Wastewater surveillance together with metaviromic data revealed the unusual resurgence of infectious diseases after the first wave of the COVID-19 outbreak.

How to address public health priorities after COVID-19 is becoming a critical task. To this end, we conducted wastewater surveillance for six leading pathogens, namely, SARS-CoV-2, norovirus, rotavirus, influenza A virus (IAV), enteroviruses and respiratory syncytial virus (RSV), in Nanchang city from January to April 2023. Metaviromic sequencing was conducted at the 1st, 4th, 7th, 9th, 12th and 14th weeks to reveal the dynamics of viral pathogens that were not covered by qPCR. Amplicon sequencing of the conserved region of norovirus GI and GII and the rotavirus and region encoding nonstructural protein of RSV was also conducted weekly. The results showed that after a rapid decrease in SARS-CoV-2 sewage concentrations occurred in January 2023, surges of norovirus, rotavirus, IAV and RSV started at the 6th, 7th, 8th and 11th weeks, respectively. The dynamics of the sewage concentrations of norovirus, rotavirus, IAV and RSV were consistent with the off-season resurgence of the above infectious diseases. Notably, peak sewage concentrations of norovirus GI, GII, rotavirus, IAV and RSV were found at the 6th, 3rd, 7th, 7th and 8th weeks, respectively. Astroviruses also resurge after the 7th week, as revealed by metaviromic data, suggesting that wastewater surveillance together with metaviromic data provides an essential early warning tool for revealing patterns of infectious disease resurgence.

Tailored wastewater surveillance framework uncovered the epidemics of key pathogens in a Northwestern city of China.

Wastewater surveillance enables rapid pathogen monitoring and community prevalence estimation. However, how to design an integrated and tailored wastewater surveillance framework to monitor major health threats in metropolises remains a major challenge. In this study, we first analyzed the historical clinical data of Xi'an city and designed a wastewater surveillance framework covering five key endemic viruses, namely, SARS-CoV-2, norovirus, influenza A virus (IAV), influenza B virus (IBV), respiratory syncytial virus (RSV), and hantavirus. Amplicon sequencing of SARS-CoV-2, norovirus and hantavirus was conducted biweekly to determine the prevalent community genotypes circulating in this region. The results showed that from April 2023 to August 2023, Xi'an experienced two waves of SARS-CoV-2 infection, which peaked in the middle of May-2023 and late August-2023. The sewage concentrations of IAV and RSV peaked in early March and early May 2023, respectively, while the sewage concentrations of norovirus fluctuated throughout the study period and peaked in late August. The dynamics of the sewage concentrations of SARS-CoV-2, norovirus, IAV, RSV, and hantavirus were in line with the trends in the sentinel hospital percent positivity data, indicating the role of wastewater surveillance in enhancing the understanding of epidemic trends. Amplicon sequencing of SARS-CoV-2 revealed a transition in the predominant genotype, which changed from DY.1 and FR.1.4 to the XBB and EG.5 subvariants. Amplicon sequencing also revealed that there was only one predominant hantavirus genotype in the local population, while highly diverse genotypes of norovirus GI and GII were found in the wastewater. In conclusion, this study provided valuable insights into the dynamics of infection trends and predominant genotypes of key pathogens in a city without sufficient clinical surveillance, highlighting the role of a tailored wastewater surveillance framework in addressing public health priorities. More importantly, our study provides the first evidence demonstrating the applicability of wastewater surveillance for hantavirus, which is a major health threat locally.

Targeted amplicon sequencing facilitated a novel risk assessment framework for assessing the prevalence of broad spectrum bacterial and coronavirus diseases.

How to effectively leverage wastewater data to estimate the risk of various infectious diseases remains a great challenge. To address this issue, we conducted continuous wastewater surveillance in Dalian city during the summer-autumn seasons of 2022, targeting coronavirus and bacterial diseases. The surveillance included daily sampling at a wastewater treatment plant (WWTP) and weekly sampling in three sewersheds. Targeting the bacteria's 16S rRNA gene and the coronavirus's RNA-dependent RNA polymerase (RdRp) gene, we first employed RT-PCR and amplicon sequencing techniques to analyze the presence and phylogenetic relationship of detected coronavirus and bacterial pathogens. Next, qPCR was used to quantify the abundances of detected coronavirus and bacterial species. Based on the daily shedding dynamics of SARS-CoV-2, a novel model was developed to predict daily new cases. Based on the medium shedding density of 12 pathogens, two thresholds of sewage pathogen load (indicating 0.1 % and 1 % infection rates) were proposed. Our PanCoV RT-PCR detected coronavirus on 12th August and from 26th August to 12th September 2022. Targeted amplicon sequencing further identified human coronavirus OC43 (hCoV-OC43) on 12th August and the SARS-CoV-2 Omicron variant since 26th August in samples from WWTPs and sewersheds. Phylogenetic analysis revealed that hCoV-OC43 from this study belonged to genotype K and suggested a close relationship between the amplified coronavirus sequences from wastewater and clinical samples in a local COVID-19 outbreak on 26th August. Amplicon sequencing targeting the bacterial 16S rRNA gene also revealed the presence of several bacterial pathogens. Finally, we assessed the microbial risk of specific pathogens in sewersheds and identified a number of pathogens that reached high (>1 % prevalence) and medium risk levels (>0.1 % prevalence) at sewershed B. Our findings underline wastewater surveillance as a valuable early warning system for coronavirus and other waterborne bacterial diseases, complementing public health response measures.

Surveillance, epidemiology, and impact of the coronavirus disease 2019 interventions on the incidence of enterovirus infections in Nanchang, China, 2010-2022.

Introduction: Pathogen spectrum of Hand, foot and mouth disease (HFMD) has substantially changed in the past decade in China. Growing evidence has indicated that anti-COVID-19 nonpharmaceutical interventions (NPIs) can support control of various infectious diseases, including intestinal diseases. Methods: In this study, HFMD cases were enrolled from sentinel hospitals of Nanchang, Jiangxi province, and enteroviruses were genotyped using specific real time RT-PCR. We systematically characterized the epidemiology of HFMD based on the continuous molecular surveillance and estimated the impact of COVID-19 intervention on HFMD incidence using seasonal autoregressive integrated moving average (ARIMA) models. Results: A total of 10247 HFMD cases were included during 2010-2022, of which 6121 enterovirus (EV)-positive cases (59.7%) were identified by real-time RT-PCR. Over 80% cases were associated with EV-A71 and coxsackievirus A16 (CVA16) during 2010-2012, while the type distribution significantly changed as CVA6 emerged to be dominant, accounting for 22.6%-59.6% during 2013-2022. It was observed that the prevalence patterns of EV-A71 and CVA16 were similar and both of them peaked in the second quarter and then leveled off. However, CVA6 was generally prevalent around the fourth quarter, demonstrating a staggered prevalence during 2010-2019. During the COVID-19 epidemic, the seasonal HFMD epidemic peak was restrained, and the ARIMA analysis indicated that the COVID-19 intervention had mitigated EV transmission during the first COVID-19 outbreak in early 2020. In addition, bivariate Spearman's cross-correlation coefficients were estimated for the major types CVA6, CVA16 and EV-A71. Our analyses indicated the possible existence of correlations among CVA6, CVA16 and EV-A71 prevalence in the epidemiological level. Discussion: Taken together, the type distribution of HFMD has substantially changed over the last decade and CVA6 and CVA16 are currently the most predominant types co-circulating in Nanchang. The anti-COVID-19 NPIs significantly reduced the incidence of EV infections.

Longitudinal wastewater surveillance of four key pathogens during an unprecedented large-scale COVID-19 outbreak in China facilitated a novel strategy for addressing public health priorities-A proof of concept study.

Wastewater-based epidemiology (WBE) is a promising tool for monitoring the spread of SARS-CoV-2 and other pathogens, providing a novel public health strategy to combat disease. In this study, we first analysed nationwide reports of infectious diseases and selected Salmonella, norovirus, and influenza A virus (IAV) as prioritized targets apart from SARS-CoV-2 for wastewater surveillance. Next, the decay rates of Salmonella, norovirus, and IAV in wastewater at various temperatures were established to obtain corrected pathogen concentrations in sewage. We then monitored the concentrations of these pathogens in wastewater treatment plant (WWTP) influents in three cities, establishing a prediction model to estimate the number of infected individuals based on the mass balance between total viral load in sewage and individual viral shedding. From October 2022 to March 2023, we conducted multipathogen wastewater surveillance (MPWS) in a WWTP serving one million people in Xi'an City, monitoring the concentration dynamics of SARS-CoV-2, Salmonella, norovirus, and IAV in sewage. The infection peaks of each pathogen were different, with Salmonella cases and sewage concentration declining from October to December 2022 and only occasionally detected thereafter. The SARS-CoV-2 concentration rapidly increased from December 5th, peaked on December 26th, and then quickly decreased until the end of the study. Norovirus and IAV were detected in wastewater from January to March 2023, peaking in February and March, respectively. We used the prediction models to estimate the rate of SARS-CoV-2 infection in Xi'an city, with nearly 90 % of the population infected in urban regions. There was no significant difference between the predicted and actual number of hospital admissions for IAV. We also accurately predicted the number of norovirus cases relative to the reported cases. Our findings highlight the importance of wastewater surveillance in addressing public health priorities, underscoring the need for a novel workflow that links the prediction results of populations with public health interventions and allocation of medical resources at the community level. This approach would prevent medical resource panic squeezes, reduce the severity and mortality of patients, and enhance overall public health outcomes.

Development of quantitative wastewater surveillance models facilitated the precise epidemic management of COVID-19.

Wastewater surveillance serves as a promising approach to elucidate the silent transmission of SARS-CoV-2 in communities. To understand the decay of the coronavirus in sewage pipes, the decay of the coronavirus traveling over 20 km distance of pipeline was analyzed. Based on the decay model, a WWTP and a community model were then proposed for predicting COVID-19 cases in Xi'an and Nanchang city during the COVID-19 outbreak in 2021 and 2022. The results suggested that Monte Carol simulations estimated 23.3, 50.1, 127.3 and 524.2 infected persons in the Yanta district of Xi'an city on December 14th, 18th, 22nd and 26th of 2021, respectively, which is largely consistent with the clinical reports. Next, we further conducted wastewater surveillance in two WWTPs that covered the whole metropolitan region in Nanchang to validate the robustness of the WWTP model from December 2021 to April 2022. SARS-CoV-2 signals were detected in two WWTPs from March 15th to April 5th. Predicted infection numbers were in agreement with the actual infection cases, which promoted precise epidemic control. Finally, community wastewater surveillance was conducted for 40 communities that were not 100 % covered by massive nucleic acid testing in Nanchang city, which accurately identified the SARS-CoV-2 carriers not detected by massive nucleic acid testing. In conclusion, accurate prediction of COVID-19 cases based on WWTP and community models promoted precise epidemic control. This work highlights the viability of wastewater surveillance for outbreak evaluation and identification of hidden cases, which provides an extraordinary example for implementing precise epidemic control of COVID-19.

Horizontal transfer of antibiotic resistance genes within the bacterial communities in aquacultural environment.

Very little is known about how microbiome interactions shape the horizontal transfer of antibiotic resistance genes in aquacultural environment. To this end, we first conducted 16S rRNA gene amplicon sequencing to monitor the dynamics of bacterial community compositions in one shrimp farm from 2019 to 2020. Next, co-occurrence analysis was then conducted to reveal the interactions network between Vibrio spp. and other species. Subsequently, 21 V. parahaemolyticus isolates and 15 related bacterial species were selected for whole-genome sequencing (WGS). The 16S rDNA amplicon sequencing results identified a remarkable increase of Vibrio and Providencia in September-2019 and a significant rise of Enterobacter and Shewanella in Septtember-2020. Co-occurrence analysis revealed that Vibrio spp. positively interacted with the above species, leading to the sequencing of their isolates to further understand the sharing of the resistant genomic islands (GIs). Subsequent pan-genomic analysis of V. parahaemolyticus genomes identified 278 horizontally transferred genes in 10 GIs, most of which were associated with antibiotic resistance, virulence, and fitness of metabolism. Most of the GIs have also been identified in Providencia, and Enterobacter, suggesting that exchange of genetic traits might occur in V. parahaemolyticus and other cooperative species in a specific niche. No genetic exchange was found between the species with negative relationships. The knowledge generated from this study would greatly improve our capacity to predict and mitigate the emergence of new resistant population and provide practical guidance on the microbial management during the aquacultural activities.

Receptor profile and immunogenicity of the non-epidemic norovirus GII.8 variant.

Noroviruses are causative agents of acute nonbacterial gastroenteritis epidemics worldwide. There are various genotypes, among which the non-epidemic genotype GII.8 can cause norovirus outbreaks. We previously demonstrated that the immunogenicity of GII.8 differed from that of epidemic variants. This study aimed to comprehensively compare the receptor profile and immunogenicity of the GII.8 variant with those of the epidemic variants. Using the baculovirus-insect cell expression system, we observed that recombinant capsid protein VP1 of the norovirus GII.8 GZ2017-L601 strain formed virus-like particles (VLPs) with a diameter of approximately 30 nm, as evidenced by transmission electron microscopy analysis. The GII.8 VLPs showed weak or moderate binding with all secretor histo-blood group antigens (HBGAs), but not with non-secretors, as evidenced by the HBGA-VLP binding test. The GII.8 VLP antiserum obtained from immunized BALB/c mice was tested for cross-reactivity with other norovirus genotypes (n = 28). The results showed that this antiserum demonstrated moderate cross-reactivity with GI.1, GII.3, and GII.15; however, no cross-reactivity with the epidemic variants of GII.2, GII.4, and GII.17 was observed. Additionally, the blocking-antibody activity of GII.8 antisera against GII.4 VLP-HBGAs and GII.17 VLP-HBGAs interactions and the cross-blocking of GII.8 VLP-HBGAs interactions by GI.1 and GII.4 antisera were evaluated using the HBGAs-VLP blocking test. However, no cross-blocking effect was observed. In summary, the characterization of norovirus GII.8 VLPs and derived antisera revealed that the GII.8 immunogenicity differed from that of epidemic variants.

The Impact of the Closure of the Live Poultry Market due to COVID-19 on the Avian Influenza Virus in Nanchang, Jiangxi Province, China.

This article aims to understand the changes in the detection rates of H5, H7, and H9 subtypes of avian influenza viruses (AIVs) in the live poultry markets (LPMs) in Nanchang City, Jiangxi Province, before and after the outbreak of the COVID-19. From 2019 to 2020, we monitored the LPM and collected specimens, using real-time reverse transcription polymerase chain reaction technology to detect the nucleic acid of type A AIV in the samples. The H5, H7, and H9 subtypes of influenza viruses were further classified for positive results. We analyzed 1,959 samples before and after the outbreak and found that the positive rates of avian influenza A virus (39.69%) and H9 subtype (30.66%) after the outbreak were significantly higher than before the outbreak (26.84% and 20.90%, respectively; P < 0.001). In various LPMs, the positive rate of H9 subtypes has increased significantly (P ≤ 0.001). Positive rates of the H9 subtype in duck, fecal, daub, and sewage samples, but not chicken samples, have increased to varying degrees. This study shows that additional measures are needed to strengthen the control of AIVs now that LPMs have reopened after the relaxing of COVID-19-related restrictions.

Pathogen change of avian influenza virus in the live poultry market before and after vaccination of poultry in southern China.

BACKGROUND: The fifth wave of H7N9 avian influenza virus caused a large number of human infections and a large number of poultry deaths in China. Since September 2017, mainland China has begun to vaccinate poultry with H5 + H7 avian influenza vaccine. We investigated the avian influenza virus infections in different types of live poultry markets and samples before and after genotype H5 + H7 vaccination in Nanchang, and analyzed the changes of the HA subtypes of AIVs. METHODS: From 2016 to 2019, we monitored different live poultry markets and collected specimens, using real-time reverse transcription polymerase chain reaction (RT-PCR) technology to detect the nucleic acid of type A avian influenza virus in the samples. The H5, H7 and H9 subtypes of influenza viruses were further classified for the positive results. The χ2 test was used to compare the differences in the separation rates of different avian influenza subtypes. RESULTS: We analyzed 5,196 samples collected before and after vaccination and found that the infection rate of AIV in wholesale market (21.73%) was lower than that in retail market (24.74%) (P < 0.05). Among all the samples, the positive rate of sewage samples (33.90%) was the highest (P < 0.001). After vaccination, the positive rate of H5 and H7 subtypes decreased, and the positive rate of H9 subtype and untypable HA type increased significantly (P < 0.001). The positive rates of H9 subtype in different types of LPMs and different types of samples increased significantly (P < 0.01), and the positive rates of untypable HA type increased significantly in all environmental samples (P < 0.05). CONCLUSIONS: Since vaccination, the positive rates of H5 and H7 subtypes have decreased, but the positive rates of H9 subtypes have increased to varying degrees in different testing locations and all samples. This results show that the government should establish more complete measures to achieve long-term control of the avian influenza virus.

Changes of avian influenza virus subtypes before and after vaccination in live poultry in Nanchang, China from 2016 to 2019.

We investigated fluctuations in the detection rates of avian influenza virus (AIV) subtypes H5, H7, and H9 in live poultry in Nanchang city, Chinese province Jiangxi, before and after the Chinese nationwide AIV vaccination campaign against highly pathogenic (HP) AIV subtype H5 and H7. Samples were tested for nucleic acid of type A avian influenza virus by real-time reverse transcription polymerase chain reaction technology. The H5, H7 and H9 subtypes of influenza viruses were further classified for the positive results. Based on the analysis of 2119 samples collected from February 2016 to December 2019, we found that AIV subtypes H5, H7, H9 showed a seasonal pattern, and the positive rate of avian influenza tended to reach its peak in the colder season. The detection rate of AIV subtypes H5, H7, H9 of chickens (39.26%) was significantly higher than that of ducks (5.78%) and pigeons (4.31%). After vaccination, the positive rates of the H5 subtype (0.27%) and the H7 subtype (0.00%) decreased significantly, while the positive rate of the H9 subtype (29.95%) increased significantly. The H9 subtype has become the dominant subtype detected in live poultry and occupies a dominant position in the live bird market. This study showed that the government of China should establish measures for the long-term control of avian influenza.

Surveillance, Epidemiology and Impact of EV-A71 Vaccination on Hand, Foot, and Mouth Disease in Nanchang, China, 2010-2019.

After the first national-scale outbreak of Hand, foot, and mouth disease (HFMD) in China, a national surveillance network was established. Here we described the epidemiology and pathogenic profile of HFMD and the impact of EV-A71 vaccination on pathogen spectrum of enteroviruses in the southeastern Chinese city of Nanchang during 2010-2019. A total of 7,951 HFMD cases from sentinel hospitals were included, of which 4,800 EV-positive cases (60.4%) were identified by real-time RT-PCR. During 2010-2012, enterovirus 71 (EV-A71) was the main causative agent of HFMD, causing 63.1% of cases, followed by 19.3% cases associated with coxsackievirus A16 (CV-A16). Since 2013, the proportion of other enteroviruses has increased dramatically, with the sub genotype D3 strain of Coxsackievirus A6 (CV-A6) replacing the dominance of EV-A71. These genetically diverse native strains of CV-A6 have co-transmitted and co-evolved in Nanchang. Unlike EV-A71 and CV-A16, most CV-A6 infections were concentrated in autumn and winter. The incidence of EV-A71 infection negatively correlated with EV-A71 vaccination (r = -0.990, p = 0.01). And severe cases sharply declined as the promotion of EV-A71 vaccines. After 2-year implementation of EV-A71 vaccination, EV-A71 is no longer detected from the reported HFMD cases in Nanchang. In conclusion, EV-A71 vaccination changed the pattern of HFMD epidemic, and CV-A6 replaced the dominance of EV-A71 over time.

National Safety Survey of Animal-use Commercial Probiotics and Their Spillover Effects From Farm to Humans: An Emerging Threat to Public Health.

BACKGROUND: Human-use probiotics have recently been associated with clinical infections and antibiotic resistance transfer, raising public concern over their safety. However, despite their extensive application in aquaculture and animal husbandry, the safety of animal-use probiotics remains poorly described. METHODS: We evaluated the safety of 92 animal-use probiotics from China. The pattern of spread of pathogens from probiotics and the consequent public health implications were also examined by conducting in-field genomic surveillance at 2 farms. RESULTS: A total of 123 probiotic Bacillus species isolates were obtained from 92 brands of probiotics, of which 45 isolates were resistant to antibiotics. Notably, 33.7% of probiotic products were contaminated with life-threatening pathogens such as Klebsiella pneumoniae. Genomic surveillance at a chicken farm identified an anthrax toxin-positive Bacillus cereus strain in a probiotic product used as a feed supplement, which was transferred into the groundwater and to a nearby fish farm. Following up retrospective analysis of the surveillance data during 2015-2018 in 3 provinces retrieved 2 B. cereus strains from human with intestinal anthrax symptoms and confirmed the transmission of B. cereus from farm to human. Surveillance of anthrax toxin revealed that cya was detected in 8 of 31 farms. CONCLUSIONS: This study provides the first national safety survey of animal-use probiotics in China and confirms the spillover effects of probiotics from the farms to human. These results suggest that the large-scale application of pathogen-containing probiotics leads to the transfer of pathogens, with worrisome implications for public health. Good Manufacturing Practice should be implemented during the production of all probiotics.Animal-use probiotic products are frequently contaminated with viable pathogenic bacteria. This study revealed that virulent probiotic organisms and contaminating pathogens were colonized with farm animals and shed into the environment, which facilitated the transfer of pathogens to humans.

Avian influenza H9N2 virus isolated from air samples in LPMs in Jiangxi, China.

BACKGROUND: Recently, avian influenza virus has caused repeated worldwide outbreaks in humans. Live Poultry Markets (LPMs) play an important role in the circulation and reassortment of novel Avian Influenza Virus (AIVs). Aerosol transmission is one of the most important pathways for influenza virus to spread among poultry, from poultry to mammals, and among mammals. METHODS: In this study, air samples were collected from LPMs in Nanchang city between April 2014 and March 2015 to investigate possible aerosol transmission of AIVs. Air samples were detected for Flu A by Real-Time Reverse Transcription-Polymerase Chain Reaction (RRT-PCR). If samples were positive for Flu A, they were inoculated into 9- to 10-day-old specific-pathogen-free embryonated eggs. If the result was positive, the whole genome of the virus was sequenced by MiSeq. Phylogenetic trees of all 8 segments were constructed using MEGA 6.05 software. RESULTS: To investigate the possible aerosol transmission of AIVs, 807 air samples were collected from LPMs in Nanchang city between April 2014 and March 2015. Based on RRT-PCR results, 275 samples (34.1%) were Flu A positive, and one virus was successfully isolated with embryonated eggs. The virus shared high nucleotide homology with H9N2 AIVs from South China. CONCLUSIONS: Our study provides further evidence that the air in LPMs can be contaminated by influenza viruses and their nucleic acids, and this should be considered when choosing and evaluating disinfection strategies in LPMs, such as regular air disinfection. Aerosolized viruses such as the H9N2 virus detected in this study can increase the risk of human infection when people are exposed in LPMs.

Molecular epidemiology of an outbreak of hand, foot, and mouth disease associated with subgenotype C4a of enterovirus A71 in Nanchang, China in 2014.

An outbreak of hand, foot, and mouth disease was reported through hospital-based surveillance in Nanchang, China in 2014. A total of 244 cases were reported, 176 (72.1%) cases were tested positive for enteroviruses by direct reverse transcription-polymerase chain reaction, in which enterovirus A71 (EV-A71), coxsackievirus A16 (CV-A16), and untyped enteroviruses (UEV) accounted for 84.1%, 3.4%, and 12.5%, respectively. In this outbreak, children under 5 years old constituted more than 98% of the positive cases, and the ratio of male to female cases was 2.6 to 1 (P < 0.01). Phylogenetic analysis indicated that the Nanchang EV-A71 strains belonged to subgenotype C4a undergoing continuously evolutionary changes.

Coexistence of Avian Influenza Virus H10 and H9 Subtypes among Chickens in Live Poultry Markets during an Outbreak of Infection with a Novel H10N8 Virus in Humans in Nanchang, China.

Infection with the novel H10N8 virus in humans has raised concerns about its pandemic potential worldwide. We report the results of a cross-sectional study of avian influenza viruses (AIVs) in live poultry markets (LPMs) in Nanchang, China, after the first human case of H10N8 virus infection was reported in the city. A total of 201 specimens tested positive for AIVs among 618 samples collected from 24 LPMs in Nanchang from December 2013 to January 2014. We found that the LPMs were heavily contaminated by AIVs, with H9, H10, and H5 being the predominant subtypes and more than half of the LPMs providing samples that were positive for the H10 subtype. Moreover, the coexistence of different subtypes was common in LPMs. Of the 201 positive samples, 20.9% (42/201) had mixed infections with AIVs of different HA subtypes. Of the 42 mixed infections, 50% (21/42) showed the coexistence of the H9 and H10 subtypes, with or without H5, and were from chicken samples. This indicated that the H10N8 virus probably originated from segment reassortment of the H9 and H10 subtypes.

Investigation of avian influenza virus in poultry and wild birds due to novel avian-origin influenza A(H10N8) in Nanchang City, China.

Multiple reassortment events within poultry and wild birds had resulted in the establishment of another novel avian influenza A(H10N8) virus, and finally resulted in human death in Nanchang, China. However, there was a paucity of information on the prevalence of avian influenza virus in poultry and wild birds in Nanchang area. We investigated avian influenza virus in poultry and wild birds from live poultry markets, poultry countyards, delivery vehicles, and wild-bird habitats in Nanchang. We analyzed 1036 samples from wild birds and domestic poultry collected from December 2013 to February 2014. Original biological samples were tested for the presence of avian influenza virus using specific primer and probe sets of H5, H7, H9, H10 and N8 subtypes by real-time RT-PCR. In our analysis, the majority (97.98%) of positive samples were from live poultry markets. Among the poultry samples from chickens and ducks, AIV prevalence was 26.05 and 30.81%, respectively. Mixed infection of different HA subtypes was very common. Additionally, H10 subtypes coexistence with N8 was the most prevalent agent during the emergence of H10N8. This event illustrated a long-term surveillance was so helpful for pandemic preparedness and response.

Molecular epidemiology of human enterovirus 71 strains in the Nanchang region of China in 2011.

Hand, foot, and mouth disease (HFMD) is caused by enteroviruses, most commonly enterovirus 71 (EV71) and coxsackievirus A16 (CA16). In general, EV71 infection is more likely to induce severe complications and mortality than other enterovirus infections. The present study focuses on the molecular epidemiology of human EV71 strains in the Nanchang region of China in 2011. Overall, 651 specimens (throat or rectal swabs) were collected, and one-step reverse transcriptase-polymerase chain reaction was performed for analysis. Enteroviruses were detected in 62.2% (405/651) of the specimens. EV71, CA16, and other enteroviruses were found in 292, 73, and 40 specimens, respectively. Phylogenetic analysis of the VP1 region of the 8 EV71 strains found in the Nanchang region indicated that these strains belong to the C4 subgenotype. This study shows that the C4 subgenotype strain of EV71 was prevalent in the HFMD cases of Nanchang in 2011, and it reports the first incidence of adults being infected by EV71 in the Nanchang region. Thus, the surveillance of HFMD epidemiology and monitoring of HFMD severity should be continued.

[Antiviral activity of Ouyi antipyretic detoxicate soft capsule against influenza a virus H1N1 in vitro].

OBJECTIVE: Our study aims to evaluate the antiviral effects of Ouyi antipyretic detoxicate soft capsule against influenza A virus H1N1 in vivo, so as to find an effective Chinese medicinal formulae for the treatment of the virus infection, which may lay a theoretical foundation for clinic treatment of patient infected with Influenza A Virus H1N1. METHOD: With the observation of cytopathic effect (CPE) that induced by virus ,we investigated viral inhibition rate by MTT colorimetric assay and valued antiviral activity of drugs by therapeutic index (TI) . Meanwhile, Oseltamivir phosphate capsule (Tamiflu) was used as positive control , we carried out experiments through the three ways of preventive effect, direct inactivation and propagation inhibition. RESULT: Ouyi antipyretic detoxicate soft capsule could effectively inhibit cytopathic effect (CPE) that induced by Influenza A Virus H1N1. The preventive effect, direct inactivation , and inhibition of endogenous multiplication of Ouyi antipyretic detoxicate soft capsule and Tamiflu against influenza A virus H1N1 were observed. And three types of action therapeutic index (TI) from Ouyi antipyretic detoxicate soft capsule were (15.5 +/- 0.71), (0.55 +/- 0.071), (6.4 +/- 1.27) severally, comparing Tamiflu with (0.4 +/- 0.14), (1.88 +/- 0.29), (4.6 +/- 0.15), respectively. CONCLUSION: Ouyi antipyretic detoxicate soft capsule showed more remarkable preventive effect than Tamiflu in vitro (P<0.01). The possible mechanism of the antiviral activity observed in our study might be the protection of the MDCK cells from viral infection by inhibiting the viral absorption. We need a further study to certify three effects in vivo.