Project description:During August 2006-April 2010, in Beijing, China, 2 rare human enterovirus serotypes, coxsackievirus A21 and enterovirus 68, were detected most frequently in human enterovirus-positive adults with acute respiratory tract infections. Thus, during some years, these 2 viruses cause a substantial proportion of enterovirus-associated adult acute respiratory tract infections.
Project description:Hand, foot, and mouth disease (HFMD) surveillance was initiated in the Inner Mongolia Autonomous Region of China in 2007, a crucial scrutiny for monitoring the prevalence of enterovirus serotypes associated with HFMD patients. However, this surveillance mostly focused on enterovirus 71 (EV-A71) and coxsackievirus A16; therefore, information on other enterovirus serotypes is limited. To identify the other circulating enterovirus serotypes in the HFMD outbreaks in Inner Mongolia in 2010, clinical samples from HFMD patients were investigated. Six coxsackievirus B4 (CVB4) strains were isolated and phylogenetic analyses of VP1 sequences were performed. Full-length genome sequences of two representative CVB4 isolates were acquired and similarity plot and bootscanning analyses were performed. The phylogenetic dendrogram indicated that all CVB4 strains could be divided into 5 genotypes (Genotypes I-V) with high bootstrap support (90-100%). The CVB4 prototype strain (JVB) was the sole member of genotype I. CVB4 strains belonging to genotype II, which were once common in Europe and the Americas, seemingly disappeared and gave way to genotype III and IV strains, which appear to be the dominant circulating strains in the world. All Chinese CVB4 strains belonged to Genotype V, a newly identified genotype supported by a high bootstrap value (100%), and are circulating only in mainland of China. Intertypic recombination occurred in the Chinese CVB4 strains with novel unknown serotype EV-B donor sequences. Two Chinese CVB4 strains had a virulent residue at position 129 of VP1, and one strain also had a virulent residue at position 16 of VP4. Increased surveillance is needed to monitor the emergence of new genetic lineages of enteroviruses in areas that are often associated with large-scale outbreaks. In addition, continued monitoring of enteroviruses by clinical surveillance and genetic characterization should be enhanced.
Project description:Human enterovirus 68 (EV-D68) is a rarely reported virus that has been linked to respiratory disease. In recent years, reports about EV-D68 infection have markedly increased worldwide. However, the epidemiological features of this emerging infection are not well understood. To evaluate the emerging EV-D68 epidemic, we isolated the circulating viral strain and investigated the seroprevalence of neutralizing antibodies (NAbs) in Beijing between 2004 and 2011. We found that the titers of EV-D68 NAbs were generally low in all age groups in sampled populations in 2004 but significantly higher in 2009. From 2007 to 2011, the NAbs against EV-D68 significantly increased over time. These findings indicate that EV-D68 has spread widely in the Chinese population in recent years, although only a limited number of cases were reported.
Project description:Like all biological populations, viral populations exist as networks of genotypes connected through mutation. Mapping the topology of these networks and quantifying population dynamics across them is crucial to understanding how populations adapt to changes in their selective environment. The influence of mutational networks is especially profound in viral populations which rapidly explore their mutational neighborhoods via high mutation rates. Using a novel single-cell sequencing method, scRNAseq-Enabled Acquisition of mRNA and Consensus Haplotypes Linking Individual Genotypes and Host Transcriptomes (SEARCHLIGHT), we captured and assembled viral haplotypes from hundreds of individual infected cells to reveal the complexity of viral populations. We obtained these genotypes in parallel with host cell transcriptome information, enabling us to link host cell transcriptional phenotypes to the genetic structures underlying virus adaptation.
Project description:EV-D68 is associated with respiratory tract infections (RTIs). Since its first isolation, EV-D68 has been detected sporadically. However, the US and Canada have experienced outbreaks of EV-D68 infections between August and December 2014. This study aimed to investigate the molecular epidemiology and clinical characteristics of EV-D68 in Chongqing, Southwestern China. From January 2012 to November 2014, 1876 nasopharyngeal aspirate specimens (NPAs) were collected from hospitalized children with RTIs. Among the 1876 NPAs, EV-D68 was detected in 19 samples (1.0%, 19/1876). Of these, 13 samples were detected in September and October 2014 (9.8%, 13/132). Phylogenetic analysis showed that all 13 strains detected in the 2014 Chongqing had high homology with the main strains of the 2014 US outbreak. Among the children with EV-D68 infection, 13 (68%) had a history of recurrent wheezing. A total of 13 children had a discharge diagnosis of asthma. Of these, 11 children were diagnosed with acute asthma exacerbation. EV-D68 was the predominant pathogen that evoked asthma exacerbation in September and October 2014. In conclusion, our results found that a history of recurrent wheezing may be a risk factor for the detection of EV-D68 and viral-induced asthma exacerbation may be a clinical feature of EV-D68 infection.
Project description:Enterovirus 68 (EV68) is a rare enterovirus associated with respiratory illness that, unlike other enteroviruses, has been identified only from respiratory specimens. We identified EV68 from respiratory specimens of children hospitalized with a diagnosis of severe pneumonia in Leyte, Republic of the Philippines. Twenty-one samples showed high similarity with EV68 by sequencing of 5' nontranslated region; 17 of these samples were confirmed as EV68 by sequencing of viral protein 1 capsid coding region. Most previously reported EV68 cases had been identified as sporadic cases. All 21 patients we identified had severe illness, and 2 died, possibly the first reported fatal cases associated with EV68 infection. Our study suggests that EV68 may be a possible causative agent of severe respiratory illnesses.
Project description:Tick-borne infectious diseases pose a serious health threat in certain regions of the world. Emerging infectious diseases caused by novel tick-borne pathogens have been reported that are causing particular concern. Several tick-borne diseases often coexist in the same foci, and a single vector tick can transmit two or more pathogens at the same time, which greatly increases the probability of co-infection in host animals and humans and can lead to an epidemic of tick-borne disease. The lack of epidemiological data and information on the specific clinical symptoms related to co-infection with tick-borne pathogens means that it is not currently possible to accurately and rapidly distinguish between a single pathogen infection and co-infection with multiple pathogens, which can have serious consequences. Inner Mongolia in the north of China is endemic for tick-borne infectious diseases, especially in the eastern forest region. Previous studies have found that more than 10% of co-infections were in host-seeking ticks. However, the lack of data on the specific types of co-infection with pathogens makes clinical treatment difficult. In our study, we present data on the co-infection types and the differences in co-infection among different ecological regions through genetic analysis of tick samples collected throughout Inner Mongolia. Our findings may aid clinicians in the diagnosis of concomitant tick-borne infectious diseases.
Project description:BackgroundOutbreaks of enterovirus D68 (EV-D68) respiratory infections in children were reported globally in 2014. In Japan, there was an EV-D68 outbreak in the autumn of 2015 (September-October). The aim of this study was to compare EV-D68-specific polymerase chain reaction (PCR)-positive and EV-D68-specific PCR-negative patients.MethodsPediatric patients admitted for any respiratory symptoms between September and October 2015 were enrolled. Nasopharyngeal swabs were tested for multiplex respiratory virus PCR and EV-D68-specific reverse transcription-PCR. EV-D68-specific PCR-positive and -negative patients were compared regarding demographic data and clinical information.ResultsA nasopharyngeal swab was obtained from 76 of 165 patients admitted with respiratory symptoms during the study period. EV-D68 was detected in 40 samples (52.6%). Median age in the EV-D68-specific PCR-positive and -negative groups was 3.0 years (IQR, 5.5 years) and 3.0 years (IQR, 4.0 years), respectively. The rates of coinfection in the two groups were 32.5% and 47.2%, respectively. There was no significant difference in the history of asthma or recurrent wheezing, length of hospitalization, or pediatric intensive care unit admission rate between the groups. The median days between symptom onset and admission was significantly lower for the EV-D68-positive group (3.0 days vs 5.0 days, P = 0.001). EV-D68 was identified as clade B on phylogenetic analysis. No cases of acute flaccid myelitis were encountered.ConclusionsMore than half of the samples from the children admitted with respiratory symptoms were positive for EV-D68-specific PCR during the outbreak. Asthma history was not associated with the risk of developing severe respiratory infection.