Modelling livestock infectious disease control policy under differing social perspectives on vaccination behaviour.

The spread of infection amongst livestock depends not only on the traits of the pathogen and the livestock themselves, but also on the veterinary health behaviours of farmers and how this impacts their implementation of disease control measures. Controls that are costly may make it beneficial for individuals to rely on the protection offered by others, though that may be sub-optimal for the population. Failing to account for socio-behavioural properties may produce a substantial layer of bias in infectious disease models. We investigated the role of heterogeneity in vaccine response across a population of farmers on epidemic outbreaks amongst livestock, caused by pathogens with differential speed of spread over spatial landscapes of farms for two counties in England (Cumbria and Devon). Under different compositions of three vaccine behaviour groups (precautionary, reactionary, non-vaccination), we evaluated from population- and individual-level perspectives the optimum threshold distance to premises with notified infection that would trigger responsive vaccination by the reactionary vaccination group. We demonstrate a divergence between population and individual perspectives in the optimal scale of reactive voluntary vaccination response. In general, minimising the population-level perspective cost requires a broader reactive uptake of the intervention, whilst optimising the outcome for the average individual increased the likelihood of larger scale disease outbreaks. When the relative cost of vaccination was low and the majority of premises had undergone precautionary vaccination, then adopting a perspective that optimised the outcome for an individual gave a broader spatial extent of reactive response compared to a perspective wanting to optimise outcomes for everyone in the population. Under our assumed epidemiological context, the findings identify livestock disease intervention receptiveness and cost combinations where one would expect strong disagreement between the intervention stringency that is best from the perspective of a stakeholder responsible for supporting the livestock industry compared to a sole livestock owner. Were such discord anticipated and achieving a consensus view across perspectives desired, the findings may also inform those managing veterinary health policy the requisite reduction in intervention cost and/or the required extent of nurturing beneficial community attitudes towards interventions.

Association of ovine gammaherpesvirus 2 with an outbreak of acute respiratory disease in dairy cattle.

This study investigated the cause of an outbreak of an acute respiratory disease syndrome followed by episodes of diarrhea in a dairy cattle herd from Southern Brazil. Deep nasal swabs (DNS) from asymptomatic calves, calves with pulmonary discomfort, and diarrheic calves after episodes of respiratory distress were used in molecular assays designed to detect the principal pathogens associated with bovine respiratory disease (BRD). Fecal samples were used for the molecular detection of bovine enteric disease agents. Pulmonary tissues from three calves and a cow that died were evaluated by molecular assays to identify 11 agents associated with the development of BRD. The intestinal and pulmonary fragments of one calf and the cow revealed atrophic enteritis and interstitial pneumonia by histopathology, respectively. Immunohistochemistry (IHC) identified intralesional antigens of a malignant catarrhal fever virus, genus Macavirus, within epithelial cells of the lungs and intestines. Molecular assays amplified ovine gammaherpesvirus 2 (OvGHV2) from most of the DNS, and the pulmonary and intestinal fragments from the animals that died, confirming that the Macavirus identified by IHC was OvGHV2. Concomitant pulmonary infections of OvGHV2 with bovine gammaherpesvirus 6 and bovine coronavirus were identified. Additionally, bovine viral diarrhea virus 1b and Aichivirus B were detected in the fecal samples. These findings demonstrated that OvGHV2, a Macavirus, was the disease agent most frequently (81.2%; 13/16) associated with singular pulmonary infections during this outbreak of BRD, suggesting that this virus may be another potential agent of respiratory disease of cattle.

Modeling between-farm transmission dynamics of porcine epidemic diarrhea virus: Characterizing the dominant transmission routes.

The role of transportation vehicles, pig movement between farms, proximity to infected premises, and feed deliveries has not been fully considered in the dissemination dynamics of porcine epidemic diarrhea virus (PEDV). This has limited efforts for disease prevention, control and elimination restricting the development of risk-based resource allocation to the most relevant modes of PEDV dissemination. Here, we modeled nine pathways of between-farm transmission represented by a contact network of pig movements between sites, farm-to-farm proximity (local transmission), four distinct contact networks of transportation vehicles (trucks that transport pigs from farm-to-farm and farm-to-markets, as well as trucks transporting feed and staff), the volume of animal by-products in feed diets (e.g., fat and meat-and-bone-meal) to reproduce PEDV transmission dynamics. The model was calibrated in space and time with weekly PEDV outbreaks. We investigated the model performance to identify outbreak locations and the contribution of each route in the dissemination of PEDV. The model estimated that 42.7% of the infections in sow farms were related to vehicles transporting feed, 34.5% of infected nurseries were associated with vehicles transporting pigs between farms, and for both farm types, local transmission or pig movements were the next most relevant transmission routes. On the other hand, finishers were most often (31.4%) infected via local transmission, followed by the vehicles transporting feed and pigs between farms. Feed ingredients did not significantly improve model calibration metrics, sensitivity, and specificity; therefore, it was considered to have a negligible contribution in the dissemination of PEDV. The proposed modeling framework provides an evaluation of PEDV transmission dynamics, ranking the most important routes of PEDV dissemination and granting the swine industry valuable information to focus efforts and resources on the most important transmission routes.

Cluster analysis of bovine respiratory disease (BRD)-associated pathogens shows the existence of two epidemiological patterns in BRD outbreaks.

A hierarchical cluster analysis was used to classify outbreaks of bovine respiratory disease (BRD; n = 156) in natural groups according to the detection of nine pathogens (parainfluenza 3 virus (PI-3), bovine respiratory syncytial virus (BRSV), bovine coronavirus (BCV), bovine viral diarrhea virus (BVDV), and bovine herpesvirus 1 (BHV-1), Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, and Mycoplasma bovis. Pathogens were detected by individual q-PCRs. Two clusters were identified. Cluster 1 was characterized by a relatively high frequency (40-72%) of four BRD-associated viruses, supporting their primary involvement in BRD. Cluster 2 was characterized by frequencies of PI-3, BRSV, or BVDV below 10% each. P. multocida and M. haemolytica were detected with high frequencies in both clusters (P > 0.05), while M. bovis and H. somni showed a significantly higher frequency in cluster 1and 2, respectively. Outbreaks in cluster 1 were associated with preweaning calves younger than 5 months (OR 2.2; 95% CI 1.1-4.5) and with cold months, whereas cluster 2 was associated with fattening calves older than 5 months after arrival to feedlots and without any seasonality. Thus, in addition to the classic epidemiological BRD pattern characterized by the primary involvement of viruses occurring preferably during winter and affecting young calves, there is a second pattern in which viruses would be less relevant, affecting mainly calves older than 5 months at any time of the year. This study allows a better understanding of the BRD epidemiology, which can be useful when implementing management and prophylaxis measures for a better control of this disease.

Descriptive epidemiology and spatial analysis of African swine fever epidemics in Can Tho, Vietnam, 2019.

The objectives of this study were to describe the epidemiology of African swine fever (ASF) and to identify factors that increased commune-level risk for ASF in Can Tho, a province in the Mekong River Delta of Vietnam. In 2019, a total of 2377 of the 5220 pig farms in Can Tho were ASF positive, an incidence risk of 46 (95% CI 44-47) ASF positive farms for every 100 farms at risk. Throughout the outbreak ASF resulted in either the death or culling of 59,529 pigs out of a total population size of 124,516 (just under half of the total pig population, 48%). After the first detection in Can Tho in May 2019, ASF spread quickly across all districts with an estimated dissemination ratio (EDR) of greater than one up until the end of July 2019. A mixed-effects Poisson regression model was developed to identify risk factors for ASF. One hundred unit increases in the number of pigs per square kilometre was associated with a 1.28 (95% CrI 1.05-1.55) fold increase in commune-level ASF incidence rate. One unit increases in the number of pig farms per square kilometre was associated with a 0.91 (95% CrI 0.84-0.99) decrease in commune-level ASF incidence rate. Mapping spatially contiguous communes with elevated (unaccounted-for) ASF risk provide a means for generating hypotheses for continued disease transmission. We propose that the analyses described in this paper might be run on an ongoing basis during an outbreak and disease control efforts modified in light of the information provided.

An investigation into an outbreak of pancytopenia in cats in the United Kingdom.

BACKGROUND: In spring 2021 increasing numbers of cats presenting with severe pancytopenia were noted in United Kingdom (UK). OBJECTIVE: To describe process and outcome of the investigation performed into the outbreak of pancytopenia in cats. ANIMALS: Five hundred and eighty client owned cats that presented with severe bi- or pancytopenia of unknown cause. METHODS: Real-time data collection was performed by an online registration forum available to all veterinary surgeons in UK. Data collected included demographics, clinicopathological findings, diagnostic testing, dietary and drug history, outcome and COVID household status. Mycotoxicological feed analysis was performed on feed samples of 3 diets frequently mentioned in the database and 3 control diets. RESULTS: Five hundred and eighty cats presented to 378 veterinary practices were included for analysis. Case fatality rate was 63.3%. Dietary history was available for 544 (93.8%) cats, of which 500 (86%) were fed 1 of 3 diets (which were recalled midinvestigation). 54 (9.3%) cats were not fed a recalled product, with diet information unknown in 26 (4.5%) cats. Analysis of feed samples revealed concentrations of hematotoxic trichothecene T-2/HT-2 mycotoxins greater than recommended by the European Commission in 5/7 recalled diet samples but in none of control diet samples. The trichothecene mycotoxin diacetoxyscirpenol (DAS) was detectable in all recalled diet samples but not in any of control samples. CONCLUSION AND CLINICAL IMPORTANCE: Contaminated-feed induced trichothecene mycotoxicosis should be considered as a differential diagnosis for pancytopenia in cats.

Zoonotic potential of guinea pigs: Outbreak of cryptosporidiosis combined with chlamydiosis in a breeding guinea pig herd.

INTRODUCTION: In a guinea pig herd with 26 breeding animals, several individuals of all age categories died (16/26) after three animals had been newly introduced from another herd. Furthermore, the population suffered of apathy, anorexia, severe weight loss and conjunctivitis, as well as abortions and stillbirths. At the same time, the owner experienced a SARS-CoV-2 infection with pneumonia, which was confirmed by taking a PCR test. Chlamydia caviae was detected from the conjunctiva and vagina/uterus in one juvenile animal together with an intestinal Cryptosporidium wrairi infection. Oocysts were found histologically in the small intestine, which was confirmed by PCR. C. wairi is a parasite adapted to guinea pigs with zoonotic potential, which causes diarrhoea with frequent deaths in larger guinea pig herds. C. caviae is also a zoonotic pathogen and often the cause of conjunctivitis, pneumonia and abortions in guinea pigs and can lead to upper respiratory tract disease, conjunctivitis but also severe pneumonia in humans. The increased death cases and the clinical signs could be traced back to an infection with Cryptosporidium wrairi, complicated by a co-infection of C. caviae. We suspect that the abortions were caused by C. caviae, but since the population was treated with various antibiotics effective against chlamydial infections, it was no longer possible to verify this by PCR testing. Unfortunately, more animals succumbed and finally only two animals of the originally 26 were left. With this case report, we would like to point out to veterinarians that guinea pigs can be an important source of zoonotic infections for various pathogens, especially since they are popular pets and often come into close contact with children where hygiene might not always be strictly followed.

INTRODUCTION: Dans un groupe de cobayes de 26 animaux reproducteurs, plusieurs individus de toutes les catégories d'âge sont morts (16/26) après l'introduction de trois animaux provenant d'un autre groupe. En outre, la population a souffert d'apathie, d'anorexie, de perte de poids sévère et de conjonctivite ainsi que d'avortements et de mortinatalité. La présence de Chlamydia caviae a pu être détectée dans la conjonctive et le vagin/utérus d'un animal juvénile, ainsi qu'une infection intestinale à Cryptosporidium wrairi. Des oocystes ont été trouvés histologiquement dans l'intestin grêle, ce qui a été confirmé par PCR. C. wairi est un parasite adapté aux cobayes avec un potentiel zoonotique, qui provoque des diarrhées avec des morts fréquentes dans les grands groupes de cobayes. C. caviae est également un agent pathogène zoonotique et est souvent à l'origine de conjonctivites, de pneumonies et d'avortements chez les cobayes ; il peut entraîner des maladies des voies respiratoires supérieures, des conjonctivites mais aussi des pneumonies graves chez l'homme. L'augmentation des cas de décès et les signes cliniques pourraient être attribués à une infection par Cryptosporidium wrairi, compliquée par une co-infection par C. caviae. Nous soupçonnons que les avortements ont été causés par C. caviae, mais comme la population a été traitée avec divers antibiotiques efficaces contre les infections à chlamydia, il n'était plus possible de le vérifier par des tests PCR. Malheureusement, d'autres animaux ont succombé et il ne restait finalement que deux animaux sur les 26 d'origine. Avec ce rapport de cas, nous aimerions attirer l'attention des vétérinaires sur le fait que les cochons d'Inde peuvent être une source importante d'infections zoonotiques pour divers pathogènes, d'autant plus qu'il s'agit d'animaux de compagnie populaires qui sont souvent en contact étroit avec des enfants avec lesquels l'hygiène n'est pas toujours strictement respectée.

High genetic diversity of Babesia canis (Piana & Galli-Valerio, 1895) in a recent local outbreak in Berlin/ Brandenburg, Germany.

Canine babesiosis caused by Babesia canis (Piana & Galli-Valerio, 1895) is emerging in new regions in Europe since its vector Dermacentor reticulatus (Fabricius, 1794) is expanding its geographic range. In the Berlin/Brandenburg area in northeast Germany, D. reticulatus is highly abundant but in the past only one autochthonous B. canis infection was reported. Since 2015, autochthonous cases were occasionally diagnosed but numbers increased since autumn 2019. The aim of the study was to genotype autochthonous canine Babesia spp. infections from Berlin/Brandenburg. Between 04/2015 and 01/2022, 46 dogs with acute babesiosis were presented to the small animal clinic (one dog was infected twice resulting in 47 samples). There were 32 dogs that had never left Berlin/Brandenburg and 14 others that had not left the region in the 6 weeks prior to disease onset. PCRs targeting the 18S rRNA and the Bc28.1 merozoite surface antigen were positive in 47 and 42 samples, respectively. Sequencing of cloned PCR products identified all samples as B. canis with 17 18S rRNA and 12 Bc28.1 haplotypes. Based on network analysis for 18S rRNA sequences and a previously described polymorphic dinucleotide, samples were assigned to two distinct clusters. One contained 31 and the other 16 samples. Using network analysis, the Bc28.1 haplotypes could also be separated into two clusters differing by at least five polymorphisms. Analyses of sequences from multiple clones indicated the presence of up to five 18S rRNA and eight Bc28.1 haplotypes and thus high parasite variability in an individual host. The genetic diversity could suggest that the parasites in the region have multiple origins, but diversity in individual dogs and dog populations from endemic regions is unknown. The suitability of both markers for genotyping is questionable due to potential intragenomic diversity for the rRNA and high intergenomic variability for the Bc28.1 marker.

The changing epidemiology of lumpy skin disease in Russia since the first introduction from 2015 to 2020.

Lumpy skin disease (LSD) is an economically important transboundary disease affecting cattle, causing large economic losses such as decreased production and trade restrictions. LSD has been a historically neglected disease since it previously caused disease limited to the African continent. Currently, the epidemiology of LSD virus is based on how the disease is transmitted in tropical and sub-tropical climates. The understanding of its epidemiology in hemiboreal climates is not well understood and needs urgent attention to expand the current knowledge. In this study, the epidemiological findings on LSD in Russia over a 6-year period are summarized and discussed. A total of 471 outbreaks were identified spanning over a 9000 km range. The outbreaks of LSD occur primarily in small holder farms (backyard) compared to commercial farms between mid-May through mid-November including weather conditions with snow and freezing temperatures that preclude vector activity. Mortality and morbidity varied across the 6 years ranging from 1.19% to 61.8% and 0% to 50%, respectively, with a tendency to decline from 2015 to 2020. The geographic pattern of spread was assessed by means of directionality, indicating a northward movement from 2015 to 2016, with a consequent East turn in 2017 through Siberia to the Far East by 2020. All cases occurred along the border with Kazakhstan. Mathematical modelling showed that the disease tended to form statistically verified annual spatiotemporal clusters in 2016-2018, whereas in 2019 and 2020 such segregation was not evident. The trend of spread was mainly either from south to north or from south to a north-east direction.

Molecular characterization of a novel recombinant lumpy skin disease virus isolated during an outbreak in Tyumen, Russia, in 2019.

Lumpy skin disease virus causes a debilitating pox disease of domesticated cattle and water buffalos. In the last decade, LSDV has spread from Africa into the Middle East, Europe and most recently Asia. As of 2017, atypical outbreaks caused by novel LSDV strains were reported in Russia, followed by China and Vietnam between 2018 and 2020. In this work, we describe another unique recombinant LSDV strain recovered from Tyumen, Russia in 2019. Typing of the virus using currently available qPCR protocols produced inconclusive results and subsequently the complete genome of the isolate was determined. The consensus genome contained statistically significant signals of possible recombination events between parental strains KSGPO-240/Kenya/1958 and the live attenuated vaccine LW/1958. The novel strain carries 25 unique breakpoints different from the known recombinant strains. Additionally, the findings reiterate the importance of complete genome sequencing when analysing outbreak samples caused in particular by mosaic LSDV, in contrast to only performing specified qPCRs.

Foot-and-mouth disease status in India during the second decade of the twenty-first century (2011-2020).

Foot-and-mouth disease (FMD) is a major disease of livestock in India and causes huge economic losses. The formal FMD control program started in 2003-04 in selected districts and was gradually expanded. The present study provides a descriptive review of the FMD outbreaks, prevalent serotypes, and genetic and antigenic features of the FMD virus (FMDV) that circulated in the country between 2011 and 2020. FMD outbreaks were regularly reported in cloven-hoofed domestic livestock and wildlife, with three serotypes including O, A, and Asia1. During the study period, a total of 2226 FMD outbreaks were documented and serotypes confirmed. FMDV serotype O dominated the outbreak scenario, accounting for about 92% of all outbreaks, followed by Asia1 (5% of all outbreaks) and A (3% of all outbreaks). Two major epidemics of FMD on an unprecedented scale during the years 2013 and 2018 by serotype O were recorded. The spatial distribution of FMD was characterized by a larger number of outbreaks in the southern region of the country. In an annual-scale analysis, 2020 was the year with the lowest outbreaks, and 2013 was the year with the highest. The month-scale analysis showed that outbreaks were reported throughout the year, with the highest numbers between October and March. The emergence of three major lineages (O/ME-SA/Ind2001d, O/ME-SA/Ind2001e, and O/ME-SA/Ind2018) of serotype O was observed during the period. In the cases of serotype A and Asia1, the appearance of at least one novel lineage/genetic group, including A/G-18/non-deletion/2019 and Asia1/Group-IX, was documented. While serotype A showed the advent of antigenic variants, serotypes O and Asia1 did not show any antigenic diversity. It was noticed during the course of an outbreak that animal movement contributes significantly to disease transmission. Except for 2018, when numerous FMD outbreaks were recorded, the number of annual outbreaks reported after 2016 has been lower than in the first half of the decade, probably due to mass vaccination and COVID-19 pandemic-linked movement restrictions. Even during outbreaks, disease symptoms in ruminant populations, including cattle, were found to be less severe. Regular six-monthly immunization certainly has a positive impact on the reduction of disease burden and should be followed without fail and delay, along with intensive disease surveillance.

Detection and genetic characterization of novel infectious bronchitis viruses from recent outbreaks in broiler and layer chicken flocks in southern China, 2021.

Avian infectious bronchitis virus (IBV) is a prevalent RNA virus that causes respiratory distress, nephritis, salpingitis, and egg production decline in chickens, resulting in significant economic loss. IBV is composed of complex genotypes and serotypes, which poses a great challenge for disease control. The current study reports 2 IBV outbreaks which were characterized by respiratory symptoms in IBV vaccinated commercial broilers and layers in Guangdong, China, in 2021. Two IBV strains, ZH01 and HH09, were identified via a RT-PCR assay through targeting the N gene and further characterization through full-length spike (S) gene sequence analysis. Phylogenetic analysis of S1 gene revealed that both ZH01 and HH09 belonged to the GI-19 lineage but contained a certain genetic distance from the GI-19 strain. Of note, the ZH01 and HH09 strains share a low homology of 70 and 86%, respectively, with common vaccine strains (H120), resulting in low vaccine protection. Further recombination analysis based on the S1 sequence suggested the newly identified IBV strains emerged through an intragroup recombination events between CK/CH/SCDY2003-2 and I0305/19 from G1-19 lineage. In addition, a number of novel mutations such as T273I, T292A, and S331K were found in the emerging IBV strains. Taken together, this study reports the genetic characteristics of 2 recent IBV outbreaks in southern China and emphasizes the urgent need for enhanced surveillance and development of novel vaccines for the control of IBV.

Has the Spread of African Swine Fever in the European Union Been Impacted by COVID-19 Pandemic?

African Swine Fever (ASF) is a contagious viral disease of domestic and wild pigs, listed as notifiable by the World Organization for Animal Health (OIE). It causes substantial economic losses to pig farming in the affected countries, with consequent enormous damage to livestock production due to mortality of the animals, and to the restrictions on national and international trade in pigs and derivative products that the presence of the infection implies. To prevent or reduce the risk of ASF introduction, the World Trade Organization (WTO) and the OIE recommend preventive and control measures, such as the ban of live swine and their products traded from ASF-affected to ASF-free countries or zones. The current spread of ASF into Europe poses a serious risk to the industrialized and small-scale pig sector, as demonstrated by observed cases in different EU areas. In this paper the authors discuss the impact of the COVID-19 pandemic on ASF, and the indirect effects including the impact on animal health and disease management. They suggest that the COVID-19 pandemic has severely affected animal disease surveillance control. ASF requires rapid responses and continuous monitoring to identify outbreaks and prevent their spread, and both aspects may have been greatly reduced during the COVID-19 pandemic.

The between-farm transmission dynamics of porcine epidemic diarrhoea virus: A short-term forecast modelling comparison and the effectiveness of control strategies.

A limited understanding of the transmission dynamics of swine disease is a significant obstacle to prevent and control disease spread. Therefore, understanding between-farm transmission dynamics is crucial to developing disease forecasting systems to predict outbreaks that would allow the swine industry to tailor control strategies. Our objective was to forecast weekly porcine epidemic diarrhoea virus (PEDV) outbreaks by generating maps to identify current and future PEDV high-risk areas, and simulating the impact of control measures. Three epidemiological transmission models were developed and compared: a novel epidemiological modelling framework was developed specifically to model disease spread in swine populations, PigSpread, and two models built on previously developed ecosystems, SimInf (a stochastic disease spread simulations) and PoPS (Pest or Pathogen Spread). The models were calibrated on true weekly PEDV outbreaks from three spatially related swine production companies. Prediction accuracy across models was compared using the receiver operating characteristic area under the curve (AUC). Model outputs had a general agreement with observed outbreaks throughout the study period. PoPS had an AUC of 0.80, followed by PigSpread with 0.71, and SimInf had the lowest at 0.59. Our analysis estimates that the combined strategies of herd closure, controlled exposure of gilts to live viruses (feedback) and on-farm biosecurity reinforcement reduced the number of outbreaks. On average, 76% to 89% reduction was seen in sow farms, while in gilt development units (GDU) was between 33% to 61% when deployed to sow and GDU farms located in probabilistic high-risk areas. Our multi-model forecasting approach can be used to prioritize surveillance and intervention strategies for PEDV and other diseases potentially leading to more resilient and healthier pig production systems.

Outbreak in African lions of Yersinia pseudotuberculosis infection, with aberrant bacterial morphology.

A concurrent outbreak of infection with Yersinia pseudotuberculosis occurred in adult captive African lions (Panthera leo). Two 17-y-old male lions and one 14-y-old female lion developed respiratory distress, lethargy, ataxia, and hyporexia. Within 3-5 d of the onset of clinical signs, one male and the female lion died and were submitted for postmortem examination. Macroscopically, the liver and spleen had multifocal-to-coalescing, semi-firm, pale-tan nodules throughout the parenchyma. The lungs were non-collapsed and marked by petechiae. Histologic examination identified lytic, necrosuppurative foci in the liver, spleen, lungs, and kidney, with abundant intralesional gram-negative coccobacilli in the male lion. Similar findings were seen in the female lion in the liver, spleen, kidney, and mesenteric lymph node; however, the intralesional bacterial colonies were more pleomorphic, comprising rod and filamentous morphologies. Aerobic bacterial culture of the liver, spleen, and lung revealed Y. pseudotuberculosis growth. The source of infection is unknown, and an epidemiologic study was performed. Sources to be considered are from the predation of rodent and/or bird reservoirs, or contaminated soil or water. Mortality associated with Y. pseudotuberculosis has been described in an African lion cub, however, to our knowledge, Y. pseudotuberculosis has not been reported in adult African lions, and this is only the second report of Y. pseudotuberculosis with aberrant bacterial morphology observed histologically.

Diarrhoea outbreak caused by coinfections of Cryptosporidium parvum subtype IIdA20G1 and rotavirus in pre-weaned dairy calves.

Diarrhoea is one of the most important syndromes in neonatal calves. In industrialized nations with intensive animal farming, Cryptosporidium spp. and rotavirus are primary causes of calf diarrhoea, but the role of these and other enteric pathogens is not clear in China. In November and December 2018, a diarrhoea outbreak was identified in over 150 pre-weaned calves on a dairy farm in Heilongjiang Province, northeast China and approximately 60 calves died. To determine the cause of the outbreak, we analyzed 131 faecal samples collected from pre-weaned calves (0-2 months) during (n = 114) and after the outbreak (n = 17). Initially, 10 diarrheic samples during the outbreak and 10 non-diarrheic samples after the outbreak were screened for rotavirus, coronavirus, Escherichia coli K99 and Cryptosporidium parvum by using an enzymatic immunoassay (EIA). In addition, 81 other samples were tested specifically for rotavirus by EIA, and all 131 samples were analyzed for Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi by PCR. The initial EIA analysis identified C. parvum (8/10) and rotavirus (5/10) as the dominant pathogens in calves during the outbreak, while both pathogens were detected at lower frequency after the outbreak (2/10 and 1/10, respectively). Further PCR analyses indicated that the occurrence of C. parvum infections in calves was significantly higher during the outbreak (75.4%, 86/114) than after the outbreak (11.8%, 2/17; odds ratio [OR] = 23.0), and was significantly associated with the occurrence of watery diarrhoea (OR = 15.7) and high oocyst shedding intensity. All C. parvum isolates were identified as subtype IIdA20G1. Among other pathogens analyzed, the overall prevalence of rotavirus, G. duodenalis and E. bieneusi was 19.8% (20/101), 38.9% (51/131) and 42.0% (55/131) in calves, respectively, without significant differences during and after the outbreak. Among the three pathogens, only the rotavirus infection was associated with diarrhoea in calves. More importantly, coinfections of C. parvum and rotavirus were significantly associated with the occurrence of watery diarrhoea in calves and were seen only during the outbreak. Thus, C. parvum subtype IIdA20G1 and rotavirus appeared to be responsible for this diarrhoea outbreak. Control measures should be implemented to effectively prevent the concurrent transmission of these enteric pathogens in pre-weaned dairy calves in China.

Ecological niche modeling predicting the potential distribution of African horse sickness virus from 2020 to 2060.

African horse sickness is a vector-borne, non-contagious and highly infectious disease of equines caused by African horse sickness viruses (AHSv) that mainly affect horses. The occurrence of the disease causes huge economic impacts because of its high fatality rate, trade ban and disease control costs. In the planning of vectors and vector-borne diseases like AHS, the application of Ecological niche models (ENM) used an enormous contribution in precisely delineating the suitable habitats of the vector. We developed an ENM to delineate the global suitability of AHSv based on retrospective outbreak data records from 2005 to 2019. The model was developed in an R software program using the Biomod2 package with an Ensemble modeling technique. Predictive environmental variables like mean diurnal range, mean precipitation of driest month(mm), precipitation seasonality (cv), mean annual maximum temperature (oc), mean annual minimum temperature (oc), mean precipitation of warmest quarter(mm), mean precipitation of coldest quarter (mm), mean annual precipitation (mm), solar radiation (kj /day), elevation/altitude (m), wind speed (m/s) were used to develop the model. From these variables, solar radiation, mean maximum temperature, average annual precipitation, altitude and precipitation seasonality contributed 36.83%, 17.1%, 14.34%, 7.61%, and 6.4%, respectively. The model depicted the sub-Sahara African continent as the most suitable area for the virus. Mainly Senegal, Burkina Faso, Niger, Nigeria, Ethiopia, Sudan, Somalia, South Africa, Zimbabwe, Madagascar and Malawi are African countries identified as highly suitable countries for the virus. Besides, OIE-listed disease-free countries like India, Australia, Brazil, Paraguay and Bolivia have been found suitable for the virus. This model can be used as an epidemiological tool in planning control and surveillance of diseases nationally or internationally.

Environmental factors and spatiotemporal distribution characteristics of the global outbreaks of the highly pathogenic avian influenza H5N1.

The spread of highly pathogenic avian influenza H5N1 has posed a major threat to global public health. Understanding the spatiotemporal outbreak characteristics and environmental factors of H5N1 outbreaks is of great significance for the establishment of effective prevention and control systems. The time and location of H5N1 outbreaks in poultry and wild birds officially confirmed by the World Organization for Animal Health from 2005 to 2019 were collected. Spatial autocorrelation analysis and multidistance spatial agglomeration analysis methods were used to analyze the global outbreak sites of H5N1. Combined with remote sensing data, the correlation between H5N1 outbreaks and environmental factors was analyzed using binary logistic regression methods. We analyzed the correlation between the H5N1 outbreak and environmental factors and finally made a risk prediction for the global H5N1 outbreaks. The results show that the peak of the H5N1 outbreaks occurs in winter and spring. H5N1 outbreaks exhibit aggregation, and a weak aggregation phenomenon is noted on the scale close to 5000 km. Water distance, road distance, railway distance, wind speed, leaf area index (LAI), and specific humidity were protective factors for the outbreak of H5N1, and the odds ratio (OR) were 0.985, 0.989, 0.995, 0.717, 0.832, and 0.935, respectively. Temperature was a risk factor with an OR of 1.073. The significance of these ORs was greater than 95%. The global risk prediction map was obtained. Given that the novel coronavirus (COVID-19) is spreading globally, the methods and results of this study can provide a reference for studying the spread of COVID-19.