Publications by authors named "Donal Sammin"

Outbreaks of COVID-19 in meat processing plants (MPPs) were recorded globally throughout the pandemic. There was speculation these outbreaks resulted in dissemination of COVID-19 throughout the surrounding county leading to high incidence rates. We aimed to investigate the dynamics of spread between MPPs and their surrounding counties.

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The diagnostic protocol currently used globally to identify Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection is RT-qPCR. The spread of these infections and the epidemiological imperative to describe variation across the virus genome have highlighted the importance of sequencing. SARS-CoV-2 rapid antigen diagnostic tests (RADTs) are designed to detect viral nucleocapsid protein with positive results suggestive of the presence of replicating virus and potential infectivity.

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Throughout the COVID-19 pandemic, meat processing plants have been vulnerable to outbreaks of SARS-CoV-2 infection. Transmission of the virus is difficult to control in these settings because of a combination of factors including environmental conditions and the specific nature of the work. This paper describes a retrospective outbreak investigation in a meat processing plant, a description of the measures taken to prevent or contain further outbreaks, and insights on how those with specific knowledge of the working environment of these plants can collaborate with public health authorities to ensure optimal outbreak control.

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Transmission of bluetongue (BT) virus serotype 8 (BTV-8) via artificial insemination of contaminated frozen semen from naturally infected bulls was investigated in two independent experiments. Healthy, BT negative heifers were hormonally synchronized and artificially inseminated at oestrus. In total, six groups of three heifers received semen from four batches derived from three bulls naturally infected with BTV-8.

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We examined the pathogens, morphologic patterns, and risk factors associated with bovine respiratory disease (BRD) in 136 recently weaned cattle ("weanlings"), 6-12 mo of age, that were submitted for postmortem examination to regional veterinary laboratories in Ireland. A standardized sampling protocol included routine microbiologic investigations as well as polymerase chain reaction and immunohistochemistry. Lungs with histologic lesions were categorized into 1 of 5 morphologic patterns of pneumonia.

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Schmallenberg virus (SBV) disease emerged in Europe in 2011, with the virus initially identified in Germany, and the first confirmed case of SBV infection in Ireland diagnosed in a dairy calf in October 2012. SBV was subsequently confirmed by RT-PCR in 49 cattle herds and 39 sheep flocks. While these studies provide a good representation of the spatial distribution of SBV in Ireland, they do not quantify the impact of SBV on productivity.

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Background: Hepatitis E is an acute viral disease of humans, occurring in explosive outbreaks in the developing world and as sporadic cases in returning travellers. Increasing recognition of indigenous transmission in Western countries suggests a zoonotic source of infection, most likely pigs. To determine if hepatitis E virus is present in Irish pigs, sera from 330 animals were examined for antibodies using a commercially available ELISA.

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Toxoplasma gondii and Chlamydophila abortus are the 2 most common infectious causes of ovine abortion worldwide. These obligate intracellular pathogens are associated with severe placentitis leading to abortion or stillbirth in pregnant ewes, and resulting in significant economic losses. The objectives of the current study were the development, validation, and application of a duplex real-time polymerase chain reaction (PCR) assay capable of quantifying the burden of infection by T.

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Although few studies have investigated the prevalence of chlamydial infections in cattle, reported prevalence rates vary hugely. In order to assess the prevalence of this infection in cattle in Ireland, serum samples (100 herds, 20 samples/herd) collected for statutory screening for brucellosis were examined by soluble chlamydial antigen indirect ELISA. The assay detects antibodies to the two most common Chlamydiaceae spp.

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Chlamydophila abortus, the aetiological agent of enzootic abortion of ewes (EAE), replicates in trophoblast cells leading to their destruction and dissemination of the bacterium to foetal organs. To further understand the pathogenesis of EAE, amniotic and allantoic fluids were collected from experimentally infected pregnant ewes at 30 (7 samples from each fluid), 35 (8 samples from each fluid), 40 (10 samples from each fluid) and 43 (6 amniotic fluids and 7 allantoic fluids) days post-infection to determine pathogen numbers and other markers of infection. Whilst experimentally infected ewes had characteristic placental lesions, only two amniotic and seven allantoic fluid samples were positive for C.

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Enzootic abortion of ewes (EAE) caused by Chlamydophila abortus is an important disease resulting in significant lamb loss in most sheep producing countries. Ewes are considered to be naturally infected with C. abortus via the oral-nasal route and may become persistent carriers, shedding during subsequent oestrous cycles and at lambing.

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A neuropathologic survey was conducted on mink brains from the 5 licensed mink farms in Ireland. The survey was part of a transmissible spongiform encephalopathy surveillance study. Aleutian disease (AD) was present on 4 of the 5 farms (80%).

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Six tests for detection of antibodies against the non-structural proteins of foot-and-mouth disease virus (FMDV) were compared at an international workshop in Brescia, Italy in 2004 on the basis of dichotomous test results. However, as results from all of these assays were also available on a continuous scale, validation was extended by calculating and subsequently analysing the receiver-operator characteristic (ROC) curves and likelihood ratios (LR) for each test method. For the purposes of these analyses, test results for a total of 1337 sera were selected from the Brescia workshop dataset, 237 sera that had been obtained from cattle exposed to FMDV and 1100 sera obtained from cattle that were not exposed to the virus; sera from "exposed" cattle were considered to be "true positives" and sera from "non-exposed" cattle were considered to be "true negatives".

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There has been much debate about the use of the so-called "vaccinate-to-live" policy for the control of foot-and-mouth disease (FMD) in Europe, according to which, spread of the FMD virus (FMDV) from future outbreaks could be controlled by a short period of "emergency" vaccination of surrounding herds, reducing the need for large-scale preemptive culling of at-risk animals. Since vaccinated animals may become subclinically infected with FMDV following challenge exposure, it is necessary to either remove all vaccinates (vaccinate-to-kill) or to detect and remove vaccinates in which virus is circulating or has established persistent infections (vaccinate-to-live), in order to rapidly regain the most favoured trading status of FMD-free without vaccination. The latter approach can be supported by testing vaccinated animals for the presence of antibodies to certain non-structural proteins (NSP) of FMDV, which are induced by infection with the virus, but not by vaccination with purified FMD vaccines.

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