Anaplasmosis outbreaks in taurine and zebu cattle in Brazil: causes, treatments, and Anaplasma marginale genetic diversity.

This study aimed to investigate seven outbreaks of A. marginale infection in two regions of Brazil, affecting taurine, zebu, and crossbred cattle. We assessed the possible causes, treatment measures, and genetic diversity of A. marginale. These outbreaks occurred in two states (Goiás: outbreaks 1-7; Mato Grosso do Sul: outbreak 3), breeds (Holstein, Nellore, and crossbreed), age groups (beef cattle: 18-25 days old and 7-8 months; dairy cattle: 18-25 days old, 13-14 months, and cow after the first birth) and rearing systems (feedlot, pasture, pen in a wood shaving bedding system and compost bedded-pack barns). Metaphylactic or prophylactic treatments varied according to outbreak (imidocarb dipropionate: outbreaks 1-4 and 6; enrofloxacin: outbreaks 5 and 7; diminazene diaceturate: outbreak 5). In outbreaks 6 and 7, the packed cell volume was monitored. In all outbreaks, the practice of needle/syringe sharing was discontinued. For outbreaks 1-3, clinical signs and mortality (range, 4.8-13.3%) occurred 36-45 days after entry into the feedlot. In outbreak 4, A. marginale was diagnosed in 66.2% of the calves (bacteremia, 0-4.5%), with a mortality of 8.6%. Among nursing calves aged 60 days during outbreak 5, 53.8% were infected with A. marginale, with average bacteremia of 2.7% (range, 0-21.3%), and a mortality of 13.8%. In dairy heifers aged 14 months, raised in paddocks lacking vegetation cover and infested with R. microplus, then transitioned to a rotational grazing system also infested with R. microplus, the A. marginale bacteremia ranged from 3.2 to 6.7%, with a mortality of 20%. Before monitoring during outbreak 7, the mortality was 17.9%, but no further deaths were observed after monitoring initiation. In conclusion, possible causes triggering the outbreaks included primary tick infestation, needle/syringe sharing, and stress factors which may have affected the immunological statues of animals in the feedlots. Control measures performed in all outbreaks were effective. The partial msp4 gene sequences of A. marginale generated herein belonged to two haplotypes, but further research would be needed to investigate if this finding has any clinical significance.

Stranding and mass mortality in humboldt penguins (Spheniscus humboldti), associated to HPAIV H5N1 outbreak in Chile.

The highly pathogenic Avian Influenza virus (HPAIV) H5N1 has caused a global outbreak affecting both wild and domestic animals, predominantly avian species. To date, cases of the HPAIV H5 Clade 2.3.4.4b in penguins have exclusively been reported in African Penguins. In Chile, the virus was confirmed in pelicans in December 2022 and subsequently spread across the country, affecting several species, including Humboldt penguins. This study aims to provide an overview of the incidents involving stranded and deceased Humboldt penguins and establish a connection between these events and HPAIV H5N1. Historical data about strandings between 2009 and 2023 was collected, and samples from suspected cases in 2023 were obtained to confirm the presence of HPAIV H5N1. Between January and August 2023, 2,788 cases of stranded and deceased penguins were recorded. Out of these, a total of 2,712 penguins deceased, evidencing a significative increase in mortality starting in early 2023 coinciding with the introduction and spreading of HPAIV H5N1 in the country. Thirty-seven events were categorized as mass mortality events, with the number of deceased penguins varying from 11 to 98. Most cases (97 %) were observed in the North of Chile. One hundred and eighty-one specimens were subjected to HPAIV diagnosis, four of which tested positive for HPAIV H5N1. Spatial analysis validates the correlation between mass mortality events and outbreaks of HPAIV in Chile. However, the limited rate of HPAIV H5N1 detection, which can be attributed to the type and quality of the samples, requiring further exploration.

Risk assessment of a highly pathogenic H5N1 influenza virus from mink.

Outbreaks of highly pathogenic H5N1 clade 2.3.4.4b viruses in farmed mink and seals combined with isolated human infections suggest these viruses pose a pandemic threat. To assess this threat, using the ferret model, we show an H5N1 isolate derived from mink transmits by direct contact to 75% of exposed ferrets and, in airborne transmission studies, the virus transmits to 37.5% of contacts. Sequence analyses show no mutations were associated with transmission. The H5N1 virus also has a low infectious dose and remains virulent at low doses. This isolate carries the adaptive mutation, PB2 T271A, and reversing this mutation reduces mortality and airborne transmission. This is the first report of a H5N1 clade 2.3.4.4b virus exhibiting direct contact and airborne transmissibility in ferrets. These data indicate heightened pandemic potential of the panzootic H5N1 viruses and emphasize the need for continued efforts to control outbreaks and monitor viral evolution.

Bird flu appears entrenched in U.S. dairy herds.

New measures to control H5N1 in cows are "a drop in the bucket," scientists say.

Unveiling genotypic diversity of Theileria orientalis in lethal outbreaks among bovines in Karnataka, India.

Theileria orientalis, the causal agent of oriental theileriosis, is known to cause mild disease in cattle and buffalo across the world. Recently, different genotypes of T. orientalis have emerged as pathogenic, causing high reported morbidity in cattle. This study focuses on investigating three suspected outbreaks of oriental theileriosis that resulted in fatalities among crossbred and indigenous bulls in Karnataka, India. Examination of blood smears revealed the presence of T. orientalis piroplasms within erythrocytes. The genetic characterization of T. orientalis was conducted by targeting specific markers, including the mpsp gene, p23 gene, and ribosomal DNA markers (18S rRNA gene, ITS-1, and ITS-2). Analysis based on the 18S rRNA gene unveiled the presence of both Type A and Type E genotypes of T. orientalis in the outbreaks. The mpsp gene-based analysis identified genotype 7 of T. orientalis in crossbred cows, whereas genotype 1 (Chitose B) was found to be present in indigenous bulls. Haplotype network analysis based on the mpsp gene revealed the presence of 39 distinct haplotypes within the 12 defined genotypes of T. orientalis with a high haplotype diversity of 0.9545 ± 0.017. Hematological and biochemical analysis revealed a decrease in calcium, hemoglobin levels, red blood cell counts, and phosphorus. This study constitutes the initial documentation of a clinical outbreak of oriental theileriosis in indigenous bulls with genotype 1 (Chitose 1B). Substantial epidemiological investigations are imperative to gain a comprehensive understanding of the geographical distribution of distinct genotypes and the diverse clinical manifestations of the disease across various hosts.

Outbreak of Highly Pathogenic Avian Influenza A(H5N1) Virus in Seals, St. Lawrence Estuary, Quebec, Canada1.

We describe an unusual mortality event caused by a highly pathogenic avian influenza (HPAI) A(H5N1) virus clade 2.3.4.4b involving harbor (Phoca vitulina) and gray (Halichoerus grypus) seals in the St. Lawrence Estuary, Quebec, Canada, in 2022. Fifteen (56%) of the seals submitted for necropsy were considered to be fatally infected by HPAI H5N1 containing fully Eurasian or Eurasian/North American genome constellations. Concurrently, presence of large numbers of bird carcasses infected with HPAI H5N1 at seal haul-out sites most likely contributed to the spillover of infection to the seals. Histologic changes included meningoencephalitis (100%), fibrinosuppurative alveolitis, and multiorgan acute necrotizing inflammation. This report of fatal HPAI H5N1 infection in pinnipeds in Canada raises concerns about the expanding host of this virus, the potential for the establishment of a marine mammal reservoir, and the public health risks associated with spillover to mammals.Nous décrivons un événement de mortalité inhabituelle causé par un virus de l'influenza aviaire hautement pathogène A(H5N1) clade 2.3.4.4b chez des phoques communs (Phoca vitulina) et gris (Halichoerus grypus) dans l'estuaire du Saint-Laurent au Québec, Canada, en 2022. Quinze (56%) des phoques soumis pour nécropsie ont été considérés comme étant fatalement infectés par le virus H5N1 de lignées eurasiennes ou de réassortiment eurasiennes/nord-américaines. Un grand nombre simultané de carcasses d'oiseaux infectés par le H5N1 sur les sites d'échouement a probablement contribué à la contamination de ces phoques. Les changements histologiques associés à cette infection incluaient : méningo-encéphalite (100%), alvéolite fibrinosuppurée et inflammation nécrosante aiguë multi-organique. Cette documentation soulève des préoccupations quant à l'émergence de virus mortels, à la possibilité d'établissement de réservoirs chez les mammifères marins, et aux risques pour la santé publique associés aux propagations du virus chez les mammifères.

Emerging Variants of Canine Enteric Coronavirus Associated with Outbreaks of Gastroenteric Disease.

A 2022 canine gastroenteritis outbreak in the United Kingdom was associated with circulation of a new canine enteric coronavirus closely related to a 2020 variant with an additional spike gene recombination. The variants are unrelated to canine enteric coronavirus-like viruses associated with human disease but represent a model for coronavirus population adaptation.

Novel estimation of African swine fever transmission parameters within smallholder villages in Lao P.D.R.

African Swine Fever (ASF) disease transmission parameters are crucial for making response and control decisions when faced with an outbreak, yet they are poorly quantified for smallholder and village contexts within Southeast Asia. Whilst disease-specific factors - such as latent and infectious periods - should remain reasonably consistent, host, environmental and management factors are likely to affect the rate of disease spread. These differences are investigated using Approximate Bayesian Computation with Sequential Monte-Carlo methods to provide disease parameter estimates in four naïve pig populations in villages of Lao People's Democratic Republic. The villages represent smallholder pig farmers of the Northern province of Oudomxay and the Southern province of Savannakhet, and the model utilised field mortality data to validate the transmission parameter estimates over the course of multiple model generations. The basic reproductive number between-pigs was estimated to range from 3.08 to 7.80, whilst the latent and infectious periods were consistent with those published in the literature for similar genotypes in the region (4.72 to 6.19 days and 2.63 to 5.50 days, respectively). These findings demonstrate that smallholder village pigs interact similarly to commercial pigs, however the spread of disease may occur slightly slower than in commercial study groups. Furthermore, the findings demonstrated that despite diversity across the study groups, the disease behaved in a consistent manner. This data can be used in disease control programs or for future modelling of ASF in smallholder contexts.

Genotypic analysis of a localised hotspot of Pestivirus A (BVDV-1) infections in Northern Ireland.

BACKGROUND: Bovine viral diarrhoea (BVD) is caused by Pestivirus A and Pestivirus B. Northern Ireland (NI) embarked on a compulsory BVD eradication scheme in 2016, which continues to this day, so an understanding of the composition of the pestivirus genotypes in the cattle population of NI is required. METHODS: This molecular epidemiology study employed 5' untranslated region (5'UTR) genetic sequencing to examine the pestivirus genotypes circulating in samples taken from a hotspot of BVD outbreaks in the Enniskillen area in 2019. RESULTS: Bovine viral diarrhoea virus (BVDV)-1e (Pestivirus A) was detected for the first time in Northern Ireland, and at a high frequency, in an infection hotspot in Enniskillen in 2019. There was no evidence of infection with BVDV-2 (Pestivirus B), Border disease virus (pestivirus D) or HoBi-like virus/BVDV-3 (pestivirus H). LIMITATIONS: Only 5'UTR sequencing was used, so supplementary sequencing, along with phylogenetic trees that include all BVDV-1 genotype reference strains, would improve accuracy. Examination of farm locations and animal movement/trade is also required. CONCLUSIONS: Genotype BVDV-1e was found for the first time in Northern Ireland, indicating an increase in the genetic diversity of BVDV-1, which could have implications for vaccine design and highlights the need for continued pestivirus genotypic surveillance.

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

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

Pine needle abortions in cattle due to consumption of Pinus ponderosa in Argentina: Case reports.

Two outbreaks of pine needle abortions in cattle are here reported for the first time in Argentina. The cases occurred in Chubut and Neuquén provinces in the Patagonia region, causing 29.6% and 9% of abortions in each herd respectively. In both outbreaks, the dams were in the last third of gestation, and, due to a period of cold, snow and lack of available forage, they gained access to Pinus ponderosa and Pinus contorta forests. No pathological lesions, serological, molecular, or microbiological evidence of infectious causes were observed in any of the six fetuses analyzed. Microhistological analysis of feces confirmed higher presence of fragments of Pinus spp. needles in the diet of affected dams than in that of non-affected ones (12.2 vs 3.0%). Moreover, toxicological analysis showed higher tetrahydroagathic acid in the sera of affected dams than in that of non-affected ones (10.05 vs 2.81 ppm). In addition, this acid was detected in different fetal fluids (3.6-8.1 ppm) of the six fetuses analyzed. Interestingly, isocupressic acid was detected only in needles of P. ponderosa, and its content was lower than that found in other areas of the world (0.31 and 0.5% in Chubut and Neuquén respectively). These results confirm that the consumption of P. ponderosa by dams could have been the cause of these abortion outbreaks, a fact that should be considered as differential diagnosis in abortions of cattle, especially in silvopastoral systems of Argentina.

Risk assessment of wild fish as environmental sources of red sea bream iridovirus (RSIV) outbreaks in aquaculture.

Red sea bream iridovirus (RSIV) causes substantial economic damage to aquaculture. In the present study, RSIV in wild fish near aquaculture installations was surveyed to evaluate the risk of wild fish being an infection source for RSIV outbreaks in cultured fish. In total, 1102 wild fish, consisting of 44 species, were captured from 2 aquaculture areas in western Japan using fishing, gill nets, and fishing baskets between 2019 and 2022. Eleven fish from 7 species were confirmed to harbor the RSIV genome using a probe-based real-time PCR assay. The mean viral load of the RSIV-positive wild fish was 101.1 ± 0.4 copies mg-1 DNA, which was significantly lower than that of seemingly healthy red sea bream Pagrus major in a net pen during an RSIV outbreak (103.3 ± 1.5 copies mg-1 DNA) that occurred in 2021. Sequencing analysis of a partial region of the major capsid protein gene demonstrated that the RSIV genome detected in the wild fish was identical to that of the diseased fish in a fish farm located in the same area in which the wild fish were captured. Based on the diagnostic records of RSIV in the sampled area, the RSIV-infected wild fish appeared during or after the RSIV outbreak in cultured fish, suggesting that RSIV detected in wild fish was derived from the RSIV outbreak in cultured fish. Therefore, wild fish populations near aquaculture installations may not be a significant risk factor for RSIV outbreaks in cultured fish.

A molecular epidemiological investigation of contagious caprine pleuropneumonia in goats and captive Arabian sand gazelle (Gazella marica) in Oman.

BACKGROUND: Contagious caprine pleuropneumonia (CCPP) is a fatal WOAH-listed, respiratory disease in small ruminants with goats as primary hosts that is caused by Mycoplasma capricolum subspecies capripneumoniae (Mccp). Twelve CCPP outbreaks were investigated in 11 goat herds and a herd of captive Arabian sand gazelle (Gazella marica) in four Omani governorates by clinical pathological and molecular analysis to compare disease manifestation and Mccp genetic profiles in goats and wild ungulates. RESULTS: The CCPP forms in diseased and necropsied goats varied from peracute (5.8%), acute (79.2%) and chronic (4.5%) while all of the five necropsied gazelles showed the acute form based on the clinical picture, gross and histopathological evaluation. Colonies of Mccp were recovered from cultured pleural fluid, but not from lung tissue samples of one gazelle and nine goats and all the isolates were confirmed by Mccp-specific real time PCR. Whole genome-single nucleotide polymorphism (SNP) analysis was performed on the ten isolates sequenced in this study and twenty sequences retrieved from the Genbank database. The Mccp strains from Oman clustered all in phylogroup A together with strains from East Africa and one strain from Qatar. A low variability of around 125 SNPs was seen in the investigated Omani isolates from both goats and gazelles indicating mutual transmission of the pathogen between wildlife and goats. CONCLUSION: Recent outbreaks of CCPP in Northern Oman are caused by Mccp strains of the East African Phylogroup A which can infect goats and captive gazelles likewise. Therefore, wild and captive ungulates should be considered as reservoirs and included in CCPP surveillance measures.