Zoi Athanasakopoulou

Associations between environmental and demographic predictors and herd-level seropositivity for Neospora caninum, Toxoplasma gondii, and Coxiella burnetii were evaluated using ELISA results from 737 cattle in 42 Greek dairy herds (2018–2019). At the individual level, apparent seropositivity was 24.56% (95% CI: 11.53–37.58) for N. caninum, 15.74% (95% CI: 7.69–23.79) for T. gondii, and 21.17% (95% CI: 14.38–27.95) for C. burnetii. Herd-level seropositivity was 64.29% (95% CI: 49.17–77.01) for N. caninum, 50.00% (95% CI: 35.53–64.47) for T. gondii, and 57.14% (95% CI: 42.21–70.88) for C. burnetii. Factor analyses were used to summarize correlated environmental predictors. Factor scores and additional variables were evaluated in pathogen-specific multivariable logistic models. A temperature-related factor was negatively associated with N. caninum seropositivity (OR = 0.21, 95% CI: 0.07; 0.67, p = 0.008) but positively with T. gondii seropositivity (OR = 170.2; 95% CI: 5.74–5042.8, p = 0.003). A vegetation-related factor was positively associated with seropositivity for T. gondii (OR = 6.25; 95% CI: 1.63–23.97, p = 0.008) and C. burnetii (OR = 3.23; 95% CI: 1.18–8.82, p = 0.022). Elevation was positively associated with T. gondii seropositivity (OR = 1.015; 95% CI: 1.0016–1.029, p = 0.029). A precipitation-related factor was negatively associated with C. burnetii seropositivity (OR = 0.34; 95% CI: 0.13–0.87, p = 0.024). Tetrachoric correlations were −0.786 for N. caninum–T. gondii, −0.688 for N. caninum–C. burnetii, and 0.880 for T. gondii–C. burnetii. Pathogen-specific suitability areas and areas requiring extrapolation were mapped; prevalence and disease risk were not estimated.

Equids, primarily horses, are mostly used for recreational purposes, although in some rural areas they also serve as working animals, maintaining close and frequent contact with humans. Their risk of exposure to vector-borne and zoonotic pathogens can be affected by host-related factors, management practices and environmental conditions. This study aimed to investigate the seroprevalence and associated risk factors for infections by Babesia caballi, Toxoplasma gondii, Coxiella burnetii, and Borrelia burgdorferi sensu lato in equids from Southwestern Greece. A total of 159 equids were tested using commercial serological assays. Weighted prevalence estimates were applied to account for unequal sampling. Associations were assessed using chi-square tests and logistic regression. Ecological niche modelling was employed to evaluate geographic patterns and environmental correlates. Seroprevalence was highest for B. caballi (8.81%), followed by T. gondii (7.55%) and C. burnetii (1.26%). No seropositive animals were detected for B. burgdorferi sensu lato. Ecological niche modelling showed acceptable predictive performance for B. caballi, with BIO14 and BIO6 emerging as the main environmental predictors. In contrast, the T. gondii model exhibited unacceptable predictive performance, and its environmental associations should therefore be interpreted cautiously. Complementary Random Forest analyses yielded comparable environmental rankings but showed higher classification performance for T. gondii than for B. caballi. Overall, the findings contribute to understanding pathogen exposure patterns in equids and underscore the importance of integrating epidemiological and environmental data in surveillance efforts.

This study investigates the relationship between biosecurity implementation and the prevalence of ESBL-producing bacteria in Greek swine farms, revealing an alarming 82% prevalence rate, which is significantly higher than in other European nations. Our findings indicate that comprehensive biosecurity measures are more effective than focusing on priority controls alone. Notably, there was a lack of significant associations between farm size and individual biosecurity parameters, underscoring the importance of cumulative improvements across multiple measures. Moreover, we identified a critical threshold for biosecurity implementation: farms scoring less than a critical level were consistently vulnerable to ESBL contamination. Escherichia coli emerged as the dominant species among ESBL isolates, reflecting patterns seen globally. This suggests a need for targeted biosecurity strategies, as mixed species occurrences imply shared resistance pressures. Our results advocate for a paradigm shift in biosecurity practices, emphasizing holistic improvements across all measures rather than isolating specific controls. With current implementation levels averaging only 35% of recommended biosecurity practices, our findings highlight the urgent need for comprehensive interventions to mitigate antimicrobial resistance in the Greek swine industry.

This study investigates the relationship between biosecurity implementation and the prevalence of ESBL-producing bacteria in Greek swine farms, revealing an alarming 82% prevalence rate, which is significantly higher than in other European nations. Our findings indicate that comprehensive biosecurity measures are more effective than fo-cusing on priority controls alone. Notably, there was a lack of significant associations between farm size and individual biosecurity parameters, underscoring the im-portance of cumulative improvements across multiple measures. Moreover, we identi-fied a critical threshold for biosecurity implementation: farms scoring less than a criti-cal point, were consistently vulnerable to ESBL contamination. Escherichia coli emerged as the dominant species among ESBL isolates, reflecting patterns seen globally. This suggests a need for targeted biosecurity strategies, as mixed species occurrences imply shared resistance pressures. Our results advocate for a paradigm shift in biosecurity practices, emphasizing holistic improvements across all measures rather than isolating specific controls. With current implementation levels averaging only 35% of recom-mended biosecurity practices, our findings highlight the urgent need for comprehen-sive interventions to mitigate antimicrobial resistance in the Greek swine industry.

Aujeszky’s disease, or pseudorabies, is a viral infection caused by Suid herpesvirus 1 (pseudorabies virus), with swine as its natural host. Although eradicated in domestic pigs in many European countries, PRV remains endemic in wild boar populations, posing a risk to other species, including carnivores. In this study, we report eight fatal cases of PRV infection in hunting dogs from Epirus and Thessaly, Greece, all of which followed direct contact with hunted wild boars. Postmortem brain samples tested positive for PRV via PCR targeting the glycoprotein C (gC) gene. Partial sequencing and phylogenetic analysis of the amplified gC fragments revealed genetic divergence among the examined isolates. The Epirus-derived strains formed a distinct cluster, closely related to previously reported Greek strains from the region of Central Macedonia as well as to the French strain FRA 527 and the German isolate GER614BW. In contrast, the two Thessaly sequenced isolates were phylogenetically distant from all other Greek strains, potentially representing an independently evolving lineage, and clustered more closely with the Kaplan strain. These findings underscore the persistent threat of PRV transmission from wild to domestic species and highlight the genetic heterogeneity of PRV strains circulating in Greece. Veterinary practitioners should consider PRV in the differential diagnosis of encephalitic symptoms in hunting dogs. Enhanced molecular surveillance and public awareness are critical to mitigating the risks posed by this emerging threat.

Astroviruses and caliciviruses are important causative agents of gastroenteritis in humans worldwide. They have been detected in a variety of animal species, including dogs, but their role in the induction of disease in animals remains uncertain. In a molecular study that was conducted in Greece, including healthy and gastroenteritis-affected dogs of different ages, astrovirus (AstV) and sapovirus (SaV) were detected in 15% and 26% of the examined animals, respectively. A specialized questionnaire was filled out for each of the dogs participating in the study, including information about different characteristics and risk factors that could possibly affect their health status. This information was analyzed with the use of two innovative statistical methods, i.e., a Multiple Correspondence Analysis (MCA) and the Ascending Hierarchical Classification (AHC). Based on their results, it was possible to define various groups of dogs based on their characteristics. AstV seems to occur more often in low-health-status dogs, usually mongrels, living in rural areas, showing vomit, diarrhea, and diet changes. Dogs of this group usually live with other pets in the same household and have frequent contact with stray animals. The presence of SaV does not seem to be associated with any of the examined factors.

West Nile virus (WNV), a zoonotic mosquito-borne virus, has recently caused human outbreaks in Europe, including Greece. Its transmission cycle in nature includes wild birds as amplifying hosts and ornithophilic mosquito vectors. The aim of this study was to assess WNV circulation among wild birds from two regions of Greece, Peloponnese and Western Greece, during 2022. To this end, a total of 511 birds belonging to 37 different species were sampled and molecularly screened. WNV RNA was detected from February to November in a total of 71 wild birds of nine species originating from both investigated regions. The first eight positive samples were sequenced on a part of NS3 and, according to the phylogenetic analysis, they belonged to evolutionary lineage 2 and presented similarity to previous outbreak-causing Greek strains (Argolis 2017, Macedonia 2010 and 2012). It was more likely to identify a PCR positive bird as the population density and the distance from water sources decreased. The present report provides evidence of WNV occurrence in both Peloponnese and Western Greece during 2022 and underlines its possible overwintering, highlighting the need for avian species surveillance to be conducted annually and throughout the year. Magpies are proposed as sentinels for WNV monitoring.

Swine influenza is a highly contagious respiratory disease caused by influenza A virus infection. Pigs play an important role in the overall epidemiology of influenza because of their ability to transmit influenza viruses of avian and human origin, which plays a potential role in the emergence of zoonotic strains with pandemic potential. The aim of our study was to assess the seroprevalence of Swine Influenza Viruses (swIAVs) in commercial pig farms in Greece. A total of 1416 blood samples were collected from breeding animals (gilts and sows) and pigs aged 3 weeks to market age from 40 different swIAV vaccinated and unvaccinated commercial farrow-to-finish pig farms. For the detection of anti-SIV antibodies, sera were analyzed using an indirect ELISA kit CIVTEST SUIS INFLUENZA^®, Hipra (Amer, Spain). Of the total 1416 animals tested, 498 were seropositive, indicating that the virus circulates in both vaccinated (54% seroprevalence) and unvaccinated Greek pig farms (23% seroprevalence). In addition, maternally derived antibody (MDA) levels were lower in pigs at 4 and 7 weeks of age in unvaccinated farms than in vaccinated farms. In conclusion, our results underscore the importance of vaccination as an effective tool for the prevention of swIAV infections in commercial farrow-to-finish pig farms.

This study aimed to research the involvement of enterotoxigenic E. coli (ETEC) and C. difficile or C. perfringens type C in the aetiology of neonatal piglet diarrhoea in Greece and to identify preventive factors for them. A total of 78 pooled faecal samples were collected randomly from 234 suckling piglets (1–4 days of age) with diarrhoea from 26 pig farms (3 piglets × 3 litters × 26 farms = 234 piglets = 78 faecal pool samples). The collected samples were initially screened for the presence of E. coli and C. difficile or C. perfringens via cultivation on MacConkey and anaerobic blood agar, respectively. Subsequently, the samples were pooled on ELUTE cards. From samples tested, 69.23% of those in the farms were ETEC F4-positive, 30.77% were ETEC F5-positive, 61.54% ETEC were F6-positive, 42.31% were ETEC F4- and E. coli enterotoxin LT-positive, 19.23% were ETEC F5- and LT-positive, 42.31% were ETEC F6- and LT-positive, while LT was found in 57.69% of those in the farms. C. difficile was involved in many cases and identified as an emerging neonatal diarrhoea etiological agent. Specifically, Toxin A of C. difficile was found in 84.62% and Toxin B in 88.46% of those in the farms. Antibiotic administration to sows in combination with probiotics or acidifiers was revealed to reduce the detection of antigens of ETEC and the enterotoxin LT of E. coli.

The aim of this study was to develop a multiplex bead assay using a Brucella rLPS antigen, a Brucella suis smooth antigen, and a Yersinia enterocolitica O:9 antigen that not only discriminates Brucella-infected from Brucella-uninfected pigs and wild boar, but also overcomes the cross reactivity with Y. enterocolitica O:9. Sera from 126 domestic pigs were tested: 29 pigs were Brucella infected, 80 were non-infected and 17 were confirmed to be false positive serological reactors (FPSR). Sera from 49 wild boar were tested: 18 were positive and 31 were negative. Using the rLPS antigen, 26/29 Brucella-infected domestic pigs and 15/18 seropositive wild boar were positive, while 75/80 non-Brucella infected domestic pigs, all FPSR, and all seronegative wild boar were negative. Using the smooth B. suis 1330 antigen, all Brucella-infected domestic pigs, 9/17 FPSR and all seropositive wild boar were positive, while all non-infected pigs and 30/31 seronegative wild boar were negative. The ratio of the readouts from the smooth B. suis antigen and Y. enterocolitica O:9 antigen enabled discriminating all Brucella infected individuals from the FPSR domestic pigs. These results demonstrate the potential of this assay for use in the surveillance of brucellosis, overcoming the cross-reactivity with Y. enterocolitica.