分布滞后非线性模型评估气温对赣州市流感发病的影响

目的 利用模型评估气温对流感发病的影响,为流感发病的预警预测提供依据。方法 收集2014－2016年赣州市流感日发病资料和同期气温资料,采用分布滞后非线性模型(distributed lag non-linear model,DLNM)分析气温与流感发病的关系。结果 流感日发病人数与日平均气温、日最高气温、日温差呈负相关(均P<0.05),与日最低气温无关(P>0.05)。流感发病随日平均气温变化而变化,呈非线性关系,25 ℃为最适温度。当日平均温度<16.00 ℃,当天流感发病风险明显上升(RR＞1,95%CI＞1)。当日平均温度<25.00 ℃,滞后1 d的流感发病风险明显上升(RR＞1,95%CI＞1)。结论 气温与流感发病明显相关,但滞后效应较弱。     

Climatic, reservoir and occupational variables and the transmission of haemorrhagic fever with renal syndrome in China

BACKGROUND: Being a zoonosis, the transmission of haemorrhagic fever with renal syndrome (HFRS) is influenced by climatic, reservoir and occupational factors. This paper has quantified the incidence and potential risk factors of HFRS in Yingshang County, a low-lying epidemic focus of the disease in China. METHODS: Correlation and regression analyses were conducted among climatic variables, the density of mice, autumn crop production and annual incidence of HFRS during the autumn-winter seasons in the County over the period 1980-1996. RESULTS: Rainfall (r = -0.63, P = 0.009), the density of mice (r = 0.90, P = 0.000) and autumn crop production (r = 0.67, P = 0.01) were statistically correlated with the incidence of HFRS. Multiple regression analysis indicated that these factors are potential predictors for HFRS transmission. CONCLUSIONS: Rainfall, the density of mice and autumn crop production could be used as predictors of HFRS transmission in low-lying epidemic foci.     

The impact of temperature on mortality in Tianjin, China: a case-crossover design with a distributed lag nonlinear model

Background: Although interest in assessing the impacts of temperature on mortality has increased, few studies have used a case-crossover design to examine nonlinear and distributed lag effects of temperature on mortality. Additionally, little evidence is available on the temperature–mortality relationship in China or on what temperature measure is the best predictor of mortality.Objectives: Our objectives were to use a distributed lag nonlinear model (DLNM) as a part of case-crossover design to examine the nonlinear and distributed lag effects of temperature on mortality in Tianjin, China and to explore which temperature measure is the best predictor of mortality.Methods: We applied the DLNM to a case-crossover design to assess the nonlinear and delayed effects of temperatures (maximum, mean, and minimum) on deaths (nonaccidental, cardiopulmonary, cardiovascular, and respiratory).Results: A U-shaped relationship was found consistently between temperature and mortality. Cold effects (i.e., significantly increased mortality associated with low temperatures) were delayed by 3 days and persisted for 10 days. Hot effects (i.e., significantly increased mortality associated with high temperatures) were acute and lasted for 3 days and were followed by mortality displacement for nonaccidental, cardiopulmonary, and cardiovascular deaths. Mean temperature was a better predictor of mortality (based on model fit) than maximum or minimum temperature.Conclusions: In Tianjin, extreme cold and hot temperatures increased the risk of mortality. The effects of cold last longer than the effects of heat. Combining the DLNM and the case-crossover design allows the case-crossover design to flexibly estimate the nonlinear and delayed effects of temperature (or air pollution) while controlling for season.     

基于分布滞后非线性模型探讨日均气温对曲靖市手足口病发病的影响

目的  探究气象因素对曲靖市手足口病(hand, foot, and mouth disease, HFMD)发病的影响及其滞后效应。 方法  采用分布滞后非线性模型(distributed lag non-linear model, DLNM)分析2017-2019年曲靖市气象因素与HFMD发病的相关性及滞后效应。 结果  2017-2019年曲靖市共报告25 902例HFMD,HFMD日发病数与日均气温、降雨量呈正相关,与日照时数呈负相关,以气温对HFMD发病影响最为明显(r=0.51);DLNM拟合结果显示,日均温度20 ℃左右时对HFMD发病的影响最大(RR=1.408, 95% CI: 1.064~1.864, P=0.017);日均温度在无滞后情况下,对HFMD产生的影响最大,随后逐渐降低直至消失。 结论  气温是曲靖市手足口病发病的重要影响因素,其影响有明显的滞后效应;不同温度对不同人群的滞后效应明显不同,高温影响更为显著。     

Platelet dysfunction contributes to the haemostatic defect in haemorrhagic fever with renal syndrome.

To characterize further the nature of haemostatic impairment in haemorrhagic fever with renal syndrome, we assessed platelet function in 9 patients in whom the diagnosis was serologically confirmed. Defective platelet aggregation was demonstrated in every patient. An abnormality of the granule release reaction was demonstrated in all of 7 patients tested. Gel-filtered platelets from a normal subject showed normal aggregation in plasma from a patient with impaired aggregation, which is evidence for an intrinsic platelet defect, and against the presence of a circulating inhibitor in this patient.     

Development of inactivated vaccine against virus causing haemorrhagic fever with renal syndrome

B-1 virus belonging to the hantavirus group was serially passaged in the brains of newborn mice. Inactivated vaccine was prepared from the brains after inactivation with formalin and then purification by ultracentrifugation. The antigenic potency of this vaccine in vitro was determined by antibody-bound enzyme-linked immunosorbent assay (ELISA) and serial diluted vaccine bound to an aluminium hydroxide gel was inoculated into Balb/c mice to test immunogenicity. After two injections of this vaccine preparation, antibodies were detected in the mice by immunofluorescent, neutralizing and haemagglutination inhibition antibody tests. When mice immunized with this vaccine were challenged with B-1 virus and Hantaan virus (KHF-83-61BL strain), the virus titres in their lungs and spleens were significantly less than those in non-immunized mice. These results suggest that inactivated B-1 virus vaccine is effective against virus challenge by homotypic (B-1 virus) and heterotypic (Hantaan virus) viruses.     

Preparation of candidate vaccinia-vectored vaccines for haemorrhagic fever with renal syndrome.

Two vaccinia-vectored candidate vaccines for haemorrhagic fever with renal syndrome were prepared by inserting cDNA, representing the medium (M) genome segment, or the M and the small (S) genome segments of Hantaan virus into the thymidine kinase gene of the Connaught vaccine strain of vaccinia virus. In the single recombinant, the M segment was placed under control of the vaccinia virus 7.5 kDa promoter. In the double recombinant, the M and S segments were placed under control of the vaccinia virus 7.5 kDa and 11 kDa promoters, respectively. An immunoplaque assay technique was developed to select recombinants without the need for expression of irrelevant genes or use of potential mutagens. Proteins indistinguishable from authentic viral envelope glycoproteins and nucleocapsid protein were observed by immunoprecipitation with antibodies to Hantaan virus. The recombinant expressing both the M and the S segments was selected for further development and testing as a human vaccine.     

Daily temperature and mortality: a study of distributed lag non-linear effect and effect modification in guangzhou

ABSTRACT: BACKGROUND: Although many studies have documented health effects of ambient temperature, little evidence is available in subtropical or tropical regions, and effect modifiers remain uncertain. We examined the effects of daily mean temperature on mortality and effect modification in the subtropical city of Guangzhou, China. METHODS: A Poisson regression model combined with distributed lag non-linear model was applied to assess the non-linear and lag patterns of the association between daily mean temperature and mortality from 2003 to 2007 in Guangzhou. The case-only approach was used to determine whether the effect of temperature was modified by individual characteristics, including sex, age, educational attainment and occupation class. RESULTS: Hot effect was immediate and limited to the first 5 days, with an overall increase of 15.46% (95% confidence interval: 10.05% to 20.87%) in mortality risk comparing the 99th and the 90th percentile temperature. Cold effect persisted for approximately 12 days, with a 20.39% (11.78% to 29.01%) increase in risk comparing the first and the 10th percentile temperature. The effects were especially remarkable for cardiovascular and respiratory mortality. The effects of both hot and cold temperatures were greater among the elderly. Females suffered more from hot-associated mortality than males. We also found significant effect modification by educational attainment and occupation class. CONCLUSIONS: There are significant mortality effects of hot and cold temperatures in Guangzhou. The elderly, females and subjects with low socioeconomic status have been identified as especially vulnerable to the effect of ambient temperatures.     

山东省肾综合征出血热死亡病例分析

目的探讨山东省2004~2005年肾综合征出血热（Hemorrhagic Fever with Renal Syndrome,HFRS）病例的死亡原因,以便采取相应对策。方法按中国疾病预防控制中心《全国流行性出血热监测方案》中的个案调查表对山东省2004~2005年全部HFRS死亡病例进行调查,并进行统计学分析。结果山东省2004,2005年HFRS病死率分别比前一年上升95.45%和2.32%,死亡病例平均年龄为51.15岁,农民占77.78%,男女性别比例2.6∶1。对41例进行了特异性抗体检测,阳性率为75.61%。大部分病例临床症状不典型,从发病到就诊时间间隔平均为3.93 d,死亡前有鼠类接触史。结论山东省2004,2005年HFRS病死率有上升趋势;病例症状不典型、就诊时间晚、诊疗水平低和经济状况是造成病死率较高的重要原因;HFRS病死率升高可能是由于姬鼠型病例增多和病毒变异、毒力增加引起。     

肾综合征出血热与鼠的监测和防控

肾综合征出血热(HFRS)的主要储存宿主是黑线姬鼠(姬鼠型)和褐家鼠(家鼠型)。在疫区,鼠密度与发病率密切相关,因此,监测鼠密度对预测疫情具有重要意义。防控的主要方法是防鼠和灭鼠。灭鼠应使用灭鼠药,大面积同时进行。只有当鼠密度明显下降后,才能有效控制HFRS流行。必要时,可接种HFRS疫苗。     

The antigenic analysis of haemorrhagic fever with renal syndrome viruses in China by monoclonal antibodies

Thirty-six strains of haemorrhagic fever with renal syndrome (HFRS) virus were isolated from patients and a number of host animals in various areas in China. They were analysed by an immunofluorescence test (IFAT) using 10 monoclonal antibodies (McAbs) specific for the HFRS virus; antigenic differences among the strains have been demonstrated. The HFRS virus strains revealed nine different reactions with the McAbs, showing that there are at least nine different antigenic determinants including group-, type- and strain-specific. Analysis of the results shows that antigenic differences among the HFRS virus strains are mainly related to differences in the host animals.     

山东省发热伴血小板减少综合征发病危险因素分析

目的 探讨影响山东省发热伴血小板减少综合征（SFTS）发病的危险因素,为科学防制该病提供依据。方法 应用1∶2匹配的病例对照研究方法,调查收集病例、对照的基本情况、可疑暴露因素等信息,采用单因素和多因素的配对条件logistic回归分析发病危险因素。结果 本研究共纳入374例SFTS确诊病例和748例对照。分析结果显示,有病例接触史（OR = 5.84,95%CI:1.11～30.88）、有家养动物（OR = 1.74,95%CI: 1.02～2.96）、近1个月见过蜱（OR = 5.85,95%CI: 2.73～12.53）、近2周有蜱叮咬史（OR = 29.58,95%CI: 6.70～130.60）、从事田间作业（OR = 2.63,95%CI:1.41～4.91）、住宅周围环境有杂草/农作物/菜地（OR = 3.24,95%CI:1.74～6.05）和住宅卫生条件差（OR = 2.20,95%CI:1.32～3.66）是SFTS发病的危险因素（P＜0.05）,近1个月有亲邻发病（OR = 0.01,95%CI:0～0.03）、采取防护措施（OR = 0.21,95%CI:0.10～0.46）是SFTS发病的保护因素（P＜0.05）。结论 接触病例、饲养家养动物、蜱叮咬、无防护措施的野外作业及住宅周围环境卫生较差等是影响山东省SFTS发病的危险因素。应加强重点人群SFTS健康教育和行为干预,减少危险因素暴露,以控制SFTS传播。     

肾综合征出血热高发疫区疫情监测与控制研究

目的：为控制肾综合征出血热（HFRS）高发疫区的发病率。方法：以肾综合征出血热疫苗接种，控制鼠密度等措施。结果：在从事野外劳动的16—60岁青壮年农民中，免疫覆盖率达51．86％，其免疫阳转率为97．6％，从而使沙畈乡5个村的发病率1997年的490．23／10万，至1999～2005年发病率均为零。结论：以疫苗接种为主，灭鼠等防治措施，对HFRS高发疫区的控制，效果理想。     

The antigenic analysis of haemorrhagic fever with renal syndrome viruses in China by monoclonal antibodies.

Thirty-six strains of haemorrhagic fever with renal syndrome (HFRS) virus were isolated from patients and a number of host animals in various areas in China. They were analysed by an immunofluorescence test (IFAT) using 10 monoclonal antibodies (McAbs) specific for the HFRS virus; antigenic differences among the strains have been demonstrated. The HFRS virus strains revealed nine different reactions with the McAbs, showing that there are at least nine different antigenic determinants including group-, type- and strain-specific. Analysis of the results shows that antigenic differences among the HFRS virus strains are mainly related to differences in the host animals.     

Prevalence of serum IgG antibodies to Puumala virus (haemorrhagic fever with renal syndrome) in northern Sweden.

A stratified and randomly-selected population sample was identified in 1990 in order to study the seroprevalence of nephropathia epidemica (haemorrhagic fever with renal syndrome) in Northern Sweden. Sera from 1538 subjects (750 men, 788 women), 25-64 years of age, were analysed for the presence of Puumala virus (PUV) specific-IgG by the indirect immunofluorescence antibody test. Specific IgG was detected in sera from 83 subjects (5.4%). Men and women had similar seroprevalence rates. The highest seroprevalences were found in subjects 55 years or older (8.0%) and among farmers and forestry workers (15.9%). The geographic distribution of seropositive individuals was uneven and there were significantly more seropositive persons in rural than in urban areas (P < 0.05).     

Changes in populations of immune effector cells during the course of haemorrhagic fever with renal syndrome.

To characterize the immune response in haemorrhagic fever with renal syndrome, serial changes in immune effector cells were measured in 14 patients. Significant findings included initial elevations of all major leucocyte populations, increases in suppressor T cells and B cells, decreases in helper/suppressor cell ratios, and a dramatic increase in activated T cells. These changes were most marked in severely ill patients. Changes reverted to normal over approximately one week.     

气温对不同特征人群肾综合征出血热发病影响的研究

目的探讨辽宁省葫芦岛市气温对不同特征人群肾综合征出血热(HFRS)发病的影响。方法收集葫芦岛市2005年1月—2012年12月的HFRS发病数及气象数据,对气象因素进行筛选后,在控制长期趋势、季节趋势及其他气象因素的基础上,采用广义相加模型(GAM)分析月平均气温与HFRS月发病数的关系,并进行不同特征人群分析。结果月平均气温对全人群HFRS月发病数影响的RR值为0.969(95%CI:0.960～0.979),滞后期为2个月。不同特征人群分析中,气温对男性、女性、35～59岁人群HFRS月发病数有影响,滞后期分别为2、0、0个月时效应最强,RR值分别为0.968(95%CI:0.959～0.978),0.969(95%CI:0.949～0.989),0.968(95%CI:0.952～0.984),但0～34岁、≥60岁人群的效应无统计学意义(P>0.05)。结论葫芦岛市气温对HFRS发病的影响有滞后效应,且对不同特征人群影响不同。