Infected Farms Research Articles

Genetic Characterization of African Swine Fever Virus from Pig Farms in South Korea during Outbreaks in 2019-2021.

In South Korea, a total of 21 African swine fever (ASF) infected farms were confirmed during 2019-2021. ASF viruses (ASFVs) were isolated from the blood and spleen samples of the 21 affected farms and their genetic characteristics were analyzed. Phylogenetic analysis indicated that the 21 Korean ASFV strains belonged to p72 genotype II and serogroup 8. All isolates were of the intergenic region (IGR) II variant with 10 tandem repeat sequences between I73R and I329L and the central variable region (CVR) 1 variant of the B602L gene. There were no IGR variations between the A179L and A137R and between the MGF 505 9R and10R nor mutations in the O174L, K145R, MGF 505-5R, CP204L, and Bt/Sj regions. The genes of the 21 ASFV strains were identical to those of Georgia 2007/1 and Chinese and Vietnamese strains (Pig/HLJ/2018, China/2018/AnhuiXCGQ, and ASFV_NgheAn_2019); however, X69R of the J268L region of the 18th isolate (Korea/Pig/Goseong/2021) had three nucleotide (CTA) insertions at the 209th position, which led to the addition of one tyrosine (Y) at the C-terminal. This suggests that there are variations among ASFVs circulating in South Korea and the 18th ASFV-infected farm was due to a variant different from those of the other 20 pig farms.

Dissection of Besnoitia besnoiti intermediate host life cycle stages: From morphology to gene expression.

Cyst-forming Apicomplexa (CFA) of the Sarcocystidae have a ubiquitous presence as pathogens of humans and farm animals transmitted through the food chain between hosts with few notable exceptions. The defining hallmark of this family of obligate intracellular protists consists of their ability to remain for very long periods as infectious tissue cysts in chronically infected intermediate hosts. Nevertheless, each closely related species has evolved unique strategies to maintain distinct reservoirs on global scales and ensuring efficient transmission to definitive hosts as well as between intermediate hosts. Here, we present an in-depth comparative mRNA expression analysis of the tachyzoite and bradyzoite stages of Besnoitia besnoiti strain Lisbon14 isolated from an infected farm animal based on its annotated genome sequence. The B. besnoiti genome is highly syntenic with that of other CFA and also retains the capacity to encode a large majority of known and inferred factors essential for completing a sexual cycle in a yet unknown definitive host. This work introduces Besnoitia besnoiti as a new model for comparative biology of coccidian tissue cysts which can be readily obtained in high purity. This model provides a framework for addressing fundamental questions about the evolution of tissue cysts and the biology of this pharmacologically intractable infectious parasite stage.

Two major epidemics of highly pathogenic avian influenza virus H5N8 and H5N1 in domestic poultry in France, 2020-2022.

The spread of highly pathogenic avian influenza (HPAI) viruses worldwide has serious consequences for animal health and a major economic impact on the poultry production sector. Since 2014, Europe has been severely hit by several HPAI epidemics, with France being the most affected country. Most recently, France was again affected by two devastating HPAI epidemics in 2020-21 and 2021-22. We conducted a descriptive analysis of the 2020-21 and 2021-22 epidemics, as a first step towards identifying the poultry sector's remaining vulnerabilities regarding HPAI viruses in France. We examined the spatio-temporal distribution of outbreaks that occurred in France in 2020-21 and 2021-22, and we assessed the outbreaks' spatial distribution in relation to the 2016-17 epidemic and to the two 'high-risk zones' recently incorporated into French legislation to strengthen HPAI prevention and control. There were 468 reported outbreaks during the 2020-21 epidemic and 1375 outbreaks during the 2021-22 epidemic. In both epidemics, the outbreaks' distribution matched extremely well that of 2016-17, and most outbreaks (80.6% and 68.4%) were located in the two high-risk zones. The southwestern high-risk zone was affected in both epidemics, while the western high-risk zone was affected for the first time in 2021-22, explaining the extremely high number of outbreaks reported. As soon as the virus reached the high-risk zones, it started to spread between farms at very high rates, with each infected farm infecting between two and three other farms at the peaks of transmission. We showed that the spatial distribution model used to create the two high-risk zones was able to predict the location of outbreaks for the 2020-21 and 2021-22 epidemics. These zones were characterized by high poultry farm densities; future efforts should, therefore, focus on reducing the density of susceptible poultry in highly dense areas.

Estimation of introduction time window of highly pathogenic avian influenza virus into broiler chicken farms during the 2020 – 2021 winter season outbreak in Japan

When an infectious disease occurs in an area, early detection of infected farms is important to respond quickly and contain the outbreak on a small scale. Estimating the time window for the introduction of the infection is important for its prevention and control. The aim of this study was to estimate the farm-specific time window from the introduction of the highly pathogenic avian influenza (HPAI) virus into poultry farms using field data from the HPAI H5N8 outbreak in the 2020–2021 winter season in Japan. Daily mortality data from 12 broiler chicken farms during the outbreak were used for the analysis. A mathematical model (Susceptible-Exposed-Infectious-Removed, SEIR model) was applied to generate the within-flock transmission of HPAI. The model-predicted mortality was fitted to the observed excess mortality data induced by HPAI to estimate the farm-specific transmission rate and the time of virus introduction. The estimated value of the transmission rate in each farm was 1.449 day−1 in median (min: 0.661 day−1, max: 3.387 day−1). The time window from the introduction of the virus to notification in each farm was estimated at 14.0 days in median (min: 8.6 days, max: 24.1 days) in the deterministic model. In addition, in the stochastic model considering the randomness of transmission in the early phase of the outbreak, the upper value of 95 % credible interval of the time window ranged from 12 to 34 days, with a median of 21 days. The results suggest that although one to three weeks had elapsed on most farms until notification after the virus introduction, the time window could exceed three weeks considering the stochasticity of disease transmission. As for the potential farm characteristics affecting within-flock transmission, the transmission rate was smaller (p-value=0.02) and the estimated time window from introduction to notification was longer (p-value=0.02) when birds were older. This study provides reliable information for setting up a tracing period for a potential source farm and enhancing the efforts for early detection.

Multilayer network analysis of FMD transmission and containment among beef cattle farms

As a highly contagious livestock viral disease, foot-and-mouth disease poses a great threat to the beef-cattle industry. Direct animal movement is always considered as a major route for between-farm transmission of FMD virus. Sharing contaminated equipment and vehicles have also attracted increasing interests as an indirect but considerable route for FMD virus transmission. With the rapid development of communication technologies, information-sharing techniques have been used to control epidemics. In this paper, we built farm-level time-series three-layer networks to simulate the between-farm FMD virus transmission in southwest Kansas by cattle movements (direct-contact layer) and truck visits (indirect-contact layer) and evaluate the impact of information-sharing techniques (information-sharing layer) on mitigating the epidemic. Here, the information-sharing network is defined as the structure that enables the quarantine of farms that are connected with infected farms. When a farm is infected, its infection status is shared with the neighboring farms in the information-sharing network, which in turn become quarantined. The results show that truck visits can enlarge the epidemic size and prolong the epidemic duration of the FMD outbreak by cattle movements, and that the information-sharing technique is able to mitigate the epidemic. The mitigation effect of the information-sharing network varies with the information-sharing network topology and different participation levels. In general, an increased participation leads to a decreased epidemic size and an increased quarantine size. We compared the mitigation performance of three different information-sharing networks (random network, contact-based network, and distance-based network) and found the outbreak on the network with contact-based information-sharing layer has the smallest epidemic size under almost any participation level and smallest quarantine size with high participation. Furthermore, we explored the potential economic loss from the infection and the quarantine. By varying the ratio of the average loss of quarantine to the loss of infection, we found high participation results in reduced economic losses under the realistic assumption that culling costs are much greater than quarantine costs.

From the Intersection of Food-Borne Zoonoses and EU Green Policies to an In-Embryo One Health Financial Model.

The European Union (EU) adopts the One Health (OH) approach, based on the relationships between human, animal, and environmental health. OH concerns a multitude of aspects, some of which are discussed here. OH overlaps the European Green Deal plan and its relaunched Farm to Fork Strategy, which aims at spreading organic farms adopting the circular economy, in order to improve human health through both better environmental conditions and healthier food. Nevertheless, zoonoses cause sanitary cost in terms of infected farm personnel, lower productivity, and lower fertility of infected farm animals. In such scenarios, the decreased breeding yield and the lower income induce higher cost of farm products, meaning that the market price rises, becoming uncompetitive when compared to the prices of industrial products. Consequently, lower revenues can hinder the farm growth expected in the framework of the EU Green Deal. Since zoonosis control is a key element in aligning EU policies aimed at achieving the EU Green Deal goal of “ZERO environmental impact” by 2050, the authors suggest the inclusion of the parameter economic health in the OH approach, in order to individuate EU Member States (MSs) economically unable to conduct eradication programmes and to finance them. Economic health is here considered as a starting point of the new ethical and science-based One Health Financial Model that the authors suggest as an in-embryo model, in which specific rules should regulate public funds, private investments, and trading, which should exclusively concern public services and private enterprises complying with most of the OH parameters. In this way, economic losses due to collateral negative effects deriving from human activities can be progressively decreased, and the entire planet will benefit from the process. Despite the considerable efforts being carried out in the context of the OH approach, war causes tragic and devastating effects on the physical and mental health of human beings, on their lives, on pandemic and zoonotic threats, on animals, on plants and, last but not least, on the environment. War is incompatible with OH. Enormous efforts for peace are therefore urgently needed.

The effect of gilt flow management during acclimation on Mycoplasma hyopneumoniae detection

The objective of this study was to characterize the Mycoplasma hyopneumoniae (M. hyopneumoniae) detection and seroconversion patterns in recently acclimated gilts to be introduced to endemically infected farms using different types of replacement management. Three gilt developing units (GDUs) belonging to sow farms were included in this investigation: two farms managed gilts in continuous flow, and one farm managed gilts all-in/all-out. Two replicates of 35 gilts each were selected per GDU and sampled approximately every 60 days for a total of four or five samplings, per replicate and per GDU. Detection of M. hyopneumoniae was evaluated by PCR, while antibodies were measured using a commercial ELISA assay. Also, M. hyopneumoniae genetic variability was evaluated using Multiple-Locus Variable number tandem repeat Analysis. Detection of M. hyopneumoniae was similar across GDUs. Although a significant proportion of gilts was detected positive for M. hyopneumoniae after acclimation, an average of 30.3 % of gilts was negative at any point during the study. Detection of M. hyopneumoniae antibodies was similar among GDUs regardless of flow type or vaccination protocol. The genetic variability analysis revealed a limited number of M. hyopneumoniae types within each GDU. Results of this study showed a similar pattern of M. hyopneumoniae detection by PCR and seroconversion by ELISA among GDUs, regardless of the type of flow management strategies applied to gilts.

Cattle transport network predicts endemic and epidemic foot-and-mouth disease risk on farms in Turkey

The structure of contact networks affects the likelihood of disease spread at the population scale and the risk of infection at any given node. Though this has been well characterized for both theoretical and empirical networks for the spread of epidemics on completely susceptible networks, the long-term impact of network structure on risk of infection with an endemic pathogen, where nodes can be infected more than once, has been less well characterized. Here, we analyze detailed records of the transportation of cattle among farms in Turkey to characterize the global and local attributes of the directed—weighted shipments network between 2007-2012. We then study the correlations between network properties and the likelihood of infection with, or exposure to, foot-and-mouth disease (FMD) over the same time period using recorded outbreaks. The shipments network shows a complex combination of features (local and global) that have not been previously reported in other networks of shipments; i.e. small-worldness, scale-freeness, modular structure, among others. We find that nodes that were either infected or at high risk of infection with FMD (within one link from an infected farm) had disproportionately higher degree, were more central (eigenvector centrality and coreness), and were more likely to be net recipients of shipments compared to those that were always more than 2 links away from an infected farm. High in-degree (i.e. many shipments received) was the best univariate predictor of infection. Low in-coreness (i.e. peripheral nodes) was the best univariate predictor of nodes always more than 2 links away from an infected farm. These results are robust across the three different serotypes of FMD observed in Turkey and during periods of low-endemic prevalence and high-prevalence outbreaks.

Risk factors and the overall characterization of Yersinia enterocolitica as an initial model of pathogen surveillance in the pig production system in Serbia

A survey was undertaken to determine the overall prevalence of Yersinia enterocolitica in pigs of slaughter age and to characterize the isolates in relation to bio-serotype, the presence of virulence genes, genetic diversity, and antimicrobial resistance. Moreover, possible risk factors associated with Y. enterocolitica infection during the pre-harvested and harvested phase of pig production were studied. The overall Y. enterocolitica prevalence in the pigs was 10.4% (95% confidence interval, CI = 8.5–12.3%). The most common Y. enterocolitica bio-serotype was 4/O:3, accounting for 81.6% of investigated isolates. The pathogenicity of 63 Y. enterocolitica 4/O:3 isolates, originating from all infected farms, was confirmed by the presence of both the ail and ystA virulence-associated genes and the absence of ystB gene (100%). Characterization with PFGE of 63 confirmed Y. enterocolitica 4/O:3 isolates identified five different genotypes with shared identical genetic profiles (100% similarity) within each genotype. Isolates originating from farrow-to-finish farms were only resistant to ampicillin, while resistance to nalidixic acid, tetracycline, and chloramphenicol at fattening farms was also observed. Risk factors related to Y. enterocolitica pig infection include fattening farms (odds ratio, OR = 2.3, 95% CI = 1.4–3.8, P < 0.001), a 3–6 h lairage period (OR = 1.6, 95% CI = 1.0–2.6, P = 0.035) and winter season (OR = 3.8, 95% CI = 2.0–7.4, P < 0.001). In addition to the overall characterization of Y. enterocolitica isolates, identification of the main risks associated with infection allows better application of preventive measures to reduce the occurrence and distribution of Y. enterocolitica infection.

Epidemiological investigation of morbidity and mortality of improved breeds of chickens in small holder poultry farms in selected districts of Sidama Region, Ethiopia

BackgroundA longitudinal study was conducted in six intensive and three semi-intensive poultry farms in Shebedino and Dale districts of Sidama Region, Ethiopia from November 2018 to May 2019. The objectives of the study were to estimate incidence rates of mortality and morbidity, identify the risk factors associated with morbidity and mortality and establish differential diagnosis of major diseases affecting poultry in the area. Chickens belonging to two breeds namely Sasso, and Bovans Brown reared in purposively selected small-scale farms was included from two districts. The chickens on the selected farms were monitored for morbidity and mortality every week. Diagnosis of different diseases was made based on the flock history, age of birds, clinical signs, characteristic gross and microscopic lesions, and fecal flotation technique for coccidiosis. Semi-structured questionnaires were also administered to gather information on the risk factors and farming practices. ResultsThe incidence rate of morbidity and mortality in the studied farms was 16.14 and 12.69 per 1000 chicken-week at risk, respectively. The minimum and maximum incidence rates of morbidity were 2.02 and 58.43 cases per 1000 chicken-week at risk, respectively. The minimum and maximum incidence rates of mortality were 0.21 and 58.18 deaths per 1000 chicken-week at risk, respectively. Among the risk factors studied feed type, age of chickens, and number of sick chickens on farms were significantly associated (p < 0.05) with the incidence of disease. Age of chickens and number of sick chickens found on the farms were significantly associated (p < 0.05) with the incidence of death using multivariable logistic regression. Newcastle Disease (ND), Infectious Bursal Disease (IBD), Fowl typhoid, and Coccidiosis were the important diseases identified during the follow up period in the study area. Of the overall mortality and morbidity, 90.48% and 42% were respectively attributed to ND. Infectious bursal disease and Coccidia co-infection occurred in 31.55% of chicken in the infected farms. ConclusionsThe present study documented the incidence rate of morbidity and mortality in smallholder poultry farms in selected districts of Sidama Region. The study findings indicated that infectious diseases appear to be a major constraint to improve chicken production in the study areas. Therefore, the veterinary and livestock authorities should take this into account when planning poultry development activities and setting up systems of livestock production and health monitoring.

Bacterial diseases outbreaks in some freshwater fish farms in Kafr El-Sheikh, Egypt

ABSTRACT Bacterial fish diseases are one of the challenges facing the aquaculture industry and lead to tremendous economic losses. After surveying the infected farms understudy from April 2018 to November 2019, we collected 480 samples from 12 tilapia and carp farms experiencing mortalities in Kafr El-Sheikh region of Egypt with major aquaculture production. Clinically, hemorrhages, exophthalmia, and ulceration were the most common symptoms. We then determined the frequency, bacteriological and molecular identity, antibiotic sensitivity, pathogenicity, and histopathological characteristics of pathogens. For molecular identification was used a set of specific primers (16S rRNA, 16SPSEflu, and Sin-1b). Our results showed that Aeromonas hydrophila, Pseudomonas fluorescens, and Streptococcus iniae were the most important causes. Antibiotic sensitivity test revealed that all isolates were highly sensitive to ciprofloxacin. Additionally, naturally and experimentally infected fish are the same in pathognomonic signs. Overall, a valuable tool for diagnosis is the combination of both bacteriological and molecular examination. Besides, choosing the best antibiotics by sensitivity test helps avoid drug resistance phenomenon.

The SLI-SC Mathematical Model of African Swine Fever Transmission among Swine Farms: The Effect of Contaminated Human Vector

In this paper, a mathematical model for African swine fever is modified by considering the swine farm with the contaminated human vector that is able to infect and spread the disease among swine farms. In the developed model, we have divided the swine farm density into three related groups, namely the susceptible swine farm compartment, latent swine farm compartment, and infectious swine farm compartment. On the other hand, the human vector population density has been separated into two classes, namely the susceptible human vector compartment and the infectious human vector compartment. After that, we use this model and a quarantine strategy to analyze the spread of the infection. In addition, the basic reproduction number R0 is determined by using the next-generation matrix, which can analyze the stability of the model. Finally, the numerical simulations of the proposed model are illustrated to confirm the results from theorems. The results showed that the transmission coefficient values per unit of time per individual between the human vector and the swine farm resulted in the spread of African swine fever.

A New Sampling Approach for the Detection of Swine Influenza a Virus on European Sow Farms.

Simple SummaryDue to concerns in public health and its negative impact on the pig industry the need for Influenza A virus (IAV) surveillance is rising. The gold standard procedure for detecting IAV is to sample acutely diseased pigs. Endemic infections with unspecific clinical signs and low disease prevalence need new approaches. Our study aimed to evaluate a standardized sampling procedure for the detection of IAV in epidemically and endemically infected farms. We performed a cross-sectional study in 131 farms investigating three different age groups per farm in 12 European countries. The results of our investigation indicate that 10 nasal swabs each in suckling piglets, weaners and middle of nursery is a valuable tool for influenza detection and identification of subtypes. However, for farms with a lower prevalence than 15% it is advisable to either increase the number of nasal swabs in each age group or to use group sampling methods. Interestingly, different subtypes were found in different age groups. Thus, our study underlines that sampling of different age groups is mandatory to obtain a comprehensive overview on all circulating variants on farm. In addition, our results highlight that sampling strategies should also consider piglets without obvious clinical signs for IAV infection.Swine influenza A virus (swIAV), which plays a major role in the porcine respiratory disease complex (PRDC), is eliminated from the respiratory tract within 7–9 days after infection. Therefore, diagnosis is complicated in endemically infected swine herds presenting no obvious clinical signs. This study aimed to investigate the right time point for sampling to detect swIAV. A cross-sectional study was performed in 131 farms from 12 European countries. The sampling protocol included suckling piglets, weaners, and nursery pigs. In each age group, 10 nasal swabs were collected and further examined in pools of 5 for swIAV by Matrix rRT-PCR, followed by a multiplex RT-PCR to determine the influenza subtype. SwIAV was detected in 284 (37.9%) of the samples and on 103 (78.6%) farms. Despite the highest number of animals with clinical signs being found in the nursery, the weaners were significantly more often virus-positive compared to nursery pigs (p = 0.048). Overall, the swIAV detection rate did not significantly differ between diseased or non-diseased suckling and nursery piglets, respectively; however, diseased weaners had significantly more positive pools than the non-diseased animals. Interestingly, in 9 farms, different subtypes were detected in different age groups. Our findings indicate that to detect all circulating swIAV subtypes on a farm, different age groups should be sampled. Additionally, the sampling strategy should also aim to include non-diseased animals, especially in the suckling period.

Evaluation of Control Program Against Streptococcus agalactiae Infection in Dairy Herds During 2019-2021 in Emilia-Romagna Region, Northern Italy.

Streptococcus agalactiae (group B Streptococcus, GBS) is a causative agent of mastitis in dairy cattle, mainly causing a subclinical disease associated with a high somatic cell count (SCC), and a consequent decrease in production yield and quality of milk. GBS has been almost eradicated in many Northern European countries, but there are warnings of its re-emergence as a zoonotic threat. In Italy, only two regions carry out a GBS control program: Lombardy and Emilia-Romagna. In Emilia-Romagna, the program has been in place since 2019 and provides for the bacteriological culture of bulk-tank milk (BTM) of all dairy farms every 6 months and the voluntary application of herd eradication programs in the case of positive results. To assess the progress of the program in Emilia Romagna, in terms of herd-level prevalence and GBS transmission between herds, we analyzed the results of 17,056 BTM cultures from 2,831 dairy herds, sampled bi-annually in the period 2019–2021 (six rounds total). The impact of GBS infection on SCC and milk production was also evaluated. The results show a decreasing trend in both the incidence rate (from 3.0 to 1.5%) and apparent prevalence (from 8.9 to 5.2%) of GBS over the study period. By using a susceptible-infected-susceptible (SIS) model for the estimation of the transmission parameters, a basic reproductive number R0 of 1.4 was calculated, indicating an active spread of GBS in the dairy cattle population of the Emilia-Romagna region. GBS infected farms have a consistently higher BTM SCC than negative ones (+77,000 cells/ml), corresponding to a 0.4 kg/cow/day milk loss. Moreover, GBS infected herds resulted in almost three times more likelihood of having non-marketable milk by exceeding the legal SCC limit. This study demonstrates the need to maintain the current control program against GBS to lower its occurrence and prevent significant market losses to farmers.

SARS-CoV-2 wildlife surveillance surrounding mink farms in British Columbia, Canada.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can infect many wild and domestic animal species. Farmed American mink (Neovison vison) are particularly susceptible to infection. Outbreaks of SARS-CoV-2 were detected in farmed mink on three mink farms in British Columbia (BC), Canada between December 2020 and May 2021. In BC, mink farm density and proximity to wildlife habitats increase transmission risks from infected farmed mink. The objective of this study is to investigate the risk of SARS-CoV-2 spreading to and from wildlife in the area surrounding infected mink farms in BC, Canada, as well as to compare the effectiveness of physical and camera trapping surveillance methodologies. A combination of physical and camera trapping was used on and around three BC mink farms with active SARS-CoV-2 infections between January 22, 2021, and July 10, 2021. Samples from trapped animals, including escaped farmed mink, were tested for SARS-CoV-2. Camera images from one mink farm were reviewed to determine species and proximity to the mink barn. Seventy-one animals of nine species were captured and sampled. Three captured mink tested positive for SARS-CoV-2 by polymerase chain reaction and serology; the remaining samples were negative for SARS-CoV-2. Genotyping of the three positive mink indicated these were domestic (vs. wild) mink. A total of 440 animals of 16 species were photographed at the one farm where cameras were deployed. Detection of SARS-CoV-2 in escaped farmed mink is concerning and demonstrates the potential for transmission from farmed mink to wildlife, particularly given the observation of wildlife known to be susceptible to SARS-CoV-2 near infected mink farms. Combined use of physical and camera trapping contributed to the breadth of the results and is strongly recommended for future surveillance.

One Health response to SARS-CoV-2-associated risk from mink farming in British Columbia, Canada, October 2020 to October 2021.

Mink farms are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreaks and carry an associated risk of novel SARS-CoV-2 variant emergence and non-human reservoir creation. In Denmark, control measures were insufficient to prevent onward transmission of a mink-associated variant, contributing to the nation-wide culling of farmed mink. To date, British Columbia (BC) is the only Canadian province to report mink farm SARS-CoV-2 outbreaks. The objective of this study is to describe BC's One Health response to SARS-CoV-2-associated risk from mink farming, its outcomes, and insights from implementation. The detection of two mink farm outbreaks in December 2020 catalyzed BC's risk mitigation response for both infected and uninfected farms, including the following: farm inspections and quarantines; Public Health Orders mandating mink mortality surveillance, enhanced personal protective equipment, biosafety measures and worker coronavirus disease 2019 vaccination, at-a-minimum weekly worker viral testing, and wildlife surveillance. A One Health approach enabled a timely, evidence-informed and coordinated response as the situation evolved, including the use of various legislative powers, consistent messaging and combined human and mink phylogenetic analysis. Ongoing mink and worker surveillance detected asymptomatic/subclinical infections and facilitated rapid isolation/quarantine to minimize onward transmission. Voluntary testing and mandatory vaccination for workers were acceptable to industry; enhanced personal protective equipment requirements were challenging. Regular farm inspections helped to assess and improve compliance. British Columbia's One Health response reduced the risk of additional outbreaks, viral evolution and reservoir development; however, a third outbreak was detected in May 2021 despite implemented measures, and long-term sustainability of interventions proved challenging for both industry and governmental agencies involved.

SARS-CoV-2 in mink farms in British Columbia, Canada: A report of two outbreaks in 2020-2021.

Since April 2020, mink have been recognized as a potential reservoir for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and a potential source of new variants. The objective of this report is to describe the epidemiological investigation and public health response to two coronavirus disease 2019 (COVID-19) outbreaks that involved both humans and farmed mink. An outbreak was declared on December 4, 2020, following detection of two COVID-19-positive farmworkers and elevated mink mortality on a mink farm (Farm 1) in British Columbia. The second cluster was detected on Farm 3 following detection of 1) a COVID-19 case among farm staff on April 2, 2021, 2) an indeterminate result from farm staff on May 11, 2021, and 3) subsequent SARS-CoV-2-positive mink in May 2021. Quarantine of infected farms, isolation of workers and their close contacts, and introduction of enhanced infection control practises were implemented to break chains of transmission. Among mink farmworkers, 11 cases were identified at Farm 1 and 6 cases were identified at Farm 3. On both Farm 1 and Farm 3, characteristic COVID-19 symptoms were present in farm employees before signs were observed in the minks. The viral sequences from mink and human samples demonstrated close genetic relation. Phylogenetic analyses identified mink intermediates linking human cases, suggesting anthropo-zoonotic transmission. These were the first COVID-19 outbreaks that included infected mink herds in Canada and identified potential anthropogenic and zoonotic transmission of SARS-CoV-2. We provide insight into the positive impact of regulatory control measures and surveillance to reduce the spillover of SARS-CoV-2 mink variants into the general population.

Detection of clinical and subclinical Foot and Mouth Disease Virus in Cattle in Al-Najaf Province.

Foot-and-mouth disease (FMD) is a highly transmissible disease caused by Aphthovirus of the family Picornaviridae. This study aimed to investigate the serological approach (non-structural protein [NSP] analysis) of 3ABC enzyme-linked immunosorbent assay (ELISA) to diagnose FMD cattle in vaccinated and unvaccinated animals. A total of 84 serum specimens, including non-vaccinated, single-vaccinated, and multi-vaccinated samples, were collected from four districts in Baghdad Province, Iraq, to evaluate the antibodies to NSP of the FMD virus. The ELISA was used to detect antibodies (NSP) of FMDV in the serum of cattle. The result showed that the seroprevalence was estimated at 34% (29/84) in farm animals. The seroprevalence rates of FMD in relation to the age of infected animals were obtained at 21%, 7%, and 6% in 9-23-, 24-36-, and ≥ 36-month-old groups, respectively. The consequences of the examination of the sera from naive, immunized, and non-immunized infected farm animals applying 3ABC-ELISA were presented; accordingly, the incidence rates of FMD infection in non-vaccinated and vaccinated animals were 18 (75%) and 11 (18%) respectively. Negative results were recorded in the immunized group 49 (82%) higher than in the non-immunized group 6 (25%). Evaluation of NSP antibodies to isolate vaccinated animals from infected ones showed that the application of these assays was significantly useful for FMD prevention and control management programs in infected areas.

Phylogenetic analysis of RT-PCR detected infectious bronchitis virus locally infected broiler farms in Diyala Governorate-IRAQ

Background and Aim: One of the primary pathogenic causes linked to economic losses in the chicken business is the infectious bronchitis virus. This virus exploited its S (spike) gene-encoded protein to hook into the host receptor. The biological diversity of the viral S gene may be linked to the chicken industry's vaccination status. Recently, the virus was detected in broilers of six farms located in different districts of Diyala Governorate by the use of RT-PCR. The current study aimed to explore the pattern of biological diversity of infectious bronchitis viruses based on the possibility of genetic variations of the S gene. Materials and Methods: Ten tissue samples were collected from broilers of six farms located in different districts of Diyala Governorate and named R1 to R10. The chickens were recently vaccinated, but naturally infected with infectious bronchitis virus; a particular RT-PCR fragment partially encompassing the coding domains of the S gene was recently obtained. The amplified fragments were immediately submitted to direct sequencing tests to examine the genetic variation pattern in the samples acquired from various chicken sources. Then unique comprehensive trees were generated to validate the correct genotyping of the identified variations and their phylogenetic distribution.

Mechanisms behind the varying severity of Aleutian mink disease virus: Comparison of three farms with a different disease status

Aleutian mink disease virus (AMDV) is distributed widely among mink farms and wild mustelids despite ongoing attempts to stop the spread. The severity of Aleutian disease (AD) varies from subclinical to fatal but the reasons for its varying severity are complex and unclear. Recently, breeding of tolerant mink has drawn attention as the possible solution to reduce the effects of AD in farms. The aim of this study was to gather information on the effects of breeding based on overall health, production traits, and antibody titer on AD severity by comparing a positive farm (farm 1) that has been breeding for tolerance in mink to an infected farm without tolerance selection, and an AMDV-free farm. During the 2.5-year follow-up, the mink in farm 1 remained mostly free of clinical AD, had normal pelt quality and litter size, and had low virus copy numbers in tissues and low antibody titers in ELISA. In histopathological studies, most of the farm 1 mink had no/mild lesions in their kidneys. 29–43% of the mink were ELISA negative but PCR positive throughout the follow-up and frequent changes in virus strains and coinfections were observed. Several differences in gene expression between animals from different farms were also detected. These results indicate that the disease burden of AMDV can be reduced, with seemingly normal health and production rates, despite continual circulation of ADMV in cases where eradication attempts are unsuccessful.