[Show abstract][Hide abstract] ABSTRACT: Hemorrhagic fever with renal syndrome (HFRS) is caused by different hantaviruses within the Bunyaviridae family. HFRS is a fulminant, infectious disease that occurs worldwide and is endemic in all 31 provinces of China. Since the first HFRS case in Hubei Province was reported in 1957, the disease has spread across the province and Hubei has become one of the seriously affected areas in China with the greatest number of reported HFRS cases in the 1980's. However, the epidemic characteristics of HFRS in Hubei are still not entirely clear and long-term, systematic investigations of this epidemic area have been very limited.
The spatiotemporal distribution of HFRS was investigated using data spanning the years 1980 to 2009. The annual HFRS incidence, fatality rate and seasonal incidence between 1980 and 2009 were calculated and plotted. GIS-based spatial analyses were conducted to detect the spatial distribution and seasonal pattern of HFRS. A spatial statistical analysis, using Kulldorff's spatial scan statistic, was performed to identify clustering of HFRS.
A total of 104,467 HFRS cases were reported in Hubei Province between 1980 and 2009. Incidence of and mortality due to HFRS declined after the outbreak in 1980s and HFRS cases have been sporadic in recent years. The locations and scale of disease clusters have changed during the three decades. The seasonal epidemic pattern of HFRS was characterized by the shift from the unimodal type (autumn/winter peak) to the bimodal type.
Socioeconomic development has great influence on the transmission of hantaviruses to humans and new epidemic characteristics have emerged in Hubei Province. It is necessary to reinforce preventative measures against HFRS according to the newly-presented seasonal variation and to intensify these efforts especially in the urban areas of Hubei Province.
[Show abstract][Hide abstract] ABSTRACT: Hantaan viruses cause two severe diseases lacking efficient treatment, yet no effective prophylactic vaccines are available. Continued exploration of alternative antiviral agents to treat hantavirus-related syndromes remains compulsory. The fluorescence-based quantitative real-time PCR (qPCR) has become the touchstone for target gene quantification. In the present study, standard curves for Hantaan virus (HTNV), mouse, and human glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were generated by serial 10-fold dilutions of the constructed recombinant plasmid pGEM-T/HTNV, pGEM-T/mouse-GAPDH, and pGEM-T/human-GAPDH, respectively. Comparisons between the indirect immunofluorescence assay and qPCR assay in the detection of HTNV-infected Vero E6 cells showed improved detection limit and sensitivity of latter method. To characterize the inhibitory effect of several conventional antivirals (arbidol and ribavirin) and unconventional antivirals (indomethacin and curcumin) on HTNV, the levels of viral RNAs were measured for 4 days post-treatment of HTNV-infected Vero E6 cells and 18 days post-inoculation of HTNV-infected suckling mice. Our results validated that HTNV was sensitive to ribavirin and arbidol treatment, while indomethacin and curcumin may also be therapeutically effective in treating HTNV infection. As a result, the establishment and application of qPCR may be a useful tool for the evaluation of potential antivirals for Hantaan virus infection in vitro and in vivo.
[Show abstract][Hide abstract] ABSTRACT: Aim:
To study whether epigallocatechin gallate (EGCG), a green tea-derived polyphenol, exerted anti-influenza A virus activity in vitro and in vivo.
Madin-Darby canine kidney (MDCK) cells were tested. The antiviral activity of EGCG in the cells was determined using hemagglutination assay and qPCR. Time of addition assay was performed to determine the kinetics of inhibition of influenza A by EGCG. The level of reactive oxygen species (ROS) were determined with confocal microscopy and flow cytometry. BALB/c mice were treated with EGCG (10, 20 or 40 mg·kg−1·d−1, po) for 5 d. On the 3rd d of the treatment, the mice were infected with influenza A virus. Histopathological changes, lung index and virus titers in the lungs were determined.
Treatment of influenza A-infected MDCK cells with EGCG (1.25–100 nmol/L) inhibited influenza A replication in a concentration-dependent manner (the ED50 value was 8.71±1.11 nmol/L). Treatment with EGCG (20 nmol/L) significantly suppressed the increased ROS level in MDCK cells following influenza A infection. In BALB/c mice infected with influenza virus, oral administration of EGCG (40 mg·kg−1·d−1) dramatically improved the survival rate, decreased the mean virus yields and mitigated viral pneumonia in the lungs, which was equivalent to oral administration of oseltamivir (40 mg·kg−1·d−1), a positive control drug.
The results provide a molecular basis for development of EGCG as a novel and safe chemopreventive agent for influenza A infection.
[Show abstract][Hide abstract] ABSTRACT: To characterize hantaviruses currently circulating in the hemorrhagic fever with renal syndrome (HFRS) epidemic area of Hubei Province, rodents were captured and serum samples were collected from several HFRS patients. The partial S segment of the hantaviruses amplified from two serum samples had a high degree of sequence identity to the corresponding hantavirus strain isolated from Apodemus agrarius (designated as HV004). The complete S, M, and L segment sequences of HV004 were determined. The sequence identities between strain HV004 and other Hantaan viruses (HTNVs) were 83 %-90 % at the nucleotide level and 95 %-99 % at the amino acid level. Phylogenetic analysis showed that HV004 belonged to a new HTNV lineage. These data suggest the presence of a new HTNV subtype, which probably caused the HFRS cases in the endemic area of Hubei Province.
No preview · Article · Jun 2012 · Archives of Virology
[Show abstract][Hide abstract] ABSTRACT: Hantaan virus (HTNV) and Seoul virus (SEOV) are two major zoonotic pathogens of hemorrhagic fever with renal syndrome (HFRS) in Asia. Hubei province, which is located in the central-south China, had been one of the most severe epidemic areas of HFRS. To investigate phylogenetic relationships, genetic diversity and geographic distribution of HTNV and SEOV in their reservoir hosts, a total of 687 rodents were trapped in this area between 2000 and 2009. Sequences of partial S- and M-segments of hantaviruses and mitochondrial D-loop gene from 30 positive samples were determined. Our data indicated that SEOV and HTNV were co-circulating in Hubei. Phylogenetic analysis based on partial S- and M-segment sequences revealed two and three previously undefined lineages of SEOV, and a novel genetic lineage of HTNV, respectively. Four inter-lineage reassortment SEOVs carried by Rattus norvegicus and Apodemus agrarius were observed. It suggests that SEOV may cause spillover infections to A. agrarius naturally. The abundance of the phylogenetic lineages of SEOV suggested that central-south China was a radiation center for SEOVs.