Laboratory diagnosis of ruminant abortion in Europe

Abstract

Abortion in ruminants is a major cause of economic loss worldwide, and the management and control of outbreaks is important in limiting their spread, and in preventing zoonotic infections. Given that rapid and accurate laboratory diagnosis is central to controlling abortion outbreaks, the submission of tissue samples to laboratories offering the most appropriate tests is essential. Direct antigen and/or DNA detection methods are the currently preferred methods of reaching an aetiological diagnosis, and ideally these results are confirmed by the demonstration of corresponding macroscopic and/or histopathological lesions in the fetus and/or the placenta. However, the costs of laboratory examinations may be considerable and, even under optimal conditions, the percentage of aetiological diagnoses reached can be relatively low. This review focuses on the most commonly occurring and important abortifacient pathogens of ruminant species in Europe highlighting their epizootic and zoonotic potential. The performance characteristics of the various diagnostic methods used, including their specific advantages and limitations, are discussed.

Current trends in bovine abortion in Argentina

“…This result is not surprising, and consistent with previous reports of Argentina that shows the association between the high seroprevalence to N. caninum and the presence of abortions in beef and dairy cattle herds (Moore et al 2002, Fernández et al 2007, Morrell 2010. The IHC confirm the diagnosis of N. caninum as the cause of abortion when characteristic microscopic lesions and detectable antigens are both present in tissues, and no other infectious causes are identified (Anderson 2007, Borel et al 2014. In this study, positive immunostaining to N. caninum tachyzoites was detected in the brain of 11 fetuses with focal lymphohistiocytic encephalitis with necrosis and/or gliosis.…”

“…The culture is not practical because is costly and time-consuming. Silver stained histologic sections and DFAT are frequently used, but their sensibilities are low and experienced personnel are required (Anderson 2007, Holler 2012, Borel et al 2014. Nevertheless, 11 cases of leptospirosis were diagnosis by DFAT and subsequently confirmed by PCR.…”

“…Oportunistic bacteria (Escherichia coli, Pasteurella spp., Salmonella spp., Staphylococcus spp., Streptococcus spp., Listeria spp., etc) and mycotic abortions cause sporadic bovine abortion at any stage of gestation, but more frequently during the last trimester , Anderson 2007, Borel et al 2014). These microorganism are commonly found on mucosal surfaces of the host or its environments (poorly fermented silages, moldy stored or processed feedstuffs), but in some circumstances they can produce septicemia into the dam causing abortion.…”

A Review on Chlamydial Diseases in Animals: Still a Challenge for Pathologists?

“…The histopathology shows a purulent to necrotizing placentitis with vasculitis and, if well preserved, intratrophoblastic basophilic chlamydial inclusions might be observed (Fig. 5) (reviewed in Borel et al 21 and Sachse et al 146 ). If a large number of organisms are present in infected placental specimens, the disease can be diagnosed by stained smears, antigen tests, immunofluorescence, or immunohistochemistry (IHC) labeling or by molecular methods such as PCR.…”

Ultrasonography as a promising methodology to indicate captured‐induced abortion in viviparous elasmobranchs

“…Obviously, during the period of intrauterine development, morphological changes are expected to ensure embryo retention (Albers et al, 2015;Arora et al, 2016). However, except for humans and some farm animals, nothing is known about the uterine recovery time and vulnerability to infections after abortion (Borel et al, 2014;Reshma et al, 2016;Roe & Bartz, 2017). Consequently, even if the females are released after capture, it is possible that the morphophysiological changes caused by abortion combined with the nutritional and immunological disruptions due to capture stress can irreversibly compromise fertility.…”