The emergence in 2014 and persistence of African Swine Fever (ASF) in Lithuania has been linked to infected wild boar movement and close contact with the carcasses of other infected wild boars. Over time the number of reported cases of ASF in wild boars gradually increased, but no detailed epidemiological data has been available. Therefore, the objective of the present study was to determine ASF virus prevalence in wild boars and domestic pigs during the 2014–2017 period and further explore the current geographical distribution of the virus. Our study results show that ASF virus prevalence in hunted wild boars using PCR analysis increased from 0.83% (95% CI 0.69–0.98) to 2.27% (95% CI 2.05–2.48) from 2014 to 2016 respectively. However, there was a dramatic jump in the number of ASF positive wild boars cases in 2017 resulting in prevalence of 12.39% (95% CI 11.91–12.86) (p < 0.05). The average prevalence of ASF-specific antibodies in wild boar population during years 2014–2017 was 0.45% (95% CI 0.39–0.51) based on ELISA test results. Prevalence of ASF virus in domestic pigs ranged from 0.24% (95% CI 0.17% - 0.32) in 2015 to 2.74% (95% CI 2.33% - 3.15) in 2017. The average seasonal prevalence of ASF virus in pigs was statistically significant (p < 0.05) and ranged from 0% in spring to 3.68% (95% CI 3.32–4.05) in summer. Correlation between the pig density and number of recorded pig ASF cases in affected regions was only found in 2017 (R = 0.78, p < 0.05). No correlation was detected between the wild boar density and number of recorded pig or wild boar ASF - positive cases. This study provides the first results of ASF virus prevalence changes in Lithuania during the 2014–2017. The overall results confirm the relatively high prevalence of ASF virus in wild boar that was gradually increasing from 2014 to 2017. In the last year of study, the number of ASF positive cases in both domestic pigs and wild boars had unexpectedly increased several times. A better understanding of current status of the disease will enable better control and prevent further spread of ASF virus in Western Europe.

Hepatitis E virus (HEV) is one of the major causes of acute viral hepatitis worldwide. In Europe, food-borne zoonotic transmission of HEV genotype 3 has been associated with domestic pigs and wild boar. Controversial data are available on the circulation of the virus in animals that are used for human consumption, and to date, no gold standard has yet been defined for the diagnosis of HEV-associated hepatitis. To investigate the current HEV infection status in Lithuanian pigs and wild ungulates, the presence of viral RNA was analyzed by nested reverse transcription polymerase chain reaction (RT-nPCR) in randomly selected samples, and the viral RNA was subsequently genotyped. In total, 32.98 and 22.55% of the domestic pig samples were HEV-positive using RT-nPCR targeting the ORF1 and ORF2 fragments, respectively. Among ungulates, 25.94% of the wild boar samples, 22.58% of the roe deer samples, 6.67% of the red deer samples and 7.69% of the moose samples were positive for HEV RNA using primers targeting the ORF1 fragment. Using primers targeting the ORF2 fragment of the HEV genome, viral RNA was only detected in 17.03% of the wild boar samples and 12.90% of the roe deer samples. Phylogenetic analysis based on a 348-nucleotide-long region of the HEV ORF2 showed that all obtained sequences detected in Lithuanian domestic pigs and wildlife belonged to genotype 3. In this study, the sequences identified from pigs, wild boars and roe deer clustered within the 3i subtype reference sequences from the GenBank database. The sequences obtained from pig farms located in two different counties of Lithuania were of the HEV 3f subtype. The wild boar sequences clustered within subtypes 3i and 3h, clearly indicating that wild boars can harbor additional subtypes of HEV. For the first time, the ORF2 nucleotide sequences obtained from roe deer proved that HEV subtype 3i can be found in a novel host. The results of the viral prevalence and phylogenetic analyses clearly demonstrated viral infection in Lithuanian pigs and wild ungulates, thus highlighting a significant concern for zoonotic virus transmission through both the food chain and direct contact with animals. Unexpected HEV genotype 3 subtype diversity in Lithuania and neighboring countries revealed that further studies are necessary to understand the mode of HEV transmission between animals and humans in the Baltic States region.

In recent years, the intake of ultra-processed foods has increased dramatically worldwide. Missing natural foods in the diet raise the need of biologically active food components that could compensate for this deficiency and help maintain proper immune status. This study used pigs as an animal model for the assessment of the impact of consumption of Origanum vulgare plant extract combined with Mentha piperita and Thymus vulgaris essential oils on microbial profile in intestines. A single group of weaned pigs received basal diet, while the other group basal diet supplemented with plant extract and two essential oils in the form of bilayer tablets prepared using “liquid/solid” phase technology. Metagenomic sequencing was performed with the aim to investigate changes of microbial communities in ileum, caecum, and colon. The results demonstrated that the combination of essential oils was non cytotoxic, and had a positive effect on the microbial composition in the large intestine of pigs due to significant increase in the number of probiotic bacteria. The amount of Lactobacillus was 2.5 times and Bifidobacterium 1.9 times higher in the animal group fed with supplement. The combination, however, had some negative impact on the variety of minor species in the distal part of the ileum. Additional studies need to be performed to obtain knowledge on how combinations of essential oils can change bacterial variety in the proximal part of the gastrointestinal tract.

Various animal species have been evaluated in depth for their potential as Tick-borne encephalitis virus (TBEV) sentinel species, although evidence for equine capacity is incomplete. Therefore, a comprehensive cross-sectional stratified serosurvey and PCR analysis of selected horses (n = 301) were performed in TBEV endemic localities in Lithuania. Attached and moving ticks (n = 241) have been collected from aforementioned hosts to evaluate natural infectivity of TBEV vectors (Ixodes spp.) in the recreational environments surrounding equestrian centers. All samples were screened for TBEV IgG and positive samples were confirmed by virus neutralization test (VNT). 113 (37.5%) horses from all counties of Lithuania tested positive for TBEV IgG, revealing age and sex indifferent results of equine seroprevalence that were significantly dependent on pedigree: horses of mixed breed were more susceptible to infection possibly due to their management practices. TBEV prevalence in equine species corresponded to TBEV-confirmed human cases in the precedent year. As much as 3.9% of horses were viraemic with TBEV-RNA with subsequent confirmation of TBEV European subtype. 4/38 of tested tick pools were positive for TBEV-RNA (Minimal infectious rate 1.2%). Several unknown microfoci were revealed during the study indicating areas of extreme risk close to popular human entertainment sites. The study provides important evidence in favor of horses’ usage as sentinel species, as equines could provide more detailed epidemiological mapping of TBEV, as well as more efficient collection of ticks for surveillance studies.

Dietary components, such as lactic acid bacteria (LAB), bovine colostrum, apple production by-products, and essential oils, can favorably alter the host immune system and gut microbiota, however, their cumulative effect as multicomponent nutraceutical supplement has not been investigated. Therefore, the present study is the first one to evaluate a combination of LAB, bovine colostrum, dehydrated apple pomace, and essential oils for their immunomodulatory and prebiotic properties in the swine model. This study shows that supplementary feeding of pigs using multicomponent nutraceutical resulted in a statistically significant decrease in proportions of T cytotoxic and double-positive (CD4⁺CD8^+low) cells within the CD3⁺ cell population at 28 DPI, compared to the beginning of the experiment (0DPI). Conversely, a statistically significant increase in proportions of B cells (accompanied by an increase in IgG concentration) and macrophage/monocyte cells within viable cell population at 28 DPI, compared to the beginning of the experiments, was observed. Furthermore, changes in the bacterial composition of gut microbiota in pigs fed with multicomponent nutraceutical changed significantly, with a 1.78 times higher number of probiotic strains (Bifidobacterium, Streptococcus, Faecilbacterium) at the end of the experiment, compared to control group animals. This study shows a positive effect of the nutraceutical formula used on the changes of gut microbiota by facilitating an increase in probiotic bacteria strains and possible anti-inflammatory properties.