Systematic Epidemiological Investigations of Cases of Senecavirus A in US Swine Breeding Herds

Epidemiological investigations were conducted on a case series of six Senecavirus A (SVA)‐affected breeding herds in the United States to determine potential routes of introduction and enhance the swine industry's knowledge of SVA's clinical presentation and spread. Each SVA‐affected herd was evaluated using a standard form to ensure that all relevant data were collected. The form was used to guide a detailed discussion about the clinical presentation of SVA and risk events that occurred in the 4 weeks prior to the first observation of clinical signs with the herd veterinarian and farm personnel. Each event was then subjectively assigned a risk level of low, medium or high likelihood for SVA introduction by the investigation team. The clinical presentation of SVA varied by case. All SVA‐affected herds (six of six) reported increases in pre‐weaning mortality and sow anorexia. Vesicular lesions were observed in four of six herds, and mild‐to‐moderate neonatal diarrhoea was observed in three of six herds. No gross anatomic or histologic lesions were observed in neonatal pigs that tested positive for SVA via PCR. Multiple potential routes of introduction were identified. Events subjectively rated as high risk for SVA introduction were on‐farm employee entry (six of six), carcass disposal (four of six), cull sow removal (three of six) and breeding replacement entry (two of six). Non‐swine domestic animals, rodents, other visitors, repairs outside swine barns, feed delivery, weaned pig removal and semen entry were assigned a high risk level in one of six herds. Cases occurred in breeding herds of all sizes with variable biosecurity in both swine dense and swine sparse areas.     

The First Identification and Complete Genome of Senecavirus A Affecting Pig with Idiopathic Vesicular Disease in China

Senecavirus A (SVA) infection was recently confirmed in pigs in Brazil. In March, 2015, an outbreak of vesicular disease occurred in Guangdong, China, characterized by vesicular lesions in sows and acute death of neonatal piglets. Cumulative incidence of porcine idiopathic vesicular disease in farm A was 258, which had a total number of 5500 sows. Sows in farm B displayed typical vesicular symptoms by May, 2015, which also had 5500 sows. A total of 278 and 142 of 5500 sows in farm B demonstrated lame and presented vesicles, respectively, associated with a total of 186 mortality in piglets. Routine differential diagnoses for swine vesicular disease were carried out to exclude infection with foot‐and‐mouth disease virus, swine vesicular disease virus, vesicular exanthema of swine virus and vesicular stomatitis virus. In this study, seven pairs of primer were designed to amplify the complete genome of SVA in RT‐PCR assays. Sequence alignment showed that this Chinese strain shares 94.4–97.1% sequence identity to other eight strains of SVA. This is the first report of SVA in China and provides information about the association between SVA infection and vesicular disease.     

Identification and Complete Genome of Seneca Valley Virus in Vesicular Fluid and Sera of Pigs Affected with Idiopathic Vesicular Disease,Brazil

Numerous, ongoing outbreaks in Brazilian swine herds have been characterized by vesicular lesions in sows and acute losses of neonatal piglets. The complete genome of Seneca Valley virus (SVV) was identified in vesicular fluid and sera of sows, providing evidence of association between SVV and vesicular disease and viraemia in affected animals.     

Identification and genomic characterization of the emerging Senecavirus A in southeast China, 2017

Senecavirus A (SVA ) is an emerging non‐enveloped virus with a single‐stranded, positive‐sense RNA genome that belongs to the Senecavirus genus in the Picornaviridae family. Senecavirus A‐associated swine idiopathic vesicular disease and epidemic transient neonatal losses have caused substantial economic losses for the swine industry. Here, we describe a case of re‐emerging vesicular disease among sows and finishing pigs on a swine farm in Fujian Province of southeast China. Other causative pathogens, including FMDV , SVDV and VSV , were excluded, and a novel SVA strain, CH ‐FJZZ ‐2017, was isolated. Sequencing and phylogenetic analysis of the complete genome and individual viral proteins revealed that CH ‐FJZZ ‐2017 is closely related to the US strains in 2015. The results further showed that Chinese SVA s have formed two distinct subclades with 2016 as the turning point. Viruses causing outbreaks after late 2016 shared higher nucleotide identities with the US strains in 2015. There is still some evolutionary distance between CH ‐FJZZ ‐2017 and other strains isolated in late 2016, suggesting that Chinese SVA isolates have been evolving in different directions. This study provides a basis for the development of effective prevention and control strategies.     

Carp Edema Virus/Koi Sleepy Disease: An Emerging Disease in Central‐East Europe

Koi sleepy disease (KSD), also known as carp edema virus (CEV), was first reported from juvenile colour carp in Japan in the 1970s. Recently, this pox virus was detected in several European countries, including Germany, France and the Netherlands. In England, in addition to colour carp, outbreaks in common carp are reported. KSD/CEV is an emerging infectious disease characterized by a typical sleepy behaviour, enophthalmia, generalized oedematous condition and gill necrosis, leading to hypoxia. High mortality, of up to 80–100%, is seen in juvenile koi collected from infected ponds. In Austria, this disease had not been detected until now. In spring 2014, diagnostic work revealed the disease in two unrelated cases. In one instance, a pond with adult koi was affected; in the other, the disease was diagnosed in adult common carp recently imported from the Czech Republic. A survey was carried out on recent cases (2013/2014), chosen from those with similar anamnestic and physical examination findings, revealing a total of 5/22 cases positive for KSD/CEV. In this study, two paradigmatic cases are presented in detail. Results together with molecular evidence shaped the pattern of the first diagnosis of KSD/CEV in fish from Austrian ponds. In the light of the positive cases detected from archived material, and the spread of the disease through live stock, imported from a neighbouring country, the need for epidemiological investigations in Austria and surrounding countries is emphasized.     

Presence of atypical porcine pestivirus (APPV) in Brazilian pigs

Recently, a putative new pestivirus species, provisionally named as Atypical Porcine Pestivirus (APPV ), was associated with the congenital tremor in piglets in North America and consequently in Europe and Asia. The present research aimed to describe the detection and characterization of APPV employing NS 5B gene partial sequencing, gross pathology and histologic examination of piglets displaying congenital tremor from two different farms of Southern Brazil. No gross lesions were observed, and the histological findings revealed moderate vacuolization of the white matter of the cerebellum. RT ‐PCR followed by DNA sequencing and a phylogenetic analysis confirmed the presence of APPV in samples from the two farms, which the samples were distinct in nature. Phylogenetic reconstruction reinforced the high genetic variability within the APPV s previously reported. This is the first report of APPV in South America suggesting that this new group of viruses may be widespread in swine herds in other countries as it is in Brazil.     

Clinical and Serological Dynamics of Besnoitia besnoiti Infection in Three Endemically Infected Beef Cattle Herds

The dynamics of bovine besnoitiosis were studied in an area where the disease is endemic. A four‐year longitudinal study was conducted for the first time in three infected beef cattle herds located in the Urbasa‐Andía Mountains (Navarra, Spain). Each herd was visited four to seven times, and clinical and serological prevalence rates and incidence rates were estimated. Clinical inspections to identify compatible clinical signs with the disease stages were conducted at the beginning and end of the study. Serological assessment was initially performed by ELISA. Seronegative animals with clinical signs and seropositive animals with relative index per cent (RIPC) values lower than 30 that did not increase during the study period were analysed by Western blot to optimize the sensitivity and specificity of the ELISA test. Clinical prevalence rates were slightly higher (62% on average) than the seroprevalence rates (50% on average), and tissue cysts located in the vestibulum vaginae and sclera were the most frequently detected clinical signs. The proportion of seropositive animals with clinical signs varied from 16.7% to 73.6% among the herds, and 17% of cattle with clinical signs proved to be seronegative by both serological tests. An average 22% serological incidence rate was also reported in addition to clinical incidence rates that varied from 12.5% to 16.7%. Additionally, parasitemia was investigated in the herd that showed the highest clinical and seroprevalence rates. Only one PCR positive blood sample was detected. Thus, the role that blood may play in parasite transmission needs to be further investigated. Infected herds maintained both high prevalence and incidence rates in the absence of control measures and a high number of parasite carriers. Finally, economic impact studies on reproductive and productive losses associated with besnoitiosis need to be performed to implement a cost–benefit control programme.     

Infection of pigs with African swine fever virus via ingestion of stable flies (Stomoxys calcitrans)

Within Eastern Europe, African swine fever virus (ASFV ) has unexpectedly spread to farms with high biosecurity. In an attempt to explain this process, pigs were allowed to ingest flies that had fed on ASFV ‐spiked blood, which had a realistic titre for an infected pig. Some of the pigs became infected with the virus. Thus, ingestion of blood‐sucking flies, having fed on ASFV ‐infected wild boar before entering stables, represents a potential route for disease transmission.     

Modelling the variation in skin‐test tuberculin reactions,post‐mortem lesion counts and case pathology in tuberculosis‐exposed cattle: Effects of animal characteristics,histories and co‐infection

Correctly identifying bovine tuberculosis (bTB ) in cattle remains a significant problem in endemic countries. We hypothesized that animal characteristics (sex, age, breed), histories (herd effects, testing, movement) and potential exposure to other pathogens (co‐infection; BVDV , liver fluke and Mycobacterium avium reactors) could significantly impact the immune responsiveness detected at skin testing and the variation in post‐mortem pathology (confirmation) in bTB ‐exposed cattle. Three model suites were developed using a retrospective observational data set of 5,698 cattle culled during herd breakdowns in Northern Ireland. A linear regression model suggested that antemortem tuberculin reaction size (difference in purified protein derivative avium [PPD a ] and bovine [PPD b ] reactions) was significantly positively associated with post‐mortem maximum lesion size and the number of lesions found. This indicated that reaction size could be considered a predictor of both the extent (number of lesions/tissues) and the pathological progression of infection (maximum lesion size). Tuberculin reaction size was related to age class, and younger animals (<2.85 years) displayed larger reaction sizes than older animals. Tuberculin reaction size was also associated with breed and animal movement and increased with the time between the penultimate and disclosing tests. A negative binomial random‐effects model indicated a significant increase in lesion counts for animals with M. avium reactions (PPD b− PPD a <  0) relative to non‐reactors (PPD b− PPD a =  0). Lesion counts were significantly increased in animals with previous positive severe interpretation skin‐test results. Animals with increased movement histories, young animals and non‐dairy breed animals also had significantly increased lesion counts. Animals from herds that had BVDV ‐positive cattle had significantly lower lesion counts than animals from herds without evidence of BVDV infection. Restricting the data set to only animals with a bTB visible lesion at slaughter (n  = 2471), an ordinal regression model indicated that liver fluke‐ infected animals disclosed smaller lesions, relative to liver fluke‐negative animals, and larger lesions were disclosed in animals with increased movement histories.     

Tuberculosis in Southern Brazilian wild boars (Sus scrofa): First epidemiological findings

Bovine tuberculosis (bTB ) is a zoonosis caused mainly by Mycobacterium bovis that affects domestic and wild animals. In Brazil, there are no epidemiological studies on tuberculosis in wild animal populations and their possible role in the disease maintenance in cattle herds; thus, the aim of this study was to evaluate the occurrence of tuberculosis in wild boars in Rio Grande do Sul, southern Brazil. Tissue samples of animals hunted under government consent were submitted to histopathology and M. bovis polymerase chain reaction (PCR ) as screening tests; the positive samples were subsequently submitted to bacterial isolation, the gold standard diagnosis. Eighty animals were evaluated, of which 27.9% and 31.3% showed histopathological changes and M. bovis genome presence, respectively. Moreover, 23.8% of the animals had at least one organ with isolates classified as Mycobacterium tuberculosis complex (MTC ). Three hunting points were risk factors for positive results on screening tests. This study shows the occurrence of tuberculosis in a wild boars’ population, and raise the possibility of these animals to play a role as disease reservoirs in southern Brazil. These results may help to improve the Brazilian tuberculosis control programme, as well as elucidate the circulation of mycobacteria in this country.     

Single nucleotide polymorphisms in Renalase and KCNQ1 genes and female infertility: A cross‐sectional study in Pakistan

A global increase in the incidence of subfertility is observed, and research suggests strong genetic influences that might restrict fertility directly or indirectly. It therefore becomes important to rule out the existence of genetic causes and counsel infertile couples before offering “Advanced Infertility Treatment Techniques.” This cross‐sectional study aimed to explore the association of KCNQ1 (rs2237895) and Renalase (rs2576178 and rs10887800) single nucleotide polymorphisms with different causes of infertility by analysing 508 fertile and 164 infertile women. Gene variant (AC/CC) of KCNQ1 rs2237895 showed a slight difference in the endometriosis group compared to the fertile group (p = .049), with the C allele showing a significant association with infertility overall (OR = 1.42 [1.100–1.833]; p < .0069). The variant AG/GG of Renalase rs2576178 was significantly associated with overall infertility (OR = 2.266; p < .001), with a strong G allele association with unexplained infertility OR = 2.796 (p = .002) that remained significant after adjusting for age and body mass index. Similarly, Renalase rs10887800 AG/GG and G allele showed significant association with both infertility due to polycystic ovarian syndrome and unexplained infertility. Expression of single nucleotide polymorphism rs2237895 and rs2576178 in both KCNQ1 and Renalase genes might be responsible for altering reproductive potential, hence leading to infertility in women.     

Herd‐Level Risk Factors for the Seropositivity to Mycoplasma hyopneumoniae and the Occurrence of Enzootic Pneumonia Among Fattening Pigs in Areas of Endemic Infection and High Pig Density

The aim of the present study was to identify potential risk factors for the occurrence of enzootic pneumonia (EP) in herds situated in a region of high pig density, where a majority of herds is endemically infected with Mycoplasma hyopneumoniae. Between 2006 and 2010, overall 100 herds were enrolled in a case–control study. Data were collected through personal interview with the farmers, clinical examination of pigs and their environments, and serological testing for M. hyopneumoniae, swine influenza virus and porcine reproductive and respiratory syndrome virus. There were 40 case herds (coughing index high, seroprevalence high) with a mean coughing index of 4.3 and a seroprevalence of 86.6%. There were two control groups. Control group I consisted of 25 herds (coughing index low, seroprevalence low) with mean values of 0.7 and 11.2%, and 35 herds were allocated to control group II (coughing index low, seroprevalence high) where the mean coughing index was 0.9 and seroprevalence 86.3%. Case herds and control II herds had an increased age of piglets at weaning compared to control I herds. Any contact between fattening pigs of different age during restocking of compartments increased the risk for the occurrence of EP in a herd. Finally, farms that use living animals for the exposure to gilts during the acclimatization and farms that had increased number of weaned piglets per sow and year were less likely to test positive for M. hyopneumoniae and less likely to develop clinical symptoms of EP in fattening pigs.     

Vaccinia virus detection in dairy products made with milk from experimentally infected cows

Vaccinia virus (VACV) is the agent of bovine vaccinia (BV), an emerging zoonosis that causes exanthematic lesions on the teats of dairy cows and on the hands of milkers. The virus has been detected in the milk of naturally infected cows. The objective of this study was to investigate and quantify VACV DNA as well as the presence of infectious virus particles in samples of cheese curd, cheese whey and pasteurized milk produced using milk from cows experimentally inoculated with VACV‐GP2, a Brazilian isolate of VACV (VACV‐BR). VACV DNA was detected in samples of cheese and pasteurized milk at different time points, even after the resolution of the typical lesions caused by VACV, which occurred after 22 days post‐infection (dpi), on average. Moreover, it was possible to detect infectious viral particles in cheese samples on alternate days until 27 dpi. The presence of both VACV DNA and infectious viral particles in cheese samples throughout the clinical course of BV and even after the disappearance of the typical clinical signs of disease draws attention to the risk associated with consumption of the cheese. Furthermore, VACV‐contaminated milk and cheese may represent an occupational risk to cheesemakers who often manipulate milk and cheese curd without wearing gloves.     

Leishmaniasis in cat shelters: A serological,molecular and entomological study

An epidemiological Leishmania spp. and entomological Phlebotomine sandflies survey was performed in cat shelters at leishmaniasis endemic area of Brazil. Blood and conjunctival swab (CS) samples were collected from 94 cats in two animal protection shelters. These samples were subjected to serological tests using the indirect immunofluorescence antibody test (IFAT) and indirect enzyme‐linked immunosorbent assay (ELISA) and to molecular test by polymerase chain reaction (PCR). In addition, a Phlebotomine sandflies survey was performed in the same shelters. The analyses revealed a positivity of 31.91% (30/94) through ELISA and 29.79% (28/94) through IFAT. The two serological tests showed a positive association with perfect agreement (k = 0.925). None of the cats were positive by Leishmania spp. DNA. One Lutzomyia (Lutzomyia) longipalpis male was found in one of the cat shelters. The results and the implications of our findings are discussed below.     

Epidemiological and Molecular Studies on Lumpy Skin Disease Outbreaks in Turkey during 2014–2015

This study was carried out to explore epidemiological and molecular features of lumpy skin disease virus (LSDV) in the Aegean, Central Anatolian and Mediterranean regions of Turkey, to evaluate the risk factors associated with LSDV infection and to investigate the financial impact of LSD and potential role of the Culicoides spp. in the transmission of LSDV. Samples were obtained from 611 cattle, each from different farms, and each clinically suspected to be infected with LSDV during the months of July 2014 and June 2015. Culicoides spp. were trapped from April to June 2015. Genetic characterization of the local LSDV field isolates was conducted by sequencing G‐protein‐coupled chemokine receptor gene segment. Real‐time PCR high‐resolution melting analysis was used for distinguishing each type of capripoxviruses. Viral DNA was detected in 448 of the 611 animals and Culicoides midges. Three hundred and ninety‐three of the 448 affected farms were surveyed. The morbidity and mortality rates detected were 12.3% and 6.4%, respectively. Phylogenetic analysis showed that the field isolates in this study were clustered together with other Africa and Middle East isolates. Genotyping of isolates from infected cattle has revealed the presence of LSDV. A generalized mixed linear model showed that there were positive associations between LSDV infection, European breeds, small‐sized family‐type farms and nearness of farm to a lake. The financial cost of disease presence in surveyed cattle farms was estimated to be 72.75 GBP per head. The sequence analysis of the mitochondrial cytochrome oxidase subunit I gene showed that the species of Culicoides in LSDV‐positive pools was Culicoides punctatus. Detection of LSDV in Culicoides punctatus suggests that it may have played a role in transmitting LSDV. Furthermore, movement of infected animals into disease‐free areas increases the risk of the transmission of LSD. Control strategies for LSDV infection should include consideration of the risk factors identified in this study.     

Liver fluke (Fasciola hepatica) co‐infection with bovine tuberculosis in cattle: A prospective herd‐level assessment of herd bTB risk in dairy enterprises

Co‐infection of tuberculosis (TB) and helminths is recognized as a significant problem in regions where such pathogens are endemic and chronic cases exist. Co‐infection can modulate the immune system leading to interference with diagnostic tests, increased pathological impacts and pathogen persistence. However, research has found that such interactions between pathogens can be context and species specific. Recent studies have suggested that liver fluke, Fasciola hepatica, infection may impact on immunological responses and diagnostics for bovine tuberculosis (bTB; caused by Mycobacterium bovis) in cattle. Where evidence of such interaction exists, there would be an onus on policy makers to adjust eradication programs to minimize impacts. We assessed the association between herd‐level bTB breakdown risk and seasonal variation in liver fluke exposure based on 5,753 bulk tank milk (BTM) samples from 1,494 dairy herds across Northern Ireland. BTM was tested by an IDEXX antibody specific enzyme‐linked immunosorbent assay (ELISA) using the ‘f2’ antigen as a detection agent. The ELISA determined the result based on a sample to (known) positive ratio (S/P%) from which binary status and categories of exposure were derived. Associations were tested using multivariable random effects models. Models predicting bTB risk were not improved with the inclusion of liver fluke exposure levels. Variations in modelling liver fluke exposure (S/P%, binary, categories of exposure) and bTB risk (skin test breakdowns, post‐mortem confirmed breakdowns, breakdown size and lag effects) also failed to support associations (neither positive nor negative) between the pathogens at herd‐level. These results, along with previously published animal‐level data from Northern Ireland, suggest that the nexus between bTB and F. hepatica may have small size effects at the population‐level. However, our results also highlight the high prevalence of F. hepatica in cattle in our study population, and therefore we cannot fully discount the potential hypothesis of population‐level depression of immune response to M. bovis due to co‐infection.