ISSN 1003-8280 CN 10-1522/R 中国疾病预防控制中心 主办
Objective To analyze the sequence of Hantavirus(HV) from Zhejiang, Fujian provinces and Shanghai municipal. Methods The sequence of M segment of several HV strains from coastal areas of Zhejiang, Fujian province and Shanghai municipal were collected and analyzed by Mega 4.0 and DNAStar software, phylogenetic trees were built by neighbor joining method (NJ) and analyzed to compare the similarity of HV strains isolated from Zhejiang, Fujian provinces and Shanghai municipal. Results The phylogenetic tree revealed that the similarity of isolates in the same province is much higher than the other, meanwhile, in same province or city, the nucleotide similarity of the same region is higher than the other regions. The distributions of the isolates from closer regions share higher sequence similarity in the phylogenetic branches. The ZH53 strain of HTN isolated from Fujian province, Gou3 strain and ZJ5 strain of SEO isolated from Jiande region in Zhejiang province formed a distinct phylogenic lineage in HTNV clade and SEOV clade respectively, and these strains were different from other variants and international standard strains with the similarity of 82.7%-86.3% and 84.0%-85.3% respectively. The SEOV strains in Zhejiang were isolated from field mouse indicating the phenomenon of “host spillover”. Conclusion The sequence similarity and the phylogeny of HV in southeast costal area of Zhejiang, Fujian provinces and Shanghai is closed related to the isolated regions, indicating geographic distribution of HV.
Objective To analyze the epidemic situation of hemorrhagic fever with renal syndrome (HFRS) and the population distribution and virus-carrying status of the hosts in Zhejiang province, China, in 2013, and to provide scientific evidences for establishing further prevention and control measures. Methods The descriptive epidemiological method was used to analyze the three-dimensional (time, region, and population) distribution of HFRS. Rodents were captured by night trapping in five HFRS monitoring points in Zhejiang province. Lung and serum samples were collected followed by detection of hantavirus antigen and antibody using an immunofluorescence assay, and the rodent population distribution and virus-carrying status in Zhejiang province were analyzed. Results A total of 527 HFRS cases were reported in 2013 in Zhejiang province. The incidence rate was 0.9622/100 000, resulting in a 3.89% increase compared with 2012, and no death was reported. The cases were mostly seen in five cities (Ningbo, Taizhou, Shaoxing, Quzhou and Lishui), and all the prefectural level cities had cases reported except Zhoushan. There were two peaks of incidence, one in spring (May-June) and the other in winter (around December). The high-risk age group of HFRS was between 20 and 65 years, accounting for 93.17% of the overall incidence rate (491/527). A total of 13 785 effective traps were set in the five monitoring points, and 546 rodents were captured, so the average density of rodents was 3.96%. A total of 678 rodent serum samples were collected and 80 were positive (positive rate: 11.80%). A total of 669 lung samples were collected and 44 were positive (positive rate: 6.58%). There were significant differences in the positive rate of HFRS antibody and the virus-carrying rate between the five HFRS monitoring points (χ2=30.962, P<0.05 and χ2=9.83, P<0.05, respectively). Conclusion The incidence of HFRS in Zhejiang province in 2013 is on a rising trend compared with that in 2012, and the density of host animals and virus-carrying rate are both higher. Preventive measures should be taken into consideration to control the epidemic situation.
Objective To analyze the prevalence and genotypes of Hantavirus (HV) among rodents in the epidemic areas of hemorrhagic fever with renal syndrome (HFRS) in Zhejiang province, China from 2008 to 2011. Methods Direct immunofluorescence assay and RT-PCR were used to detect the antigen and nucleic acid of HV. Mongolian gerbils and Vero-E6 cells were used to isolate viruses from the HV-positive rodents, and the M segments of HV isolates were subjected to sequence analysis. Results Apodemus agrarius was the dominant species of the rodents captured in the epidemic areas of HFRS in Zhejiang province from 2008 to 2011. Six strains of HV were isolated from the lungs of this rodent species. The sequence analysis showed that the six isolates belonged to Hantaan virus (HTNV), wherein Z521, 524, and 534 were classified as H7 subtype, and TT-27, T-43, and R88 might be classified as a new subtype. The six HV isolates showed high gene homology between them and with the strains previously isolated in Zhejiang province. Conclusion HTNV was prevalent in rodent in the epidemic areas of HFRS in Zhejiang province from 2008 to 2011.
Objective To study the mechanism of the toxicity of celangulin against Aedes albopictus larvae and its influence on various aspects, such as the growth and development of mosquito larvae. Methods Conventional biological approaches were employed for determination of the toxicity and the impact on the larva growth and development: the changes in the gastrointestinal morphology were identified by HE staining; the antifeedant activity was measured through the colorimetric determination of chromium oxide. Results With increasing concentrations, celangulin had strengthening toxicity against the fourth instar larvae of Ae. albopictus, with the LC50 of 22.66 (18.38-27.95) mg/L and LC95 of 84.51 (60.87-142.27) mg/L. Celangulin could reduce the pupation rate and extend the average pupation time and the average eclosion time of Ae. albopictus larvae, though it had no significant effect on the eclose rate. As the concentration of celangulin increased, its antifeedant activity became stronger, leading to gastrointestinal morphological changes: brush border loss and midgut degeneration and disintergration. Conclusion Celangulin was able to kill Ae. albopictus larvae through gastrointestinal toxicity, antifeedant activity and contact toxicity, and inhibit their growth and development.
Objective To provide a preliminary evaluation of the self?made horseradish peroxidase (HRP) marked Hantavirus (HV) recombinant N protein (rNP) rNP?IgM direct capture ELISA diagnostic kit. Methods Assessment of the specificity and stability of the kit and comparison of clinical results with similar products were performed to evaluate the sensitivity of the kit in the detection of serum anti?HV?IgM. Results (1) The kit was only responsive to anti?HV?IgM positive serum, and irresponsive to anti?varicella?zoster virus?IgM (anti?VZV?IgM), anti?Japanese encephalitis virus?IgM (anti?JEV?IgM), anti?dengue virus?IgM (anti?DV?IgM), anti?hand, foot and mouth EV71 virus?IgM (anti?EV71?IgM) positive sera. No obvious reduction in serum anti?HV?IgM detecting capability was noticed after placement at 37 ℃ for 3 d. (2) In 144 sera samples in 120 patients with suspected hemorrhagic fever with renal syndrome, inconsistency was observed only in the anti?HV?IgM test results in 12 sera of 12 patients between the two kinds of kits, in which 8 primary sera samples were detected positive by the kit and negative by commercial ones (the secondary sera samples were positive for both kits); 3 primary samples (the secondary samples unavailable) were at the critical value for the kit and negative for commercial kits. Meanwhile, one other primary serum sample was positive for the kit and negative for the commercial ones (the secondary and tertiary ones positive for both). Conclusion The laboratory developed capture ELISA anti?HV?IgM diagnostic kits had favorable specificity, stability and sensitivity, suitable for the clinical diagnosis and epidemiological surveillance of HV infections.
Objective To histochemically locate the lipid peroxidation induced by photosensitized α-terthienyl(α-T) in Aedes albopictus larvae. Methods Cold-schiff was employed to observe the Ae. albopictus larvae exposed to photosensitized α-T under optical microscope in comparison to the control group to evaluate the histochemical localization of lipid peroxidation. Results Tissues in the control group remaining unstained, the midgut epithelium, the peritrophic membrane, the brush border and the lumen of malpighian tubules were stained purple in the experimental group. Conclusion Photosensitized α-T could induce lipid peroxidation in tissues of Ae. albopictus larvae, involving primarily the midgut and malpighian tubules.
【Abstract】 Objective To clarify the natural infection situation of rodents by Hantavirus (HV) and HV strains in Zhejiang province in 2007,and provide science evidence for the prevention and control of hemorrhagic fever with renal syndrome (HFRS).Methods Lung tissue and serum from rodent were sampled, and IgG antibody from serum was tested by indirect immunofluorscence assay and direct immunofluorscence assay was adopted to test HV antigens from lung tissues. HV was isolated by Vero?E6 cells, and HV strains were identified by Anti?McAb.Results A total of 1129 rodents were captured in 2007.The dominant specie was Apodemus agrarius, and the positive rate of HV antigen in rodent lungs was 3.0%. The IgG antibody of 57 blood samples was positive, and the positive rate was 8.0%. Six strains of hantaan (HTN) virus were isolated, five strains from A.agrarius and one from Rattus norvegicus. Conclusion There are natural foci of HFRS which main infection sources are A.agrarius in Zhejiang province, and HTN strain could be the main prevalence strains of HV.
【Abstract】 Objective To explore the epidemiological characteristics of hemorrhagic fever with renal syndrome(HFRS) in Zhejiang province for establishing pertinent prevention strategy. Methods Descriptive epidemiology method was applied for the analysis of epidemic situation. The antibody in the serum of HFRS patients was detected by indirect immunoflorscence method, and the HV antigen in the rodent lung was assayed by direct immunoflorscence method. Results There were 757 cases in the whole province in 2007, mainly distributed in Ningbo, Shaoxing, Taizhou, Lishui and Quzhou, accounting for about 86.79% of the total (657/757). There were two incidence peaks in summer, winter and spring. Most of the cases were young and middle?aged peasants. Conclusion The incidence rate of HFRS in Zhejiang province has been stable in recent years, but it was still high in some counties and cities. Therefore, the prevention and control of HFRS in the main epidemic areas should be strengthened.