Molecular characterization of lumpy skin disease virus in North Central Vietnam during 2021 and early 2022.

In October 2020, the first outbreaks of lumpy skin disease (LSD) in Lang Son Province, Vietnam were reported by our laboratory. The disease had rapidly spread to the South, and it was reported in 55 of 63 provinces and cities of Vietnam by the end of 2021. The most economic loss caused by this disease occurred in the north-central region in 2021 where approximately 46,788 LSD virus (LSDV) infected cattle and buffaloes have been reported and 8,976 animals have been culled. However, the information on this pathogen circulating in this region is missing. Here, we describe the molecular characterization of LSDV circulating in north-central Vietnam in 2021 and early 2022. In total, 155 LSDV samples were collected during this period and three of these samples from each province were further characterized by Sanger sequencing analysis based on three key maker genes (GPCR, RPO30, and p32). Sequence comparison and phylogenetic analysis based on GPCR, RPO30, and p32 genes indicated that LSDV strains circulating in north-central Vietnam are closely related to previously reported strains in Vietnam regions which bordered China and all LSDV strains were 100% identical. These results show the importance of continuous monitoring and characterization of circulating LSDV strains and are important for vaccine development for the control and eradication of LSD in Vietnam.

An insight into emergence of lumpy skin disease virus: a threat to Indian cattle.

Lumpy skin disease (LSD) is a highly infectious and economically devastating viral disease of cattle. It is caused by Lumpy Skin Disease Virus (LSDV) belonging to the genus Capripoxvirus and family Poxviridae. The origin of lumpy skin disease has been traced to Zambia, (an African nation) in Southern part during the year 1929. The first reported case of LSD besides Africa was from Israel, a Middle Eastern nation, thus proving inter-continental spread. Subsequently, the disease entered Middle East, Eastern Europe and Asia with numerous outbreaks in the recent years. LSD has emerged as a significant concern in the Indian sub-continent, due to outbreaks reported in countries such as Bangladesh, India, China in 2019. In the following years, other South and East Asian countries like Taipei, Nepal, Sri Lanka, Myanmar, Bhutan, Vietnam, Hong Kong, Thailand, Malaysia, Laos, Cambodia, Pakistan, Indonesia and Singapore also faced severe outbreaks. At present, LSD is considered to be an emerging disease in the Indian sub-continent due to the recent status of disease. Considering the global scenario, LSDV is changing its transmission dynamics as evidenced by a shift in its epidemiology. As a result of high morbidity and mortality rate among cattle, the current outbreaks have been a major cause of socio-economic catastrophe. This contagious viral disease has eminent repercussions as the estimated monetary damage incurred is quite high. Despite having networked surveillance and comprehensive databases, the recurring outbreaks have raised major concern among researchers. Therefore, this review offers brief insights into the emergence of LSDV by amalgamating the newest literature related to its biology, transmission, clinico-pathology, epidemiology, prevention strategies, and economic consequences. Additionally, we have also provided the epidemiological insights of the recent outbreaks with detailed state wise studies.

Field and laboratory investigation of highly pathogenic avian influenza H5N6 and H5N8 in Quang Ninh province, Vietnam, 2020 to 2021.

BACKGROUND: Avian influenza (AI) is a contagious disease that causes illness and death in poultry and humans. High pathogenicity AI (HPAI) H5N6 outbreaks commonly occur in Quang Ninh province bordering China. In June 2021, the first HPAI H5N8 outbreak occurred at a Quang Ninh chicken farm. OBJECTIVES: This study examined the risk factors associated with HPAI H5N6 and H5N8 outbreaks in Quang Ninh. METHODS: A retrospective case-control study was conducted in Quang Ninh from Nov 2021 to Jan 2022. The cases were households with susceptible poultry with two or more clinical signs and tested positive by real-time reverse transcription polymerase chain reaction. The controls were households in the same village as the cases but did not show clinical symptoms of the disease. Logistic regression models were constructed to assess the risk factors associated with HPAI outbreaks at the household level. RESULTS: There were 38 cases with H5N6 clade 2.3.4.4h viruses (n = 35) and H5N8 clade 2.3.4.4b viruses (n = 3). Compared to the 112 controls, raising poultry in uncovered or partially covered ponds (odds ratio [OR], 7.52; 95% confidence interval [CI], 1.44-39.27), poultry traders visiting the farm (OR, 8.66; 95% CI, 2.7-27.69), farms with 50-2,000 birds (OR, 3.00; 95% CI, 1.06-8-51), and farms with ≥ 2,000 birds (OR, 11.35; 95% CI, 3.07-41.94) were significantly associated with HPAI outbreaks. CONCLUSIONS: Combining biosecurity measures, such as restricting visitor entry and vaccination in farms with more than 50 birds, can enhance the control and prevention of HPAI in Quang Ninh and its spread across borders.

A comparison of risk factor investigation and experts' opinion elicitation analysis for identifying foot-and-mouth disease (FMD) high-risk areas within the FMD protection zone of South Africa (2007-2016).

Foot-and-mouth disease is a controlled disease in accordance with the South African Animal Diseases Act (Act 35 of 1984). The country was classified by the World Organisation for Animal Health (WOAH) as having a FMD free zone without vaccination in 1996. However, this status was suspended in 2019 due to a FMD outbreak outside the controlled zones. FMD control in South Africa includes animal movement restrictions placed on cloven-hoofed species and products, prophylactic vaccination of cattle, clinical surveillance of susceptible species, and disease control fencing to separate livestock from wildlife reservoirs. The objectives of this study were to evaluate differences in identifying high-risk areas for FMD using risk factor and expert opinion elicitation analysis. Differences in risk between FMD introduction and FMD spread within the FMD protection zone with vaccination (PZV) of South Africa (2007-2016) were also investigated. The study was conducted in the communal farming area of the FMD PZV, which is adjacent to wildlife reserves and characterised by individual faming units. Eleven risk factors that were considered important for FMD occurrence and spread were used to build a weighted linear combination (WLC) score based on risk factor data and expert opinion elicitation. A multivariable conditional logistic regression model was also used to calculate predicted probabilities of a FMD outbreak for all dip-tanks within the study area. Smoothed Bayesian kriged maps were generated for 11 individual risk factors, overall WLC scores for FMD occurrence and spread and for predicted probabilities of a FMD outbreak based on the conditional logistic regression model. Descriptively, vaccine matching was believed to have a great influence on both FMD occurrence and spread. Expert opinion suggested that FMD occurrence was influenced predominantly by proximity to game reserves and cattle density. Cattle populations and vaccination practices were considered most important for FMD spread. Highly effective cattle inspections were observed within areas that previously reported FMD outbreaks, indicating the importance of cattle inspection (surveillance) as a necessary element of FMD outbreak detection. The multivariable conditional logistic regression analysis, which was consistent with expert opinion elicitation; identified three factors including cattle population density (OR 3.87, 95% CI 1.47-10.21) and proximities to game reserve fences (OR 0.82, 95% CI 0.73-0.92) and rivers (OR 1.04, 95% CI 1.01-1.07) as significant factors for reported FMD outbreaks. Regaining and maintaining an FMD-free status without vaccination requires frequent monitoring of high-risk areas and designing targeted surveillance.

Seroprevalence and molecular detection of foot and mouth disease virus in cattle in selected districts of Wolaita Zone, Southern Ethiopia.

Foot and mouth disease (FMD) is a highly contagious, endemic, and acute viral cattle ailment that causes major economic damage in Ethiopia. Although several serotypes of the FMD virus have been detected in Ethiopia, there is no documented information about the disease's current serostatus and serotypes circulating in the Wolaita zone. Thus, from March to December 2022, a cross-sectional study was conducted to evaluate FMDV seroprevalence, molecular detection, and serotype identification in three Wolaita Zone sites. A multistage sample procedure was used to choose three peasant associations from each study region, namely Wolaita Sodo, Offa district, and Boloso sore district. A systematic random sampling technique was employed to pick 384 cattle from the population for the seroprevalence research, and 10 epithelial tissue samples were purposefully taken from outbreak individuals for molecular detection of FMDV. The sera were examined using 3ABC FMD NSP Competition ELISA to find antibodies against FMDV non-structural proteins, whereas epithelial tissue samples were analyzed for molecular detection using real-time RT-PCR, and sandwich ELISA was used to determine the circulating serotypes. A multivariable logistic regression model was used to evaluate the associated risk variables. The total seroprevalence of FMD in cattle was 46.88% (95% CI 41.86-51.88), with Wolaita Sodo Town having the highest seroprevalence (63.28%). As a consequence, multivariable logistic regression analysis revealed that animal age, herd size, and interaction with wildlife were all substantially related to FMD seroprevalence (p < 0.05). During molecular detection, only SAT-2 serotypes were found in 10 tissue samples. Thus, investigating FMD outbreaks and identifying serotypes and risk factors for seropositivity are critical steps in developing effective control and prevention strategies based on the kind of circulating serotype. Moreover, further research for animal species other than cattle was encouraged.

Oral Fluids for the Early Detection of Classical Swine Fever in Commercial Level Pig Pens.

The early detection of classical swine fever (CSF) remains a key challenge, especially when outbreaks are caused by moderate and low-virulent CSF virus (CSFV) strains. Oral fluid is a reliable and cost-effective sample type that is regularly surveilled for endemic diseases in commercial pig herds in North America. Here, we explored the possibility of utilizing oral fluids for the early detection of CSFV incursions in commercial-size pig pens using two independent experiments. In the first experiment, a seeder pig infected with the moderately-virulent CSFV Pinillos strain was used, and in the second experiment, a seeder pig infected with the highly-virulent CSFV Koslov strain was used. Pen-based oral fluid samples were collected daily and individual samples (whole blood, swabs) every other day. All samples were tested by a CSFV-specific real-time RT-PCR assay. CSFV genomic material was detected in oral fluids on the seventh and fourth day post-introduction of the seeder pig into the pen, in the first and second experiments, respectively. In both experiments, oral fluids tested positive before the contact pigs developed viremia, and with no apparent sick pigs in the pen. These results indicate that pen-based oral fluids are a reliable and convenient sample type for the early detection of CSF, and therefore, can be used to supplement the ongoing CSF surveillance activities in North America.

The Effectiveness of Protection and Surveillance Zones in Detecting Further African Swine Fever Outbreaks in Domestic Pigs-Experience of the Baltic States.

In the event of an outbreak of African swine fever (ASF) in pig farms, the European Union (EU) legislation requires the establishment of a restricted zone, consisting of a protection zone with a radius of at least 3 km and a surveillance zone with a radius of at least 10 km around the outbreak. The main purpose of the restricted zone is to stop the spread of the disease by detecting further outbreaks. We evaluated the effectiveness and necessity of the restricted zone in the Baltic States by looking at how many secondary outbreaks were detected inside and outside the protection and surveillance zones and by what means. Secondary outbreaks are outbreaks with an epidemiological link to a primary outbreak while a primary outbreak is an outbreak that is not epidemiologically linked to any previous outbreak. From 2014 to 2023, a total of 272 outbreaks in domestic pigs were confirmed, where 263 (96.7%) were primary outbreaks and 9 (3.3%) were secondary outbreaks. Eight of the secondary outbreaks were detected by epidemiological enquiry and one by passive surveillance. Epidemiological enquiries are legally required investigations on an outbreak farm to find out when and how the virus entered the farm and to obtain information on contact farms where the ASF virus may have been spread. Of the eight secondary outbreaks detected by epidemiological investigations, six were within the protection zone, one was within the surveillance zone and one outside the restricted zone. Epidemiological investigations were therefore the most effective means of detecting secondary outbreaks, whether inside or outside the restricted zones, while active surveillance was not effective. Active surveillance are legally prescribed activities carried out by the competent authorities in the restricted zones. Furthermore, as ASF is no longer a rare and exotic disease in the EU, it could be listed as a "Category B" disease, which in turn would allow for more flexibility and "tailor-made" control measures, e.g., regarding the size of the restricted zone.

The role of vehicle movement in swine disease dissemination: Novel method accounting for pathogen stability and vehicle cleaning effectiveness uncertainties.

Several propagation routes drive animal disease dissemination, and among these routes, contaminated vehicles traveling between farms have been associated with indirect disease transmission. In this study, we used near-real-time vehicle movement data and vehicle cleaning efficacy to reconstruct the between-farm dissemination of the African swine fever virus (ASFV). We collected one year of Global Positioning System data of 823 vehicles transporting feed, pigs, and people to 6363 swine production farms in two regions in the U.S. Without cleaning, vehicles connected up to 2157 farms in region one and 437 farms in region two. Individually, in region one vehicles transporting feed connected 2151 farms, pigs to farms 2089 farms, pigs to market 1507 farms, undefined vehicles 1760 farm, and personnel three farms. The simulation results indicated that the contact networks were reduced the most for crew transport vehicles with a 66% reduction, followed by vehicles carrying pigs to market and farms, with reductions of 43% and 26%, respectively, when 100% cleaning efficacy was achieved. The results of this study showed that even when vehicle cleaning and disinfection are 100% effective, vehicles are still connected to numerous farms. This emphasizes the importance of better understanding transmission risks posed by vehicles to the swine industry and regulatory agencies.

Streptococcus zooepidemicus in dogs: Exploring a canine pathogen through multilocus sequence typing.

Streptococcus equi. subsp. zooepidemicus (S. zooepidemicus) associated diseases in dogs have emerged as a significant concern over recent decades. S. zooepidemicus occurs sporadically in dog populations globally, with increased prevalence in shelters/kennels. This study used multilocus sequence typing (MLST) of 149 independent canine S. zooepidemicus isolates to assess associations between sequence type and breed, country of origin, disease severity, sampling type, year, and behaviour within an outbreak. No clear associations for breed, country, sampling type and year were determined in this study. ST-10 and 123 strains were present within all disease categories, from no clinical signs to severe disease. Assessment of S. zooepidemicus infection in 3 UK outbreaks at the same location found ST-10, 18, 123 strains, and a ST-173 strain in a US outbreak, were associated with haemorrhagic pneumonia and persisted in kennelled populations over time. The ST-173 clonal complex has been noted to have severe virulence capabilities in dogs and other species. S. zooepidemicus seems to thrive in environments with a high risk of transmissibility, overcrowding, stress and naïve populations, particularly for those in shelters/kennels. MLST alone cannot determine the virulence phenotype of S. zooepidemicus in dogs. However, a level of conservancy and diversity within ST allelic loci aids the opportunity to cause severe disease in dogs. Thus, further research into whole genome sequencing and characterising the virulence factors of S. zooepidemicus is warranted in dogs.

Coxiella burnetii infection persistence in a goat herd during seven kidding seasons after an outbreak of abortions: the effect of vaccination.

Coxiella burnetii infection was monitored during seven kidding seasons (2017-2023) in a dairy goat herd that after an outbreak of Q fever abortions was vaccinated with an inactivated phase I vaccine. Due to the high infection rate just after the outbreak, only the replacement stock was vaccinated during the first three kidding seasons, and when the average herd immunity had decreased (fourth kidding season onwards), the whole herd was vaccinated. Vaginal swabs, feces, and milk were analyzed by PCR to monitor infection, and dust and aerosols were analyzed to measure C. burnetii environmental contamination. One year after the onset of the outbreak, a significant reduction in C. burnetii shedding loads was observed, but the percentage of shedding animals remained high until the third kidding season. By the seventh kidding season, no shedders were detected. The bacterial load excreted was significantly lower in vaccinated compared with unvaccinated animals, and in yearlings compared with multiparous. C. burnetii was detected by PCR in aerosols collected inside the animal premises throughout the study period except in the last season; whereas, aerosols collected outdoors tested negative in the last three kidding seasons. Viable C. burnetii was detectable in environmental dust collected inside the barn until the third kidding season following the outbreak. These results indicate that after an outbreak of Q fever, the risk of infection for humans and susceptible animals can remain high for at least three kidding seasons when the number of C. burnetii animal shedders is still high, even when bacterial excretion is low. IMPORTANCE: Q fever is a zoonosis distributed worldwide. Ruminants are the main reservoir, and infection can cause high rates of abortion. After entering a farm, Coxiella burnetii infection can persist in the animal population over several lambing/kidding periods. Once infection is established in a herd, vaccination with the inactivated Phase I vaccine significantly reduces bacterial shedding, but although at low levels, excretion may continue to occur for several lambing/kidding seasons. The time that C. burnetii remains viable in the farm environment after an outbreak of Q fever determines the period when risk of infection is high for the people in close contact. This work showed that this period extends at least three kidding seasons after the outbreak. These results provided valuable information on the epidemiology of C. burnetii infection in goat herds and may help to develop guidelines for controlling the disease and reducing infection risk for susceptible people and animals.

Detection and Genome Sequencing of Lumpy Skin Disease Viruses in Wildlife Game Species in South Africa.

Lumpy skin disease virus (LSDV) has recently undergone rapid spread, now being reported from more than 80 countries, affecting predominantly cattle and to a lesser extent, water buffalo. This poxvirus was previously considered to be highly host-range restricted. However, there is an increasing number of published reports on the detection of the virus from different game animal species. The virus has not only been shown to infect a wide range of game species under experimental conditions, but has also been naturally detected in oryx, giraffe, camels and gazelle. In addition, clinical lumpy skin disease has previously been described in springbok (Antidorcas marsupialis), an African antelope species, in South Africa. This report describes the characterization of lumpy skin disease virus belonging to cluster 1.2, from field samples from springbok, impala (Aepyceros melampus) and a giraffe (Giraffa camelopardalis) in South Africa using PCR, Sanger and whole genome sequencing. Most of these samples were submitted from wild animals in nature reserves or game parks, indicating that the disease is not restricted to captive-bred animals on game farms or zoological gardens. The potential role of wildlife species in the transmission and maintenance of LSDV is further discussed and requires continuing investigation, as the virus and disease may pose a serious threat to endangered species.

Enzootic Circulation, Massive Gull Mortality and Poultry Outbreaks during the 2022/2023 High-Pathogenicity Avian Influenza H5N1 Season in the Czech Republic.

In 2022/2023, Europe experienced its third consecutive season of high-pathogenicity avian influenza. During this period, the Czech Republic was again severely affected. For the first time, the number of culled birds approached one million, which was three times higher than in previous seasons. In parallel to the outbreaks in poultry, mass die-offs of gulls were also observed. In the present study, we performed whole-genome sequencing and phylogenetic analysis of 137 H5N1 strains collected in the Czech Republic in 2022/2023 (94.6% of all outbreaks or locations). The analysis revealed four distinct genotypes: AB, CH, BB and AF. Phylogenetic analysis suggested that the AF genotype persisted from the previous H5N1 season without reassortment. In addition, the genotype BB, which was detected mainly in gulls, showed a noticeable strain diversity at the local level. This virus was also responsible for a single outbreak in commercially bred turkeys. Finally, an interesting spatio-temporal cluster with three co-circulating H5N1 genotypes, AB, CH and AF, was identified with no evidence of intrasubtype reassortment. Highly sensitive molecular surveillance and the timely sharing of genomic sequences and associated metadata could greatly assist in tracking the spread and detecting molecular changes associated with the increased virulence of this potentially zoonotic pathogen.

Identification of neuropathogenic Varicellovirus equidalpha1 as a potential cause of respiratory disease outbreaks among horses in North Xinjiang, China, from 2021-2023.

BACKGROUND: Varicellovirus equidalpha1 (formerly Equid alphaherpesvirus 1, EqAHV-1) is among the most important viruses responsible for respiratory disease outbreaks among horses throughout the world. No reports to date have detailed the association between EqAHV-1 and respiratory disease among horses in China. This study described one such outbreak among a population of horses in north Xinjiang that occurred from April 2021 - May 2023. RESULTS: qPCR revealed that EqAHV-1 was detectable in all samples and this virus was identified as a possible source of respiratory disease, although a limited subset of these samples were also positive for EqAHV-2, EqAHV-4, and EqAHV-5. In total, three EqAHV-1 strains responsible for causing respiratory illness in horses were isolated successfully, and full-length ORF33 sequence comparisonsand phylogenetic analyses indicated that these isolates may have originated from EqAHV-1 strains detected in Yili horse abortions. ORF30 sequence data additionally suggested that these strains were neuropathic, as evidenced by the presence of a guanine residue at nucleotide position 2254 corresponding to the aspartic acid present at position 752 in the DNA polymerase encoded by this virus. CONCLUSION: This study is the first report of an outbreak of respiratory disease among horses in China caused by EqAHV-1. ORF30 sequence characterization revealed that these EqAHV-1 strains harbored a neuropathogenic genotype. Given the detection of this virus in horses suffering from respiratory disease, concern is warranted with respect to this neuropathogenic EqAHV-1 outbreak.

Emergence of lumpy skin disease virus (LSDV) infection in domestic Himalayan yaks (Bos grunniens) in Himachal Pradesh, India.

In this study, we investigated and confirmed natural lumpy skin disease virus (LSDV) infection in Himalayan yaks (Bos grunniens) in Himachal Pradesh, India, based on clinical manifestations and results of genome detection, antibody detection, virus isolation, and nucleotide sequencing. Subsequent phylogenetic analysis based on complete GPCR, RPO30, and EEV gene sequences revealed that the LSDV isolates from these yaks and local cattle belonged to LSDV subcluster 1.2.1 rather than the dominant subcluster 1.2.2, which is currently circulating in India, suggesting a separate recent introduction. This is the first report of natural LSDV infection in yaks in India, expanding the known host range of LSDV. Further investigations are needed to assess the impact of LSDV infection in yaks.

Multifaceted analysis of temporal and spatial distribution and risk factors of global poultry HPAI-H5N1, 2005-2023.

The purpose of this study was to analyze the characteristics of occurrence and spread of highly pathogenic avian influenza H5N1 (HPAI-H5N1) globally, understand its spatiotemporal characteristics, investigate the risk factors influencing outbreaks, and identify high-risk areas for disease occurrence. We collected the data on global poultry HPAI-H5N1 outbreaks from January 2005 to April 2023, and conducted a thorough analysis of the spatial and temporal characteristics of the disease through time series decomposition and directional distribution analysis. Additionally, an ecological niche model was established to explore the major factors influencing the occurrence of HPAI-H5N1 and to pinpoint high-risk areas. Our findings revealed that HPAI-H5N1 outbreaks were cyclical, and seasonal, exhibiting a rising trend, with a predominant northwest-southeast transmission direction. The ecological niche model highlighted that species factors and economic trade factors are critical in influencing the outbreak of HPAI-H5N1. Variables such as chicken and duck density, population density, isothermality, and road density, contributed to importantly risk of outbreaks. High-risk areas for HPAI-H5N1 occurrence were primarily identified in Europe, West Africa, Southeast Asia, and Southeast China. This study provided valuable insights into the spatial and temporal distribution characteristics and risk factors of global poultry HPAI-H5N1 outbreaks. The identification of high-risk areas provides essential information that can be used to develop more effective prevention and control policies.

Environmental relationships and anthrax epidemiology: field experiences of host resistance as opposed to dose-dependent experiments.

Even though anthrax is a disease of antiquity that has been studied for centuries, serious concerns have been raised about our understanding of its epidemiology. Since the 1960s, we have based the epidemiology of anthrax on the results of dose-dependent experiments, especially those involving cattle at that time. In this species the experiments demonstrated that the severity of infection was dependent upon the numbers of Bacillus anthracis spores ingested. The opinion was that ingesting only a few spores would be insufficient to cause an apparent infection; any infection that resulted would be latent (i.e., unrecognized). Based on the results of these experiments, it was accepted that the ingestion of large numbers of spores was the source of infection for hundreds of anthrax outbreaks. However, many investigations of both human and animal anthrax outbreaks have failed to identify sources of large numbers of spores, suggesting that these outbreaks are only rarely a consequence of ingestion or inhalation of large quantities of spores. This opinion piece builds upon the indirect evidence previously presented in an article focused on the existence of latent infections. Much of the evidence for the existence of latent infections was predicated upon a reduction of host resistance, which revealed how latent infections could be a source of more severe forms of the infection. That is, a latent infection can be the source of a severe infection, but the cause of the severe infection is the reduced host resistance. That first article concentrated on the arguments for latent infections, while this article concentrates on the arguments for host resistance. Host resistance is virtually impossible to measure objectively in the field. To provide a subjective measure of host resistance during anthrax outbreaks, we suggest the use of the opinions of livestock owners and or their veterinary practitioners and or field workers during investigations of anthrax outbreaks. When veterinary personal work in the field they are much like field biologists. In some ways field biologists better appreciate environmental factors, population ecology and other perspectives that are of use to epidemiologists. The more diverse the information the better the epidemiology is understood. To this effect we present our personal anecdotal and theoretical ideas from our experiences as well as a collection of bibliographic observations from others'. Our conclusions are that a combination of latent infections and reduced host resistance based on the host's relationship with its environment would better explain the epidemiology of severe infections in anthrax outbreaks for which large quantities of spores have not been located. This applies especially if the area has a history of the disease and/or if necropsies have shown the presence of latent infections in otherwise normal animals in the area and/or if environmental conditions are considered stressful and include intense insect activity.

Spatio-temporal analysis and risk modeling of foot-and-mouth disease outbreaks in China.

FMD is an acute contagious disease that poses a significant threat to the health and safety of cloven-hoofed animals in Asia, Europe, and Africa. The impact of FMD exhibits geographical disparities within different regions of China. The present investigation undertook an exhaustive analysis of documented occurrences of bovine FMD in China, spanning the temporal range from 2011 to 2020. The overarching objective was to elucidate the temporal and spatial dynamics underpinning these outbreaks. Acknowledging the pivotal role of global factors in FMD outbreaks, advanced machine learning techniques were harnessed to formulate an optimal prediction model by integrating comprehensive meteorological data pertinent to global FMD. Random Forest algorithm was employed with top three contributing factors including Isothermality(bio3), Annual average temperature(bio1) and Minimum temperature in the coldest month(bio6), all relevant to temperature. By encompassing both local and global factors, our study provides a comprehensive framework for understanding and predicting FMD outbreaks. Furthermore, we conducted a phylogenetic analysis to trace the origin of Foot-and-mouth disease virus (FMDV), pinpointing India as the country posing the greatest potential hazard by leveraging the spatio-temporal attributes of the collected data. Based on this finding, a quantitative risk model was developed for the legal importation of live cattle from India to China. The model estimated an average probability of 0.002254% for FMDV-infected cattle imported from India to China. TA sensitivity analysis identified two critical nodes within the model: he possibility of false negative clinical examination in infected cattle at destination (P5) and he possibility of false negative clinical examination in infected cattle at source(P3). This comprehensive approach offers a thorough evaluation of FMD landscape within China, considering both domestic and global perspectives, thereby augmenting the efficacy of early warning mechanisms.