than 6 months. These 16 positive HBoV children exhibited coughing and abnormal chest radiography findings and more than 60% of these children had wheezing and fever. Ten children were clinically diagnosed with pneumonia, 2 bronchiolitis, 2 acute bronchitis and 2 asthma. One child died. CONCLUSIONS: HBoV was detected in about 5% of children with acute lower respiratory infection seen in Beijing Children's Hospital. Further investigations regarding clinical and epidemiologic characteristics of HBoV infection are needed.

Urine metabolomics of women from small villages exposed to high environmental cadmium levels.

The present study aimed to identify urine metabolites in women exposed to high cadmium (Cd) levels. Twenty-one women exposed to environmental Cd and 12 age-matched controls were categorized as high exposure (urine Cd ≥ 15 µg/g creatinine; n = 9) or low exposure (15 µg/g creatinine > urine Cd > 5 µg/g creatinine; n = 12). Low-molecular weight metabolites in urine were analyzed by gas chromatography and mass spectrometry after derivatization. An orthogonal partial least-squares discriminant analysis model was constructed, and metabolites from the dimensional model were selected according to the variable importance in projection (>1). Metabolites differing significantly in abundance between different exposure groups were identified by searching mass spectral databases, and related pathways were analyzed using the Kyoto Encyclopedia of Genes and Genomes. Approximately 110 significantly different metabolites were detected with variable importance in projection > 1, and 48 of them were found to differ markedly in abundance among the 3 groups. Twenty-seven matched with known metabolites, including 22 significantly increased and 5 markedly decreased in the high-exposure group (p < 0.01). Kyoto Encyclopedia of Genes and Genomes results indicated that carbohydrate, amino acid, bone, and intestinal flora metabolism and the tricarboxylic acid cycle were affected by Cd exposure. The present study identified metabolites that differed in abundance in response to Cd exposure. Further studies may connect these biomarkers to early damage caused by Cd.

Complete genome sequence of human adenovirus type 7 associated with fatal infant pneumonia.

The Chinese human adenovirus 7 (HAdV7) 0901HZ/ShX/CHN/2009 was isolated from the hydrothorax fluid of an infant with fatal pneumonia in Shaanxi, China, in 2009. Comparison of the entire genome with the genomes of the other 10 strains of HAdV7 from GenBank revealed homologies of 89.9 to 99.9%, with geographic polymorphism among HAdV-7 field strains circulating in mainland China.

Genome and bioinformatic analysis of a HAdV-B14p1 virus isolated from a baby with pneumonia in Beijing, China.

The genome of HAdV-B14p1 strain BJ430, isolated from a six-month-old baby diagnosed with bronchial pneumonia at the Beijing Children's Hospital in December 2010, was sequenced, analyzed, and compared with reference adenovirus genome sequences archived in GenBank. This genome is 34,762 bp in length, remarkably presenting 99.9% identity with the genome from HAdV14p1 strain 303600, which was isolated in the USA (2006). Even more remarkable, it is 99.7% identical with the HAdV-B14p (prototype "de Wit" strain) genome, isolated from The Netherlands in 1955. The patient and its parents presumably had no or limited contact with persons from the USA and Ireland, both of which reported outbreaks of the re-emergent virus HAdV-14p1 recently. These genome data, its analysis, and this report provide a reference for any additional HAdV-B14 outbreak in China and provide the basis for the development of adenovirus vaccines and molecular pathogen surveillance protocols in high-risk areas.

Multiple-locus variable-number tandem-repeat analysis of pathogenic Yersinia enterocolitica in China.

The predominant bioserotypes of pathogenic Yersinia enterocolitica in China are 2/O: 9 and 3/O: 3; no pathogenic O: 8 strains have been found to date. Multiple-Locus Variable-Number Tandem-Repeat Analysis (MLVA) based on seven loci was able to distinguish 104 genotypes among 218 pathogenic Y. enterocolitica isolates in China and from abroad, showing a high resolution. The major pathogenic serogroups in China, O: 3 and O: 9, were divided into two clusters based on MLVA genotyping. The different distribution of Y. enterocolitica MLVA genotypes maybe due to the recent dissemination of specific clones of 2/O: 9 and 3/O: 3 strains in China. MLVA was a helpful tool for bacterial pathogen surveillance and investigation of pathogenic Y. enterocolitica outbreaks.

[Analysis on pathogen detection for 53 influenza outbreaks].

OBJECTIVE: In order to provide a scientific basis for influenza prevention and control, analyzing the epidemic characteristics and laws of influenza outbreaks in Xuzhou area during 2005-2011. METHOD: Using fluorescent-PCR method to detect influenza virus nucleic acid on Nasopharyngeal swab specimens collected from influenza outbreak cases during 2005-2011 and fast classifying influenza virus A1 (H1N1), A3 (H3N2), new H1N1 BV (Victoria) and BY (Yamagate) on subtypes. At the same time, isolating the influenza virus with MDCK cells, and sending them to the National Influenza Center for review, after the preliminary identification of the isolated influenza virus. RESULTS: During 2005-2011, there are 53 influenza outbreaks in Xuzhou area, which caused by influenza virus subtype BV accounting for 26.42% (14/53), A3 accounting for 49.1% (26/53), A3 and A1 mixture accounting for 3.77% (2/53) and the new H1N1 accounting for 20.75% (11/53). The outbreaks in 2007 and 2009 mainly caused by A3, and show that the winter spring (January) and summer autumn (September) as two popular peaks during 2005-2011; BV mainly causes the outbreaks from Feb. to Jun. CONCLUSION: In Xuzhou area, since the winter of 2005, influenza virus subtype BV, the A3, and new H1N1 has alternately as mainly predominant strain, caused local influenza outbreaks. In which BV has increased trend year by year during 2005-2011. The students in primary and secondary schools are the major crowd of influenza outbreaks. Fluorescent-PCR detection methods could be a preferred method for reliable and rapid diagnostic of epidemic influenza outbreaks.

[Etiological analysis of influenza surveillance data in Xuzhou from 2005 to 2011].

OBJECTIVE: To investigate the prevalence and subtypes of influenza viruses in Xuzhou city from 2005 to 2011 and to provide the scientific supports for influenza prevention and control in this religion. METHODS: The throat swab samples were collected from the influenza-like cases from national influenza like illness sentinel hospital in Xuzhou. The samples were used for influenza virus isolation and identification, sent on the national flu center to confirm according to the "national influenza surveillance program" and "influenza virus and experimental technology". RESULTS: From Oct. 2005 to Dec. 2011, a total of 9561 swab specimens were collected in which 1152 strains were identified for influenza viruses with total isolated rate of 12.0%. Among these strains, 708 strains were A1 (H1N1) subtype (14.2%), 466 strains were A3 (H3N2) subtype (40.5%), 78 strains were new H1N1 subtype (6.8%), 362 strains were BV (Victoia) subtype (31.4%) and 82 strains were BY (Yamagate) subtype (7.1%). The top detection rate (25.9%) arose in 2007, secondary detection rate (17.4%) occurred at 2009 and the lowest one (2.3%) appeared in 2011. From the winter of 2005 to the spring of 2006 A1 (H1N1) subtype had appeared as predominant strains but in the winter of 2006 the predominant strains were BV subtype. It changed to A3 subtype in 2007 to 2009 and the other three dominant strains were A1, BV and BY in 2008. In the winter of 2009, both A3 (H3N2) and new H1N1 subtype were predominant strains. BV subtype was predominant strains in 2010 to 2011. The prevalence of A3 subtype appeared in all the year while prevalence of BV only arose in the spring and winter. So the detection rate was high in January (34.4%) but low in August (2.2%). The influenza population is correlated with age, the highest detection rate arose in 5-age group and the lowest detection rate appeared in 25-age group. CONCLUSION: Influenza subtype A1, A3, New H1N1 are all appeared as predominant strains in Xuzhou city from 2005 to 2010. Besides, the prevalence of BV subtype is stronger in recently.

[Research on the aetiology of suspected enterovirus infected patients in Xuzhou district in 2009].

OBJECTIVE: To understand and master the situation in which enterovirus caused hand-foot-and-mouth disease (HFMD) in Xuzhou district in 2009 so as to provide scientific basis for the control and prevention of hand-foot-and-mouth disease. METHODS: The researchers adopted fluorescence RT-PCR method to detect EV and EV71 as well as the CA16 specificity RNA from 222 samples of anal swabs and oropharyngeal swabs from the 240 cases who were diagnosed clinically as hand-foot-mouth disease infected by enterovirus. Also, the researchers conducted EV71-IgM antibody detection on 114 samples of acute phase serum with ELA method. RESULTS: Among the 240 enterovirus infected patients, the total EV infection rate is 72.50% (174/240), among which EV71 infection rate is 57.92% (139/240), CoxA16 infection rate is 9.17% (22/240), and other EV infection rate is 5.42% (13/240). The EV71-RNA positive rate of the samples of 222 anus swabs among the 240 suspected enterovirus infected patients is 45.94% (102/222), the samples of swallow swab EV71-RNA positive rate is 25.68% (57/222) and the EV71-IgM antibody positive rate of 114 samples of acute phase serum is 86.84% (99/114). The EV71-RNA positive rate of oropharyngeal swabs of 254 healthy children is 1.57% (4/254) , and no CoxA16-RNA was detected. In the oropharyngeal swabs of 54 close contacts (medical personnel), the EV-RNA detected is negative. The positive rate of EV71-IgM antibody of the 258 healthy children's serum samples is 2.71% (7/258). CONCLUSION: The widespreading of hand-foot-mouth disease in Xuzhou district is caused mainly by type 71 enterovirus. Inapparent infection of type 71 enterovirus exists among children under the age of 3 during the time of widespreading period and IgM antibody develops in them. It is difficult for adults to be infected by EV71 even if they contact the contagion source closely. The positive rate of EV71-IgM antibody in the samples of acute phase serum of suspected cases is the highest (86.84%), and the second highest is the positive rate of RNA of EV71 of anal swabs (45.94%) and of the EV71 of oropharyngeal swabs (25.68%). ELA reagent kit is used in the early diagnosis of EV71 infection for it is easy to operate, fast and economic, so, it is worth popularizing in the grass-root medical units.

[The study of human rhinovirus in infants with lower respiratory tract infections].

OBJECTIVE: We want to explore the harm degree of human rhinovirus in infants in Beijing area. METHODS: From May 2008 to September 2009, 240 nasopharyngeal aspirates were collected from the children and infants who were hospitalized and with lower respiratory tract infections. These specimens were screened for HRV by real-time reverse transcription PCR (RT-PCR) and statistically analysised. RESULT: In all of 240 hospitalized children, 208 cases were admission diagnosis of pneumonia, accounting for 86.67% (208/240), no deaths, the ratio of male and female patients was 1.93 : 1, and the collected samples reached to a maximum number in February 2009. Real-time PCR used to detect human rhinovirus, positive samples number is 71, positive rate is 29.58% (71/240), and the main symptoms and clinical diagnosis was pneumonia. Most cases were less than 2 years old, making up 81.69% (58/71), amony them, 13 months-18 months age and > or = 24 months groups have the highest incidence rates, the incidence rate is 33.33%. CONCLUSION: Human rhinovirus happened in spring and winter seasons, especially the infants who were under 2 years are the main infection groups, the important symptoms are lower respiratory infections such as pneumonia, bronchitis and bronchiolitis et al. Human rhinovirus is seasonal and contagious, spreads fast, so protective measures in hospitals should be prepared to avoid cross-infection.