A coxsackievirus B5-associated aseptic meningitis outbreak in Shandong Province, China in 2009

Seasonal Testing, Results, and Effect of the Pandemic on Coxsackievirus Serum Studies

Coxsackieviruses (CVs) are common causes of infections and can be life-threatening. Unfortunately, rigorous studies guiding the clinician in interpreting CV serum antibody titer testing is lacking. To explore the epidemiology of circulating CVs and the serological test utility in aiding diagnosis of CV infections in our community, we obtained results of CV immunologic diagnostic tests between 2018 and 2022 from a regional healthcare database. For CV type A, rare individuals had positive CF (complement fixation) tests whereas all 16 individuals with IFA testing showed at least one positive serotype. For CV type B CF testing, 52.2% of 222 patients had at least one serotype positive, with B5 being most common and also the most common with higher titers (14.8% with ≥1:32). We found a significant reduction in seropositivity rate during the pandemic in 2020 compared to 2018, which continued through 2022 (OR: 0.2, 95% CI: 0.08-0.49, p-value < 0.001). During the pandemic, the seasonal pattern of positive tests varied from the pre-pandemic pattern. Testing for CVs was increased after the first year of the pandemic. Overall, the variability by month and seasonal change in our data support that CF testing can be used to identify recent CVB infection.

Non-Polio Enterovirus Surveillance in the Ural Federal District and Western Siberia, 2022: Is There a Need for a Vaccine?

Human non-polio enteroviruses (NPEVs) are the etiological agents involved in most cases of hand-foot-and-mouth disease (HFMD), herpangina and aseptic meningitis. Information on the epidemiology profiles of NPEV in the Ural Federal District and Western Siberia is very limited, with no published data available. The aim of this study is to describe NPEV incidence in the Ural Federal District and Western Siberia among patients with different forms of non-polio enterovirus infections (NPEVIs) during 2022, stratified by age and clinical manifestations. A total of 265 samples that tested positive for NPEV using a polymerase chain reaction (PCR) were genotyped by semi-nested PCR for the VP1 gene. The results showed that 21 genotypes were identified among patients in this study. CVA6 was the most common genotype for HFMD. CVA6, along with CVA10, accounted for the majority of herpangina cases, while CVA9 was implicated in most meningitis cases. Sequence and phylogenetic analysis showed that nearly all of the CVA6 strains identified in this study displayed a close genetic relationship to strains identified in other cities in Russia and strains from China. NPEV surveillance allows for monitoring the circulation of clinically relevant genotypes, resulting in continuous data about NPEV epidemiology. This is important for improving case prevention, diagnosis and guiding clinical management.

Prevalence of Non-Polio Enteroviruses in the Sewage of Guangzhou City, China, from 2013 to 2021

Continuous surveillance of enteroviruses (EVs) in urban domestic sewage can timely reflect the circulation of EVs in the environment and crowds, and play a predictive and early warning role in EV-related diseases. To better understand the long-term epidemiological trends of circulating EVs and EV-related diseases, we conducted a 9-year (2013 to 2021) surveillance study of non-polio EVs (NPEVs) in urban sewage in Guangzhou city, China. After concentrating and isolating the viruses from the sewage samples, NPEVs were detected and molecular typing was performed. Twenty-one different NPEV serotypes were identified. The most isolated EVs were echovirus 11 (E11), followed by coxsackievirus (CV) B5, E6, and CVB3. EV species B prevailed in sewage samples, but variations in the annual frequency of different serotypes were also observed in different seasons, due to spatial and temporal factors. E11 and E6 were detected continuously before 2017, and the number of isolates was relatively stable during the surveillance period. However, after their explosive growth in 2018 and 2019, their numbers suddenly decreased significantly. CVB3 and CVB5 had alternating trends; CVB5 was most frequently detected in 2013 to 2014 and 2017 to 2018, while CVB3 was most frequently detected in 2015 to 2016 and 2020 to 2021. Phylogenetic analysis showed that at least two different transmission chains of CVB3 and CVB5 were prevalent in Guangzhou City. Our results show that in the absence of a comprehensive and systematic EV-related disease surveillance system in China, environmental surveillance is a powerful and effective tool to strengthen and further investigate the invisible transmission of EVs in the population. IMPORTANCE This study surveilled urban sewage samples from north China for 9 years to monitor enteroviruses. Samples were collected, processed, and viral identification and molecular typing were performed. We detected 21 different non-polio enteroviruses (NPEVs) with yearly variations in prevalence and peak seasons. In addition, this study is very important for understanding the epidemiology of EVs during the COVID-19 pandemic, as the detection frequency and serotypes of EVs in sewage changed considerably around 2020. We believe that our study makes a significant contribution to the literature because our results strongly suggest that environmental surveillance is an exceptionally important tool, which can be employed to detect and monitor organisms of public health concern, which would otherwise be missed and under-reported by case-based surveillance systems alone.

Vaccines against Group B Coxsackieviruses and Their Importance

The group B coxsackieviruses (CVBs) exist in six serotypes (CVB1 to CVB6). Disease associations have been reported for most serotypes, and multiple serotypes can cause similar diseases. For example, CVB1, CVB3, and CVB5 are generally implicated in the causation of myocarditis, whereas CVB1 and CVB4 could accelerate the development of type 1 diabetes (T1D). Yet, no vaccines against these viruses are currently available. In this review, we have analyzed the attributes of experimentally tested vaccines and discussed their merits and demerits or limitations, as well as their impact in preventing infections, most importantly myocarditis and T1D.

Molecular Epidemiology Reveals the Co-Circulation of Two Genotypes of Coxsackievirus B5 in China

Coxsackievirus B5 (CVB5) is an important enterovirus B species (EV-Bs) type. We used the full-length genomic sequences of 53 viral sequences from the national hand, foot, and mouth disease surveillance network in the Chinese mainland (2001-2021). Among them, 69 entire VP1 coding region nucleotide sequences were used for CVB5 genotyping and genetic evolution analysis. Phylogenetic analysis based on a data set of 448 complete VP1 sequences showed that CVB5 could be divided into four genotypes (A-D) worldwide. Sequences from this study belonged to genotypes B and D, which dominated transmission in the Chinese mainland. Two transmission lineages of CVB5 have been discovered in the Chinese mainland, lineage 2 was predominant. Markov chain Monte Carlo analysis indicated that the tMRCA of CVB5 in the Chinese mainland could be traced to 1955, while the global trend could be traced to 1862, 93 years earlier than China. The evolution rate of CVB5 was higher in the Chinese mainland than worldwide. The spatiotemporal dynamics analysis of CVB5 assessed that virus transportation events were relatively active in Central, Northeast, North and Northwest China. Recombination analysis revealed frequent intertypic recombination in the non-structural region of CVB5 genotypes B and D with the other EV-Bs, revealing eight recombination lineages. Our study showed the molecular evolution and phylogeography of CVB5 that could provide valuable information for disease prevention.

[Enteroviral (Picornaviridae: Enterovirus) (nonpolio) vaccines]

Non-polio enteroviruses (NPEVs) are ubiquitous and are one of the main causative agents of viral infections in children. NPEVs most commonly infect newborns and young children, due to their lack of antibodies. In children, clinical manifestations can range from acute febrile illness to severe complications that require hospitalization and lead in some cases to disability or death. NPEV infections can have severe consequences, such as polio-like diseases, serous meningitis, meningoencephalitis, myocarditis, etc. The most promising strategy for preventing such diseases is vaccination. No less than 53 types of NPEVs have been found to circulate in Russia. However, of epidemic importance are the causative agents of exanthemic forms of the disease, aseptic meningitis and myocarditis. At the same time, the frequency of NPEV detection in the constituent entities of the Russian Federation is characterized by uneven distribution and seasonal upsurges. The review discusses the epidemic significance of different types of enteroviruses, including those relevant to the Russian Federation, as well as current technologies used to create enterovirus vaccines for the prevention of serious diseases.

Epidemiological and etiological characteristics of viral meningitis for hospitalized pediatric patients in Yunnan, China

BACKGROUND

Viral infection is the most common cause of aseptic meningitis. The purpose of this study was to identify the viruses responsible for aseptic meningitis to better understand the clinical presentations of this disease.

METHOD

Between March 2009 and February 2010, we collected 297 cerebrospinal fluid specimens from children with aseptic meningitis admitted to a pediatric hospital in Yunnan (China). Viruses were detected by using "in house" real-time quantitative polymerase chain reaction or reverse-transcription real-time quantitative polymerase chain reaction from these samples. Phylogenetic analyses were conducted using the Molecular Evolutionary Genetic Analysis version 7.0 software, with the neighbor-joining method.

RESULTS

Viral infection was diagnosed in 35 of the 297 children (11.8%). The causative viruses were identified to be enteroviruses in 25 cases (71.4%), varicella-zoster virus in 5 cases (14.3%), herpes simplex virus 1 in 2 cases (5.7%), and herpes simplex virus 2, Epstein-Barr virus, and human herpesvirus 6 in 1 case each (2.9% each). Of the enteroviruses, coxsackievirus B5 was the most frequently detected serotype (10/25 cases; 40.0%) and all coxsackievirus B5 strains belonged to C group.

CONCLUSIONS

In the study, a causative virus was only found in the minority of cases, of them, enteroviruses were the most frequently detected viruses in patients with viral meningitis, followed by varicella-zoster virus and herpes simplex virus. Our findings underscore the need for enhanced surveillance and etiological study of aseptic meningitis.

Atomic Structures of Coxsackievirus B5 Provide Key Information on Viral Evolution and Survival

Coxsackie virus B5 (CVB5), a main serotype in human Enterovirus B (EVB), can cause severe viral encephalitis and aseptic meningitis among infants and children. Currently, there is no approved vaccine or antiviral therapy available against CVB5 infection. Here, we determined the atomic structures of CVB5 in three forms: mature full (F) particle (2.73 Å), intermediate altered (A) particle (2.81 Å), and procapsid empty (E) particle (2.95 Å). Structural analysis of F particle of CVB5 unveiled similar structures of “canyon,” “puff,” and “knob” as those other EV-Bs. We observed structural rearrangements that are alike during the transition from F to A particle, indicative of similar antigenicity, cell entry, and uncoating mechanisms shared by all EV-Bs. Further comparison of structures and sequences among all structure-known EV-Bs revealed that while the residues targeted by neutralizing MAbs are diversified and drive the evolution of EV-Bs, the relative conserved residues recognized by uncoating receptors could serve as the basis for the development of antiviral vaccines and therapeutics.

IMPORTANCE As one of the main serotypes in Enterovirus B, CVB5 has been commonly reported in recent years. The atomic structures of CVB5 shown here revealed classical features found in EV-Bs and the structural rearrangement occurring during particle expansion and uncoating. Also, structure- and sequence-based comparison between CVB5 and other structure-known EV-Bs screened out key domains important for viral evolution and survival. All these provide insights into the development of vaccine and therapeutics for EV-Bs.

Coxsackievirus B5 virus-like particle vaccine exhibits greater immunogenicity and immunoprotection than its inactivated counterpart in mice

Coxsackievirus B group 5 (CVB5) represents one of the major pathogens that cause diseases such as hand, foot and mouth disease (HFMD) and aseptic meningitis et al. Currently, no specific drugs and vaccines are available, and a safe and effective CVB5 vaccine is of great value for control of the diseases. In this study, CVB5 P1 precursor and 3CD protease were co-expressed in Sf9 cells by using a baculovirus expression system. The P1 was processed by 3CD and self-assembled into CVB5 virus-like particles (VLPs). VP1 and VP3 capsid proteins of CVB5 could be detected by SDS-PAGE and Western blotting. Transmission electron microscopy revealed that the CVB5 VLPs were spherical particles with a diameter of about 30 nm, mimicking wild-type CVB5 virus. Our study showed that the total IgG and neutralizing antibodies induced by CVB5 VLPs were higher than those induced by inactivated vaccine. More importantly, the CVB5 VLPs conferred full protection to the CVB5-challenged suckling mice via passive immunity while protection efficiency of the inactivated vaccine was only 80%. The CVB5 VLPs vaccine could protect the limb muscles, brain, and heart tissues of suckling mice from CVB5-induced damage. These results demonstrated that the CVB5 VLPs vaccine possessed stronger immunogenicity and provided more robust immunoprotection than the inactivated CVB5 vaccine, suggesting that the CVB5 VLPs promise to be a CVB5 vaccine candidate in future.

Analysis of enterovirus genotypes in the cerebrospinal fluid of children associated with aseptic meningitis in Liaocheng, China, from 2018 to 2019

BACKGROUND

Aseptic meningitis is most often caused by enteroviruses (EVs), but EVs associated with aseptic meningitis have not yet been reported in Liaocheng. The aim of this study was to determine the prevalence and genetic characteristics of EVs causing aseptic meningitis in children in Liaocheng.

METHODS

We reviewed the epidemiological and clinical characteristics of 504 paediatric cases of aseptic meningitis in Liaocheng from 2018 to 2019 and analysed the phylogeny of the predominant EV types causing this disease.

RESULTS

A total of 107 children were positive for EV in cerebrospinal fluid samples by nested PCR. Most of the positive patients were children 13 years old or younger and had symptoms such as fever, headache and vomiting (P < 0.05). The seasons with the highest prevalence of EV-positive cases were summer and autumn. The 107 EV sequences belonged to 8 serotypes, and echovirus types 18, 6 and 11 were the three dominant serotypes in Liaocheng during the 2-year study period. Phylogenetic analyses demonstrated that the E18 and E6 isolates belonged to subgenotype C2, while the E11 isolates belonged to subgenotype D5. VP1 analysis suggested that only one lineage of these three types was cocirculating in the Liaocheng region.

CONCLUSIONS

This study demonstrated the diverse EV genotypes contributing to a large outbreak of aseptic meningitis in Liaocheng. Therefore, large-scale surveillance is required to assess the epidemiology of EVs associated with aseptic meningitis and is important for the diagnosis and treatment of aseptic meningitis in Liaocheng.

Type B coxsackieviruses and central nervous system disorders: critical review of reported associations

Type B coxsackieviruses (CV-B) frequently infect the central nervous system (CNS) causing neurological diseases notably meningitis and encephalitis. These infections occur principally among newborns and children. Epidemiological studies of patients with nervous system disorders demonstrate the presence of infectious virus, its components, or anti-CV-B antibodies. Some experimental studies conducted in vitro and in vivo support the potential association between CV-B and idiopathic neurodegenerative diseases such as amyotrophic lateral sclerosis and psychiatric illness such as schizophrenia. However, mechanisms explaining how CV-B infections may contribute to the genesis of CNS disorders remain unclear. The proposed mechanisms focus on the immune response following the viral infection as a contributor to pathogenesis. This review describes these epidemiological and experimental studies, the modes of transmission of CV-B with an emphasis on congenital transmission, the routes used by CV-B to reach the brain parenchyma, and plausible mechanisms by which CV-B may induce CNS diseases, with a focus on potential immunopathogenesis.

Pediatric Enteroviral Central Nervous System Infections in Bialystok, Poland: Epidemiology, Viral Types, and Drivers of Seasonal Variation

Enteroviruses are common causes of infections of the central nervous system (CNS) that in temperate climates tend to peak in the summer. The aim of the study was to describe epidemiology, drivers of seasonality, and types of enteroviruses causing infections of the CNS in children in Northeastern Poland. We prospectively collected data on children hospitalized with infection of the CNS attributed to enteroviruses in Bialystok, Poland, from January 2015 to December 2019. In total, 224 children were included. Nineteen different enterovirus types were identified in isolates collected from 188 children. Coxsackie B5 (32%), echovirus 30 (20%), and echovirus 6 (14%) were the three most common types. Enteroviruses were more prevalent during the summer–fall season. Infections caused by echovirus 30 peaked early in June and coxsackievirus B5 in July, whereas echovirus 6 peaked late in October. Phylogenetic analyses of these three enterovirus types showed multiple lineages co-circulating in this region. Mean air temperatures and precipitation rates were independently associated with monthly number of cases. Considering lack of effective treatment or vaccine, easy transmission of enteroviruses between susceptible individuals, their high mutation rate and prolonged time of viral shedding, continued monitoring and surveillance are imperative to recognize enteroviral infections of the CNS and the changes in circulation of enteroviruses in Poland.

Detection of enteroviruses in urban sewage by next generation sequencing and its application in environmental surveillance

Environmental surveillance has been used successfully in monitoring enterovirus (EV) circulation; however cell culture method may introduce a selective bias in those EV strains that are recovered from the environment. In this study, urban sewage samples were collected monthly in Jinan, China in 2018 and concentrated via membrane adsorption/elution method. A P1 seminested RT-PCR (RT-snPCR) and NGS method was developed, by which amplicons of 4000 nucleotide in length covering the entire P1 region of EVs were obtained from sewage concentrates and were further analyzed by next generation sequencing (NGS). In addition, for each sewage concentrate, two other assays - cell culture and NGS based partial VP1 amplicon sequencing - were conducted in parallel and compared. The results showed that the P1 RT-snPCR and NGS method generated the most data, with 32 serotypes identified belonging to species EV-A (n = 11), EV-B (n = 14), and EV-C (n = 7). These serotypes covered all those detected from the methods of cell culture (n = 10) and partial VP1 amplicon sequencing (n = 16). EV serotypes from acute flaccid paralysis surveillance correlated with those from sewage. Phylogenetic analysis on coxsackievirus B5, a common pathogen of meningitis, revealed close genetic relationship between environmental and clinical sequences. These results demonstrate sewage contains different EVs related to a variety of diseases. Traditional cell culture method underestimates the existence of some serotypes. NGS based environmental surveillance provides data which are consistent with those from clinical diseases, greatly improves our understanding on the actual circulation in the population, and should be encouraged for public health surveillance.

Microbiota-independent antiviral effects of antibiotics on poliovirus and coxsackievirus

Coxsackieviruses primarily infect the gastrointestinal tract of humans, but they can disseminate systemically and cause severe disease. Using antibiotic treatment regimens to deplete intestinal microbes in mice, several groups have shown that bacteria promote oral infection with a variety of enteric viruses. However, it is unknown whether antibiotics have microbiota-independent antiviral effects for enteric viruses or whether antibiotics influence extra-intestinal, systemic infection. Here, we examined the effects of antibiotics on systemic enteric virus infection by performing intraperitoneal injections of either coxsackievirus B3 (CVB3) or poliovirus followed by quantification of viral titers. We found that antibiotic treatment reduced systemic infection for both viruses. Interestingly, antibiotics reduced CVB3 titers in germ-free mice, suggesting that antibiotic treatment alters CVB3 infection through a microbiota-independent mechanism. Overall, these data provide further evidence that antibiotics can have noncanonical effects on viral infection.

A Large-Scale Outbreak of Echovirus 30 in Gansu Province of China in 2015 and Its Phylodynamic Characterization

Background

Echovirus 30 (E-30) has been investigated and reported worldwide and is closely associated with several infectious diseases, including encephalitis; myocarditis; and hand, foot, and mouth disease. Although many E-30 outbreaks associated with encephalitis have been reported around the world, it was not reported in northwest China until 2015.

Methods

The clinical samples, including the feces, serum, throat swabs, and cerebrospinal fluid, were collected for this study and were analyzed for diagnosis. E-30 was isolated and processed according to the standard procedures. The epidemiological and phylogenetic analysis were performed to indicate the characteristics of E-30 outbreaks and phylodynamics of E-30 in China.

Results

The E-30 outbreaks affected nine towns of Gansu Province in 2015, starting at a school of Nancha town and spreading to other towns within 1 month. The epidemiological features showed that children aged 6–15 years were more susceptible to E-30 infection. The genotypes B and C cocirculated in the world, whereas the latter dominated the circulation of E-30 in China. The genome sequences of this outbreak present 99.3–100% similarity among these strains, indicating a genetic-linked aggregate outbreak of E-30 in this study. Two larger genetic diversity expansions and three small fluctuations of E-30 were observed from 1987 to 2016 in China, which revealed the oscillating patterns of E-30 in China. In addition, the coastal provinces of China, such as Zhejiang, Fujian, and Shandong, were initially infected, followed by other parts of the country. The E-30 strains isolated from mainland of China may have originated from Taiwan of China in the last century.

Conclusion

The highly similar E-30 genomes in this outbreak showed an aggregate outbreak of E-30, with nine towns affected. Our results suggested that, although the genetic diversity of E-30 oscillates, the dominant lineages of E-30 in China has complex genetic transmission. The coastal provinces played an important role in E-30 spread, which implied further development of effective countermeasures. This study provides a further insight into the E-30 outbreak and transmission and illustrates the importance of valuable surveillance in the future.

The Antibiotic Neomycin Enhances Coxsackievirus Plaque Formation

Coxsackievirus typically infects humans via the gastrointestinal tract, which has a large number of microorganisms collectively referred to as the microbiota. To study how the intestinal microbiota influences enteric virus infection, several groups have used an antibiotic regimen in mice to deplete bacteria. These studies have shown that bacteria promote infection with several enteric viruses. However, very little is known about whether antibiotics influence viruses in a microbiota-independent manner. In this study, we sought to determine the effects of antibiotics on coxsackievirus B3 (CVB3) using an in vitro cell culture model in the absence of bacteria. We determined that an aminoglycoside antibiotic, neomycin, enhanced the plaque size of CVB3 strain Nancy. Neomycin treatment did not alter viral attachment, translation, or replication. However, we found that the positive charge of neomycin and other positively charged compounds enhanced viral diffusion by overcoming the negative inhibitory effect of sulfated polysaccharides present in agar overlays. Neomycin and the positively charged compound protamine also enhanced plaque formation of reovirus. Overall, these data provide further evidence that antibiotics can play noncanonical roles in viral infections and that this should be considered when studying enteric virus-microbiota interactions.IMPORTANCE Coxsackieviruses primarily infect the gastrointestinal tract of humans, but they can disseminate systemically and cause severe disease. Using antibiotic treatment regimens to deplete intestinal microbes in mice, several groups have shown the bacteria promote infection with a variety of enteric viruses. However, it is possible that antibiotics have microbiota-independent effects on viruses. Here we show that an aminoglycoside antibiotic, neomycin, can influence quantification of coxsackievirus in cultured cells in the absence of bacteria.

Genetic characterization and molecular epidemiological analysis of novel enterovirus EV-B80 in China

Enterovirus B80 (EV-B80) is a newly identified serotype belonging to the enterovirus B species. To date, only two full-length genomic sequences of EV-B80 are available in GenBank, and few studies on EV-B80 have been conducted in China or worldwide. More information and research on EV-B80 is needed to assess its genetic characteristics, phylogenetic relationships, and association with enteroviral diseases. In this study, we report the phylogenetic characteristics of three Xinjiang EV-B80 strains and one Tibet EV-B80 strain in China. The full-length genomic sequences of four strains show 78.8-79% nucleotide identity and 94-94.2% amino acid identity with the prototype of EV-B80, indicating a tendency for evolution. Based on a maximum likelihood phylogenetic tree based on the entire VP1 region, three genotypes (A-C) were defined, revealing the possible origin of EV-B80 strains in the mainland of China. Recombination analysis revealed intraspecies recombinations in all four EV-B80 strains in nonstructural regions along with two recombination patterns. Due to the geographic factor, the coevolution of EV-B strains formed two different patterns of circulation. An antibody seroprevalence study against EV-B80 in two Xinjiang prefectures also showed that EV-B80 strains were widely prevalent in Xinjiang, China, compared to other studies on EV-B106 and EV-B89. All four EV-B80 strains are not temperature sensitive, showing a higher transmissibility in the population. In summary, this study reports the full-length genomic sequences of EV-B80 and provides valuable information on global EV-B80 molecular epidemiology.

A neonatal mouse model of central nervous system infections caused by Coxsackievirus B5

As one of the key members of the coxsackievirus B group, coxsackievirus B5 (CV-B5) can cause many central nervous system diseases, such as viral encephalitis, aseptic meningitis, and acute flaccid paralysis. Notably, epidemiological data indicate that outbreaks of CV-B5-associated central nervous system (CNS) diseases have been reported worldwide throughout history. In this study, which was conducted to promote CV-B5 vaccine and anti-virus drug research, a 3-day-old BALB/c mouse model was established using a CV-B5 clinical isolate (CV-B5/JS417) as the challenge strain. Mice challenged with CV-B5/JS417 exhibited a series of neural clinical symptoms and death with necrosis of neuronal cells in the cerebral cortex and the entire spinal cord, hindlimb muscles, and cardiomyocytes. The viral load of each tissue at various post-challenge time points suggested that CV-B5 replicated in the small intestine and was subsequently transmitted to various organs via viremia; the virus potentially entered the brain through the spinal axons, causing neuronal cell necrosis. In addition, this mouse model was used to evaluate the protective effect of a CV-B5 vaccine. The results indicated that both the inactivated CV-B5 vaccine and anti-CVB5 serum significantly protected mice from a lethal infection of CV-B5/JS417 by producing neutralizing antibodies. In summary, the first CV-B5 neonatal mouse model has been established and can sustain CNS infections in a manner similar to that observed in humans. This model will be a useful tool for studies on pathogenesis, vaccines, and anti-viral drug evaluations.

Molecular characterization of echovirus 12 strains isolated from healthy children in China

Human echovirus 12 (E-12) belongs to the enterovirus B species. To date, only one full-length genome sequence of E-12 (prototype strain Travis) is available in the GenBank database. This study determined the complete sequence of three E-12 strains, which were isolated from the stools of three healthy children in Yunnan, China, in 2013. We revealed that the three Yunnan E-12 strains had only 80.8-80.9% nucleotide identity and 96.4-96.8% amino acid identity with the Travis strain based on pairwise comparisons of the complete genome nucleotide and amino acid sequences. The three Yunnan strains shared 99.7% nucleotide identity and 99.1-99.5% amino acid similarity. Phylogenetic and similarity plot analyses showed that intertypic recombination occurred in the non-structural regions of the three Yunnan E-12 strains. This is the first report of the complete genome sequence of E-12 in China and it enriches the complete genome sequences of E-12 in the GenBank database.

Analysis of enterovirus types in patients with symptoms of aseptic meningitis in 2014 in Shandong, China

We reviewed the epidemiological and clinical characteristics of 927 aseptic meningitis patients in Shandong in 2014, and the phylogeny of predominant enterovirus (EV) types causing this disease was analyzed. A total of 209 patients that were positive for EV were identified by both cell culture and a reverse transcription-seminested PCR in cerebrospinal fluid samples. The positive patients were most likely to be children within 15 years of age, had symptoms such as fever, vomiting and nausea (P＜ .05). The 209 EV sequences belonged to 11 types, and coxsackievirus B5, echovirus types 6 and 30 were predominant types. VP1 analysis exhibited multiple lineages were co-circulating. The significance of the study could come from the fact that surveillance is important to monitor the prevalence of EV types in population, which shows enterovirus meningitis maintains an important public health problem in China.

Serological survey of neutralizing antibodies to eight major enteroviruses among healthy population

Human enteroviruses (EVs) are the most common causative agents infecting human, causing many harmful diseases, such as hand, foot, and mouth disease (HFMD), herpangina (HA), myocarditis, encephalitis, and aseptic meningitis. EV-related diseases pose a serious worldwide threat to public health. To gain comprehensive insight into the seroepidemiology of major prevalent EVs in humans, we firstly performed a serological survey for neutralizing antibodies (nAbs) against Enterovirus A71 (EV-A71), Coxsackie virus A16 (CV-A16), Coxsackie virus A6 (CV-A6), Coxsackie virus A10 (CV-A10), Coxsackie virus B3 (CV-B3), Coxsackie virus B5 (CV-B5), Echovirus 25 (ECHO25), and Echovirus 30 (ECHO30) among the healthy population in Xiamen City in 2016, using micro-neutralization assay. A total of 515 subjects aged 5 months to 83 years were recruited by stratified random sampling. Most major human EVs are widely circulated in Xiamen City and usually infect infants and children. The overall seroprevalence of these eight EVs were ranged from 14.4% to 42.7%, and most of them increased with age and subsequently reached a plateau. The co-existence of nAbs against various EVs are common among people ≥ 7 years of age, due to the alternate infections or co-infections with different serotypes of EVs, while most children were negative for nAb against EVs, especially those < 1 year of age. This is the first report detailing the seroepidemiology of eight prevalent EVs in the same population, which provides scientific data supporting further studies on the improvement of EV-related disease prevention and control.

Seroepidemiology of coxsackievirus B5 in infants and children in Jiangsu province, China

Coxsackievirus B5 (CV-B5) is associated with various human diseases such as viral encephalitis, aseptic meningitis, paralysis, herpangina, and hand, foot and mouth disease (HFMD). However, there is currently no effective vaccine against CV-B5.The seroepidemiologic characteristics of CV-B5 remained unknown. A cohort study was carried out in 176 participants aged 6-35 months from January 2012 to January 2014. The serum samples were collected and tested for CV-B5 neutralizing antibodies (NtAbs) four times during these two years. The confirmed enterovirus cases were recorded through the surveillance system, and their throat or rectal swabs were collected for pathogen detection. According to the changes of CV-B5 NtAbs, two CV-B5 epidemics were detected among these participants during the two-year follow-up. Sixty-seven cases out of all participants had seroconversion in CV-B5 NtAbs. During the first epidemic from March 2012 to September 2012, CV-B5 seropositivity rate increased significantly (6.8%, 12/176 vs. 21.6%, 38/176, P = 0.000). The seroconversion rate and geometric mean fold-increase (GMFI) were 18.2% (32/176) and 55.7, respectively; During the second epidemic from September 2012 to January 2014, CV-B5 seropositivity rate also increased (21.6%, 38/176 vs. 38.6%, 68/176, P = 0.000), and the seroconversion rate and GMFI were 19.9% (35/176) and 46.5, respectively. Only one case had CV-B5 associated HFMD during the two-year follow-up, and CV-B5 from the throat swab isolate was GI.D3 subtype, which belonged to the major pandemic strain in mainland China. CV-B5 infection was common in infants and children in Jiangsu province, China. Therefore, it's necessary to strengthen the surveillance on CV-B5 and to understand the epidemic characteristics of CV-B5 infection.

Recombination analysis of coxsackievirus B5 genogroup C

Coxsackievirus B5 (CVB5) is a member of the species Enterovirus B of the genus Enterovirus, family Picornaviridae. Based on its VP1 sequence, CVB5 is divided into four genogroups: A, B, C, and D. From 2002 to 2012, CVB5 serotype genogroup C caused an outbreak of aseptic meningitis in China. In order to study the evolution of CVB5 genogroup C, phylogenetic and recombination analysis was performed using the 399 available enterovirus B genome sequences in the GenBank database. The results indicated that 10 strains of CVB5 serotype genogroup C resulted from recombination between members of genogroup B and echovirus serotype E6, and another 5 strains resulted from recombination between members of genogroup C and serotype CVB4. These recombination events were confirmed by phylogenetic analysis.

Development of a pseudovirus based assay for measuring neutralizing antibodies against coxsackievirus B5

Coxsackievirus B5 (CV-B5), an important Coxsackie B virus from genus Enteroviruse within the family Picornaviridae, has also been isolated from Hand, Foot, and Mouth Disease (HFMD) patients, and often associated with neurological manifestations. In this study, we found out that Coxsackievirus B3 (CV-B3) replicon RNA could be encapsidated with CV-B5 capsid to assemble infectious CV-B5 pseudovirus. We then utilized this single round infection system of CV-B5 to develop a neutralizing antibody quantification assay. This pseudovirus neutralization assay showed superiority in biosafety, sensibility, quantitativity, efficiency and high throughput, and would facilitate the epidemiological studies and vaccine development of CV-B5.

Molecular detection and genotyping of enteroviruses from CSF samples of patients with suspected sepsis-like illness and/or aseptic meningitis from 2012 to 2015 in West Bank, Palestine

BACKGROUND

Human enteroviruses (HEVs) are the most frequently reported cause of aseptic meningitis with or without CSF pleocytosis in childhood. Rapid detection and genotype of HEVs is essential to determine the causative agent and variant causing sepsis-like illness and/or aseptic meningitis.

AIM

To investigate the molecular epidemiology of enteroviruses (EVs) among patients with sepsis-like illness and/or aseptic meningitis admitted to three major hospitals in West Bank, Palestine from 2012 to 2015.

METHODS

During the study period, 356 CSF samples were collected from patients with sepsis-like illness and/or aseptic meningitis. Two RT-nested PCR assays targeting a partial part of 5'UTR for direct diagnosis and the VP1 region for genotyping by sequence analysis of the viral genome were used.

RESULTS

HEV RNA was detected in 66 of 356 (18.5%) of CSF samples. Age distribution showed that 64% (42/66) were infants (<1 year), 18% were children between 1 and 5 years old, 12% were children between 5 and 10 years old, and 6% were more than 10 years old. Of the 66 EV cases, 12 were successfully genotyped. Five different EV genotypes were identified. All of them belonged to HEV-B species. The study showed that echovirus 6 genotype accounted for 42% of the sequenced cases. The HEV infections in the present study tended to show slight seasonal pattern with more cases occurring during spring and summer, yet still significant numbers were also reported in fall and winter seasons.

CONCLUSION

HEV was isolated from a significant number of children with sepsis-like illness and/or aseptic meningitis. In addition, the molecular method utilized for direct diagnosis and genotyping of HEV from CSF revealed that more than one HEV type circulated in the West Bank, Palestine during the study period.

Molecular characterization of a new human coxsackievirus B2 associated with severe hand-foot-mouth disease in Yunnan Province of China in 2012

Human coxsackievirus B2 (CVB2) belongs to the species Human enterovirus B and can cause aseptic meningitis, myocarditis and hand-foot-mouth disease (HFMD). We first determined the complete genome of the RW41-2/YN/CHN/2012 strain, isolated from a patient with HFMD and aseptic meningitis in the Yunnan Province, China in 2012. The strain shared 83.5 % and 82.2 % nucleotide similarity with CVB2 prototype strain Ohio-1, in the complete VP1 gene and the complete genome, respectively. Using phylogenetic and homogeneity analyses for the complete VP1 gene, CVB2 strains could be divided into four genogroups (A-D); the RW41-2/YN/CHN/2012 strain belonging to genogroup D. The amino acid sequence of VP1 is highly conserved. Recombination analyses showed the newly isolated RW41-2/YN/CHN/2012 strain was probably a recombinant, which was closely related to strain CVB2 (KM386639) in the genomic P1 and P2 regions and strains of other human enterovirus B (HEV-B) viruses (KT353721, JX644073, and KP262053) in the P3 region.

Molecular identification of human enteroviruses associated with aseptic meningitis in Yunnan province, Southwest China

Human enteroviruses (EVs) are the major causative agents of aseptic meningitis. In this study, a total of 524 children were admitted to the children Kunming hospital (continental China) for aseptic meningitis manifestations in 2009 and 2010. An EV infection was diagnosed in 85/524 children (16.2 %) and the viruses detected were assigned to 16 serotypes. Most serotypes belonged to the enterovirus B species. Echovirus 9 was predominant (24.7 %), followed by coxsackievirus B5 (23.5 %) and then echovirus 30 (16.5 %). Echovirus 9 was firstly identified as the predominant serotype in sporadic aseptic meningitis which occurred in Yunnan, Southwest China. This work indicates the need to perform large-scale surveillance to gain a better insight into the epidemiology of enteroviruses associated with aseptic meningitis in China.

One-year Survey of human enteroviruses from sewage and the factors affecting virus adsorption to the suspended solids

This study described the results of environmental enterovirus surveillance conducted in Shandong Province of China in 2013. Altogether 39 sewage samples were collected and 873 enterovirus isolates (including 334 polioviruses) belonging to 22 serotypes were obtained. Echovirus (E) -7, coxsackievirus (CV) -B5, E-11, E-6, and E-3 were the most commonly detected non-polio enterovirus serotypes, and phylogeny of E-7 and CV-B5 was described. The numbers of isolates of different serotypes from sewage supernatant were compared with those from the solids. Interestingly, dramatic divergence was observed between the supernatant and solids origin for the serotypes of E-3 and E-6, which were prone to the solids and supernatant, respectively. A following adsorption test with E-3 and E-6 added sewage specimens confirmed the different preference. Furthermore, the adsorption of Sabin poliovirus type 1 to the solids under different conditions was investigated, and the results showed that acid medium, cold temperature, and high solids concentration facilitated the viral adsorption to the solids, whereas change of virus titer did not influence the proportion of adsorption. These results highlighted the importance of combining the enterovirus isolates from the supernatant and solids together in environmental surveillance so as to better understand the local circulation of different serotypes.

EV-A71 vaccine licensure: a first step for multivalent enterovirus vaccine to control HFMD and other severe diseases

Enteroviruses (EVs) are the most common viral agents in humans. Although most infections are mild or asymptomatic, there is a wide spectrum of clinical manifestations that may be caused by EV infections with varying degrees of severity. Among these viruses, EV-A71 and coxsackievirus (CV) CV-A16 from group A EVs attract the most attention because they are responsible for hand, foot and mouth disease (HFMD). Other EV-A viruses such as CV-A6 and CV-A10 were also reported to cause HFMD outbreaks in several countries or regions. Group B EVs such as CV-B3, CV-B5 and echovirus 30 were reported to be the main pathogens responsible for myocarditis and encephalitis epidemics and were also detected in HFMD patients. Vaccines are the best tools to control infectious diseases. In December 2015, China's Food and Drug Administration approved two inactivated EV-A71 vaccines for preventing severe HFMD.The CV-A16 vaccine and the EV-A71-CV-A16 bivalent vaccine showed substantial efficacy against HFMD in pre-clinical animal models. Previously, research on EV-B group vaccines was mainly focused on CV-B3 vaccine development. Because the HFMD pathogen spectrum has changed, and the threat from EV-B virus-associated severe diseases has gradually increased, it is necessary to develop multivalent HFMD vaccines. This study summarizes the clinical symptoms of diseases caused by EVs, such as HFMD, myocarditis and encephalitis, and the related EV vaccine development progress. In conclusion, developing multivalent EV vaccines should be strongly recommended to prevent HFMD, myocarditis, encephalitis and other severe diseases.

Emergence of a Large-Plaque Variant in Mice Infected with Coxsackievirus B3

Coxsackieviruses are enteric viruses that frequently infect humans. To examine coxsackievirus pathogenesis, we orally inoculated mice with the coxsackievirus B3 (CVB3) Nancy strain. Using HeLa cell plaque assays with agar overlays, we noticed that some fecal viruses generated plaques >100 times as large as inoculum viruses. These large-plaque variants emerged following viral replication in several different tissues. We identified a single amino acid change, N63Y, in the VP3 capsid protein that was sufficient to confer the large-plaque phenotype. Wild-type CVB3 and N63Y mutant CVB3 had similar plaque sizes when agarose was used in the overlay instead of agar. We determined that sulfated glycans in agar inhibited plaque formation by wild-type CVB3 but not by N63Y mutant CVB3. Furthermore, N63Y mutant CVB3 bound heparin, a sulfated glycan, less efficiently than wild-type CVB3 did. While N63Y mutant CVB3 had a growth defect in cultured cells and reduced attachment, it had enhanced replication and pathogenesis in mice. Infection with N63Y mutant CVB3 induced more severe hepatic damage than infection with wild-type CVB3, likely because N63Y mutant CVB3 disseminates more efficiently to the liver. Our data reinforce the idea that culture-adapted laboratory virus strains can have reduced fitnessin vivo N63Y mutant CVB3 may be useful as a platform to understand viral adaptation and pathogenesis in animal studies.

IMPORTANCE

Coxsackieviruses frequently infect humans, and although many infections are mild or asymptomatic, there can be severe outcomes, including heart inflammation. Most studies with coxsackieviruses and other viruses use laboratory-adapted viral strains because of their efficient replication in cell culture. We used a cell culture-adapted strain of CVB3, Nancy, to examine viral replication and pathogenesis in orally inoculated mice. We found that mice shed viruses distinct from input viruses because they formed extremely large plaques in cell culture. We identified a single mutation, VP3 N63Y, that was sufficient for large-plaque formation. N63Y mutant viruses have reduced glycan binding and replication in cell culture; however, they have enhanced replication and virulence in mice. We are now using N63Y mutant CVB3 as an improved system for viral pathogenesis studies.

Environmental surveillance of human enteroviruses in Shandong Province, China, 2008 to 2012: serotypes, temporal fluctuation, and molecular epidemiology

Environmental surveillance is an effective approach in investigating the circulation of polioviruses (PVs) and other human enteroviruses (EVs) in the population. The present report describes the results of environmental surveillance conducted in Shandong Province, China, from 2008 to 2012. A total of 129 sewage samples were collected, and 168 PVs and 1,007 nonpolio enteroviruses (NPEVs) were isolated. VP1 sequencing and typing were performed on all isolates. All PV strains were Sabin-like, with the numbers of VP1 substitutions ranging from 0 to 7. The NPEVs belonged to 19 serotypes, and echovirus 6 (E6), E11, coxsackievirus B3 (CVB3), E3, E12, and E7 were the six main serotypes, which accounted for 18.3%, 14.8%, 14.5%, 12.9%, 9.0%, and 5.7% of NPEVs isolated, respectively. Typical summer-fall peaks of NPEV were observed in the monthly distribution of isolation, and an epidemic pattern of annual circulation was revealed for the common serotypes. Phylogenetic analysis was performed on environmental CVB3 and E3 strains with global reference strains and local strains from aseptic meningitis patients. Shandong strains formed distinct clusters, and a close relationship was observed between local environmental and clinical strains. As an EV-specific case surveillance system is absent in China and many other countries, continuous environmental surveillance should be encouraged to investigate the temporal circulation and phylogeny of EVs in the population.

Evaluation of a viral microarray based on simultaneous extraction and amplification of viral nucleotide acid for detecting human herpesviruses and enteroviruses

In this study, a viral microarray based assay was developed to detect the human herpesviruses and enteroviruses associated with central nervous system infections, including herpes simplex virus type 1, type 2 (HSV1 and HSV2), Epstein-Barr virus (EBV), cytomegalovirus (CMV), enterovirus 71 (EV71), coxsackievirus A 16 (CA16) and B 5(CB5). The DNA polymerase gene of human herpesviruses and 5’-untranslated region of enteroviruses were selected as the targets to design primers and probes. Human herpesviruses DNA and enteroviruses RNA were extracted simultaneously by using a guanidinium thiocyanate acid buffer, and were subsequently amplified through a biotinylated asymmetry multiplex RT-PCR with the specific primer of enteroviruses. In total, 90 blood samples and 49 cerebrospinal fluids samples with suspected systemic or neurological virus infections were investigated. Out of 139 samples, 66 were identified as positive. The specificities of this multiplex RT-PCR microarray assay were over 96% but the sensitivities were various from 100% for HSV1, HSV2, EV71 and CB5, 95.83% for CMV, 80% for EBV to 71.43% for CA16 in comparison with reference standards of TaqMan qPCR/qRT-PCR. The high Kappa values (&gt;0.90) from HSV1, HSV2, CMV, EV71 and CB5 were obtained, indicating almost perfect agreement in term of the 5 viruses detection. But lower Kappa values for EBV (0.63) and CA16 (0.74) displayed a moderate to substantial agreement. This study provides an innovation of simultaneous extraction, amplification, hybridization and detection of DNA viruses and RNA viruses with simplicity and specificity, and demonstrates a potential clinical utility for a variety of viruses’ detection.

Complete genome sequence analysis of two human coxsackievirus A9 strains isolated in Yunnan, China, in 2009

Human coxsackievirus A9 (CVA9) is a member of Enterovirus B species and may cause aseptic meningitis. The complete genome analyses of two strains CVA9 A242/YN/CHN/2009 and A108/YN/CHN/2009 isolated from aseptic meningitis cases in Yunnan Province, China, in 2009 were performed. These two strains shared 81.3 and 80.7, 81.0 and 81.1 % nucleotide similarity with prototype strain Griggs in the VP1-encoding sequence and the complete genome sequence, respectively. Through phylogenetic analysis and homogeneity analysis for twenty-eight VP1-encoding sequences, CVA9 strains could be divided into four genotypes and the Chinese strains might belong to genotype D. Similarity plot and bootscanning analyses showed evidence of recombination with other EVB viruses. In conclusion, persistent surveillance of circulating enterovirus might help understand the enterovirus evolution.

An outbreak of aseptic meningitis caused by a distinct lineage of coxsackievirus B5 in China

In 2009, an outbreak of aseptic meningitis caused by coxsackievirus B5 (CVB5) occurred in China. Epidemiological investigations of this outbreak revealed that the proportion of severe cases (14/43, 33%) was higher than in other outbreaks associated with CVB5 in China. Phylogenetic analysis of the entire VP1 sequences demonstrated that the CVB5 isolates from the severe cases form a distinct lineage belonging to genogroup E with the Shandong isolates of 2009. A substitution of serine (S) to asparagine (N) at amino acid 95 in the VP1 region may be a major virulence determinant for the virus. Our findings suggest that this new lineage of CVB5 is circulating in China. Further genetic studies are needed in order to gain a better insight into the genetic variability of CVB5 isolates and the relationship with pathogenicity.

New coxsackievirus B4 genotype circulating in Inner Mongolia Autonomous Region, China

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.

Molecular epidemiology of human enterovirus associated with aseptic meningitis in Shandong Province, China, 2006-2012

Background

Human enteroviruses (HEVs) are common causes of acute meningitis. However, there is limited information about HEV associated with aseptic meningitis in mainland China because it has not been classified as a notifiable disease.

Objectives

To characterize the HEVs associated with sporadic aseptic meningitis in China and to analyze their genetic features.

Study Design

Cerebrospinal fluid, throat swab and feces specimens were collected from patients with aseptic meningitis in 5 sentinel hospitals in Shandong Province, China between 2006 and 2012. Virological investigation (viral isolation and molecular identification) and phylogenetic analysis were performed.

Results

A total of 437 hospitalized patients were reported, and enteroviruses were detected in the specimens from 84 patients (19.2%) and were identified into 17 serotypes. The nine main serotypes were echovirus (E) 30 (27.4%), EV71 (13.1%), coxsackievirus (CV) B1 (9.5%), CVB3 (7.1%), CVB5 (7.1%), E6 (7.1%), E9 (7.1%), CVA9 (6.0%), and CVA10 (3.6%). Monthly distribution of isolated enteroviruses revealed a major peak in summer-fall season and a small second peak in winter constituted totally by EV71. Sequence analysis on VP1 coding region suggested Shandong strains had great genetic divergence with isolates from other countries.

Conclusions

Multiple serotypes were responsible for enterovirus meningitis in mainland China. Aseptic meningitis caused by EV71 and coxsackie A viruses–the predominant pathogens for the hand, foot, and mouth disease–is currently an important concern in mainland China.

Isolation and characterization of a type 2 vaccine-derived poliovirus from environmental surveillance in China, 2012

Environmental surveillance of poliovirus on sewage has been conducted in Shandong Province, China since 2008. A type 2 vaccine-derived poliovirus (VDPV) with 7 mutations in VP1 coding region was isolated from the sewage collected in the city of Jinan in December 2012. The complete genome sequencing analysis of this isolate revealed 25 nucleotide substitutions, 7 of which resulted in amino acid alteration. No evidence of recombination with other poliovirus serotypes was observed. The virus did not lose temperature sensitive phenotype at 40°C. An estimation based on the evolution rate of the P1 coding region suggested that evolution time of this strain might be 160–176 days. VP1 sequence analysis revealed that this VDPV strain is of no close relationship with other local type 2 polioviruses (n = 66) from sewage collected between May 2012 and June 2013, suggesting the lack of its circulation in the local population. The person who excreted the virus was not known and no closely related virus was isolated in local population via acute flaccid paralysis surveillance. By far this is the first report of VDPV isolated from sewage in China, and these results underscore the value of environmental surveillance in the polio surveillance system even in countries with high rates of OPV coverage.

Prevalence of nonpolio enteroviruses in the sewage of Guangzhou city, China, from 2009 to 2012

The human-pathogenic viruses in urban sewage have been extensively monitored to obtain information on circulating viruses in human communities. Enteroviruses (EVs) excreted by patients who present with diverse clinical syndromes can remain infectious in the environment for several weeks, and limited data on circulating environmental EVs are available. A 4-year (2009 to 2012) surveillance study was conducted to detect nonpolio enteroviruses (NPEVs) in the urban sewage of Guangzhou city, China. After the viruses in the sewage samples were concentrated and isolated, molecular identification was used to detect and type the NPEVs. During the 4-year study, 17 different NPEV serotypes were identified in the sewage of Guangzhou city. The most common serotypes were echovirus 11 (ECHO11), ECHO6, ECHO7, and ECHO12 and coxsackie group B viruses 5 (CVB5) and CVB3. The predominant serotypes were influenced by spatial and temporal factors and differed each year. CVB5 was commonly detected in 2009 and 2010 but was rarely isolated in 2011 and 2012. In contrast, CVB3 was not observed in 2009 and 2010 but was increasingly detected in 2011 and 2012. Our study provides an overview of the serotype distribution and circulation patterns of NPEVs in the sewage of Guangzhou, China. In the absence of a systematic EV disease surveillance system, the detection and characterization of sewage-borne NPEVs will help us better understand the changes in EV disease trends and the epidemic background of circulating EVs, which could help interpret the EV trends and warn of future outbreaks in this area.