[Epidemiological and etiological characteristics of herpes pharyngitis in 3 prefectures in Jiangsu Province].

Objective: To analyze the epidemiological and etiological characteristics of herpes pharyngitis (HA) in three prefectures of Jiangsu Province, and provide evidence for the prevention and control of HA in Jiangsu. Methods: Three surveillance sentinel hospitals in Wuxi, Suzhou and Yancheng were selected from May 2018 to December 2022, and information related to HA visits and hospitalized cases was regularly collected from the hospital inpatient management system by age groups. Enterovirus nucleic acid detection was performed by RT-PCR, and sequencing analysis, identification of genotype subtypes, and phylogenetic analysis were performed on the sequences of the gene encoding the coat protein VP1 of the main prevalent strains. Results: A total of 57 709 HA cases were recorded in the sentinel hospitals in in Wuxi, Suzhou and Yancheng, which was 1.76 times higher than the reported cases of hand, foot and mouth disease during the same period (57 709/32 831).The percentage of HA hospitalizations was 1.35% (781/57 709), and the percentage of hospitalizations showed an increasing trend from year to year (χ2=62.79, P<0.001 ).The incidence peak of HA was during May-July. The cases were mainly children aged 12-59 months (67.07%, 38 708/57 709), with the highest case number in age group 36-59 months (34.40%, 19 852/57 709). The HA positivity rate was 33.82% (644/1 904); enterovirus A was predominant (54.04%, 348/644); of these, Coxsackievirus (CV)A6 accounted for the highest percentage (52.59%, 183/348), while CVA16 and CVA4 accounted for 24.71% (86/348) and 15.23% (53/348), respectively. All 10 CVA4 HA endemic strains belonged to the C2 gene subtype, and all 6 CVA6 HA endemic strains belonged to the D3a gene subtype; and were genetically closer to and related to the strains in some areas of China (Fujian Province, Guangzhou City, Jiangxi Province, Yunnan Province, Tianjin City, etc.). Conclusions: The disease burden of HA was heavy in 3 areas in Jiangsu, children in age group 12-59-month were mainly affected, and the annual incidence peak of HA was during May-July. The pathogens causing HA varied, but predominated by enterovirus A and had low intra-typical differentiation, and no new evolutionary branches were found, suggesting that it is necessary to include HA in foot and mouth disease surveillance or regarded as a notifiable communicable disease.

Molecular epidemiology of enteroviruses from Guatemalan wastewater isolated from human lung fibroblasts.

The Global Specialized Polio Laboratory at CDC supports the Global Poliovirus Laboratory Network with environmental surveillance (ES) to detect the presence of vaccine strain polioviruses, vaccine-derived polioviruses, and wild polioviruses in high-risk countries. Environmental sampling provides valuable supplementary information, particularly in areas with gaps in surveillance of acute flaccid paralysis (AFP) mainly in children less than 15 years. In collaboration with Guatemala's National Health Laboratory (Laboratorio Nacional de Salud Guatemala), monthly sewage collections allowed screening enterovirus (EV) presence without incurring additional costs for sample collection, transport, or concentration. Murine recombinant fibroblast L-cells (L20B) and human rhabdomyosarcoma (RD) cells are used for the isolation of polioviruses following a standard detection algorithm. Though non-polio-Enteroviruses (NPEV) can be isolated, the algorithm is optimized for the detection of polioviruses. To explore if other EV's are present in sewage not found through standard methods, five additional cell lines were piloted in a small-scale experiment, and next-generation sequencing (NGS) was used for the identification of any EV types. Human lung fibroblast cells (HLF) were selected based on their ability to isolate EV-A genus. Sewage concentrates collected between 2020-2021 were isolated in HLF cells and any cytopathic effect positive isolates used for NGS. A large variety of EVs, including echoviruses 1, 3, 6, 7, 11, 13, 18, 19, 25, 29; coxsackievirus A13, B2, and B5, EV-C99, EVB, and polioviruses (Sabin 1 and 3) were identified through genomic typing in NGS. When the EV genotypes were compared by phylogenetic analysis, it showed many EV's were genomically like viruses previously isolated from ES collected in Haiti. Enterovirus occurrence did not follow a seasonality, but more diverse EV types were found in ES collection sites with lower populations. Using the additional cell line in the existing poliovirus ES algorithm may add value by providing data about EV circulation, without additional sample collection or processing. Next-generation sequencing closed gaps in knowledge providing molecular epidemiological information on multiple EV types and full genome sequences of EVs present in wastewater in Guatemala.

Enteroviruses: epidemic potential, challenges and opportunities with vaccines.

Enteroviruses (EVs) are the most prevalent viruses in humans. EVs can cause a range of acute symptoms, from mild common colds to severe systemic infections such as meningitis, myocarditis, and flaccid paralysis. They can also lead to chronic diseases such as cardiomyopathy. Although more than 280 human EV serotypes exist, only four serotypes have licenced vaccines. No antiviral drugs are available to treat EV infections, and global surveillance of EVs has not been effectively coordinated. Therefore, poliovirus still circulates, and there have been alarming epidemics of non-polio enteroviruses. Thus, there is a pressing need for coordinated preparedness efforts against EVs.This review provides a perspective on recent enterovirus outbreaks and global poliovirus eradication efforts with continuous vaccine development initiatives. It also provides insights into the challenges and opportunities in EV vaccine development. Given that traditional whole-virus vaccine technologies are not suitable for many clinically relevant EVs and considering the ongoing risk of enterovirus outbreaks and the potential for new emerging pathogenic strains, the need for new effective and adaptable enterovirus vaccines is emphasized.This review also explores the difficulties in translating promising vaccine candidates for clinical use and summarizes information from published literature and clinical trial databases focusing on existing enterovirus vaccines, ongoing clinical trials, the obstacles faced in vaccine development as well as the emergence of new vaccine technologies. Overall, this review contributes to the understanding of enterovirus vaccines, their role in public health, and their significance as a tool for future preparedness.

Unveiling of the Co-Infection of Peste des Petits Ruminants Virus and Caprine Enterovirus in Goat Herds with Severe Diarrhea in China.

Here, we report the discovery of two viruses associated with a disease characterized by severe diarrhea on a large-scale goat farm in Jilin province. Electron Microscopy observations revealed two kinds of virus particles with the sizes of 150-210 nm and 20-30 nm, respectively. Detection of 276 fecal specimens from the diseased herds showed the extensive infection of peste des petits ruminants virus (63.77%, 176/276) and caprine enterovirus (76.81%, 212/276), with a co-infection rate of 57.97% (160/276). These results were partially validated with RT-PCR, where all five PPRV-positive and CEV-positive specimens yielded the expected size of fragments, respectively, while no fragments were amplified from PPRV-negative and CEV-negative specimens. Moreover, corresponding PPRV and CEV fragments were amplified in PPRV and CEV double-positive specimens. Histopathological examinations revealed severe microscopic lesions such as degeneration, necrosis, and detachment of epithelial cells in the bronchioles and intestine. An immunohistochemistry assay detected PPRV antigens in bronchioles, cartilage tissue, intestine, and lymph nodes. Simultaneously, caprine enterovirus antigens were detected in lung, kidney, and intestinal tissues from the goats infected by the peste des petits ruminants virus. These results demonstrated the co-infection of peste des petits ruminants virus with caprine enterovirus in goats, revealing the tissue tropism for these two viruses, thus laying a basis for the future diagnosis, prevention, and epidemiological survey for these two virus infections.

Characterization of enteroviruses circulating among farm animals and children in Central African Republic.

To characterize enteroviruses (EVs) circulating in farm animals in Central African Republic (CAR), we screened 192 stools of animals under 12 months belonging to family farms located in or near Bangui. To assess whether EV exchanges exist between these animals and humans, we also screened 195 stools of children who lived in contact with farm animals, as well as control stools of 358 children with no contact with farm animals. EVs were typed based on their capsid sequences.In children, all EVs belonged to species A, B and C, with EV-Cs accounting for 60%. Some EV-Cs shared recent common ancestors with lineages of vaccine-derived poliovirus that emerged in the country in 2019-2020. In animals, we identified EV-Gs that belonged to 10 different types, including a previously unknown one that we named EV-G28, while no EV-E or EV-F were observed. The CAR EV-Gs were genetically closely related to specimens sampled in other continents and some of them harboured the torovirus-derived insertion already reported in some EV-Gs. The worldwide circulation of EV-Gs is likely due the massive international trade of live animals. Besides, two human EV-Cs (coxsackievirus A17 and coxsackievirus A24) were detected in pigs, suggesting that these viruses could cross the species barrier. Our work provides original data on the epidemiology and ecology of EVs circulating among herd animals in Africa.

Genomic epidemiology of CVA10 in Guangdong, China, 2013-2021.

Hand, Foot and Mouth Disease (HFMD) is a highly contagious viral illness primarily affecting children globally. A significant epidemiological transition has been noted in mainland China, characterized by a substantial increase in HFMD cases caused by non-Enterovirus A71 (EV-A71) and non-Coxsackievirus A16 (CVA16) enteroviruses (EVs). Our study conducts a retrospective examination of 36,461 EV-positive specimens collected from Guangdong, China, from 2013 to 2021. Epidemiological trends suggest that, following 2013, Coxsackievirus A6 (CVA6) and Coxsackievirus A10 (CVA10) have emerged as the primary etiological agents for HFMD. In stark contrast, the incidence of EV-A71 has sharply declined, nearing extinction after 2018. Notably, cases of CVA10 infection were considerably younger, with a median age of 1.8 years, compared to 2.3 years for those with EV-A71 infections, possibly indicating accumulated EV-A71-specific herd immunity among young children. Through extensive genomic sequencing and analysis, we identified the N136D mutation in the 2 A protein, contributing to a predominant subcluster within genogroup C of CVA10 circulating in Guangdong since 2017. Additionally, a high frequency of recombination events was observed in genogroup F of CVA10, suggesting that the prevalence of this lineage might be underrecognized. The dynamic landscape of EV genotypes, along with their potential to cause outbreaks, underscores the need to broaden surveillance efforts to include a more diverse spectrum of EV genotypes. Moreover, given the shifting dominance of EV genotypes, it may be prudent to re-evaluate and optimize existing vaccination strategies, which are currently focused primarily target EV-A71.

Analysis of mild and severe neonatal enterovirus infections in a Chinese neonatal tertiary center: a retrospective case-control study.

PURPOSE: To compare the clinical characteristics, virus serotype, and outcome in cases of mild and severe enteroviral infection at a tertiary neonatal intensive care unit in China. METHODS: A retrospective analysis of cases hospitalized between June and August 2019. Samples (stool or throat swabs) were examined using reverse transcription polymerase chain reaction. Positive cases were divided into two groups: mild infection and severe infection. RESULTS: A total of 149 cases were assigned to one of two groups: mild infection (n = 104) and severe infection (n = 45). There were no significant differences between the groups in terms of sex, gestational age, birth weight, mode of delivery, and onset within 7 days. Clinical symptoms in both groups mostly resembled sepsis (fever, rash, poor feeding, and lethargy); however, there were significant variations in concomitant symptoms such as hepatitis, thrombocytopenia, encephalitis, coagulopathy, and myocarditis. Severe cases were more likely to have abnormal complete blood counts, biochemical parameters, and cerebrospinal fluid markers. The predominant serotypes implicated in neonatal enterovirus infections were echoviruses and Coxsackievirus B. Invasive ventilation, intravenous immunoglobulin, vasoactive medications, and blood product transfusions were often required, with high mortality rates among severe cases. CONCLUSION: We found significant differences between mild and severe cases of neonatal enterovirus infection with respect to complications, laboratory findings, and enterovirus serotypes. It is crucial to exercise caution when newborns exhibit symptoms of sepsis, during an enterovirus outbreak. Anemia, thrombocytopenia, abnormal liver function, and coagulation dysfunction should be monitored closely as they could indicate the presence of a severe enteroviral infection.

Environmental surveillance reveals co-circulation of distinctive lineages of enteroviruses in southwest China's border cities, 2020-2022.

AIMS: Enteroviruses are significant human pathogens associated with a range of mild to severe diseases. This study aims to understand the diversity and genetic characterization of enteroviruses circulated in southwest China's border cities by using environmental surveillance. METHODS AND RESULTS: A total of 96 sewage samples were collected in three border cities and a port located in Yunnan Province, China from July 2020 to June 2022. After cell culture and VP1 sequencing, a total of 590 enterovirus isolates were identified, belonging to 21 types. All PV strains were Sabin-like with ≤6 nucleotide mutations in the VP1 coding region. Echovirus 6, echovirus 21 (a rare serotype in previous studies), and coxsackievirus B5 were the predominant serotypes, which accounted for 21.19%, 18.31%, and 13.39% of the total isolates, respectively. The prevalence of the common serotypes varied across different border cities and periods. Phylogenetic analysis revealed the presence of multiple evolutionary lineages for E21, E6, and E30, some of which formed distinct branches. CONCLUSIONS: High diversity of enteroviruses and distinct lineages of predominant serotypes circulated in southwest China's border cities.

[Progress in research of rash and fever syndrome surveillance and early warning].

Objective: To introduce the progress in research of rash and fever syndrome (RFS) surveillance and early warning both at home and abroad, and provide reference for surveillance and prevention of RFS in China. Methods: The keywords "fever" "rash" and "surveillance" and others were used for a literature retrieval by using China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, PubMed and Web of Science. The languages of literatures were limited in Chinese and English. The key information of the literatures were collected and analyzed with Excel. Results: A total of 36 study papers (21 in Chinese and 15 in English) were included. The studies mainly focused on the pathogen surveillance of RFS (n=19). The pathogens included measles virus, varicella-zoster virus, rubella virus, enterovirus, human B19 virus, dengue virus, streptococcus group A, Salmonella typhi and Salmonella paratyphoid,human herpesvirus, mumps virus and adenovirus. Eight studies were about the surveillance in major events, such as sport game, World Expo and religious gathering, or sudden natural disasters, such as earthquake and tropical storm, during 2010-2015. Eight studies focused on case or epidemic surveillance, most of which were studies from other counties. The surveillance sites were medical institutions. RFS was diagnosed according to the International Classification of Diseases, 9th (ICD-9) and symptoms descripted in chief-complaint. Only one study in Mongolia conducted RFS epidemic prediction. The analysis methods of 36 papers included simple descriptive analysis, time-based early warning models (such as regression analysis, fixed threshold method, Hugh Hart control chart method and cumulative sum control chart method) and time series analysis method. Conclusions: In the future, RFS surveillance system should cover both known pathogens and emerging pathogens. Automatic surveillance using information capture and intelligent modelling can be applied to improve the sensitivity and specificity of RFS surveillance and early warning.

Identification and genetic characterization of a recently identified enterovirus C116 in China.

Enterovirus C116 (EV-C116) is a new member of the enterovirus C group which is closely associated with several infectious diseases. Although sporadic studies have detected EV-C116 in clinical samples worldwide, there is currently limited information available. In this study, two EV-C-positive fecal specimens were detected in apparently healthy children, which harbored low abundance, through meta-transcriptome sequencing. Based on the prototypes of several EV-Cs, two lineages were observed. Lineage 1 included many types that could not cause EV-like cytopathic effect in cell culture. Three genogroups of EV-C116 were divided in the maximum likelihood tree, and the two strains in this study (XZ2 and XZ113) formed two different lineages, suggesting that EV-C116 still diffuses worldwide. Obvious inter-type recombination events were observed in the XZ2 strain, with CVA22 identified as a minor donor. However, another strain (XZ113) underwent different recombination situations, highlighting the importance of recombination in the formation of EV-Cs biodiversity. The EV-C116 strains could propagate in rhabdomyosarcoma cell cultures at low titer; however, EV-like cytopathic effects were not observed. HEp-2, L20B, VERO, and 293T cell lines did not provide an appropriate environment for EV-C116 growth. These results challenge the traditional recognition of the uncultured nature of EV-C116 strains and explain the difficulty of clinical detection.

Occurrence of poliovirus and non-polio enterovirus among children with acute flaccid paralysis in Cameroon from 2015 to 2020.

INTRODUCTION: Poliovirus (PV) and non-polio enteroviruses (NPEV) belong to the Picornaviridae family. They are found worldwide and are responsible for a wide range of diseases such as acute flaccid paralysis (AFP). This study aimed to evaluate the detection rate of PV and NPEV in stool samples from children under fifteen years of age presenting with AFP in Cameroon and their distribution over time. METHODOLOGY: Stool samples were collected as part of poliovirus surveillance throughout Cameroon from 2015 to 2020. Virus isolation was performed using RD and L20B cells maintained in culture. Molecular methods such as intratypic differentiation were used to identify PVs serotypes and analysis of the VP1 genome was performed. RESULTS: A total of 12,354 stool samples were analyzed. The EV detection rate by virus isolation was 11.42% (1411/12354). This rate varied from year to year with a mean distribution of 11.41 with a 95% confidence interval [11.37; 11.44]. Of the viruses detected, suspected poliovirus accounted for 31.3% (442/1411) and NPEV 68.67% (969/1411). No wild poliovirus (WPV) was isolated. Sabin types 1 and 3 were continuously isolated. Surprisingly, from February 2020, vaccine-derived PV type 2 (VDPV2) was detected in 19% of cases, indicating its resurgence. CONCLUSIONS: This study strongly supports the successful elimination of WPV in Cameroon and the resurgence of VDPV2. However, as long as VDPV outbreaks continue to be detected in Africa, it remains essential to monitor how they spread.

Investigation of the Correlation between Enterovirus Infection and the Climate Factor Complex Including the Ping-Year Factor and El Niño-Southern Oscillation in Taiwan.

Enterovirus infection and enterovirus infection with severe complications (EVSC) are critical issues in several aspects. However, there is no suitable predictive tool for these infections. A climate factor complex (CFC) containing several climate factors could provide more effective predictions. The ping-year factor (PYF) and El Niño-Southern Oscillation (ENSO) are possible CFCs. This study aimed to determine the relationship between these two CFCs and the incidence of enterovirus infection. Children aged 15 years and younger with enterovirus infection and/or EVSC were enrolled between 2007 and 2022. Each year was categorized into a ping-year or non-ping-year according to the PYF. Poisson regression was used to evaluate the associations between the PYF, ENSO, and the incidence of enterovirus infection. Compared to the ping-year group, the incidence rate of enterovirus infection, the incidence rate of EVSC, and the ratio of EVSC in the non-ping-year group were 1.24, 3.38, and 2.73 times higher, respectively (p < 0.001). For every one-unit increase in La Niña, the incidence rate of enterovirus infection decreased to 0.96 times (p < 0.001). Our study indicated that CFCs could be potential predictors for enterovirus infection, and the PYF was more suitable than ENSO. Further research is needed to improve the predictive model.

Emergence and circulation of enterovirus B species in infants in southern China: A multicenter retrospective analysis.

BACKGROUND: Enteroviruses (EV) are common and can cause severe diseases, particularly in young children. However, the information of EV infection in infants in China is limited due to the vast population size and extensive geographical area of the country. Here, we conducted a retrospective multicenter analysis of available EV data to assess the current epidemiological situation in the infant population in southern China. METHODS: The study enrolled infants with suspected EV infection from 34 hospitals across 12 cities in southern China between 2019 to 2022, and the confirmation of EV was done using RT-PCR and VP1 gene sequencing. RESULTS: Out of 1221 infants enrolled, 330 (27.03%) were confirmed as EV-infected. Of these, 260 (78.79%) were newborns aged 0-28 days. The EV belonged to three species: EV-B (80.61%), EV-A (11.82%), and human rhinovirus (7.58%). Newborns were more susceptible to EV-B than older infants (p < 0.001). Within EV-B, we identified 15 types, with coxsackievirus (CV) B3 (20.91%), echovirus (E) 11 (19.70%), and E18 (16.97%) being the most common. The predominant EV types changed across different years. EV infection in infants followed a seasonal pattern, with a higher incidence from May to August. Furthermore, perinatal mother-to-child EV transmission in 12 mother-newborn pairs were observed. CONCLUSION: Our study is the first to demonstrate the emergence and widespread circulation of EV-B species, mainly CVB3, E11, and E18, in southern China, primarily affecting young infants. This research provides valuable insights for future epidemic assessment, prediction, as well as the elimination of mother-to-child transmission.

Clinical course and peculiarities of Parechovirus and Enterovirus central nervous system infections in newborns: a single-center experience.

Parechovirus (HpEV) and Enterovirus (EV) infections in children mostly have a mild course but are particularly fearsome in newborns in whom they may cause aseptic meningitis, encephalitis, and myocarditis. Our study aimed to describe the clinical presentations and peculiarities of CNS infection by HpEV and EV in neonates. This is a single-center retrospective study at Istituto Gaslini, Genoa, Italy. Infants aged ≤ 30 days with a CSF RTq-PCR positive for EV or HpEV from January 1, 2022, to December 1, 2023, were enrolled. Each patient's record included demographic data, blood and CSF tests, brain MRI, therapies, length of stay, ICU admission, complications, and mortality. The two groups were compared to identify any differences and similarities. Twenty-five patients (15 EV and 10 HpEV) with a median age of 15 days were included. EV patients had a more frequent history of prematurity/neonatal respiratory distress syndrome (p = 0.021), more respiratory symptoms on admission (p = 0.012), and higher C-reactive protein (CRP) levels (p = 0.027), whereas ferritin values were significantly increased in HpEV patients (p = 0.001). Eight patients had a pathological brain MRI, equally distributed between the two groups. Three EV patients developed myocarditis and one HpEV necrotizing enterocolitis with HLH-like. No deaths occurred.  Conclusion: EV and HpEV CNS infections are not easily distinguishable by clinical features. In both cases, brain MRI abnormalities are not uncommon, and a severe course of the disease is possible. Hyper-ferritinemia may represent an additional diagnostic clue for HpEV infection, and its monitoring is recommended to intercept HLH early and initiate immunomodulatory treatment. Larger studies are needed to confirm our findings. What is Known: • Parechovirus and Enteroviruses are the most common viral pathogens responsible for sepsis and meningoencephalitis in neonates and young infants. • The clinical course and distinguishing features of Parechovirus and Enterovirus central nervous system infections are not well described. What is New: • Severe disease course, brain MRI abnormalities, and complications are not uncommon in newborns with Parechovirus and Enteroviruses central nervous system infections. • Hyper-ferritinemia may represent an additional diagnostic clue for Parechovirus infection and its monitoring is recommended.

Recent Advances on Selenium Nutrition and Keshan Disease.

Keshan disease (KD) is a type of endemic cardiomyopathy with an unknown cause. It is primarily found in areas in China with low selenium levels, from northeast to southwest. The nutritional biogeochemical etiology hypothesis suggests that selenium deficiency is a major factor in KD development. Selenium is important in removing free radicals and protecting cells and tissues from peroxide-induced damage. Thus, low environmental selenium may affect the selenium level within the human body, and selenium level differences are commonly observed between healthy people in KD and nonKD areas. From the 1970s to the 1990s, China successfully reduced KD incidence in endemic KD areas through a selenium supplementation program. After years of implementing prevention and control measures, the selenium level of the population in the KD areas has gradually increased, and the prevalence of KD in China has remained low and stable in recent years. Currently, the pathogenesis of KD remains vague, and the effect of selenium supplementation on the prognosis of KD still needs further study. This paper comprehensively reviews selenium deficiency and its connection to KD. Thus, this study aims to offer novel ideas and directions to effectively prevent and treat KD in light of the current situation.

Surveillance for Acute Flaccid Myelitis - United States, 2018-2022.

Acute flaccid myelitis (AFM) is a serious neurologic condition primarily affecting children; AFM can cause acute respiratory failure and permanent paralysis. AFM is a rare but known complication of various viral infections, particularly those of enteroviruses (EVs). Increases in AFM cases during 2014, 2016, and 2018 were associated with EV-D68 infection. This report examines trends in confirmed AFM cases during 2018-2022 and patients' clinical and laboratory characteristics. The number of AFM cases was low during 2019-2022 (28-47 cases per year); the number of cases remained low in 2022 despite evidence of increased EV-D68 circulation in the United States. Compared with cases during the most recent peak year (2018), fewer cases during 2019-2021 had upper limb involvement, prodromal respiratory or febrile illness, or cerebrospinal fluid pleocytosis, and more were associated with lower limb involvement. It is unclear why EV-D68 circulation in 2022 was not associated with an increase in AFM cases or when the next increase in AFM cases will occur. Nonetheless, clinicians should continue to suspect AFM in any child with acute flaccid limb weakness, especially those with a recent respiratory or febrile illness.

Genetic diversity and recombination of bovine enterovirus strains in China.

Bovine enterovirus (BEV) consisting of enterovirus species E (EV-E) and F (EV-F) is the causative agent associated with respiratory and gastrointestinal diseases in cattle. Here, we reported the characterization, genetic diversity, and recombination of novel BEV strains isolated from the major cattle-raising regions in China during 2012-2018. Twenty-seven BEV strains were successfully isolated and characterized. Molecular characterization demonstrated that the majority of these novel BEV strains (24/27) were EV-E, while only few strains (3/27) were EV-F. Sequence analysis revealed the diversity of the circulating BEV strains such as species and subtypes where different species or subtype coinfections were detected in the same regions and even in the same cattle herds. For the EV-E, two novel subtypes, designated as EV-E6 and EV-E7, were revealed in addition to the currently reported EV-E1-EV-E5. Comparative genomic analysis revealed the intraspecies and interspecies genetic exchanges among BEV isolates. The representative strain HeN-B62 was probably from AN12 (EV-F7) and PS-87-Belfast (EV-F3) strains. The interspecies recombination between EV-E and EV-F was also discovered, where the EV-F7-AN12 might be from EV-E5 and EV-F1, and EV-E5-MexKSU/5 may be recombined from EV-F7 and EV-E1. The aforementioned results revealed the genetic diversity and recombination of novel BEV strains and unveiled the different BEV species or subtype infections in the same cattle herd, which will broaden the understanding of enterovirus genetic diversity, recombination, pathogenesis, and prevention of disease outbreaks. IMPORTANCE: Bovine enterovirus (BEV) infection is an emerging disease in China that is characterized by digestive, respiratory, and reproductive disorders. In this study, we first reported two novel EV-E subtypes detected in cattle herds in China, unveiled the coinfection of two enterovirus species (EV-E/EV-F) and different subtypes (EV-E2/EV-E7, EV-E1/EV-E7, and EV-E3/EV-E6) in the same cattle herds, and revealed the enterovirus genetic exchange in intraspecies and interspecies recombination. These results provide an important update of enterovirus prevalence and epidemiological aspects and contribute to a better understanding of enterovirus genetic diversity, evolution, and pathogenesis.

Respiratory viral detection in the plasma and cerebrospinal fluid (CSF) of young febrile infants.

Background: Respiratory viral infections are common in febrile infants ≤90 days. However, the detection of viruses other than enterovirus in the blood and cerebrospinal fluid (CSF) of young infants is not well defined. We sought to quantify the occurrence of respiratory viruses in the blood and CSF of febrile infants ≤90 days. Methods: We conducted a nested cohort study examining plasma and CSF samples from febrile infants 15-90 days via rtPCR. The samples were tested for respiratory viruses (respiratory syncytial virus, influenza, enterovirus, parechovirus, adenovirus, bocavirus). Clinical and laboratory data were also collected to determine the presence of serious bacterial infections (SBI). Results: Twenty-four percent (30 of 126) of infants had plasma/CSF specimens positive for a respiratory virus. Enterovirus and parechovirus were the most commonly detected respiratory viruses. Viral positivity was highest in plasma samples at 25% (27 of 107) compared with CSF samples at 15% (nine of 62). SBIs (specifically urinary tract infections) were less common in infants with a sample positive for a respiratory virus compared to those without a virus detected (3% vs. 26%, p = 0.008). Conclusions: Our findings support the use of molecular diagnostics to include the identification of parechovirus in addition to enterovirus in febrile infants ≤90 days. Additionally, these data support the utilization of blood specimens to diagnose enterovirus and parechovirus infections in febrile infants ≤90 days.

Genetic characterization and molecular epidemiological analysis of enterovirus C99 in China.

Enterovirus C99 (EV-C99) is a newly identified EV serotype within the species Enterovirus C. Few studies on EV-C99 have been conducted globally. More information and research on EV-C99 are needed to assess its genetic characteristics, phylogenetic relationships, and associations with enteroviral diseases. Here, the phylogenetic characteristics of 11 Chinese EV-C99 strains have been reported. The full-length genomic sequences of these 11 strains show 79.4-80.5% nucleotide identity and 91.7-94.3% amino acid (aa) identity with the prototype EV-C99. A maximum likelihood phylogenetic tree constructed based on the entire VP1 coding region identified 13 genotypes (A-M), revealing a high degree of variation among the EV-C99 strains. Phylogeographic analysis showed that the Xinjiang Uygur Autonomous Region is an important source of EV-C99 epidemics in various regions of China. Recombination analysis revealed inter-serotype recombination events of 16 Chinese EV-C99 strains in 5' untranslated regions and 3D regions, resulting in the formation of a single recombination form. Additionally, the Chinese strain of genotype J showed rich aa diversity in the P1 region, indicating that the genotype J of EV-C99 is still going through variable dynamic changes. This study contributes to the global understanding of the EV-C99 genome sequence and holds substantial implications for the surveillance of EV-C99.

Incongruence between confirmed and suspected clinical cases of Japanese encephalitis virus infection.

Background: Japanese encephalitis (JE) is a notifiable infectious disease in China. Information on every case of JE is reported to the superior health administration department. However, reported cases include both laboratory-confirmed and clinically diagnosed cases. This study aimed to differentiate between clinical and laboratory-confirmed cases of Japanese encephalitis virus (JEV) infection, and improve the accuracy of reported JE cases by analyzing the acute-phase serum and cerebrospinal fluid of all reported JE cases in the Sichuan province from 2012 to 2022. Methods: All acute-phase serum and/or cerebrospinal fluid samples of the reported JE cases were screened for IgM(ImmunoglobulinM)to JEV using the enzyme-linked immunosorbent assay (ELISA), and the detection of the viral genes of JEV and 9 other pathogens including enterovirus (EV), using reverse transcription PCR was attempted. Epidemiological analyses of JE and non-JE cases based on sex, age, onset time, and geographical distribution were also performed. Results: From 2012 to 2022, 1558 JE cases were reported in the Sichuan province. The results of serological (JEV-specific IgM) and genetic testing for JEV showed that 81% (1262/1558) of the reported cases were confirmed as JEV infection cases (laboratory-confirmed cases). Among the 296 cases of non-JEV infection, 6 viruses were detected in the cerebrospinal fluid in 62 cases, including EV and the Epstein-Barr virus (EBV), constituting 21% (62/296) of all non-JE cases. Among the 62 non-JEV infection cases with confirmed pathogens, infections with EV and EBV included 17 cases each, herpes simplex virus (HSV-1/2) included 14 cases, varicella- zoster virus included 6 cases, mumps virus included 2 cases, and human herpes viruses-6 included 1 case. Additionally, there were five cases involving mixed infections (two cases of EV/EBV, one case of HSV-1/HSV-2, one case of EBV/HSV-1, and one case of EV/herpes viruses-6). The remaining 234 cases were classified as unknown viral encephalitis cases. Our analysis indicated that those aged 0-15 y were the majority of the patients among the 1558 reported JE cases. However, the incidence of laboratory-confirmed JE cases in the >40 y age group has increased in recent years. The temporal distribution of laboratory-confirmed cases of JE revealed that the majority of cases occurred from May to September each year, with the highest incidence in August. Conclusion: The results of this study indicate that there is a certain discrepancy between clinically diagnosed and laboratory-confirmed cases of JE. Each reported case should be based on laboratory detection results, which is of great importance in improving the accuracy of case diagnosis and reducing misreporting. Our results are not only important for addressing JE endemic to the Sichuan province, but also provide a valuable reference for the laboratory detection of various notifiable infectious diseases in China and other regions outside China.