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.

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.

Higher livestock abortion burden in arid and semi-arid lands, Kenya, 2019-2020

Tracking livestock abortion patterns over time and across factors such as species and agroecological zones (AEZs) could inform policies to mitigate disease emergence, zoonoses risk, and reproductive losses. We conducted a year-long population-based active surveillance of livestock abortion between 2019 and 2020, in administrative areas covering 52% of Kenya's landmass and home to 50% of Kenya's livestock. Surveillance sites were randomly selected to represent all AEZs in the country. Local animal health practitioners electronically transmitted weekly abortion reports from each ward, the smallest administrative unit, to a central server, using a simple short messaging service (SMS). Data were analyzed descriptively by administrative unit, species, and AEZ to reveal spatiotemporal patterns and relationships with rainfall and temperature. Of 23,766 abortions reported in all livestock species, sheep and goats contributed 77%, with goats alone contributing 53%. Seventy-seven per cent (n = 18,280) of these abortions occurred in arid and semi-arid lands (ASALs) that primarily practice pastoralism production systems. While spatiotemporal clustering of cases was observed in May-July 2019 in the ASALs, there was a substantial seasonal fluctuation across AEZs. Kenya experiences high livestock abortion rates, most of which go unreported. We recommend further research to document the national true burden of abortions. In ASALs, studies linking pathogen, climate, and environmental surveillance are needed to assign livestock abortions to infectious or non-infectious aetiologies and conducting human acute febrile illnesses surveillance to detect any links with the abortions.

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.

Potential risk factors for fetal loss due to umbilical cord torsion in the mare

Equine pregnancy failure can occur throughout gestation with etiologies varying by region. In Europe, umbilical cord torsion (UCT) has been reported to account for up to 52% of abortions and stillbirths. Little is known about what causes excessive twisting of the umbilical cord (UC), and up till now, only the length of the UC has been identified as a risk factor for UCT. The aim of the present study was to determine the association of potential maternal and fetal risk factors with UCT and umbilical cord length (UCL). A retrospective cohort study was performed on aborted or prematurely delivered stillborn fetuses submitted for necropsy, and a follow-up questionnaire survey was sent to mare owners to obtain additional anamnestic data. In total 72 cases were included in the study. Multivariable regression analyses were performed to evaluate the risk factors (mare size, period of gestation, gestational length, parity, previous abortion, UCL, maternal age at abortion and fetal sex) association with UCT and UCL, and Wilcoxon rank sum test tested pairwise differences in UCL for the risk factors mare size, period of gestation and cause of abortion. Abortion caused by UCT (UCTA) was diagnosed in 37 cases, and these had shorter gestational length (8.1 ± 0.3 months) compared to fetuses lost to other causes (8.9 ± 0.2 months) (p = 0.002). UCTAs accounted for the highest prevalence of abortions in the mid gestational period (113-227 days) (14/21, 67%) compared to the late period (228-314 days) (22/50, 44%) (p = 0.05). The cause of abortion was associated with period of gestation (p = 0.009) and UCL (p = 0.002), and fetuses aborted as a consequence of UCT had longer UCs (98.84 ± 5.14 cm) compared to abortions due to other causes (67.2 ± 4.9 cm). Mares in the mid period of gestation had 7.9 times the odds of UCTA compared to the late period (CI: 1.93, 32.2), and UCL was associated with increased odds of UCTA (OR: 1.05, CI: 1.02, 1.07). UCL was associated with mare size (p = 0.012), period of gestation (p = 0.002) and cause of abortion (p = 0.001). In conclusion, UCTA was significantly associated with UCL and gestational length. The prevalence of UCTA was not influenced by mare size, but pony fetuses from UCTAs had significantly shorter UCs compared to horse fetuses. UCs longer than 54 cm may predispose ponies for UCTA. No other maternal or fetal risk factors were found to be associated with the cause of abortion.

Campylobacter species abortion in sheep

This focus article was prepared by Jasmine Smith of the APHA Small Ruminant Species Expert Group. Data extraction and analysis was done by Anna Brzozowska of the APHA Surveillance Intelligence Unit and Leanne Dempsey from APHA Thirsk.

Detection of Anaplasma phagocytophilum in fetal and placental tissue of bovine abortions and perinatal mortalities

BACKGROUND

Anaplasma phagocytophilum is a tick-borne zoonotic bacterium that is the aetiologic pathogen of tick-borne fever (TBF) in ruminants. In clinical bovine cases of TBF, abortion and stillbirth may be observed. However, in this regard, the pathophysiology of TBF has not yet been completely elucidated, and no clear guidelines to diagnose A. phagocytophilum-related abortions and perinatal mortalities (APM) are available.

METHODS

This exploratory study aimed to investigate the presence of A. phagocytophilum in bovine cases of APM and determine whether placental or fetal spleen tissue has the greatest sensitivity for A. phagocytophilum identification. The placenta and fetal spleen of 150 late-term bovine APM cases were analysed using real-time PCR to detect A. phagocytophilum.

RESULTS

A total of 2.7% of sampled placentas were positive for A. phagocytophilum, while none of the fetal spleen samples was.

LIMITATIONS

No histopathology to detect associated lesions was performed. Consequently, no evidence of causality between the detection of A. phagocytophilum and APM events could be achieved.

CONCLUSION

The detection of A. phagocytophilum suggests a potential role of this pathogen in bovine APM, and placental tissue seems to be the most suitable tissue for its identification.

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.

Equine abortion and stillbirth in California: a review of 1,774 cases received at a diagnostic laboratory, 1990-2022

Reproductive failure represents an important cause of economic loss for the equine industry. We reviewed the cases of equine abortion and stillbirth submitted to the California Animal Health and Food Safety Laboratory System, University of California-Davis from 1990 to 2022. A total of 1,774 cases were reviewed. A confirmed cause of abortion was determined in 29.2% of the cases. Abortion or stillbirth was attributed to infectious agents in 18.7% of the cases, with Streptococcus spp., equine herpesvirus 1, and Leptospira spp. being the most prevalent. Noninfectious causes of abortion were established in 10.5% of the cases, with umbilical cord torsion being the most common. In 70.8% of the cases, a definitive cause of abortion could not be established. Our study demonstrated the difficulties in establishing an etiologic diagnosis, even when following a standard diagnostic work-up. New diagnostic approaches are needed to improve the likelihood of reaching a final diagnosis in cases of equine abortion and stillbirth.

Pregnancy and parturition in dromedary camels III. Incidence, timing and factors affecting abortions and perinatal mortality under intensive management

In this study, the incidence, timing and risk factors associated with abortion and perinatal mortality (PM) were described in dromedary camels under intensive management. In addition, overall pregnancy losses were also summarized and weekly risk of pregnancy wastage was determined throughout gestation. Data were collected over 11 breeding seasons from September 2006 through June 2017 at the world's largest camel dairy farm. A total of 229 abortions were observed (5.05%) out of 4533 pregnancies after 60 days (d) of gestation. Most abortions were singleton (n = 199, 86.9%), but twin abortions were also recorded in 30 cases (13.1%). Abortions showed a pronounced seasonal distribution, with a peak in August. The age category (P < 0.01), breed or ecotype of the female (P < 0.05) and bull influenced the occurrence of singleton abortions. Dromedaries with twins tended to abort earlier than those with a singleton fetus (median = 232.5 d vs. 257 d, P = 0.053). Perinatal mortality was observed in 174 cases (3.84%) out of 4533 pregnancies after 60 d of gestation. The condition included the premature birth of non-viable calves after shorter than normal gestation (330-350 d, n = 26, 14.9%), the birth of well-developed but dead calves after normal gestation length (n = 120, 69.0%) and neonates that died within 48 h after delivery (n = 28, 16.1%). The frequency distribution of PM was parallel with that of parturitions. The most important predisposing factor for PM was difficult calving. Thirty-nine percent (68 out of 174) of these losses were associated with dystocia. In addition, age category (P < 0.05) and parity of the female (P < 0.01), month of delivery (P < 0.05) and breeding season (P < 0.05) also affected the incidence of PM. The cause of 60 cases of PM (1.4% of all deliveries) could not be determined and was considered idiopathic. In conclusion, one-third of total pregnancy losses occurred during mid to late gestation. Approximately 10% of pregnancies after Day 60 failed, and 90% resulted in the birth of a live calf that survived beyond 48 h. More than half of these pregnancy losses were abortions before 330 d of gestation, and approximately 40% were classified as PM. The weekly mean risk of pregnancy loss after 100 d of gestation remained only a fraction of that observed during the first 2-3 months.

ABORTION AND NEONATAL MORTALITY DUE TO TOXOPLASMA GONDII IN BIGHORN SHEEP (OVIS CANADENSIS)

Low lamb recruitment can be an obstacle to bighorn sheep (Ovis canadensis) conservation and restoration. Causes of abortion and neonate loss in bighorn sheep, which may affect recruitment, are poorly understood. Toxoplasma gondii is a major cause of abortion and stillbirth in domestic small ruminants worldwide, but no reports exist documenting abortion or neonatal death in bighorn sheep attributable to toxoplasmosis. Between March 2019 and May 2021, eight fetal and neonatal bighorn lamb cadavers from four western US states (Idaho, Montana, Nebraska, and Washington) were submitted to the Washington Animal Disease Diagnostic Laboratory for postmortem examination, histologic examination, and ancillary testing to determine the cause of abortion or neonatal death. Necrotizing encephalitis characteristic of toxoplasmosis was identified histologically in six of eight cases, and T. gondii infection was confirmed by PCR in five cases with characteristic lesions. Other lesions attributable to toxoplasmosis were pneumonia (3/5 cases) and myocarditis (2/5 cases). Protozoal cysts were identified histologically within brain, lung, heart, skeletal muscle, adipose tissue, or a combination of samples in all five sheep with PCR-confirmed T. gondii infections. Seroprevalence of T. gondii ranged from 40-81% of adult females sampled in the Washington population in October and November 2018-2021, confirming high rates of exposure before detection of Toxoplasma abortions in this study. Of 1,149 bighorn sheep postmortem samples submitted to Washington Animal Disease Diagnostic Laboratory between January 2000 and May 2021, 21 of which were from fetuses or neonates, a single case of chronic toxoplasmosis was diagnosed in one adult ewe. Recent identification of Toxoplasma abortions in bighorn sheep suggests that toxoplasmosis is an underappreciated cause of reproductive loss. Abortions and neonatal mortalities should be investigated through postmortem and histologic examination, particularly in herds that are chronically small, demographically stagnant, or exhibit reproductive rates lower than expected.

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.

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.

Neospora caninum infection in aborting bovines and lost fetuses: A systematic review and meta-analysis

Background

Neospora caninum (N. caninum) is known to be a major cause of reproductive failure in cattle herds around the world. Therefore, the current comprehensive study was performed to estimate the global prevalence of N. caninum infection in bovines that had an abortion and aborted fetuses.

Methods

In this study, PubMed, ScienceDirect, Web of Science, Scopus, and ProQuest databases were systematically searched for relevant studies up until November 4, 2021. Pooled prevalence and corresponding 95% confidence intervals (CI) were estimated using a random effect model. Other analyzes performed on the data of this study include sensitivity analysis, publication bias test, and quality assessment.

Results

The final analyses included 71 studies conducted on 2965 abortive cattle and 4805 aborted fetuses. The overall prevalence rates of N. caninum infection in bovines that had an abortion were 47% and 1% using serological and molecular methods. Furthermore, overall prevalence rates of N. caninum infection in bovine aborted fetuses globally were 35% (95% CI: 8%–62%) and 43% (95% CI: 35%–52%) using serological and molecular methods.

Conclusions

The results of this study showed the high prevalence of N. caninum infection in bovines that had an abortion and aborted fetuses. It is hoped that the results of this study will help prevent abortion in bovines around the world and encourage further studies to determine the impact of this parasite on the occurrence of abortion that may help reduce the economic damage caused by abortion worldwide.

Neospora caninum infection and reproductive problems in dairy cows from Brazil: A case-control study

Neosporosis, an infectious disease caused by the protozoan Neospora caninum, has been associated with economic losses in cattle rearing worldwide. However, previous studies have not presented any evidence regarding the association between serological status of neosporosis and alteration of the reproductive parameters. Thus, this study aimed to determine whether N. caninum is associated with reproductive disorders and to evaluate the possible risk factors of the infection. Blood samples from 202 dairy cows, 51 with a history of reproductive disorders (case group) and 151 without (control group), were collected from different farms in Brazil. Epidemiological questionnaires were conducted with all the farmers. Serum samples were subjected to an indirect fluorescent antibody test to detect antibodies against the parasite. In total, 28.22% (57/202) of the cows were seropositive: 47.06% (24/51) from the case group and 21.85% (33/151) from the control group. By logistic regression, cows aged ≥48 months and cows with history of abortion were 4.8 (95% confidence interval [CI] = 1.91-12.05; p = 0.001) and 2.3 (95% CI = 1.06-5.1; p = 0.034) times more likely to be seropositive, respectively. Furthermore, our results show an association between N. caninum seropositivity and abortion in dairy cows from Brazil with poor management conditions and N. caninum seropositivity risk factors for reproductive disorders.

Development and Use of an Enzyme-Linked Immunosorbent Assay to Determine Temporal Exposure Patterns to Putative Agents of Nocardioform Placentitis

Cases of nocardioform placentitis are characterized by focal, mucoid placentitis resulting in late-term abortion, premature birth, or small, full-term foals, occur sporadically, and are most commonly associated with Crossiella equi and Amycolatopsis spp. infection. The goal of this project was to develop an enzyme-linked immunosorbent assay (ELISA) for quantifying antibodies against Crossiella equi and Amycolatopsis spp. and utilize the ELISA to determine when exposure occurs. Serum samples collected during the 2020 foaling season from Crossiella equi (n = 8) and Amycolatopsis spp. (n = 32) infected mares, as well as nonaffected mares (n = 51 mares), were used to develop and optimize bacteria-specific ELISAs. Following development of the ELISAs, banked serum samples from a single, central Kentucky Thoroughbred farm collected during 2012 to 2013 (n = 104 mares) and 2013-14 (n = 82 mares) were analyzed. Differences in various groups were analyzed using one-way analysis of variance (ANOVA). Crossiella equi-infected mares had significantly higher ELISA unit (EU) values on the Crossiella equi ELISA near parturition when compared to the other two groups (P < .001). Using the Amycolatopsis spp. ELISA, EU values were not significantly different between Amycolatopsis spp. infected and non-affected mares, suggesting this ELISA is not specific for Amycolatopsis spp. During 2013 to 2014, there were significant increases in EU values between June and late September for the Crossiella equi ELISA, suggesting exposure in the summer and early fall months. Data from the Crossiella equi ELISA may help provide a better understanding of the epidemiology of nocardioform placentitis, guide the development of a successful experimental challenge model, and allow for further refinement of these ELISAs.

Genetic features of Salmonella enterica subspecies diarizonae serovar 61:k:1,5 isolated from abortion cases in sheep, United States, 2020

Salmonella enterica subspecies diarizonae serovar 61:(k):1, 5, (7) (sheep associated S. diarizonae, SASd) is the most common Salmonella serotype identified in sheep flocks. Despite the involvement with animal and human infections, there is limited information regarding virulence profiles of SASds and their antibiotic resistance gene complement, particularly for those circulating in the U.S. In this study, we genetically characterized three SASds, 20-265, 20-269, and 20-312, isolated from sheep placental tissues during an abortion storm affecting a flock in Connecticut during 2020. SASds were the only bacteria isolated from analyzed sheep tissues. The isolates were sensitive to all the antibiotics tested, but all these SASd isolates carry the aminoglycoside resistance gene, aac(6')-Iaa, and a chromosomal substitution in the parC gene. The proportion of pseudogenes (5.3-5.5%) was similar among the isolates, and these SASds carry IncX1 type plasmids. Comparing with the SASds isolates from Enterobase, the three isolates showed an identical genomic virulence profile carrying virulence genes in the conserved set of other SASd isolates except for steC, iagB, iacP, sseI, and slrP genes. In the SNP-based phylogenetic analysis, SASd sequences were grouped into group A-C, and the group C was further subdivided into subgroup C1-C6. The three isolates clustered with other SASd isolates from the U.S. and Canada in subgroup C6. SASd isolates in the identical phylogenetic groups tended to have similar geographical origin. The results of our study did not provide conclusive evidence about which are the genetic traits that trigger SASds to become virulent in sheep, but our data will provide a point for comparative studies of this Salmonella serovar.

Molecular detection of Coxiella burnetii infection in aborted samples of domestic ruminants in Iran

BACKGROUND

Coxiella burnetii is the causative agent of Q fever which is a highly infectious zoonotic disease. C. burnetii has become one of the most important causes of abortion in livestock, which can lead to widespread abortions in these animals. There are very limited studies on the prevalence of C. burnetii infection in cases of animal abortion in Iran. The aim of this study was to investigate the occurrence of C. burnetii in ruminant abortion samples in Iran.

METHODS

Abortion samples from cattle, sheep and goats were collected from different parts of Iran and were tested using Real-time PCR targeting the IS1111 element of C. burnetii.

RESULTS

In this study, 36 samples (24.7%) of the 146 collected samples were positive for C. burnetii. The prevalence of C. burnetii was 21.3% (20 of 94 samples) in sheep samples. Also, 10 of 46 cattle samples (21.7%) were positive. All six goat abortion samples were positive for C. burnetii.

CONCLUSIONS

The findings of the study demonstrate that C. burnetii plays an important role in domestic ruminant abortions in Iran, suggesting that more attention should be paid to the role of C. burnetii in domestic animal abortions by veterinary organizations. The risk of transmitting the infection to humans due to abortion of animals should also be considered.

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.

Neospora caninum in aborted bovine fetuses in Iran: a systematic review and meta-analysis

The aim of the present study is to systematically review the studies on Neospora caninum infection in aborted bovine fetuses in Iran. Search for all published reports on N. caninum in Iran was performed from inception until January 2020. Major English (PubMed, Scopus and Science Direct) and Persian (SID, Iranmedex, and Magiran) electronic database sources were used. Finally, 16 articles were assessed for eligibility and 12 articles comprising 20 independent studies were selected for inclusion in the meta-analysis. Due to the statistically significant heterogeneity (Q=149.12, df=19, P<0.001 and I2=87.26), the random effect model was used for meta-analysis. Prevalence of N. caninum infection in 1239 aborted bovine fetuses with 351 positive ones was 34.8% (95% CI: 26.5–44.0%). Sample size was categorized as < 50 and ≥ 50 and subgroup meta-analysis was performed to compensate for the loss of precision due to inclusion of small size studies. The result showed that overall prevalence of infection in the latter group (23.1%) is significantly lower than in the first category (45.7%). It may be suggested that the subgroup with large sample size would be more precise and conservative approximation of the infection at the country level. The present meta-analysis confirms the previous findings regarding the importance of N. caninum as a major abortion agent in cattle industry in Iran and the need for appropriate action toward prevention and control of this parasite.

Cattle abortions update

This focus article has been prepared by Arthur Otter of the Cattle Expert Group at the APHA.

Abortion and various associated risk factors in dairy cow and sheep in Ili, China

We studied livestock abortion and various associated risk factors in the Ili region of northwest China. Livestock abortion prevalence was estimated and correlated with infections (Brucellosis, Salmonellosis, Mycoplasma and Chlamydia seropositivity) and management (farming type and contact with other herds/flocks) risk factors. A total of 2996 serum samples (1406 cow, 1590 sheep) were identified by RBPT (Rose Bengal Plate Test) and c-ELISA (competitive-enzyme linked immunosorbent assay), and they showed the overall seroprevalence of brucellosis in the study area was cow 6.76%, sheep 9.50%. The seroprevalence of brucellosis in X county was cow 7.06%, sheep 9.12%; in H county was cow 11.70%, sheep 10.80%; and in Q county was cow 4.22%, sheep 9.11%. The overall seroprevalence of Mycoplasma in the study area was cow 3.20%, sheep 6.42%. The seroprevalence of Mycoplasma in X county was cow 3.39%, sheep 7.98%; in H county was cow 5.26%, sheep 9.97%; and in Q county was cow 2.11%, sheep 4.33%. The Odds ratio of brucellosis for cow and sheep, respectively, were 45.909 [95% CI 26.912-78.317, P<0.001] and 70.507 [95% CI 43.783-113.544, P<0.001] times higher than other abortion-related factors including mixed farming, contact with other flocks and Mycoplasma infection. A total of 54 samples, including aborted cow (22), sheep (30) fetuses and milk samples (2), were identified as Brucella melitensis (B. melitensis) positive. A total of 38 Brucella were isolated from 16 aborted cow, 20 sheep fetuses and 2 milk samples. All of these isolates were identified, and confirmed, as B. melitensis. A phylogenetic tree showed that the Brucella isolates closely matched the B. melitensis biovar 3 isolated in Inner Mongolia, China, and B. melitensis isolated from Norway and India. These results suggest that B. melitensis biovar 3 is the main pathogen responsible for cow and sheep abortion and also pose a human health risk. Additionally, livestock reproduction can also be influenced by Mycoplasma infection and managerial factors (farming type and contact with other herds/flocks), especially in remote areas.

Patho-epidemiological and risk factor studies for detection of Neospora-associated abortion in cattle and buffaloes in Punjab, India

The diagnosis of abortion in livestock is difficult. In this paper, Neospora caninumassociated abortion in cattle and buffaloes in India is reported for the first time. A total of 184 animals (cattle, n = 133; water buffaloes, n = 51) were randomly selected for seroprevalence studies from 28 farms with a history of abortion. Antibodies to N. caninum were detected using a commercial competitive enzymelinked immunosorbent assay (c-ELISA); the percentage seropositivity was 10.5% for cattle and 21.6% for buffaloes. Risk factors such as species, i.e. buffaloes in comparison to cattle (odds ratio [OR] = 2.33, calculated probability [p] = 0.05), disposal of foetus and foetal membranes by throwing them into the field, in comparison with burning/burial (OR = 2.63, p = 0.03), and origin of the animal, i.e. purchased from outside in comparison to born on the farm (OR = 4.69, p = 0.002), were significantly associated with N. caninum seropositivity in univariate logistic regression. In multivariate analysis, only two risk factors, animal purchased from outside (OR = 6.15, p = 0.001) and buffaloes (OR = 3.20, p = 0.01), were significantly associated with Neospora seropositivity at a p-value < 0.05. Histopathological examination of aborted foetal tissues (cattle, n = 13; buffaloes, n = 8) revealed N. caninum tachyzoites in the heart and liver of three foetuses, and the diagnosis was confirmed by positive immunoreactivity to anti-N. caninum polyclonal antibody in the placenta of one foetus. To the authors' knowledge, this is the first report of confirmed neosporosis abortion in cattle and buffaloes in India.

Enzootic abortion of ewes

This focus article has been prepared by Amanda Carson and Rudolf Reichel of the APHA Small Ruminant Species Expert Group and Maggie He, data analyst at the APHA Surveillance Intelligence Unit.

Seroprevalence and associated risk factors for chlamydiosis, coxiellosis and brucellosis in sheep and goats in Borana pastoral area, southern Ethiopia

BACKGROUND

Abortion is considered an important disease problem of small ruminants in Borana pastoral area. A cross-sectional study was conducted to estimate the prevalence and risk factors of chlamydiosis, coxiellosis (Q-fever) and brucellosis in small ruminants in selected districts of Borana zone.

RESULTS

A total of 506 sheep and goats were tested using serological tests. Fifty (9.88%; 95% CI: 7.42, 12.82), 144 (28.46%; 95% CI: 24.56, 32.61) and none (0.00%; 95% CI: 0.00, 0.59) of them were positive for chlamydiosis, coxiellosis and brucellosis, respectively. History of abortion was recorded in 136 (32.00%; CI: 27.59, 36.67) of sheep and goats in the study area. The logistic regression analysis, however, showed that statistically significant difference ccurred among districts and between the species of small ruminants. The prevalence odd of antibodies against C. abortus was significantly lower in Miyo, Dire and Teltelle districts compared to Dillo. The odd of infection with this bacterium was lower in sheep than goats. Similarly the odd of infection with C. burnettii was significantly higher in Dillo district than the rest of the districts studied, higher in goats than sheep and higher in adult animals than young ones.

CONCLUSION

High prevalence of abortion is observed in sheep and goats in the study area. High seropositivity of C. burnetii and C. abortus in both sheep and goats tested implies risks of human infection by both diseases. Thus, attention needs to be paid to further study of both diseases in animals and humans in the area.

Genetic diversity of Listeria monocytogenes strains in ruminant abortion and rhombencephalitis cases in comparison with the natural environment

BACKGROUND

Listeria monocytogenes is the causative agent of listeriosis, a serious disease affecting both animals and humans. Here, multilocus sequence typing (MLST) was used to characterize the genetic diversity of Listeria monocytogenes strains isolated from the natural environment and animal clinical cases in Europe. The prevalence of clonal complexes (CCs) obtained was compared according to (i) the origin of isolation - clinical cases vs. natural environment - and (ii) the clinical form of animal listeriosis - rhombencephalitis vs. abortion. To this aim, two datasets were constructed. The clinical dataset consisted of 350 animal clinical isolates originating from France and Slovenia and supplemented with isolates from Switzerland and Great Britain. The natural environment dataset consisted of 253 isolates from the natural environment originating from Slovenia and supplemented with isolates from nine other European countries.

RESULTS

For the clinical cases, CC1, CC4-CC217 and CC412 were the most prevalent in rhombencephalitis and CC1, CC37 and CC4-CC217 in abortion. The hypervirulent CC1 and CC4-CC217 prevailed in both datasets. These results indicated that livestock is constantly exposed to hypervirulent CCs. CC1 was significantly associated with a clinical origin, whereas CC9, CC29 and CC14 were associated with the natural environment. CC1 was predominant among rhombencephalitis cases both in cattle and small ruminants, and its prevalence did not differ significantly between these two groups. A novel association of CC37 and CC6 with abortion cases was revealed.

CONCLUSIONS

Here, we show that CC1 and CC4-CC217 are prevalent in isolates of environmental and animal clinical origin, suggesting that ruminants are frequently exposed to hypervirulent CCs. The presence of CC4 in two mastitis cases calls for further attention due to direct threat to the consumer. We showed several associations between CCs and the origin of isolation or clinical form of listeriosis, e.g. CC37 and CC6 with abortion. This study improves our understanding of the population structure of L. monocytogenes isolates from the natural environment and animal clinical cases. Moreover, it provides a basis for future studies aiming to determine the underlying mechanisms of phenotypic traits of interest.

Epidemiological analysis of Trueperella abortisuis isolated from cases of pig abortion of a single farm

The present study was designed to characterize six Trueperella (T.) abortisuis strains, cultured over a period of 5 months from fetus and abortion material of six pigs of a single farm in Mecklenburg-West Pomerania federal state, Germany. It was of interest to investigate the epidemiological relationships of the six strains among each other and whether a single bacterial clone was responsible for the abortion situation of the single farm. All six strains were identified phenotypically, by MALDI-TOF MS analysis and by phylogenetic analysis based on 16S rRNA gene and gap (encoding the glyceraldehyde 3-phosphate dehydrogenase) and tuf (encoding elongation factor tu) gene sequencing. Further genotypic comparison was performed using different genomic DNA fingerprint methods including BOX-PCR, (GTG)₅-PCR, and three RAPD-PCRs. The sequence analysis of the genes gap and tuf and the genomic DNA fingerprinting results revealed, as noval findings, that the six T. abortisuis strains cultured from a single farm represent six different bacterial clones showing a genetic variability of this bacterial species in the pig population. All six T. abortisuis strains were isolated in mixed culture with several other bacterial species. However, the T. abortisuis strain, generally found in high numbers, seemed to be responsible for the abortion situation in the farm.

Cohort-level disease prediction by extrapolation of individual-level predictions in transition dairy cattle

Dairy cattle experience metabolic stress during the transition from late gestation to early lactation resulting in higher risk for several economically important diseases (e.g. mastitis, metritis, and ketosis). Metabolic stress is described as a physiological state composed of 3 processes: nutrient metabolism, oxidative stress, and inflammation. Current strategies for monitoring transition cow nutrient metabolism include assessment of plasma non-esterified fatty acids and beta-hydroxybutyrate concentrations around the time of calving. Although this method is effective at identifying cows with higher disease risk, there is often not enough time to implement intervention strategies to prevent health disorders from occurring around the time of calving. Previously, we published predictive models for early lactation diseases at the individual cow level at dry-off. However, it is unknown if predictive probabilities from individual-level models can be aggregated to the cohort level to predict cohort-level incidence. Therefore, our objective was to test different data aggregation methods using previously published models that represented the 3 components of metabolic stress (nutrient metabolism, oxidative stress, and inflammation). We included 277 cows from five Michigan dairy herds for this prospective cohort study. On each farm, two to four calving cohorts were formed, totaling 18 cohorts. We measured biomarker data at dry-off and followed the cows until 30 days post-parturition for cohort disease incidence, which was defined as the number of cows: 1) having one or more clinical transition disease outcome, and/or 2) having an adverse health event (abortion or death of calf or cow) within each cohort. We tested three different aggregation methods that we refer to as the p-central, p-dispersion, and p-count methods. For the p-central method, we calculated the averaged predicted probability within each cohort. For the p-dispersion method, we calculated the standard deviation of the predicted probabilities within a cohort. For the p-count method, we counted the number of cows above a specified threshold of predicted probability within each cohort. We built four sets of models: one for each aggregation method and one that included all three aggregation methods (p-combined method). We found that the p-dispersion method was the only method that produced viable predictive models. However, these models tended to overestimate incidence in cohorts with low observed counts and underestimate risk in cohorts with high observed counts.

Abortion in sheep: an update

This article was prepared by Amanda Carson of the APHA Small Ruminant Expert Group.

High prevalence and risk factors of Coxiella burnetii in milk of dairy animals with a history of abortion in Iran

Coxiella burnetii is causative agent of Q fever, which is a public health problem in most countries. The aim of this study was to study the prevalence rate of C. burnetii in raw milk of dairy animals in Iran with previous history of abortion. In this survey, milk samples were collected from different dairy animals with history of abortion from Qom province (center of Iran). Samples were tested by Nested PCR and Real-time PCR for detection of IS1111 gene of C. burnetii. In total, 34.92% (44 of 126) milk samples were positive for C. burnetii. Prevalence of C. burnetii in cattle, sheep and goat milk was 33.33%, 35.71% and 35.71%, respectively. Age was a significant risk factor for shedding of C. burnetii in cattle (P = 0.02) and goat (P = 0.05). Shedding of C. burnetii was high prevalence in milk of dairy animals with history of abortion in Iran. The high prevalence of this bacterium in milk (especially in animals with history of abortion) indicates that Excreted by milk as a potential source to spread of infection in the environment.

Using beef-breed semen in seropositive dams for the control of bovine neosporosis

A program for controlling bovine neosporosis based only on the use of beef semen, without culling seropositive animals, was evaluated in a closed dairy cattle herd over a 5-year period (2013-2017). The program was based on individual and periodic serological screenings to identify seropositive breeders. Seropositive cows were inseminated with beef-breed semen, thus excluding their descendants from the remount in order to prevent the vertical transmission of the disease. Seronegative animals, as well as heifers at first insemination, were tested before each insemination. Sera of 1097 cattle were examined by a commercial indirect ELISA for the detection of antibodies anti-Neospora caninum. To verify the difference in seropositivity values among years of sampling, statistical analysis through generalized estimation equations (GEEs) was performed, also considering the effects of age, lineages, and occurrence of abortion. A seroprevalence of 33.8% was found in the first screening. The prevalence and incidence of the infection within the herd decreased significantly in 2017 (P = 28.9%, I = 1.4%) (p-value = 0.0001). The family line investigation detected a higher risk of being seropositive for a cow born to a seropositive dam (p-value = 0.0001) than to a seronegative dam, decreasing both the apparently vertical and horizontal transmissions. The number of spontaneous abortions decreased after the first year of the study (23 in 2013 to 6 in 2017). Seropositive animals were associated with abortion events (p-value = 0.0001). Although an eradication of N. caninum was not achieved at the end of the study period, a significant reduction in prevalence and incidence of neosporosis in the herd and a reduction of the abortion rate was achieved with the application of this control plan in five years, without culling a high number of seropositive potential milk-producing animals.

Seroprevalence of Toxoplasma gondii and Neospora caninum infections in cattle in Mongolia

Toxoplasma gondii and Neospora caninum are protozoan parasites that cause huge economic losses in animal industries worldwide. N. caninum can cause abortion storms and high culling rates in cattle, whereas T. gondii infection is a significant concern in both human and animals because it can induce abortion and clinical symptoms in immunocompromised hosts. The aim of this study was to determine the seroprevalence of T. gondii and N. caninum in cattle in Mongolia. Specific antibodies to T. gondii and N. caninum were detected by using an indirect enzyme-linked immunosorbent assay (iELISA) based on recombinant antigens of dense granule protein 7 of Toxoplasma gondii and surface antigen 1 of Neospora caninum, respectively. A total of 1438 cattle sera from 20 of 21 provinces of Mongolia and the capital city of Ulaanbaatar were tested. Overall, 18.7% and 26.2% of cattle were positive for specific antibodies to T. gondii and N. caninum, respectively. Prevalence rates were higher (T. gondii infection: P < .0001, N. caninum infection: P = .002) in the central region of Mongolia (T. gondii infection: 27.1%, N. caninum infection: 30.8%) compared with western region, suggesting that prevalence rates might be influenced by geographical condition, particularly warmer temperatures around this area in Mongolia. The lowest prevalence rates were observed in the western region of Mongolia (T. gondii: 9%, N. caninum: 20.8%). In addition, the seroprevalence of N. caninum in female animals (27.5%) was significantly higher than that in male animals (20.4%) (P = .018), suggesting an important risk factor of abortion and stillbirth in cattle. The present results showed that T. gondii and N. caninum infections might be a risk for public health and economy of the livestock industry in Mongolia. In conclusion, this study demonstrates high seroprevalences of T. gondii and N. caninum in Mongolia and provides valuable new data for development of control measures against these infections in Mongolia.

Prevalence of Neospora spp. in donkeys in China

This study was conducted to detect specific anti-Neospora antibodies using a commercial competitive-inhibition ELISA kit, and to evaluate the risk factors for Neospora spp. infection. Out of a total of 2,228 donkey sera collected in three provinces in China, 211 (9.5%) were found to be positive for anti-Neospora antibodies. Statistical analysis revealed that age (p = 0.019, OR = 1.62, 95%CI: 1.08-2.44), feeding status (p < 0.001, OR = 3.79, 95%CI: 2.65-5.43), miscarriage history (p = 0.006, OR = 2.56, 95%CI: 1.27-4.01), and contact with dogs (p < 0.001, OR = 2.69, 95%CI: 1.86-3.88) were significant risk factors for Neospora spp. infection. This is the first evidence of Neospora infection in donkeys in China.

Military Significance of Q Fever: A Review

Q fever is undoubtedly a disease of military significance. Whilst so far it has only been described in troops operating in Mediterranean countries, the Balkans and southern Europe, it is a potential hazard for nonindigenous soldiers in at least 51 countries on 5 continents. Sheep and goats are the main source of infection, and the disease is almost entirely acquired by inhalation of dust-borne rickettsiae from an environment contaminated with infected placentae. The commonest vehicle of transmission is infected hay and straw.

On the available evidence, Q fever is simply and largely preventible as a significant military disease by implementation of the following measures: (I) Education on the source and methods of infection. (2) Banning the use of hay and straw for bedding, and the clearing and burning of hay and straw fromfarm buildings prior to occupation. (3) The exclusion of sheep and goats from military areas. (4) Regular serological surveillance of flocks adjoining military areas for evidence of heavy infection by Coxiella burnet;’ (5) Vigilance for an unusually high incidence of abortion in flocks adjoining military areas, which should initiate an immediate serological survey to determine the possibility of gross environmental contamination by the Q fever organism. (6) The possible use of short term prophylaxis with tetracycline for limited exposures to Q fever.

[Causes of abortion in horses - overview of the literature and own evaluations]

The aim of this study was to summarize the current status of the possible causes, clinical symptoms and pathogenesis of abortion in the mare and to evaluate the frequency of varying causes of abortion in German thoroughbred breeding. An analysis of the literature using electronic libraries, journals and textbooks was performed. In addition, the results of examinations of 123 abortions of thoroughbred breeding in central Germany were evaluated. In the literature, bacterial infections are the most frequently described cause of abortion. Other important causes are infections with equine herpesvirus (EHV)-1 or -4, twin pregnancy and umbilical cord anomalies. Examples of rare causes of abortion are equine viral arteritis (EVA), equine infectious anemia, fungal or parasitic infections, fetal malformations and diseases of the mare. In our study of 123 abortions, no cause was found in 47.2 % of the analyzed abortions. Infections were responsible for 26.8 % of the abortions. The main pathogens were bacteria in 17.1 % of the cases followed by viruses (EHV-1/4) in 8.9 % of the cases. Fungal infection was diagnosed in 0.8 % of the cases. The most common cause of a non-infectious abortion was twin pregnancy (21.1%). Other causes of non-infectious abortion were fetal malformations (3.3 %), umbilical cord strangulations (0.8 %) and uterine torsion (0.8 %). The results of our own study suggest that in the future greater attention should be paid to ultrasonographic examinations in the early pregnancy to reduce the rate of abortions because of a twin pregnancy. To increase the detection rate of unknown causes of abortion, rarer causes of abortion should be investigated, including for EVA and chlamydia, as a matter of routine.

Neglected zoonotic agents in cattle abortion: tackling the difficult to grow bacteria

BACKGROUND

Coxiella burnetii, Chlamydia abortus and Leptospira spp. are difficult to grow bacteria that play a role in bovine abortion, but their diagnosis is hampered by their obligate intracellular lifestyle (C. burnetii, C. abortus) or their lability (Leptospira spp.). Their importance is based on the contagious spread in food-producing animals, but also as zoonotic agents. In Switzerland, first-line routine bacteriological diagnostics in cattle abortions is regulated by national law and includes only basic screening by staining for C. burnetii due to the high costs associated with extended spectrum analysis. The aim of this study was to assess the true occurrence of these zoonotic pathogens in 249 cases of bovine abortion in Switzerland by serology (ELISA for anti-C. burnetii and C. abortus antibodies and microscopic agglutination test for anti-Leptospira spp. antibodies), molecular methods (real-time PCR and sequencing of PCR products of Chlamydiales-positive cases), Stamp's modification of the Ziehl-Neelsen (mod-ZN) stain and, upon availability of material, by histology and immunohistochemistry (IHC).

RESULTS

After seroanalysis the prevalence was 15.9% for C. burnetii, 38.5% for C. abortus and 21.4% for Leptospira spp. By real-time PCR 12.1% and 16.9% of the cases were positive for C. burnetii and Chlamydiales, respectively, but only 2.4% were positive for C. burnetii or Chlamydiales by mod-ZN stain. Sequencing of PCR products of Chlamydiales-positive cases revealed C. abortus in 10% of cases and the presence of a mix of Chlamydiales-related bacteria in 5.2% of cases. Pathogenic Leptospira spp. were detected in 5.6% of cases. Inflammatory lesions were present histologically in all available samples which were real-time PCR-positive for Chlamydiales and Leptospira spp. One of 12 real-time PCR-positive cases for C. burnetii was devoid of histological lesions. None of the pathogens could be detected by IHC.

CONCLUSION

Molecular detection by real-time PCR complemented by histopathological analysis is recommended to improve definitive diagnosis of bovine abortion cases and determine a more accurate prevalence of these zoonotic pathogens.

A study on some reproductive disorders in dromedary camel herds in Saudi Arabia with special references to uterine infections and abortion

Dromedary camels complaining from conception failure or abortion were investigated and their herders interviewed in Al Ahsa province, Kingdom of Saudi Arabia (KSA) during 2013 and 2015. The most important reproductive disorder according to the responders is uterine infection (60.2%) followed by obesity (22.3%) then physiological conditions (hormonal disturbances; 7.8%), adhesions (3.9%) and repeat breeders (2.9%). Of the camel herders, 78.6% reported previous occurrence of abortion in their herds and 46% reported abortion cases in the last season (2015/2016), while 21.4% reported no history of abortion. Most of the responders (97.1%) do not call a veterinarian for cases of abortion in their herds and 53.4% do not discard aborted materials. The majority of the herders (76.7%) deny that handling aborted materials or touching vaginal fluids can result in human infection, or replied they do not know. Uterine swab samples were collected and tested by PCR for seven potential pathogens and sera tested for antibodies against bovine viral diarrhea virus (BVDV) and Brucella. Five pathogens were identified in infected uterine samples, namely Coxiella burnetii (36%), Campylobacter spp. (27%), Brucella spp. (17%), Salmonella spp. (13%), and Chlamydia spp. (7%). Sero-prevalence of Brucella and BVDV was 8.2 and 29.1% in overall sera, respectively, and varies with regard to the region. The findings of the present study demonstrate that reproductive disorders dominated by uterine infections and abortions are widespread in dromedary camels in KSA.

Tickborne fever associated with abortion outbreak in dairy cows

Anaplasma phagocytophilum detected in aborting cows on rough grazingLead poisoning in bullocksPersistent bovine viral diarrhoea virus infection and colisepticaemia in a 20-hour-old calfAbortion due to bovine herpesvirus 1 in a four-year-old cowTickborne fever in lambsInfectious sinusitis due to Mycoplasma gallisepticum in pheasants These are among matters discussed in the disease surveillance report for May 2016 from SAC Consulting: Veterinary Services (SAC C VS).

Methodological challenges to multivariate syndromic surveillance: a case study using Swiss animal health data

BACKGROUND

In an era of ubiquitous electronic collection of animal health data, multivariate surveillance systems (which concurrently monitor several data streams) should have a greater probability of detecting disease events than univariate systems. However, despite their limitations, univariate aberration detection algorithms are used in most active syndromic surveillance (SyS) systems because of their ease of application and interpretation. On the other hand, a stochastic modelling-based approach to multivariate surveillance offers more flexibility, allowing for the retention of historical outbreaks, for overdispersion and for non-stationarity. While such methods are not new, they are yet to be applied to animal health surveillance data. We applied an example of such stochastic model, Held and colleagues' two-component model, to two multivariate animal health datasets from Switzerland.

RESULTS

In our first application, multivariate time series of the number of laboratories test requests were derived from Swiss animal diagnostic laboratories. We compare the performance of the two-component model to parallel monitoring using an improved Farrington algorithm and found both methods yield a satisfactorily low false alarm rate. However, the calibration test of the two-component model on the one-step ahead predictions proved satisfactory, making such an approach suitable for outbreak prediction. In our second application, the two-component model was applied to the multivariate time series of the number of cattle abortions and the number of test requests for bovine viral diarrhea (a disease that often results in abortions). We found that there is a two days lagged effect from the number of abortions to the number of test requests. We further compared the joint modelling and univariate modelling of the number of laboratory test requests time series. The joint modelling approach showed evidence of superiority in terms of forecasting abilities.

CONCLUSIONS

Stochastic modelling approaches offer the potential to address more realistic surveillance scenarios through, for example, the inclusion of times series specific parameters, or of covariates known to have an impact on syndrome counts. Nevertheless, many methodological challenges to multivariate surveillance of animal SyS data still remain. Deciding on the amount of corroboration among data streams that is required to escalate into an alert is not a trivial task given the sparse data on the events under consideration (e.g. disease outbreaks).

Genetic characterization of equine herpesvirus 1 isolates from abortion outbreaks in India

Equine herpesvirus 1 (EHV1) is a common pathogen of horses that causes upper respiratory tract disease, abortion, neonatal death and neurological disease. The neurological form of disease is called equine herpesvirus myeloencephalopathy (EHM). During the past decade, the incidence of EHM has been on the rise in Europe, North America, Australia and Asia. Some EHV1 isolates causing EHM exhibit a single-nucleotide polymorphism (SNP) in the DNA polymerase gene (ORF30) at position 2254 (A₂₂₅₄ to G₂₂₅₄). Further, based on polymorphism in the ORF68, EHV1 isolates have been classified into different groups. The aim of the present study was to estimate the genetic diversity of EHV1 and to determine the prevalence of the neuropathogenic genotype of EHV1 in India. Out of 133 clinical specimens from abortion cases in northern India, 56 were positive for EHV1 infection. Analysis of the A/G SNP by real-time PCR and sequence analysis revealed that 54 of 56 samples (96.43 %) were of the non-neuropathogenic genotype (A₂₂₅₄), while two (3.57 %) had the neuropathogenic marker (G₂₂₅₄). Sequence analysis of the polymorphic region of ORF68 of EHV1 isolates (n = 9) from India indicated that the Delhi/1998, Tohana-2/2013, Hisar-2/2014 and Hisar-15/1990 isolates belonged to group 4, while the Jind/1996, Rajasthan/1998, Delhi-3/2007 and Tohana-5/1996 isolates clustered within group 5. One isolate (Hisar-7/1990) exhibited SNPs at positions C₇₁₀ and C₇₁₃, forming a separate group. Here, we report for the first time the detection of neuropathogenic genotypes of EHV1 in India and show that Indian EHV1 isolates cluster within groups 4 and 5.

Disease surveillance in England and Wales, March 2016

■ Current and emerging issue ■ Highlights from the scanning surveillance network ■ Abortion in sheep--an update ■ Update on international disease threats. These are among matters discussed in the Animal and Plant Health Agency's (APHA's) March disease surveillance report.

Chlamydia-related abortions in Cattle from Graubunden, Switzerland

In 2001, the first case of bovine chlamydial abortion was reported in canton Graubunden, Switzerland. In this region, Chlamydophila (Cp.) abortus is endemic in small ruminants. Hence, we aimed to investigate the incidence of chlamydia-related abortions in cattle from Graubunden. During breeding seasons of 2003-2004, formalin-fixed and paraffin-embedded placenta specimens ( n = 235) from late-term abortions in cattle were analyzed by histopathology, immunohistochemistry with a Chlamydiaceae-specific monoclonal antibody against chlamydial lipopolysaccharide (LPS), and 2 different polymerase chain reaction (PCR) methods (16 S ribosomal ribonucleic acid [rRNA] PCR, intergenic spacer [IGS-S] PCR), followed by PCR product sequencing. In 149 of 235 cases (63.4%), histopathologic lesions such as purulent and/or necrotizing placentitis were observed. Chlamydial antigen was clearly demonstrated in immunohistochemistry in only 1 of 235 cases (0.4%). Cp. abortus or Cp. psittaci was found in 12 of 235 (5.1%) and 10 of 235 cases (4.2%) by 16 S rRNA PCR and IGS-S PCR, respectively. However, we detected, by 16 S rRNA PCR, 43 of 235 cases (18.3%) to be positive for chlamydia-like organisms. In contrast to the situation in small ruminants in the canton Graubunden, bovine abortion from Cp. abortus seems not to play an important role. Nevertheless, zoonotic potential should be taken into account when handling abortion material from cattle. The significance of chlamydia-like isolates other than Waddlia chondrophila remains an open question in abortion and needs further investigation.

Predictive Factors and Risk Mapping for Rift Valley Fever Epidemics in Kenya

Background

To-date, Rift Valley fever (RVF) outbreaks have occurred in 38 of the 69 administrative districts in Kenya. Using surveillance records collected between 1951 and 2007, we determined the risk of exposure and outcome of an RVF outbreak, examined the ecological and climatic factors associated with the outbreaks, and used these data to develop an RVF risk map for Kenya.

Methods

Exposure to RVF was evaluated as the proportion of the total outbreak years that each district was involved in prior epizootics, whereas risk of outcome was assessed as severity of observed disease in humans and animals for each district. A probability-impact weighted score (1 to 9) of the combined exposure and outcome risks was used to classify a district as high (score ≥ 5) or medium (score ≥2 - <5) risk, a classification that was subsequently subjected to expert group analysis for final risk level determination at the division levels (total = 391 divisions). Divisions that never reported RVF disease (score < 2) were classified as low risk. Using data from the 2006/07 RVF outbreak, the predictive risk factors for an RVF outbreak were identified. The predictive probabilities from the model were further used to develop an RVF risk map for Kenya.

Results

The final output was a RVF risk map that classified 101 of 391 divisions (26%) located in 21 districts as high risk, and 100 of 391 divisions (26%) located in 35 districts as medium risk and 190 divisions (48%) as low risk, including all 97 divisions in Nyanza and Western provinces. The risk of RVF was positively associated with Normalized Difference Vegetation Index (NDVI), low altitude below 1000m and high precipitation in areas with solonertz, luvisols and vertisols soil types (p <0.05).

Conclusion

RVF risk map serves as an important tool for developing and deploying prevention and control measures against the disease.

Serological evidence of type 2 (North American genotype) porcine reproductive and respiratory syndrome virus in Nepal

Porcine reproductive and respiratory syndrome virus (PRRSV) has spread throughout Asia, causing significant losses to commercial farmers and smallholders. However, little is known about PRRS in Nepal, a South Asian country with a gradually increasing pig industry. In 2011, a pilot project was initiated to identify the status of PRRSV in pigs of the Kathmandu Valley of Nepal. Out of 98 serum samples, 31 (32 %; 95 % CI 23-42 %) were found positive by ELISA. All positive samples belonged to the type 2 (North American) genotype. Molecular evaluation by real-time PCR however did not yield positive results. At the herd level, seropositivity was associated with a history of abortion and premature birth. Veterinarians, farmers and government should be aware of this threat to the Nepalese pig industry and initiate an appropriate response.

Syndromic surveillance of abortions in beef cattle based on the prospective analysis of spatio-temporal variations of calvings

Our objective was to study the ability of a syndromic surveillance system to identify spatio-temporal clusters of drops in the number of calvings among beef cows during the Bluetongue epizootic of 2007 and 2008, based on calving seasons. France was partitioned into 300 iso-populated units, i.e. units with quite the same number of beef cattle. Only 1% of clusters were unlikely to be related to Bluetongue. Clusters were detected during the calving season of primary infection by Bluetongue in 28% (n = 23) of the units first infected in 2007, and in 87% (n = 184) of the units first infected in 2008. In units in which a first cluster was detected over their calving season of primary infection, Bluetongue was detected more rapidly after the start of the calving season and its prevalence was higher than in other units. We believe that this type of syndromic surveillance system could improve the surveillance of abortive events in French cattle. Besides, our approach should be used to develop syndromic surveillance systems for other diseases and purposes, and in other settings, to avoid "false" alarms due to isolated events and homogenize the ability to detect abnormal variations of indicator amongst iso-populated units.

Integrating interdisciplinary methodologies for One Health: goat farm re-implicated as the probable source of an urban Q fever outbreak, the Netherlands, 2009

BACKGROUND

In spring 2008, a goat farm experiencing Q fever abortions ("Farm A") was identified as the probable source of a human Q fever outbreak in a Dutch town. In 2009, a larger outbreak with 347 cases occurred in the town, despite no clinical Q fever being reported from any local farm.

METHODS

Our study aimed to identify the source of the 2009 outbreak by applying a combination of interdisciplinary methods, using data from several sources and sectors, to investigate seventeen farms in the area: namely, descriptive epidemiology of notified cases; collation of veterinary data regarding the seventeen farms; spatial attack rate and relative risk analyses; and GIS mapping of farms and smooth incidence of cases. We conducted further spatio-temporal analyses that integrated temporal data regarding date of onset with spatial data from an atmospheric dispersion model with the most highly suspected source at the centre.

RESULTS

Our analyses indicated that Farm A was again the most likely source of infection, with persons living within 1 km of the farm at a 46 times larger risk of being a case compared to those living within 5-10 km. The spatio-temporal analyses demonstrated that about 60 - 65 % of the cases could be explained by aerosol transmission from Farm A assuming emission from week 9; these explained cases lived significantly closer to the farm than the unexplained cases (p = 0.004). A visit to Farm A revealed that there had been no particular changes in management during the spring/summer of 2009, nor any animal health problems around the time of parturition or at any other time during the year.

CONCLUSIONS

We conclude that the probable source of the 2009 outbreak was the same farm implicated in 2008, despite animal health indicators being absent. Veterinary and public health professionals should consider farms with past as well as current history of Q fever as potential sources of human outbreaks.

Genetic diversity of bovine Neospora caninum determined by microsatellite markers

Neospora caninum is one of the most significant parasitic organisms causing bovine abortion worldwide. Despite the economic impact of this infection, relatively little is known about the genetic diversity of this parasite. In this study, using Nc5 and ITS1 nested PCR, N. caninum has been detected in 12 brain samples of aborted fetuses from 298 seropositive dairy cattle collected from four different regions in Tehran, Iran. These specimen (Nc-Iran) were genotyped in multilocus using 9 different microsatellite markers previously described (MS4, MS5, MS6A, MS6B, MS7, MS8, MS10, MS12 and MS21). Microsatellite amplification was completely feasible in 2 samples, semi-completely in 8 samples, and failed in 2 samples. Within the two completely performed allelic profiles of Nc-Iran strains, unique multilocus profiles were obtained for both and novel allelic patterns were found in the MS8 and MS10 microsatellite markers. The Jaccard's similarity index showed significant difference between these two strains and from other standard isolates derived from GenBank such as Nc-Liv, Nc-SweB1, Nc-GER1, KBA1, and KBA2. All samples originating from the same area showed identical allelic numbers and a correlation between the number of repeats and geographic districts was observed.