Serological investigation and isolation of Salmonella abortus equi in horses in Xinjiang.

BACKGROUND: Salmonella enterica subspecies enterica serovar abortus equi (S. abortus equi) is one of the main pathogens that causes abortion in pregnant horses and donkeys, which was highly infectious and greatly restricts the healthy development of the horse industry. OBJECTIVES: In order to investigate the prevalence and biological characteristics of S. abortus equi in different regions and breeds of horses in Xinjiang. METHODS: This study conducted ELISA detection of S. abortus equi antibodies on serum samples of 971 horses collected from three large-scale horse farms and five free-range horse farms in Yili Prefecture and Bayingol Mongolian Autonomous Prefecture of Xinjiang from 2020 to 2023. On this basis, bacterial isolation, culture, identification, and drug sensitivity tests were conducted on 42 samples of aborted foal tissues and 23 mare vaginal swabs. RESULTS: The results showed that the positive rate of S. abortus equi antibody was as high as 20.91% in 971 horse serum samples. Among them, the positive rate in the Ili region (29.09%) was significantly higher than that in the Bayingole region (11.24%), and the positive rate in mares (22.45%) was higher than that in stallions (14.05%). In terms of horse breeds, the positive rates of self-propagating thoroughbred horses, half-bred horses, Ili horses and Yanqi horses were 43.22%, 28.81%, 14.72% and 11.24% respectively. In addition, S. abortus equi was more susceptible to juvenile and elderly horses, with positive rates of 70.00%and 41.86%, respectively, both of which were significantly higher than young (10.97%) and adult (19.79%) horses. Further, 9 strains of S. abortus equi were obtained through bacterial isolation, culture and identification, which were resistant to five antibiotics (Clarithromycin, Clindamycin, penicillin, Sulfamethoxazole and Rifampicin), and sensitive to 13 antimicrobial agents (Amoxicillin, Ciprofloxacin and Gentamicin, et al.). CONCLUSION: There was a high infection rate of S. abortus equi in Ili Prefecture and self-propagating thoroughbred horses, and juvenile or old mares were more susceptible, which will provide scientific basis for the prevention of S. abortus equi infection in different regions and breeds of horses in Xinjiang.

Prevalence of viral agents causing swine reproductive failure in Korea and the development of multiplex real-time PCR and RT-PCR assays.

This study aimed to investigate the prevalence of viral agents causing reproductive failure in pigs in Korea. In addition, two types of multiplex real-time PCR (mqPCR) were developed for the simultaneous detection of Aujeszky's disease virus (ADV) and porcine parvovirus (PPV) in mqPCR and encephalomyocarditis virus (EMCV) and Japanese encephalitis virus (JEV) in reverse transcription mqPCR (mRT-qPCR). A total of 150 aborted fetus samples collected from 2020 to 2022 were analyzed. Porcine reproductive and respiratory syndrome virus was the most prevalent (49/150 32.7%), followed by porcine circovirus type 2 (31/150, 20.7%), and PPV1 (7/150, 4.7%), whereas ADV, EMCV, and JEV were not detected. The newly developed mqPCR and mRT-qPCR could simultaneously detect and differentiate with high sensitivities and specificities. When applied to aborted fetuses, the newly developed mqPCR for PPV was 33.3% more sensitivities than the previously established diagnostic method. Amino acid analysis of the VP2 sequences of PPV isolates revealed considerable similarity to the highly pathogenic Kresse strain. This study successfully evaluated the prevalence of viral agents causing reproductive failure among swine in Korea, the developed mqPCR and mRT-qPCR methods could be utilized as effective and accurate diagnostic methods for the epidemiological surveillance of ADV, PPV, EMCV, and JEV.

Characteristics of unilateral and bilateral bovine twin foetuses.

Twin pregnancy in cattle is undesirable for a number of reasons, including a higher abortion risk compared to pregnancies with a single foetus. Yet, the abortion risk is significantly influenced by the intrauterine location of the foetuses, that is, the abortion risk is several times higher if they are implanted in the same uterine horn (unilateral twin pregnancy) than if they are implanted with one foetus in each uterine horn (bilateral twin pregnancy). The reason for the higher abortion risk in unilateral twin pregnancies is unknown, but it may be related to malnutrition of the outermost foetus due to a limited placental capacity, as is the case for equine twin foetuses. A slaughterhouse study was performed and the foetuses of cattle pregnant with twins were measured. We identified 65 cases of twin pregnancies, of which 35 were unilateral twin pregnancies and 30 were bilateral twin pregnancies. There was no significant difference between the outermost and the more centrally located foetus in unilateral twin pregnancies in terms of body weight and length of the metacarpal diaphysis. Growth retardation of the outermost foetus could therefore not be confirmed as the cause of the higher abortion risk in unilateral bovine twin pregnancies. Four cases of pre-slaughter foetal mortality were identified. In three of these cases, both twins were dead, of equal size and at a comparable level of degradation. In the fourth case, with approximately 40-day-old twin foetuses of equal size, only one of the foetuses showed signs of pre-slaughter death.

Infectious sporadic bovine abortions: retrospective analysis.

Infectious sporadic abortions in cattle are mainly caused by opportunistic bacteria and fungi usually present in environmental or gastrointestinal and reproductive microbiota of healthy animals. A retrospective analysis was carried out to evaluate the main opportunistic microorganisms involved in bovine abortions recorded at INTA Balcarce (Argentina) from 1997 to 2023, accounting for 2.2% of the total diagnosed etiologies of bovine abortion. The opportunistic agents identified as the cause of abortion in 29 fetuses were bacteria (90%) and fungi (10%). Escherichia coli (n = 8), Trueperella pyogenes (n = 5), and Histophilus somni (n = 4) were the bacterial species most often identified as causing infectious abortions, whereas Aspergillus spp. (n = 3) was implicated in all fungal abortions identified. Pure culture of bacteria or fungus was achieved from abomasal content and/or lung essential. Main microscopic findings were bronchopneumonia, myo- and epicarditis, meningitis, and portal hepatitis. Herein, we highlight the importance of detecting potential infectious bacteria in cultures to improve etiological diagnosis of bovine abortions associated with compatible microscopic findings to confirm the etiology.

Serosurvey and associated risk factors for Chlamydia abortus infection in Dromedary camels in Egypt.

Chlamydia abortus (C. abortus) is a gram-negative, obligate intracellular bacterium that causes major public health problems in human and reproductive problems in animals. The information about the epidemiology of this pathogen among camels in Egypt is very rare. This study aimed to evaluate the existence of antibodies against C. abortus in camels and assess the related risk factors for infection. A total of 410 blood samples were collected from camels from three Egyptian governorates and examined using commercial ELISA kit. The overall seroprevalence rate was 6.6% and the higher C. abortus seropositivity rate was found in Giza governorate. Location, sex and infestation by ectoparasites did not influence on the seroprevalence of the disease. In addition, age, herd size, contact with small ruminants and history of abortion were identified as risk factors for C. abortus infection according to the univariate analysis. Based on multivariate analysis, age group of 4-8 years, small herd size, contact of camels with sheep and goats, and history of abortion were found to be significant risk factors for chlamydiosis transmission in camels. These factors had odds ratios of 4.23, 3.51, 2.84, and 2.5, respectively. These results suggest that camels have a role in the epidemiology of C. abortus infection. This promotes awareness and severe public health concern about infectious camel illnesses, allowing for additional diagnostic advancements and effective management techniques to be developed.

Overview of the causes of abortion in horses, their follow-up and management.

Abortions in horses represent an important health and economic challenge for equine industry. Primary causes of abortion are divided in non-infectious and infectious. Non-infectious causes include abnormalities of foetal appendices (umbilical cord and placenta essentially), abnormalities of gestation, maternal and foetal origins. Infectious abortions are caused in almost cases by bacterial infections, followed by viruses, fungi and parasites. New abortive pathogens (as Leptospira, Neospora caninum, Coxiella burnetii, Chlamydophila abortus, and) have been confirmed in equines by comparison already known for their abortive properties in human or in other species. Despite an increasing number of autopsies and continuous improvements in diagnostic tools, in management and surveillance, 20%-40% of the causes of equine abortion remain unknown depending on the country. To increase the likelihood of a definitive diagnosis in cases of abortion and stillbirth in horses, new diagnostic approaches are needed.

Invited review: Bovine abortion-Incidence, risk factors and causes.

The true incidence of bovine abortion (42-260 days of gestation) is unknown because of under-reporting. This is particularly true of the first half of gestation when most abortions occur. From research studies, it is estimated that the animal-level incidence of abortion between day 45 and term is approximately 10%, being lower in suckler than in dairy cows. While wide variation exists in herd-level incidence, up to 30%, it is estimated that less than 5% of farmers report high (>5%) observed abortion rates. Given these figures, veterinary practitioners and farmers tend to use investigation thresholds close to these values, ≥5 and ≥3%, respectively. Most of the risk factors for abortion are animal-level factors (e.g. parity), but there are also herd-level factors (e.g. enterprise type). Of the many risk factors for bovine abortion, only a small number are modifiable. While the causes of bovine abortion are often classified as noninfectious or infectious, in reality, this means diagnosis not reached (DNR) or infectious. Approximately 40% of abortions are diagnosed as infectious and the remaining 60% as DNR; DNR includes both infectious and noninfectious causes not diagnosed. Increasingly, genetic causes are being diagnosed and changes to current national genetic selection indices may be warranted. Of the infectious causes, Neospora caninum is now the most commonly diagnosed abortifacient internationally, followed by Trueperella pyogenes, BVDv and fungi. Both national eradication programmes and effective vaccination programmes can reduce the burden of some infectious abortifacients, but the control of sporadic, noninfectious and Neospora-associated abortions remains challenging.

Detection of bovine gammaherpesvirus 6 in tissues of aborted fetuses from dairy cows concomitantly infected by Histophilus somni.

Bovine gammaherpesvirus 6 (BoGHV6), formerly known as bovine lymphotropic virus, is a member of the Macavirus genus, subfamily Gammaherpesvirinae, family Herpesviridae, that was initially associated with proliferative diseases in cattle. While the Macavirus genus contains agents, including alcelaphine gammaherpesvirus 1 (AlGHV1), ovine gammaherpesvirus 2 (OvGHV2), and caprine gammaherpesvirus-2 (CpGHV2), known to cause malignant catarrhal fever (MCF), and are collectively referred to as MCF virus (MCFV) group of organisms, diseases and/or clinical syndromes have not been associated with BoGHV6 and porcine lymphotropic herpesvirus (PLHV). This report investigated the occurrence of BoGHV6 in tissues of aborted dairy fetuses known to be infected by Histophilus somni to identify possible disease patterns associated with infection by this Macavirus. A nested-PCR (nPCR) assay was used to amplify the BoGHV6 polymerase gene from multiple tissues of 13 fetuses and the cow of one of these which were derived from seven dairy herds located in three geographical regions of Brazil. Direct sequencing confirmed the results of the nPCR assays. Additionally, all fetal tissues were previously investigated for the presence of H. somni, Listeria monocytogenes, Neospora caninum, Brucella abortus, Leptospira spp., bovine alphaherpesvirus 1, and bovine viral diarrhea virus (BVDV) by PCR and/or RT-PCR assays. The nPCR assay amplified BoGHV6 DNA from fetuses of most dairy herds (85.7%; 6/7) investigated, resulting in the amplification of BoGHV6 from 76.9% (10/13) of all fetuses evaluated from two geographical and important cattle-producing regions of Brazil. Furthermore, only BoGHV6 was identified in the spleen (n = 3), myocardium, and kidney (n = 2) of five fetuses, and BoGHV6 was the only agent associated with myocarditis in one of these. Nevertheless, dual, triple, and quadruple infections (including BVDV, B. abortus, and N. caninum) were identified in fetuses that were concomitantly infected by H. somni. Phylogenetic analysis revealed that the strain herein identified has 100% nucleotide (nt) sequence identity with wild type strains of BoGHV6 circulating in ruminants from Brazil and 99.8% nt identity with the reference strain of BoGHV6 but was 72.2-73.3% and 67.4-68.2% different from members of the MCFV group and PLHV, respectively. These results demonstrated that 76.9% of the fetuses evaluated were infected by BoGHV6, most likely via vertical infection resulting in transplacental transmission. Considering that most fetuses were concomitantly infected by BoGHV6 and H. somni the real impact of this viral infection cannot be efficiently determined. However, since BoGHV6 was the only pathogen identified in the myocardium of one fetus with myocarditis by histopathology, the possible participation of this Macavirus in the etiopathogenesis of the myocardial disease observed in this fetus cannot be ignored or discarded. However, the mere amplification of BoGHV6 DNA from the myocardium is not enough to establish a definite association between cause and effect, since in situ evaluations and experimental studies would be needed to confirm this agent in the etiopathogenesis of fetal diseases and/or abortions in cattle. Consequently, additional studies are needed to determine the exact role, if any, of BoGHV6 in the development of fetal disease, and possibly fetal mortality.

Outbreak of neuropathogenic equid herpesvirus 1 causing abortions in Yili horses of Zhaosu, North Xinjiang, China.

BACKGROUND: EHV-1 is one of the most serious viral pathogens that frequently cause abortion in horses around the world. However, so far, relatively little information is available on EHV-1 infections as they occur in China. In January 2021, during an abortion storm which occurred in Yili horses at the Chinese State Studs of Zhaosu (North Xinjiang, China), 43 out of 800 pregnant mares aborted. RESULTS: PCR detection revealed the presence of EHV-1 in all samples as the possible cause of all abortions, although EHV-4, EHV-2 and EHV-5 were also found to circulate in the aborted fetuses. Furthermore, the partial ORF33 sequences of the 43 EHV-1 shared 99.3-100% and 99.0-100% similarity in nucleotide and amino acid sequences respectively. These sequences not only indicated a highly conserved region but also allowed the strains to group into six clusters. In addition, based on the predicted ORF30 nucleotide sequence, it was found that all the strains carried a guanine at the 2254 nucleotide position (aspartic acid at position 752 of the viral DNA polymerase) and were, therefore, identified as neuropathogenic strains. CONCLUSION: This study is the first one that establishes EHV-1 as the cause of abortions in Yili horses, of China. Further characterization of the ORF30 sequences revealed that all the EHV-1 strains from the study carried the neuropathogenic genotype. Totally, neuropathogenic EHV-1 infection in China's horse population should be concerned although the virus only detected in Yili horse abortions.

Toxoplasma gondii is not an important contributor to poor reproductive performance of primiparous ewes from southern Australia: a prospective cohort study.

BACKGROUND: Toxoplasma gondii causes reproductive losses in sheep worldwide, including Australia. The reproductive performance of primiparous ewes is typically lower than for mature, multiparous ewes, and younger ewes are more likely to be immunologically naïve and therefore more susceptible to reproductive disease if T. gondii infection occurs during pregnancy. The aim of this study was to assess the impact of infection with T. gondii on the reproductive performance of primiparous ewes in southern Australia using a prospective cohort study. This will inform the need for targeted control strategies for T. gondii in Australian sheep. RESULTS: Toxoplasma gondii seropositivity using indirect ELISA was detected at 16/28 farms located across southern Australia. Apparent seropositivity to T. gondii was lower in primiparous ewes (1.1, 95% confidence interval (CI) 0.6, 1.8) compared to mature, multiparous ewes (8.1, 95% CI 6.0, 10.5; P < 0.001). Toxoplasma gondii seroconversion during the gestation and lambing period was confirmed for 11/1097 (1.0, 95% CI 0.5, 1.7) of pregnant primiparous ewes that failed to raise a lamb, and 1/161 (0.6, 95% CI 0.1, 2.9) primiparous ewes with confirmed mid-pregnancy abortion. CONCLUSIONS: Low frequency of detection of T. gondii seroconversion during gestation and low frequency of seropositivity to T. gondii suggests that toxoplasmosis was not an important contributor to reproductive losses in primiparous ewes on farms located over a wide geographical area in southern Australia.

Epidemic abortions due to Neospora caninum infection in farmed red deer (Cervus elaphus).

This study describes for the first time an abortion outbreak caused by Neospora caninum in farmed red deer. During a 5-year period, farmed hinds, naturally mated, were regularly ultrasound monitored to detect reproductive losses over their gestation. During the 4 years previous to the outbreak, abortion rates ranged from 4.7 to 8.6% (average 6.5%), and serology for indirect diagnosis of neosporosis and toxoplasmosis was performed. At the fifth year, the abortion rate increased to 25.3%. During this outbreak, three aborted foetuses and their placentas were recovered and submitted to laboratory for etiological diagnosis. Blood samples were collected from the 81 hinds at the end of the gestational period and the seropositivity rate for N. caninum, Toxoplasma gondii, Brucella abortus, bovine viral diarrhoea virus and bovine alphaherpesvirus type 1 was 66.7%, 67.9%, 0.0%, 8.6% and 0.0%, respectively. Neospora caninum-seropositive hinds (OR = 5.7, P = 0.0271) and hinds with high antibody titres to N. caninum (OR = 7.4, P = 0.0130) were more likely to abort than seronegative hinds. In addition, N. caninum seropositivity rate in the aborted hinds was higher (OR = 5.4, P = 0.033) than the non-aborted hinds. No association was found between T. gondii nor BVDV-seropositivity and abortions. Typical protozoal histopathologic findings (necrotizing non suppurative encephalitis, meningitis, myocarditis, hepatitis, among others) were observed in all foetuses. Neospora caninum was immunolabelled by immunohistochemistry in several tissues from two foetuses, and infection was also confirmed in the three foetuses by serology and/or DNA detection. No other abortifacient agent was detected in the foetuses. Their dams showed high N. caninum antibody titres (≥ 6400). Serologic evidence and epidemiological data recorded suggested a point-source of N. caninum infection before the occurrence of the outbreak, probably related with contaminated feedstuff with oocysts. Moreover, the intensive production system with a high stocking rate could be also considered a factor which might have increased the risk of horizontal N. caninum infection in this herd.

A 13-year retrospective study of equine abortions in Canada.

Objective: The purpose of this study was to identify the most common causes of equine abortion in Canada, and to compare findings to similar reports from other countries. Animal: Equine. Procedure: Necropsy reports from 901 equine abortion cases were acquired from provincial veterinary diagnostic laboratories across Canada. The final diagnosis was classified into basic abortion causes (infectious, non-infectious, unknown) and into primary and secondary categories for analysis. Results: Non-infectious causes of abortion were the most frequently identified in Canada, with fetoplacental causes, including umbilical cord torsion or placental insufficiency, being the most common primary diagnosis category. Streptococcus and Escherichia were the bacterial species most often identified as causing infectious abortions, whereas equine herpesvirus-1 was implicated in all viral abortions identified. Conclusion: The high rate of non-infectious causes of abortion was similar to previous studies conducted in the United Kingdom. This finding was somewhat dissimilar to the USA, which had higher rates of infectious abortions, despite Canada's geographic proximity to the USA. The reason for variations among countries in equine abortion causes is unknown. Clinical relevance: The large number of fetoplacental-related abortions identified in this study emphasized the need for submission of both the fetus and placenta, if possible, to increase the probability of a diagnosis. In addition, the high rate of unidentified diagnoses suggests a need for further study into both non-infectious and infectious causes of equine abortion, including potential development of new diagnostic tests or markers.

Objectif: Le but de cette étude était d'identifier les causes les plus courantes d'avortement chez les équidés au Canada et de comparer les résultats à des rapports similaires provenant d'autres pays. Animal: Chevaux. Procédure: Les rapports de nécropsie de 901 cas d'avortements équins ont été obtenus auprès de laboratoires provinciaux de diagnostic vétérinaire à travers le Canada. Le diagnostic final a été classé en causes d'avortement de base (infectieuses, non infectieuses, inconnues) et en catégories primaires et secondaires pour analyse. Résultats: Les causes non-infectieuses d'avortement étaient les plus fréquemment identifiées au Canada, les causes foetoplacentaires, y compris la torsion du cordon ombilical ou l'insuffisance placentaire, étant la catégorie de diagnostic principal la plus courante. Les espèces bactériennes des genres Streptococcus et Escherichia étaient les plus souvent identifiées comme étant à l'origine d'avortements infectieux, alors que l'herpèsvirus équin-1 était impliqué dans tous les avortements viraux identifiés. Conclusion: Le taux élevé de causes non-infectieuses d'avortement était similaire aux études précédentes menées au Royaume-Uni. Cette observation était quelque peu différente de celles des États-Unis, qui avaient des taux plus élevés d'avortements infectieux, malgré la proximité géographique du Canada avec les États-Unis. La raison des variations entre les pays dans les causes d'avortement équin est inconnue. Pertinence clinique: Le grand nombre d'avortements liés aux causes foetoplacentaires identifiés dans cette étude a souligné la nécessité de soumettre à la fois le foetus et le placenta, si possible, pour augmenter la probabilité d'un diagnostic. En outre, le taux élevé de diagnostics non identifiés suggère la nécessité d'une étude plus approfondie des causes non-infectieuses et infectieuses de l'avortement équin, y compris le développement potentiel de nouveaux tests de diagnostic ou marqueurs.(Traduit par Dr Serge Messier).

Spatial-temporal trends and economic losses associated with bovine abortifacients in central Argentina.

The aims of this work are, firstly, to provide the geolocalization of cases of bovine abortion with definitive diagnosis and, secondly, to estimate the economic losses due to the most frequent abortifacients diagnosed agents in cattle in Buenos Aires province, Argentina. The total beef and dairy cattle population at risk of abortion is 8,358,186 and 538,076, respectively. In beef cattle, the overall risk of abortion was estimated at 4.5% for all pregnancies, where 27.9% are due to Campylobacter fetus, Neospora caninum, Leptospira spp., Brucella abortus, and bovine viral diarrhea virus with economic losses of US$ 440 per abortion, being the annual loss to the beef industry of US$ 50,144,101. In dairy cattle, there was an 8.0% risk of suffering abortion, 26.1% produced by the same abortigenic agents. The economic losses were estimated at US$ 1,415 per abortion, which equals a total loss of US$ 17,298,498 for the dairy industry in the region. The results of this study show that infectious causes are highly prevalent in Buenos Aires province, and they caused severe economic impacts in the dairy and beef industries. Furthermore, changes in temporal trends of infectious abortion occurrence were detected, probably related to the inclusion of molecular diagnostic techniques with more sensitivity or different epidemiological or husbandry conditions in the region analyzed.

Investigation of the outbreaks of abortions and orchitis in livestock in Namibia during 2016-2018.

This study investigated outbreaks of seemingly related abortions and orchitis which occurred in the Khomas, Omaheke and Otjozondjupa regions of Namibia from 2016 to 2018, affecting cattle, sheep and goats. Fifty-nine questionnaires were administered, and 48 were completed giving an 81.4% return. The outbreaks were limited to Namibia's east and central regions, mainly on farms rearing cattle, sheep and goats and on farms with a mixture of these species. There was no significant difference between Khomas and other regions on abortion reporting at the farm level [X2 (1, N = 48) = 0.0002, p = 0.987851]. However, there was a significant difference in the abortions at the animal level among the three regions [X2 (2, N = 6246) = 239.8339, p = .00001]. In addition, the proportions of abortions calculated at the animal level at each farm were significantly different when the Khomas region was compared to the other regions. Seventeen cattle sera, 35 sheep sera, 52 caprine sera, 18 bovine liver samples, one caprine liver, five aborted cattle foetuses, two cattle placentas, 18 testes (one bull, eight bucks and nine rams) and ten bull sheath scrapings were collected and tested. Histopathology, microbiology, serology, immunohistochemistry, real-time PCR and mineral analytical techniques were used to establish the aetiology of the abortion and orchitis outbreaks. The gross and histopathological findings on the 18 testicles were characteristic of chronic orchitis. In aborted foetuses, significant histopathological findings included meconium aspiration, funisitis and cardiomyopathy. Placentitis and endometritis were the primary pathologies observed in cows. The bacteria isolated from microbiological samples included Enterococcus spp. (65.5% [19/29]), Enterobacter spp. (6.9% [2/29]) and Streptococcus spp. (10.3% [3/29]), Trueperella pyogenes (3.4% [1/29]), Stenotrophomonas maltophilia (3.4% [1/29]), Staphylococcus epidermidis (3.4% [1/29]), Providencia rettgeri (3.4% [1/29]) and Acinetobacter lwoffii (3.4% [1/29]), mostly opportunistic bacteria. On mineral analysis, 28%, 33%, 83%, 33% and 17% (n = 18) of cattle livers were low in copper, zinc, manganese, selenium and iron, respectively. Twenty-three percent (12/52) of the caprine sera were positive for Brucella melitensis on the Rose Bengal and complement fixation tests. Thirty-five ovine sera were tested for B. melitensis, B. ovis and Coxiella burnetii, and the prevalence for each was 2.9% (1/35). PCR tests on foetuses were all negative for Brucella spp., Coxiella burnetii, Chlamydia spp., Listeria monocytogenes, Salmonella spp., Campylobacter fetus spp., Leptospira pathogenic strains, bovine viral diarrhoea virus, Rift Valley fever virus, Anaplasma phagocytophilum and bovine herpes virus 4 Campylobacter fetus spp. and Trichomonas foetus spp. The authors concluded that Brucella spp., Enterococcus spp., Escherichia coli, Streptococcus spp., Trueperella pyogenes and Coxiella burnetii could have contributed to this outbreak. Micronutrient imbalances and pathogenic abiotic nanoparticles were also identified as possible contributors to the abortion outbreaks.

Chlamydia pecorum detection in aborted and stillborn lambs from Western Australia.

Lamb survival is an important welfare and productivity issue for sheep industries worldwide. Lower lamb survival has been reported for primiparous ewes, but the causes of this are not well studied. The aim of this study was to determine causes of perinatal deaths for lambs born to primiparous ewes in Western Australia, and identify if infectious diseases are implicated. Lamb mortality from birth to marking were determined for 11 primiparous ewe flocks on 10 farms in Western Australia. Lamb mortality from birth to marking averaged 14% for single-born and 26% for multiple-born lambs. Lamb necropsies (n = 298) identified starvation-mismosthering-exposure (34%), dystocia (24%) and stillbirth (15%) as the most common causes of perinatal lamb death. There was no evidence of exotic abortigenic pathogens in aborted and stillborn lambs (n = 35). Chlamydia pecorum was detected by qPCR in 15/35 aborted and stillborn lambs on 5/6 farms. Preliminary molecular characterisation of C. pecorum detected in samples from aborted and stillborn lambs (n = 8) using both Multilocus Sequence Typing and ompA genotyping indicated all strains were genetically identical to previously described pathogenic livestock strains, denoted ST23, and dissimilar to gastrointestinal strains. High frequency of detection of a pathogenic C. pecorum strains ST23 associated with ovine abortion and stillbirth on multiple farms located across a wide geographic area has not been previously reported. Chlamydia pecorum may contribute to reproductive wastage for primiparous sheep in Western Australia. Further investigation to understand C. pecorum epidemiology and impact on sheep reproduction is warranted.

Prevalence of bovine abortion, calf mortality, and bovine viral diarrhea virus (BVDV) persistently infected calves among pastoral, peri-urban, and mixed-crop livestock farms in central and Northwest Ethiopia.

BACKGROUND: Bovine Viral Diarrhea virus (BVDV) is one of important diseases of cattle worldwide causing economic losses to the cattle industry primarily due to increased premature culling and decreased reproductive performance. The virus can cross the placenta during early pregnancy and result in the birth of persistently infected (PI) calves that are efficient transmitters of BVDV and serving as the primary reservoirs for BVDV. Relatively few studies have focused on understanding BVDV seroprevalence, virus detection, genotyping and its distribution in Africa. Most BVDV research in Ethiopia has involved serologic surveys in adult cattle, rather than the identification of PI calves, despite their role in viral shedding and recurring infections. A cross-sectional study was undertaken in three different livestock production systems of Ethiopia with the objective to estimate the prevalence of bovine abortion, calf mortality, and BVDV persistently infected calves. RESULTS: Ear notch samples (882) collected from calves in 349 households were tested for BVDV antigen using antigen capture enzyme-linked immunosorbent assay (ACE). All samples tested were negative for BVDV antigen. The overall animal level crude abortion and calf mortality prevalence were 4.0% (95% CI: 2.9-5.2) and 9.2% (95% CI: 7.7-11.0) respectively. The lower BVDV PI prevalence may be due to a lower effective contact rate between cattle reared in small-scale extensive production systems in Ethiopia. CONCLUSIONS: This is the first report of BVDV Ag test in Ethiopia and no PI was detected in calves in the study areas. Since BVDV is a disease of great economic importance, this study finding must be interpreted with care since absence of evidence is not evidence of absence and even a single BVDV infected animal can serve as source of infection and contribute to the persistent spread of the virus. Greater attention needs to be given to screening for PI animals through testing large number of animals and culling positive animals. Hence, future research should focus on regions and production systems with high BVDV seroprevalence followed by antigen ELISA or BVDV real-time PCR to detect persistently infected and acutely viremic animals.

Salmonella Abortusovis: An Epidemiologically Relevant Pathogen.

The ovine pathogen Salmonella enterica serovar Abortusovis (SAO), a pathogen strictly adapted to ovine hosts, is endemic in several European and Asian countries, where it causes significant economic losses due to the high rates of abortion in infected flocks. In some countries (i.e. Switzerland and Croatia), re-emergence of infection by SAO occurred after decades during which the disease has not been reported. The introduction of (SAO) epidemic strains in new areas is difficult to control due to the asymptomatic behaviors in infected adult lambs, rams, and nonpregnant ewes. Culture-based diagnosis may provide false-negative results. Moreover, the retrospective identification of Salmonella infection in ewes is challenging as excretion of the causative agent is transient and the serum antibodies fall to low titres soon after the abortion. Therefore, regular monitoring of pathogen exposure, mainly through seroconversion assessment, is advisable to prevent disease introduction and spread in SAO-free areas, especially in case of animal export, and to reduce abortion risk.

Survey of the equine broodmare industry, abortion, and equine herpesvirus-1 vaccination in Ontario.

A survey of Ontario horse breeders was conducted in 2016 and retrospectively asked farm-level management questions regarding herd sizes, vaccination, respiratory disease, and abortion over the years 2014 to 2015. A total of 88 farm owners completed the survey, reporting 857 broodmares. Using logistic regression modelling, management influences on vaccine use, and the reporting of respiratory disease or abortion was investigated. Having veterinary records and the reasons for breeding were significantly associated with the odds of an abortion even after controlling for broodmare herd size. The odds of having respiratory illness on the farm were significantly greater if the farm was the primary source of income even after controlling for farm size. Respondents with primary breeding operations were more likely to utilize vaccines against equine herpesvirus 1 (EHV-1), independent of herd size. Veterinarians were more involved with abortions than with respiratory disease, leaving a significant gap in the opportunities for client education.

Enquête sur l'industrie poulinière, l'avortement et l'utilisation du vaccin contre l'herpèsvirus équin-1 en Ontario. Une enquête auprès des éleveurs de chevaux de l'Ontario a été menée en 2016 et a posé des questions de gestion de l'écurie concernant la taille des troupeaux, la vaccination, les maladies respiratoires et l'avortement, rétrospectivement pour les années 2014 et 2015. Au total, 88 propriétaires d'écuries ont répondu à l'enquête avec 857 juments poulinières. Utilisant des modèles de régression logistique, l'influence du style gestionnaire sur l'utilisation des vaccins et la déclaration des maladies respiratoires ou de l'avortement a été étudiée. La probabilité d'avoir un avortement était significativement associée avec l'utilisation des dossiers vétérinaires et la raison de l'élevage. Les probabilités de souffrir de maladies respiratoires au niveau de la ferme étaient significativement plus élevées si l'écurie était la principale source de revenu. Les répondants ayant des établissements principalement d'élevage étaient plus susceptibles d'utiliser des vaccins contre HVE-1. Les vétérinaires étaient plus impliqués lors de cas d'avortements que lors de maladies respiratoires, ratant une belle opportunité pour l'éducation des clients.(Traduit par les auteurs).

Characterization of the first bovine gammaherpesvirus 4 strain isolated from an aborted bovine fetus in Argentina.

Bovine herpesvirus 4 (BoHV-4) is increasingly believed to be responsible for several disorders of the bovine reproductive tract. The first characterization of BoHV-4 in Argentina was from samples from an aborted fetus. Argentinean isolates are highly diverse and are phylogenetically grouped in three genotypes. In this study, we describe the isolation of BoHV-4 from a bovine fetus with a gestational age of 8 months and without macroscopic lesions. Genetic analyses revealed that the isolated strain belongs to genotype 2. This is the first report on the presence of infectious BoHV-4 in tissues from an aborted bovine fetus.

Genomic-based identification of environmental and clinical Listeria monocytogenes strains associated with an abortion outbreak in beef heifers.

BACKGROUND: In a beef cattle facility an outbreak of abortions occurred over a 36-day period and included samples from two aborted (non-viable) fetuses and 21 post-abortion clinical cases. There are numerous etiologies, including clinical listeriosis. At the species level, Listeria monocytogenes is ubiquitous in cattle production environments, including soil, feed, and occasionally water sources, and is a common enteric resident of cattle and other mammals. There are four genetically distinct lineages of L. monocytogenes (I-IV), with most lineage III and IV isolates obtained from ruminants. Definitive diagnosis of L. monocytogenes as a causative agent in disease outbreaks relies upon case identification, appropriate sample collection, and laboratory confirmation. Furthermore, clearly establishing a relationship between a pathogen source and clinical disease is difficult. RESULTS: Of the two fetal and 21 clinical case submissions, 19 were positive for L. monocytogenes. Subsequent culture for L. monocytogenes from water and silage sources identified both as potential origins of infection. Using whole-genome sequencing and phylogenetic analyses, clinical, water and silage L. monocytogenes strains grouped into two of four lineages. All water and silage strains, plus 11 clinical strains placed in lineage III, with identical or nearly identical genomic sequences. The remaining eight clinical strains placed in lineage I, with seven having nearly identical sequences and one distinctly different. CONCLUSION: Three genetically distinct strains within two lineages of L. monocytogenes caused the abortion outbreak. The etiology of abortion in 11 cases was directly linked to water and silage contamination from a lineage III L. monocytogenes strain. The source of infection for the remaining abortion cases with two different strains from lineage I is unknown. This is the first report of L. monocytogenes genomics being used as part of an outbreak investigation of cattle abortion.