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Wei Wu,
Yize Xiao,
Guangchun Li,
Weilin Zeng,
Hualiang Lin,
Shannon Rutherford,
Yanjun Xu,
Yuan Luo,
Xiaojun Xu,
Cordia Chu, Wenjun Ma
Science of The Total Environment 04/2013; 449:355-362. · 3.29 Impact Factor
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Wei Wu,
Yize Xiao,
Guangchun Li,
Weilin Zeng,
Hualiang Lin,
Shannon Rutherford,
Yanjun Xu,
Yuan Luo,
Xiaojun Xu,
Cordia Chu, Wenjun Ma
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ABSTRACT: BACKGROUND: Numerous studies have reported the association between ambient temperature and mortality. However, few multicity studies have been conducted in subtropical regions in developing countries. The present study assessed the health effects of temperature on mortality in four subtropical cities of China. METHODS: We used "double threshold-natural cubic spline" distributed lag non-linear model (DLNM) to investigate the cold and hot effects on mortality at different lags in four subtropical cities. Then we conducted a meta-analysis to estimate the overall cold and hot effects on mortality at different lag days. RESULTS: A U-shaped relationship between temperature and mortality was found in the four cities. Cold effect was delayed and persisted for about 27days, whereas hot effect was acute and lasted for 3days. In Changsha, Kunming, Guangzhou and Zhuhai, a 1°C decrease of temperature under the low threshold was associated with a lag0-27 cumulative relative risk (RR) of 1.061 (95% confidence interval (CI): 1.023-1.099), 1.044 (95% CI: 1.033-1.056), 1.096 (95% CI: 1.075-1.117) and 1.111 (95% CI: 1.078-1.145) for total mortality, respectively. And RR for 1°C increase of temperature above the hot threshold at the lag0 was 1.020 (95% CI: 1.003-1.037), 1.017 (95% CI: 1.004-1.030), 1.029 (95% CI: 1.020-1.039) and 1.023 (95% CI: 1.004-1.042), respectively. The cold and hot effects were greater among the elderly in Changsha, Guangzhou and Zhuhai. Meta analysis showed that the hot effect decreased gradually with lag days, with the greatest effect at current day (RR=1.023, 95% CI: 1.015-1.031); while the cumulative cold effect increased gradually with lag days, with the highest effect at lag0-27 (RR=1.076, 95% CI: 1.046-1.107). CONCLUSION: Both low and high temperatures were associated with increased mortality in the four subtropical Chinese cities, and cold effect was more durable and pronounced than hot effect.
Science of The Total Environment 02/2013; 449C:355-362. · 3.29 Impact Factor
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Yuan Luo,
Yonghui Zhang,
Tao Liu,
Shannon Rutherford,
Yanjun Xu,
Xiaojun Xu,
Wei Wu,
Jianpeng Xiao,
Weilin Zeng,
Cordia Chu, Wenjun Ma
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ABSTRACT: Many studies have found extreme temperature can increase the risk of mortality. However, it is not clear whether extreme diurnal temperature range (DTR) is associated with daily disease-specific mortality, and how season might modify any association.
To better understand the acute effect of DTR on mortality and identify whether season is a modifier of the DTR effect.
The distributed lag nonlinear model (DLNM) was applied to assess the non-linear and delayed effects of DTR on deaths (non-accidental mortality (NAD), cardiovascular disease (CVD), respiratory disease (RD) and cerebrovascular disease (CBD)) in the full year, the cold season and the warm season.
A non-linear relationship was consistently found between extreme DTR and mortality. Immediate effects of extreme low DTR on all types of mortality were stronger than those of extreme high DTR in the full year. The cumulative effects of extreme DTRs increased with the increment of lag days for all types of mortality in cold season, and they were greater for extreme high DTRs than those of extreme low DTRs. In hot season, the cumulative effects for extreme low DTRs increased with the increment of lag days, but for extreme high DTR they reached maxima at a lag of 13 days for all types of mortality except for CBD(at lag6 days), and then decreased.
Our findings suggest that extreme DTR is an independent risk factor of daily mortality, and season is a modifier of the association of DTR with daily mortality.
PLoS ONE 01/2013; 8(2):e55280. · 4.09 Impact Factor
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Huiyan Xie,
Zhibin Yao,
Yonghui Zhang,
Yanjun Xu,
Xiaojun Xu,
Tao Liu,
Hualiang Lin,
Xiangqian Lao,
Shannon Rutherford,
Cordia Chu,
Cunrui Huang,
Scott Baum, Wenjun Ma
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Zhiguang Ran,
Ying Chen,
Huigang Shen,
Xiaoxiao Xiang,
Qinfang Liu,
Bhupinder Bawa,
Wenbao Qi,
Laihua Zhu,
Alan Young,
Jürgen A Richt, Wenjun Ma,
Feng Li
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ABSTRACT: The M1 protein is a major structural protein which has multiple functions in various steps within the lifecycle of the influenza A virus. However, little is currently known about the role of M1 in influenza A virus replication in vivo and the associated pathogenesis. In this study, six isogenic H1N1 WSN33 viruses, constructed to express unique M1 proteins derived from various strains, subtypes, or WSN33 itself, were tested to determine in vitro and in vivo functional exchangeability of M1 proteins in the replication and pathogenesis of the WSN33 virus. Despite five chimeric M1 viruses replicating to levels similar to those of the parental WSN33 virus in cell cultures, all M1 chimeras exhibited improved replication and enhanced virulence in mice when compared to the WSN33 virus. Interestingly, M1 proteins derived from swine viruses caused more severe clinical diseases than those from human or quail. These data indicate that the M1 protein is an important determinant of viral replication and pathogenic properties in mice, although the functions of M1 observed in vivo are not adequately reflected in simple infections of cultured cells. Chimeric M1 viruses variable in clinical manifestations described here will aid future understanding of the role of M1 in influenza A virus pathogenesis.
Journal of General Virology 12/2012; · 3.36 Impact Factor
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Huiyan Xie,
Zhibin Yao,
Yonghui Zhang,
Yanjun Xu,
Xiaojun Xu,
Tao Liu,
Hualiang Lin,
Xiangqian Lao,
Shannon Rutherford,
Cordia Chu,
Cunrui Huang,
Scott Baum, Wenjun Ma
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ABSTRACT: BACKGROUND: Few studies have been conducted to investigate the impact of extreme cold events on mortality in subtropical regions. OBJECTIVE: The present study aimed to investigate the effects of the 2008 cold spell on mortality and the possibility of mortality displacement in three subtropical cities in China. METHODS: Daily mortality, air pollution, and weather data were collected from 2006 to 2009 in Guangzhou, Nanxiong (no air pollutants) and Taishan. A polynomial distributed lag model (DLM) was used to analyze the relationship between the 2008 cold spell and mortality. To observe the mortality displacement of the cold spell, we estimated the cumulative effects at lag0, lag0-6, lag0-13, lag0-20, and lag0-27 separately. RESULTS: During the 2008 cold spell, the cumulative risk of non-accidental mortality increased significantly in Guangzhou (RR=1.60; 95%CI: 1.19, 2.14) and Taishan (RR=1.60; 95%CI: 1.06, 2.40) when lagged up to 4 weeks after the cold spell ended. Estimated effects at lag0-27 were more pronounced for males than females, for respiratory mortality than cardiovascular mortality, and for the elderly (≥75 years) than for those 0-64 years. Most of the cumulative RRs increased with longer lag times in Guangzhou and Taishan. However, in Nanxiong, the trend with cumulative RRs was less consistent, and no statistically significant associations were observed at lag0-27. CONCLUSION: The 2008 cold spell was associated with increased mortality in three subtropical cities of China. The lag effect structure of the cold spell varied with location and the type of mortality, and evidence of short-term mortality displacement was inconsistent. These findings suggest that extreme cold is an important public health problem in subtropical regions.
Environmental Health Perspectives 10/2012; · 7.04 Impact Factor
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ABSTRACT: Both H9N2 avian influenza and 2009 pandemic H1N1 viruses (pH1N1) are able to infect humans and swine, which has raised concerns that novel reassortant H9 viruses with pH1N1 genes might be generated in these hosts by reassortment. Although previous studies have demonstrated that reassortant H9 viruses with pH1N1 genes show increased virulence in mice and transmissibility in ferrets, the virulence and transmissibility of reassortant H9 viruses in natural hosts such as chickens and swine remain unknown. This study generated two reassortant H9 viruses (H9N2/CA09 and H9N1/CA09) in the background of the pH1N1 A/California/04/2009 (CA09) virus by replacing either both the haemagglutinin (HA) and neuraminidase (NA) genes or only the HA gene with the respective genes from the A/quail/Hong Kong/G1/1997 (H9N2) virus and evaluated their replication, pathogenicity and transmission in chickens and pigs compared with the parental viruses. Chickens that were infected with the parental H9N2 and reassortant H9 viruses seroconverted. The parental H9N2 and reassortant H9N2/CA09 viruses were transmitted to sentinel chickens, but H9N1/CA09 virus was not. The parental H9N2 replicated poorly and was not transmitted in pigs, whereas both H9N2/CA09 and H9N1/CA09 viruses replicated and were transmitted efficiently in pigs, similar to the pH1N1 virus. These results demonstrated that reassortant H9 viruses with pH1N1 genes show enhanced replication and transmissibility in pigs compared with the parental H9N2 virus, indicating that they may pose a threat for humans if such reassortants arise in swine.
Journal of General Virology 08/2012; 93(Pt 11):2337-45. · 3.36 Impact Factor
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Wenjun Ma,
Qinfang Liu,
Bhupinder Bawa,
Chuanling Qiao,
Wenbao Qi,
Huigang Shen,
Ying Chen,
Jingqun Ma,
Xi Li,
Richard J Webby,
Adolfo García-Sastre,
Jürgen A Richt
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ABSTRACT: The 2009 pandemic H1N1 virus (pH1N1) contains neuraminidase (NA) and matrix (M) genes from Eurasian avian-like swine influenza viruses (SIVs), with the remaining six genes from North American triple-reassortant SIVs. To characterize the role of the pH1N1 NA and M genes in pathogenesis and transmission, their impact was evaluated in the background of an H1N1 triple-reassortant (tr1930) SIV in which the HA (H3) and NA (N2) of influenza A/swine/Texas/4199-2/98 virus were replaced with those from the classical H1N1 A/swine/Iowa/15/30 (1930) virus. The laboratory-adapted 1930 virus did not shed nor transmit in pigs, but tr1930 was able to shed in infected pigs. The NA, M or both genes of the tr1930 virus were then substituted by those of pH1N1. The resulting virus with both NA and M from pH1N1 grew to significantly higher titre in cell cultures than the viruses with single NA or M from pH1N1. In a pig model, only the virus containing both NA and M from pH1N1 was transmitted to and infected sentinels, whereas the viruses with single NA or M from pH1N1 did not. These results demonstrate that the right combination of NA and M genes is critical for the replication and transmissibility of influenza viruses in pigs.
Journal of General Virology 02/2012; 93(Pt 6):1261-8. · 3.36 Impact Factor
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ABSTRACT: To describe the epidemiological characteristics of nonfatal child pedestrian injuries and provide information to help understand an important public-health problem.
This was a school-based, cross-sectional questionnaire survey. The sample (42 750 children) was obtained from two urban cities of Guangdong Province, China, using multi-stage randomized sampling. Information was collected by the respondents self-reporting in the classroom.
The incidence rate of nonfatal child pedestrian injuries in the cities was 2.0%. Boys had a higher incidence rate (2.6%) than girls (1.4%). Compared to other children, those aged 10 years are at the highest risk. The primary places of occurrence were sidewalks, residential roads, and crosswalks. High-risk behavior of the children immediately prior to injury included mid-block crossings, playing on roads, and crossing on red lights. The major vehicles that caused pedestrian injuries were bicycles, car or vans, and motorcycles. Bruises, fractures, and injuries to the internal organs were the top three types of injuries. Almost 40% of victims were hospitalized, and nearly 30% of the victims suffered long-term disabilities.
This study shows that nonfatal child pedestrian injuries are a very serious public-health problem in the urban cities of Guangdong. Based on the epidemiological characteristics, prevention strategies and further research should be carried out to reduce the occurrence of injuries.
Biomedical and Environmental Sciences 08/2011; 24(4):335-42. · 1.35 Impact Factor
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ABSTRACT: The aim of this study is to describe the characteristics of fatal drowning in Guangdong Province during the period 2004-2005. Twelve areas were randomly chosen by stratified cluster sampling, and a retrospective cross-sectional survey was conducted in 2006 to collect death cases during the 2004-2005 period. Causes of death relating to drowning were coded according to International Classification of Diseases, the tenth version. During 2004-2005, 849 unintentional drowning deaths occurred, representing a drowning rate of 5.6/100,000 per year. The rate was higher in rural areas (6.4/100,000) than in city (3.7/100,000), and the rate ratio of male to female was 1.5. The elderly aged 80 years and over and children aged 5-9 years had higher mortalities among all age groups, representing rates of 28.8 and 11.0 per 100,000 person years. For children aged 5-9 years, deaths from drowning accounted for the highest proportion (62.5%) of all injury deaths. The most common site of drowning was natural bodies of water (60.8%), and summer was the highest risk season for drowning. The results suggest drowning is an important public health problem, and it primarily threatens children in Guangdong province. Drowning intervention programs should be a health priority in Guangdong province.
International Journal of Injury Control and Safety Promotion 12/2009; 17(2):103-10. · 0.67 Impact Factor
