African swine fever (ASF) is a viral disease that affects members of the Suidae family. The notifiable disease is considered a major threat to the pig industry, animal health, and food security worldwide. According to the European Food Safety Authority, ASF virus (ASFV) survival and transmission in feed and feed materials is a major research gap. Against this background, the objective of this study was to determine the survival of ASFV on re-contaminated spray dried porcine plasma (SDPP) when stored at two different temperatures. To this means, commercial SDPP granules were contaminated with high titers of ASFV in a worst-case re-contamination scenario. Three samples per time point and temperature condition were subjected to blind passaging on macrophage cultures and subsequent haemadsorption test to determine residual infectivity. In addition, viral genome was detected by real-time PCR. The results indicate that heavily re-contaminated SDPP stored at 4°C remains infectious for at least five weeks. In contrast, contaminated SDPP stored at room temperature displayed a distinct ASFV titer reduction after one week and complete inactivation after two weeks. In conclusion, the residual risk of ASFV transmission through re-contaminated SDPP is low, if SDPP is stored at room temperature for a period of at least two weeks before feeding.

Introduction: Despite eradication and control measures applied across Europe, bovine tuberculosis (bTB) remains a constant threat. In Belgium, after several years of bTB disease freedom status, routine movement testing, as currently practiced, revealed itself inadequate to detect some sporadic breakdown herds. The aim of this study was to strike the balance between cost and effectiveness of different surveillance system components to identify sustainable alternatives for early detection and substantiation of freedom of bTB while maintaining acceptance of these amongst the different animal health stakeholders. Methods: Stochastic iteration model was built to simulate, first, the expected current surveillance system performance in terms of sensitivity and specificity of detection. These results were then descriptively compared to observed field results. Secondly, the cost and effectiveness of simulated alternative surveillance components were quantified. To measure impact of key assumptions (i.e. regarding diagnostic tests and true prevalence), sensitivity analysis was performed. Results: Discrepancies between the predicted and observed performance of bTB surveillance in Belgium were observed. Secondly, simulated alternatives revealed that targeted IFN-γ as well serological testing with Antibody ELISA towards risk herds would enable increasing the overall cost and effectiveness of the Belgian bTB surveillance system. Sensitivity analysis showed that results remained constant despite modification of some key assumptions. Discussion: Performance of current bTB surveillance system performance in Belgium was questionable. This exercise highlighted that not only sensitivity, but specificity is a key driver for surveillance performance. The quantitative and participative conceptual framework revealed itself a useful tool to allow evidence-based decision making regarding future tuberculosis surveillance in Belgium, as required by the international standards.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in Wuhan, China, and rapidly spread worldwide. This new emerging pathogen is highly transmittable and can cause fatal disease. More than 35 million cases have been confirmed and the fatality was about 2.9% up to October 9 2020. However, the original and intermediate hosts of SARS-CoV-2 remain unknown. Here, a total of 3160 poultry samples collected from 14 provinces between September and December 2019 in China were tested for the purpose of traceable surveillance for SARS-CoV-2 infection. The results indicated that all samples were SARS-CoV-2 negative, and a total of 593 avian coronaviruses were detected, including 485 avian infectious bronchitis viruses, 72 duck coronaviruses and 36 pigeon coronaviruses. The positive rates of avian infectious bronchitis virus, duck coronavirus, and pigeon coronavirus were 15.35%, 2.28% and 1.14%, respectively. Our surveillance demonstrated the diversities of avian coronaviruses in China, and higher prevalence were also recognized in some regions. The possibility of SARS-CoV-2 originating from the known avian-origin coronaviruses can be preliminarily ruled out. More surveillance and research on avian coronaviruses should be strengthened for better understanding the diversity, distribution, cross-species transmission and clinical significance of these viruses.

The aim of the present study was to evaluate the duration of protective immunity against Porcine epidemic diarrheoa virus (PEDV). To that, a two phases study was performed. In the first phase, 75 four-week-old pigs (group A) were orally inoculated (0 days post-inoculation; dpi) with a European PEDV G1b strain and 14 were kept as controls (group B). The second phase started five month later (154 dpi), when animals in group A were homologous challenged and animals in group B were challenged for first time. Clinical signs, viral shedding and immune responses were evaluated after each inoculation, including the determination of antibodies (ELISA and viral neutralisation test, IgA and IgG ELISPOTs using peripheral blood mononuclear cells and lymph node cells) and the frequency of interferon-gamma (IFN-γ) secreting cells. During the first phase, loose stools/liquid faeces were observed in all group A animals. Faecal shedding of PEDV occurred mostly during the first 14 days but, in some animals, persisted until 42 dpi. All inoculated animals seroconverted for specific-PEDV IgG and IgA, and for neutralizing antibodies (NA). At 154 dpi, 77% of pigs were still positive for NA. After that, the homologous challenge resulted in a booster for IgG, IgA, NA, as well as specific-PEDV IgG, IgA and IFN-γ secreting cells. In spite of that, PEDV was detected in faeces of all pigs from group A, indicating that the immune response did not prevent reinfection although the duration of the viral shedding and the total load of virus shed was significantly lower for previously challenged pigs (p<0.05). Taken together, the results indicated that, potentially, maintenance of PEDV infection within an endemic farm may occur by transmission to and from previously infected animals and also indicates that sterilising immunity is shorter than the productive life of pigs.

The COVID-19 pandemic poses a serious threat to global health, and one of the key epidemiological factors that shape the transmission of COVID-19 is its serial interval (SI). Although SI is commonly considered following a probability distribution at a population scale, slight discrepancies in SI across different transmission generations are observed from the aggregated statistics in recent studies. To explore the change in SI across transmission generations, we develop a likelihood-based statistical inference framework to examine and quantify the change in SI. The COVID-19 contact tracing surveillance data in Hong Kong are used for exemplification. We find that the individual SI of COVID-19 is likely to shrink with a rate of 0.72 per generation and 95%CI: (0.54, 0.96) as the transmission generation increases. We speculate that the shrinkage in SI is an outcome of competition among multiple candidate infectors within a cluster of cases. The shrinkage in SI may speed up the transmission process, and thus the nonpharmaceutical interventive strategies are crucially important to mitigate the COVID-19 epidemic.

Level and duration of protective immunity against SARS-CoV-2 after primary infection is of crucial importance for preventive approaches. In order to provide evidence for the longevity of specific antibodies, we investigated the generation and maintenance of neutralizing antibodies of convalescent SARS-CoV-2-afflicted patients over a five month period post primary infection using an immunofluorescence assay, a commercial chemiluminescent immunoassay and an in-house enzyme-linked plaque-reduction neutralization assay. We present the successful application of an improved version of the plaque-reduction neutralization assay, which can be analyzed optometrically, significantly simplifying the interpretation of the results. Based on the results of the plaque-reduction neutralization assay, neutralizing antibodies were maintained in 85.3% of convalescent individuals without significant decay over five months. Furthermore, a positive correlation between severity of infection and neutralizing titer was shown. In conclusion, SARS-CoV-2-afflicted individuals have been proven to be able to establish and maintain neutralizing antibodies over a five months’ period after primary infection which allows to hope for long-lasting presumably protective humoral immunity after wild-type infection or even after vaccination.

African Swine Fever Virus (ASFV) is a highly contagious pathogen causing disease in pigs, commonly characterised by acute haemorrhagic fever. Prior to August 2018, African Swine Fever (ASF) had not been reported in Asia, but has since spread throughout China, Mongolia, Korea, Vietnam, Laos, Cambodia, Myanmar, the Philippines, Hong Kong, Indonesia, Timor-Leste and Papua New Guinea. Using data collated from reports of confirmed cases, we applied spatio-temporal analysis to describe ASFV spread throughout Asia, from 1 August 2018 (reported start date) to 31 December 2019. Analysis revealed a propagating epidemic of ASFV throughout Asia, with peaks corresponding to increased reports from China, Vietnam and Laos. Two clusters of reported outbreaks were found. During the epidemic, ASFV primarily spread from the North-East to the South-East: a larger, secondary cluster in the North-East represented earlier reports, whilst the smaller, primary cluster in the South-East was characterised by later reports. Significant differences in country-specific epidemics, morbidity, mortality and unit types were discovered, likely attributable to differences in prevention, surveillance and control measures. The initial number of outbreaks and enterprise size are likely predictors of the speed of spread and the effectiveness of ASFV stamping out procedures. Biosecurity methods, wild boar populations and the transportation of pigs and movement of infected fomites are discussed as likely risk factors for facilitating ASFV spread across Asia.

Apoptosis is a form of programmed cell death, which maintains cellular homeostasis by eliminating pathogen-infected cells. It contains three signaling pathways: death receptor pathway, mitochondria-mediated pathway and endoplasmic reticulum pathway. Its importance in host defenses is highlighted by the observation that many viruses evade, hinder or destroy apoptosis, thereby weakening the host’s immune response. Flaviviruses such as Dengue virus, Japanese encephalitis virus and West Nile virus utilize various strategies to activate or inhibit cell apoptosis. This article reviews the research progress of apoptosis mechanism during flaviviruses infection, including flaviviruses proteins to regulate apoptosis by interacting with host proteins, as well as various signaling pathways involved in flaviviruses-induced apoptosis, which provides a scientific basis for understanding the pathogenesis of flaviviruses and helps in developing an effective antiviral therapy.

The clinical symptoms, blood laboratory data, O2 saturation and high resolution computed tomography (HRCT) findings are critical factors in diagnosis of COVID-19 infection. In this study, 105 hospitalized patients suspected of having COVID-19 were evaluated. Finally, the data of 83 confirmed cases by HRCT and RT-PCR were analyzed. 61.40% of the patients had a comorbidity disease. 89.20% had fever, 92.00% cough, 91.40% dyspnea. Abnormal CRP seen in 77.80% of the patients following by 66.70% lymphopenia, and 60.30% neutrophilia. Also, ALP (abnormal vs. normal) and score of HRCT assessment variables had a significant effect on the positiveness of HRCT findings. 87.95% had abnormal HRCT with 41% bilateral multilobar patchy ground glass opacity (GGO). Moreover, there was a statistically significant association between level of O2 saturation and HRCT results. Our findings showed that male patients with middle age and comorbidity disease were more susceptible to the COVID-19 infection. Additionally, clinical features, blood laboratory findings, O2 saturation and HRCT findings are critical factors in prognosis of COVID-19 infection.

The COVID-19 pandemic represents one of the greatest public health crises in recent history that caused unprecedented and massive disruptions of social and economic life globally. It is widely acknowledged that bats are the animal reservoir of coronavirus 2 of the severe acute respiratory syndrome (SARS-CoV-2), the causative agent of the human coronavirus disease 2019 (COVID-19). It has also long been known that coronaviruses circulate among different animal species. However, much remain to be understood of the epidemiology, the presumed existence of intermediate animal species and current and potential animal routes of SARS-Cov-2 transmission to humans. The recent observational and experimental studies also highlight the role of domestic and farmed animals in the epidemiology of COVID-19. This raises concerns of the potential spread of infection among susceptible animal species, with the risk of evolving into panzootic, and the likely occurrence of anthropozoonoses or reverse zoonosis (from humans to animals). As for other wildlife emerging pathogens, the animal-human spillover of SARS-CoV-2 is linked to a closer interface with humans, with the resulting risk of a pandemic. This knowledge has meaningful implications for the design of effective wildlife animal surveillance (epidemic intelligence) targeting CoVs in animal reservoirs, and requires the mobilization of different lines of expertise, notably veterinary epidemiologists and virologists, within a multi-disciplinary approach according to the One-Health principles.

In zoonotic disease, highly pathogenic avian influenza (HPAI) is a major threat to human and poultry health worldwide. In January 2014, HPAI virus subtype H5N8 first infected poultry farms in South Korea, and a total of 393 outbreaks were reported with enormous economic damage in the poultry industry. We analyzed the spatiotemporal distribution of HPAI H5N8 outbreaks in poultry farms using the global and local spatiotemporal interactions in the first outbreak wave from January 2014 to June 2015 and the second wave from September 2014 to June 2015. The space-time K-function analyses revealed significant interactions within three days and over 40 km in two study periods in global spatiotemporal interaction. The excess risk attributable value (D0) was maintained despite the distance in the case of HPAI H5N8 in Korea. Eleven spatiotemporal clusters were identified, and the results show the HPAI introduction from the southwestern region and the spread to the middle region in Korea. Six clusters were distributed in 0.46-9.86 km space and 3-19 days in time, while five clusters were distributed in 19.74-72.59 km space and 27-36 days in time. This global and local spatiotemporal interaction indicates that the HPAI epidemic in Korea was mostly characterized by short period transmission within a small area and dispersed by long-range jumps. This finding supports strict control strategies such as preemptive depopulation, the standstill, and poultry movement tracking. More studies are needed to understand HPAI disease transmission patterns of HPAI in Korea.

Subtilase is a potent cytotoxin that was first described in O113:H21 strain in Australia as a plasmid- encoded cytotoxin (subAB1). Subsequently, chromosomal variants including subAB2-1, subAB2-2, and subAB2-3 were described. In the present study a collection of 101 STECs isolated from various sources in Iran (2009-2016) were analyzed for the detection of different genes encoding the subtilase variants, plasmidic and chromosomal virulence genes, together with the phylogroup and serogroups. Overall, 57 isolates (56.4%) carried at least one variant of subAB. Most strains from small ruminants including 93% of sheep and 96% of caprine isolates carried at least one chromosomally encoded variant (subAB-2). In contrast, 12 cattle isolates (24%) only harbored the plasmid encoded variant (subAB1). STEC strains from other sources including deer, pony and humans were positive for subAB-2-1 and/or subAb2-2. Concerning the virulence markers, some strains showed an association with hosts the bacteria were isolated from. In particular, tia was associated with sheep, goats and pony isolates and astA gene was present in deer, pony and goats and terD was only found in deer and pony isolates. Only cattle STEC carried espP and epeA, the important markers of pO113 plasmid. Some genes were widespread among strain of various sources like ehly, iha and lpfO113 and some genes were not detected such as efa1, toxB and katP. Most strains belonged to phylogenetic group B1 (89.47%), but five strains from cattle, deer, pony and a goat were assigned to A phylogroup. Most cattle strains belonged to O113, while O5 was just detected in ovine isolates, and O128 and O113 were present in caprine strains. In conclusion, the present study reveals the presence of potentially pathogenic genotypes among LEE-negative isolates and some host specificity related to subtilase variants and other virulence markers that may aid in source tracking of STEC during outbreaks.

An 11 years-old male mixed-breed cat, with exclusively indoor life, presented 3 cough episodes after the owners tested positive by RT-PCR for SARS-CoV-2. The house is inhabited by 5 people (3 adults and 2 children), and 2 of the adults have shown mild symptoms associated with throat discomfort. The cat was vaccinated, had no history of any previous disease, and tested negative for Feline Coronavirus (FeCoV), Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV). Rectal sample collected from the cat was positive for SARS-CoV-2 by RT-PCR. Viral genome sequences recovered from human and cat samples showed an average 99.4% sequence identity. This is the first report of genome sequences of SARS-CoV-2 recovered from a cat and its owner in Latin America.

PRV1 was first detected in deceased pigs from Hong Kong in 2013. It has since been detected in the USA, Chile and most recently in Hungary. Information on the pathogenicity and global spread is sparse, however it has been speculated to play a role in the porcine respiratory disease complex. In an effort to investigate the porcine virome, we screened 53 pig samples from 29 farms using SMg within the Dutch/German border region. In five farms we detected PRV1. qPCR confirmed the presence of the virus in 2 of these farms and found an additional 6 positive farms. Phylogenetic analysis found the closest match to the first detected PRV1 strain in Hong Kong. The Dutch/German region represents a major area of pig farming within Europe and could provide important information on the characterization and circulation of porcine viruses, such as PRV1. Together with the recent detection of PRV1 in Hungary, these findings suggest widespread of PRV1 in Central Europe, highlighting the need for further research on persistence, pathogenicity and transmission in Europe.

Advanced and accurate forecasting of COVID-19 cases plays a crucial role in planning and supplying resources effectively. Artificial Intelligence (AI) techniques have proved its capability in time series forecasting of the non-linear problems. In the present study, the relationship between weather factor and COVID-19 cases was assessed and also developed a forecasting model using long short term memory (LSTM), a deep learning model. The study found that the specific humidity has a strong positive correlation, whereas there is a negative correlation with maximum temperature and positive correlation with minimum temperature was observed in various geographic locations of India. The weather data and COVID-19 confirmed cases data (1st April-30th June 2020) was used to optimize univariate and multivariate LSTM time series forecast models. The optimized models were utilized to forecast the COVID-19 cases for the period 1st July 2020 to 31st July 2020 with 1 to 14 days of lead time. The results showed that the univariate LSTM model was reasonably good for the short term (1day lead) forecast of COVID-19 cases (relative error < 20%). Moreover, the multivariate LSTM model improved the medium-range forecast skill (1-7days) after including the weather factors. The study observed that the specific humidity played a crucial role in improving the forecast skill majorly in the West and northwest region of India. Similarly, the temperature played a significant role in model enhancement in the Southern and Eastern regions of India.

The Pigeon circovirus (PiCV) which contains a circular single stranded DNA (approximately 2 kb) belongs to the genus Circovirus and the family Circoviridae. PiCV infections in pigeons (Columba livia) have been reported worldwide. Nowadays, pigeon racing is becoming increasingly popular and considered to be a national sport in China, and even, the greatest competitions of racing pigeons are stake place in China. However, there is no epidemiologic data on PiCV infections among racing pigeons in China. To trace the prevalence, genetic variation and evolution of PiCV in sick and healthy racing pigeons, 622 samples were collected from 11 provinces or municipalities of China from 2016 to 2019. Samples were tested by polymerase chain reaction. The results showed that the positive rate of PiCV was 19.3% (120/622) at the sample level; 59.0% (23/39) at the club level, suggesting that the virus was prevalent in Chinese racing pigeons. A sequence analysis revealed that the cap genes of the PiCV strains identified in our study display high genetic diversity and shared nucleotide homologies of 71.9%–100% and amino acid homologies of 71.7%–100%. 28 and 37 unique amino acid substitutions were observed among the cap proteins and rep proteins of our PiCV strains, respectively. Furthermore, two initiation codons (GTG and ATT) of cap gene were newly found. A cap-gene-based phylogenetic analysis showed that the strains in this study could be further divided into six groups (A, B, C, E, G, H and I) and some of our strains are closely related to worldwide strains from different types of pigeons. A large number of recombination events (31 events) were also detected in the PiCV genomes from Chinese racing pigeons. These findings suggest that PiCV strains circulating in China exhibits higher genetic diversity.

Avian pathogenic E. coli (APEC) are generally considered to be the reservoir for human extraintestinal pathogenic E. coli (ExPEC): they share similar genetic characteristics and pathogenicity with no or minimal host specificity. In this study, we successfully isolated and identified an E. coli strain as the culprit responsible for serious colibacillosis outbreaks in intensive chicken farms in China in 2016. We investigated its phylogenetic classification (A, B1, B2, C, D, E, and F) by PCR analysis; its virulence and host range using challenge experiments with different animals; and its virulence factors, drug resistance genes, sequence type (ST), and related biological information through high-throughput sequencing. This isolate was found to belong to ST95, group B2, and serotype O18. The E. coli strain shows strong virulence in chickens with a minimum lethal dose (MLD) of 3 × 103 CFU/chicken and a strong virulence in mice with an MLD of 3 × 102 CFU/mouse and in rabbits with an MLD of 3 × 103 CFU/rabbit. Whole-genome sequencing showed that it consists of six types of prevalent resistance genes, 33 antibiotic efflux genes, and nine recognized virulent factors. The detailed data are available from GenBank (SRR13005645) for further study.

The larva of Taeniidae species can infect a wide range of mammals, causing major public health and food safety hazards worldwide. The Qinghai-Tibet Plateau (QTP), a biodiversity hotspot, is home to many species of rodents, which act as the critical intermediate hosts of many Taeniidae species. In this study, we identified two new larvae of Taenia spp., named as T. caixuepengi and T. tianguangfui, collected from the plateau pika (Ochotona curzoniae) and the Qinghai vole (Neodon fuscus), respectively in QTP, and their mitochondrial genomes were sequenced and annotated. Phylogenetic trees based on the mitochondrial genome showed that T. caixuepengi has the closest genetic relationship with T. pisiformis, while T. tianguangfui was contained in a monophyletic group with T. crassiceps, T. twitchelli and T. martis. Biogeographic scenarios analysis based on split time speculated that the speciation of T. caixuepengi (~5.49 Mya) is due to host switching caused by the evolution of its intermediate host. Although the reason for T. tianguangfui (~13.11 Mya) speciation is not clear, the analysis suggests that it should be infective to a variety of other rodents following the evolutionary divergence time of its intermediate host and the range of intermediate hosts of its genetically close species. This study confirms the species diversity of Taeniidae in the QTP, and speculates that the uplift of the QTP has not only a profound impact on the biodiversity of plants and animals, but also that of parasites.

In the present study, the highly pathogenic bovine Deltapapillomavirus (δPV) was investigated by liquid biopsy in blood samples of 168 clinically normal goats using both droplet digital PCR (ddPCR) and quantitative real time PCR (qPCR). Overall, ddPCR detected BPV E5 DNA in ~61.3% of the blood samples examined, while real time qPCR revealed the virus in ~10.7% of the same samples. Moreover, ddPCR showed BPV E5 DNA in ~78.8% of blood samples from goats that were in close contact with cattle and in 20% of blood samples from goats living in closed pens without any contact with cattle. In addition, ddPCR revealed a single BPV genotype in ~59.2% and multiple genotypes in ~40.8% of goats harboring BPV DNA, while real time qPCR detected single genotypes in ~17% and multiple genotypes in ~1%. Of the BPV co-infections detected by ddPCR, 28 (~67%) involved two genotypes, eight (~19%) three genotypes, and six (~14%) four genotypes. In contrast, real time qPCR revealed BPV co-infection by two genotypes in only one sample and failed to detect co-infection by three or four genotypes. BPV2 and BPV13 were the most prevalent viruses responsible for single and multiple co-infections, respectively. The present study showed that the ddPCR technique has much higher sensitivity and specificity in the detection of these viruses, and suggested that animal husbandry practices contribute to cross-species transmission of BPVs.

Pigeon aviadenovirus A and Pigeon circovirus are both viruses that can cause disease in pigeons. This study reports the identification of a natural co-infection of Pigeon aviadenovirus A and Pigeon circovirus in a breeding pigeon flock in central Anatolia, Turkey. Both viruses were isolated from pooled internal organs of pigeons using primary chicken embryo kidney cell cultures (CEKC) and specific pathogen free (SPF) embryonated chicken eggs. Both viruses were identified by PCR amplification followed by Sanger sequencing, while histopathological examination showed degenerated hepatocytes with basophilic intranuclear viral inclusions. The viruses have similar transmission characteristics and common clinical manifestations, but it is possible that coinfection may exacerabate disease. This is the first report of its kind in Turkey and is important for the protection against disease in pigeons.

Objective: To investigate the causes of early COVID-19 complicated with platelets(PLT) abnormality, and to analyze the possible mechanisms. Methods: The case datum of early COVID-19 complicated with PLT increase or decrease was collected. (125-350) ×109/L defined as the normal level of PLT(Group C), <125×109/L was defined as the PLT decrease group (Group A), >350×109/L defined as the PLT increase group (Group B) . The data were analyzed after collected. Results: Our statistical results showed that the incidence of COVID-19 combined PLT decreased was about 11.94% and the incidence of combined PLT increased was about 9.33% at admission. Compared with Group B and C, Group A showed a significant decrease in white blood cell, neutrophil and CD4 (P<0.05). The lymphocyte in Group A and C decreased significantly, but not find in Group B (P<0.05). Compared with Group A and C, IL-4 was increased in Group B, but lymphocyte decline was not significant (P>0.05). Conclusion: PLT abnormalities occur in all patients with different types of COVID-19. It may be related to the severity of inflammation and infection, immune regulation and megakaryocyte function, etc.

Astroviruses (AstVs) are major causative agents of gastroenteritis in children and had been detected worldwide. Recently, the novel neurotropic AstV associated with encephalitis and meningitis has been found in different species including human, bovine and ovine. However, little is known about the prevalence of neurotropic AstVs in water buffalo of China. In this study, we examined fecal samples from water buffalo in the Guangxi province of China and found different lineages of Water Buffalo Astrovirus (BufAstV) infections. In addition, we confirmed that the BufAstV infection of the brain tissues of a dead calf by immunohistochemistry technology in this study. Based on the 3’RACE and next-generation sequencing technologies, 2 full-length genomes (BufAstV-NNA-14 and BufAstV-NNA-12) and 2 ORF2 genes (BufAstV-NND-s2 and BufAstV-NNA-17) of AstVs from this source were sequenced. Phylogenetic analysis of the ORF2 indicated 3 major lineages of BufAstVs including a novel neurotropic BufAstV, a BufAstV which is related to Bovine Astrovirus (BoAstV) and a classical BufAstV. Moreover, the occurrence of genomic recombination between BufAstV and BoAstV strains have been identified. This is the first report to found a BufAstV infected in brain of water buffalo in China and details of the epidemiology, genetic diversity and possible interspecies transmission of BoAstV and BufAstV in water buffalo from the Guangxi province of China are described. KEYWORDS: astrovirus, water buffalo, bovine, neurotropic, genetic diversity, Guangxi province

Bovine leptospirosis is a bacterial disease that affects bovine herds, causing economic losses due to reproductive problems, which require expensive treatments. The main source of transmission for cattle is still uncertain, but it has been described that small wild mammals can play an important role in the transmission cycle by being maintenance hosts for the pathogenic species of the bacterium and spreading it through urine. In this study, we characterize possible risk areas for bovine leptospirosis in the state of Veracruz, Mexico; based on the geographical distribution of small wild hosts of Leptospira sp. reported in Mexico in addition with climatic, geographic, land use and human activities variables, and validated risk map with bovine seroprevalence data. We used a generalized linear regression model to understand the association between the appearance of bovine leptospirosis seroprevalences and the favorability of wild hosts of Leptospira sp. as well as environmental variables. The parameterized model explains 13.58% of the variance. The seroprevalence in cattle showed a negative relationship with elevation, geographic length and human population density, and a positive relationship with environmental favorability for the bats reservoirs and favorability for at least one rodent and opossum reservoir. The variation in seroprevalence is mainly explained by a longitudinal gradient (10.4% of the variance) and the favourability for bats (3.0% of the variance). Describing the possible risks of seroprevalence in an important and neglected livestock geographical region, we contribute to the selection of areas of strategies for diagnosis and prevention of this relevant disease.

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a newly identified swine enteropathogenic coronavirus that causes watery diarrhea in neonatal piglets, leading to significant economic losses to the swine industry. Currently there are no suitable serological method to assess the infection of SADV-CoV and effectiveness of vaccines, making an urgent need to exploit effect enzyme-linked immunosorbent assay (ELISA) to compensate for this deficiency. In this study, an indirect ELISA (S-iELISA) based on recombinant spike (S) protein expressed in Baculovirus was developed and evaluated. The reaction conditions of S-iELISA were optimized and cut-off value determined as 0.3711 by analyzing OD450nm values of 40 SADS-CoV-negative sera confirmed by immunoinfluscent assay (IFA) and Western Blot. The coefficients of variation of 6 positive sera within and between runs of S-iELISA were both less than 10% and cross-reactivity assays demonstrated that S-iELISA was non-cross-reactive with other swine viruses’ sera. Furthermore, the overall coincidence rate between IFA and S-iELISA was 97.3% based on testing 111 clinical serum samples. Virus neutralization test with 7 different OD450nm value sera showed that the OD450nm values tested by S-iELISA are positive correlated with virus neutralization. Finally, a total of 300 pig field serum samples were tested by S-iELISA and commercial kits of other swine enteroviruses showed that the IgG-positive for SADS-CoV, TGEV, PDCoV and PEDV were 81.7%, 54%, 65.3%, 6%, respectively. The results suggest this S-iELISA is specific, sensitive, repeatable and can be applied for vaccines evaluation and detection the SADS-CoV infection in swine industry.