Zika virus (ZIKV) was first isolated in 1947. It is known to circulate mainly in tropical areas and can be transmitted through Aedes mosquitoes. In 2015, an outbreak of ZIKV began in Brazil and then spread rapidly to the Latin Americans and Caribbean. Accumulating evidence indicates that there are associations between ZIKV infection and human nervous disorders, such as the occurrence of microcephaly in neonates and Guillain-Barré syndrome in adults. The current ZIKV outbreak has been declared a public health emergency of international concern. Here, we review the virological features, transmission and epide-miological characteristics of ZIKV and the clinical featrues and prevention of ZIKV infection.

ObjectiveTo investigate the context-sensitive half-times of etomidate. Methods Twenty patients ( ASA Ⅰ - Ⅱ ) underwent selective thoracic operation were divided into 2 groups by random digits table with 10 cases each,the patients were allocated to receive either continuous infusion etomidate 10μg/(kg·min) for 1 h(Gl group) or continuous infusion etomidate 10 μg/(kg·min) for 2 h(G2 group) of maintenance anesthesia. The samples were collected at the following time points: 1 min before stop infusion,2,5, 10,15,20,30,40,50 and 60 min after stop infusion. The plasma concentrations of etomidate were measured by high-performance liquid chromatography and the changes of the context-sensitive half-times of etomidate were calculated. ResultsThe context-sensitive half-times of etomidate was ( 17.1 ± 13.1 )min in G1 group and (21.7 ± 15.1 ) min in G2 group. There was no significant difference between two groups (P＞0.05). ConclusionThe context-sensitive half-times of etomidate is short and its pharmacokinetic profile is suitable for continuous infusion.

In 2009, hepatitis E virus was first detected in wild rats ( Rattus norvegicus) in Germany and was designated as rat hepatitis E virus (rat HEV). Since then, rat HEV has been detected in various murine rodents in many geographic regions. The potential of rat HEV to infect human has been ignored as the viral genomic nucleotide sequences of rat HEV and the HEV strains of human sources are only about 50%-56% identical. Recently, a few clinical hepatitis E cases with chronic or acute rat HEV infection have been reported and raised many concerns. Here, advances in studies of the prevalence of rat HEV in animals and the clinical hepatitis E cases caused by rat HEV were reviewed.

Objective To study the influence of the modification of the special neutralizing epitopes of the HIV-1 envelope (Env) on its assembly of functional pseudovirus and neutralizing activity. Methods Site-directed mutations were performed using cycling mutagenesis and selection of mutants with Dpn I . With this method, the 2G12 and 2F5 neutralizing epitopes were integrated into Env of subtype BC which was without the two epitopes, then the capability of forming pseudovirus and the neutralizing activity against 2G12 and 2F5 were compared with pre-modified Env. Results The special Env neutralizing epitopes of five HIV pseudovirus (BC02, BC03, BC04, BC05 and BC12) were modified. Among the five pseudovirus, BC04 and BC12 pseudovirus can't be formed after the 2G12 epitope was modified, whilst the BC02, BC03 and BC05 pseudovirus can be formed after the 2G12 and 2F5 epitopes were added, and there was no variation of the pseudovirus titer; On the aspect of neutralizing activity, BG03 pseudovirus against 2G12 and 2F5 was enhanced, BC02 and BC05 pseudovirus against 2F5 was enhanced while which against 2G12 was not changed. Conclusion The modification of 2G12 epitope influences the forming of pseudovirus and the addition of neutralizing epitopes can enhance the neutralizing activity of pseudovirus, which offers new approach for the optimization of HIV immunogen.

The serum samples and corresponding cervical swabs were collected fi'om 50 women with genital warts from Tianjin city,China.The neutralizing antibodies against HPV-16,-18,-58,-45,-6 and-11 in serum samples were tested by using pseudovirus-based neutralization assays and HPV DNAs in cervical swabs were also tested by using a typing kit that can detect 21 types of HPV.The results revealed that 36%(18/50)of sera were positive for type-specific neutralizing antibodies with a titer range of 160-2560,of which 22%(11/50),12%(6/50),10%(5/50),4%(2/50),4%(2/50)and 2%(1/50)were against HPVs-6,-16,-18,-58,.45 and-11,respectively.Additionally,60%(30/50)of samples were HPV DNA-positive,in which the most common types detected were HPV-68(18%),HPV-16(14%),HPV-58(12%),HPV-33(8%)and HPV-6,HPV-11,HPV-18 and HPV-52(6% each).The concordance between HPV DNA and corresponding neutralizing antibodies was 56%(28/50)with a significant difference(P＜0.05).The full-length sequences of five HPV types(HPV-42,-52,-53,-58 and-68)were determined and exhibited 98%-100% identities with their reported genomes.The present data may have utility for investigating the natural history of HPV infection and promote the development of HPV vaccines.

Objective To evaluate the quality of four domestic and three imported fourth-generation HIV diagnostic reagents.Methods The specificity and sensitivity of these assays were analyzed when testing HIV negative samples and HIV-1 RNA positive samples.The relative seroconversion sensitivity index was analyzed when testing BBI seroconversion panels.Results The sensitivity of seven 4th-generation assays were 100％ (95％ CI:99.86％-100％ ),and one sample at the window period of HIV-1 infection were detected as positive.Of the seven assays,one imported assay exhibited the relative largeδ + value (1.0892),and the small δ+ value were found on the remaining six assays (0.0836-0.3003 ).For the samples negative for HIV antibody,varying degrees of false positives were observed on the seven assays ( specificity:97.80％ -99.60％,δ- value:-1.3803 to -0.4778).When testing the BBI seroconversion panels,the relative seroconversion sensitivity index of domestic assays were -0.500-0,however,which of imported assays were -0.600 and -0.700.Conclusion The seven reagents exhibited high sensitivity and specificity.The 4th generation HIV assays can be used as blood screening reagents to find the samples at window period of HIV-1 infection,thus indicating the certain meaning in reducing the transmission risk of HIV-1 for fourth-generation HIV diagnostic reagents.However,the better efficiency to detect HIV-1 early infection was observed on the imported assays than on the domestic assays.

Objective To evaluate the differences between the third and the fourth generations of anti-HIV assays,and different kits within the same generation.Methods A total of 989 HIV-negative samples,185 samples positive for HIV-1 RNA.1st-generation international references of HIV antibodies and samples from 9 sets of BBI seroconversion panels were detected by 8 kits of the third generation and 4 kits of the fourth.Results The fourth generation kits can detect HIV infection earlier than the third generation kits.However,the detected days of HIV infection with different kits of the fourth generation were different whilst no significant difierences were found with difierent kits of the third generation.Furthermore,the capacity of detecting samples with different genotypes for different reagents was different,especially the capacity of domestic reagents on detecting HIV-1 O group and HIV-2 samples was relatively weak.Conclusion These data provided information to improve the quality of anti-HIV diagnostic reagents further.

Objective To sequence and analyze the full-length genome of one HEV strain,W2-1 isolated from a sporadic hepatitis E patient hospitalized in 1999 in Xinjiang,China.Methods Nested RT-PCR assays with 4 sets primers were used to amplify the entire genome.The PCR products were purified and sequenced.The full-length genome was acquired by assembling the fragmental sequences using the DNAstar 5.01 software.The genome of W2-1 was analyzed by comparing with the reference HEVs from GenBank.Results The complete genome of W2-1 is 7212 nt in length,including three open reading frames (ORF1-3) with 5079,1980 and 345 nt respectively,27 nt 5'UTR and 83 nt 3'UTR,and a 3' poly A tail.Phylogenetic analysis based on full-length genome showed that W2-1 belonged to genotype 1,subtype 1b.W2-1 had high homology with the HEV strains isolated in the large hepatitis E epidemic in Xinjiang in 1987-1989,sharing 97.2％-98.5％ nucleotide identity in the full length genome.W2-1 also showed high homology with 1b strains isolated in China after 2000,with 97.6％-99.2％ nucleotide identity.The specific amino acid sites in ORF1-3 proteins that distinct between genotype 1 HEV and the potential zoonotic strains did not change in W2-1.Conclusion W2-1 belongs to subtype 1b.The study indicates subtype 1b HEV has been circulating in China in a long period after hepatitis E outbreak in Xinjiang in 1986-1989.The amino acids of ORF1-3 of subtype 1b are conserved.

Objective To establish HIV-1 seroconversion panels with the samples collected by National Institutes for Food and Drug Control ( NIFDC) and to evaluate the window periods of HIV enzyme immunoassay ( EIA) diagnostic kits used for blood screening with them. Methods Serum specimens were collected from different plasma donation stations in China. All suspected HIV infection specimens were screened for HIV by using the nucleic acid amplification testing (NAT), Western blot confirmatory assay and P24 quantitative detection assay. The HIV env gene sequences were amplified by RT-PCR for further confirmation of HIV infection. The PCR products were sequenced and genotyped. The confirmed seroconver-sion panels were used to evaluate the early detection capabilities of the 4th and 3rd generation HIV EIA diag-nostic kits used in blood screening in china. Results A total of 8 sets of HIV seroconversion panels com-prised of 36 samples were confirmed in this study, including 6 sets of AE subtype, 1 set of B subtype and 1 set of unknown genotype. Those seroconversion panels were tested with HIV diagnostic kits produced by 19 different manufacturers. For the early detection of HIV infection, the 4th generation HIV diagnostic kits with a score of 9. 4 points were better than the 3rd generation HIV diagnostic kits whose score was 3. 6 points (P<0. 01, t=8. 547). Some of the domestic 4th generation HIV diagnostic kits were similar to the imported kits in the early detection of HIV infection. In terms of the diagnosis of HIV infection, the HIV-1 NAT was at least 2 weeks earlier than the HIV EIA diagnostic kits. The sensitivity of confirmatory assay was lower than that of the diagnostic kits. Four out of five 4th generation HIV diagnostic kits showed declined signal to cut off ( S/CO ) ratio , indicating the probability of false detection during the second window period . Conclusion Eight sets of NIFDC HIV-1 seroconversion panels were established in this study. With those panels we found that there were differences in the window period between different EIA diagnostic kits used for HIV blood screening.

Marburg virus (MARV) is a lethal virus that causes fatal hemorrhagic fever.It belongs to the Filoviridae family which also includes Ebola virus.MARV is similar to Ebola virus in structure and infection mechanism.Moreover,the diseases caused by them have similar clinical symptoms.However,researches on MARV are less than those on Ebola virus.In this review,we focus on the viral structure,especially the structure of MARV glycoprotein (GP) which determines its infectivity,functions of MARV GP as well as protective antibodies and vaccines against this protein.