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Coxiella burnetii is an important zoonotic pathogen of worldwide distribution that can infect a wide range of wild and domestic species. The European wild rabbit (Oryctolagus cuniculus) can play a role as a reservoir for this bacterium in certain epidemiological scenarios, but, to date, a very limited numbers of large-scale serosurveys have been conducted for this species worldwide. Although exposure in hare species has also been described, C. burnetii in Iberian hare (Lepus granatensis) has never been assessed. Here, we aimed to determine the seroprevalence and risk factors associated with C. burnetii exposure in wild lagomorphs in the Mediterranean ecosystems of southern Spain. Between the 2018/2019 and 2021/2022 hunting seasons, blood samples from 638 wild lagomorphs, including 471 wild rabbits and 167 Iberian hares, were collected from 112 hunting grounds distributed across all eight provinces of Andalusia (southern Spain). The overall apparent individual seroprevalence was 8.9% (57/638; 95% CI: 6.8–11.4). Antibodies against C. burnetii were found in 11.3% (53/471; 95% CI: 8.4–14.1) of the wild rabbits and 2.4% (4/167; 95% CI: 0.1–4.7) of the Iberian hares. Seropositive animals were detected for 16 (14.3%; 95% CI: 7.8–20.8) of the 112 hunting grounds tested and in all the hunting seasons sampled. A generalized estimating equations model showed that the geographical area (western Andalusia) and presence of sheep were risk factors potentially associated with C. burnetii exposure in wild lagomorphs. A statistically significant spatial cluster (p < 0.001) was identified in the south-west of Andalusia. Our results provide evidence of moderate, endemic and heterogeneous circulation of C. burnetii in wild lagomorph populations in Spanish Mediterranean ecosystems. Risk-based strategies for integrative surveillance programs should be implemented in these species to reduce the risk of transmission of the bacterium to sympatric species, including humans.

Background: Several species belonging to the genus Ehrlichia are considered pathogenic for animals and humans. Although wildlife are known to play an important role in the epidemiology of these bacteria, information on the role of wild lagomorphs in their sylvatic cycle is limited. Thus, the objective of the present study was to assess the occur‑ rence of Ehrlichia spp. in ticks collected from wild lagomorphs in Spanish Mediterranean ecosystems. Methods: A total of 1122 pooled ticks (254 pools) collected from 506 wild rabbits (Oryctolagus cuniculus) and 29 Iberian hares (Lepus granatensis) were analysed using a nested PCR assay targeting the partial groEL gene. Ehrlichia spp.‑positive samples were further subjected to a second PCR assay targeting 16S rRNA. Results: Three (1.2%) tick pools comprising Rhipicephalus pusillus collected from nine wild rabbits were positive for Ehrlichia spp. All the Ehrlichia DNA sequences were identical, and use of sequence and phylogenetic analyses allowed us to identify a novel Ehrlichia species. Conclusions: We provide evidence that a novel Ehrlichia species, named herein as ‘Candidatus Ehrlichia andalusi’, which may be of concern for animal and public health, is circulating in R. pusillus in Spanish Mediterranean ecosys‑ tems. Further studies are warranted to assess the epidemiology, pathogenicity and zoonotic potential of this Ehrlichia species.

Viruses that affect lagomorphs have decades of reported history of spillover events. One of these viruses is the causative agent of the so-called rabbit or ‘lagomorph’ haemorrhagic disease (e.g. Lagovirus europaeus/GI.1 and L. europaeus/GI.2). In particular, L. europaeus/GI.2 has shown a great capacity to recombine with existing lagoviruses. In fact, it has replaced the former GI.1 genotype in the wild, and recently, an increase on spillover events has been detected among several lagomorph species including European and North American species of hares. In this study, we report for the first time the infection of a wild Iberian hare with GI.2 (RHDV2/b), potential shedding and associated histopathological alterations. We identify the recombinant GI.4P-GI.2 as causative of the infection and discuss plausible causes regarding the origin of the spillover event and its potential consequences for the Iberian hare wild populations, which is an endemic species of the Iberian Peninsula as well as an important game and prey species for many predators, including endangered species.

El desarrollo de la actividad cinegética, particularmente en el sector de la caza mayor, ha determinado que las poblaciones de ungulados silvestres de interés cinegético se encuentren en franca expansión en la península Ibérica. Este hecho ha dado lugar a escenarios epidemiológicos complejos, que limitan la implantación eficaz de los programas de control de diversas enfermedades en las especies domésticas, favoreciendo un incremento significativo en la prevalencia de distintos procesos patológicos con importancia en sanidad animal y en salud pública (Górtazar et al., 2006). Todo ello, ha supuesto una mayor demanda por parte de la sociedad de profesionales cualificados en relación a la gestión y sanidad de las especies silvestres

West Nile virus (WNV) is a zoonotic arboviral pathogen affecting humans, birds, and horses. Vaccines are available for veterinary use, which efficiently prevent the infection in horses. Most common diagnostic tools rely on the identification of the agent (RT-PCR, virus isolation), or on the detection of antibodies (IgM and IgG) recognizing structural proteins of the virus or neutralizing virus infection in cell cultures (virus-neutralization tests). The recent emergence of WNV in different parts of the world has resulted in an increase in the vaccination of horses in many countries. Methods for differentiation between infected and vaccinated animals (“DIVA” assays) would be useful for surveillance and control purposes but are still not available. A usual approach in this regard is the use of antibodies to nonstructural proteins as markers of nonvaccinated, infected animals, and the nonstructural NS1 protein of WNV has been proposed as a candidate for such a marker. The aim of this study was to test the hypothesis that NS1 can be a useful antigen in DIVA assays for differentiating WNV vaccinated and infected horses in field conditions. For that, we examined serum samples from either vaccinated and infected horses both from experimental infections/vaccinations (under controlled conditions) and from the field, exposed to natural infection or vaccinated in response to a risk of infection. The overall conclusion of the study is that NS1 antigen can effectively differentiate WNV infected from vaccinated horses in experimental (controlled) conditions, but this differentiation might be difficult depending on the conditions prevailing in the field.

El desarrollo de la actividad cinegética, particularmente en el sector de la caza mayor, ha determinado que las poblaciones de ungulados silvestres de interés cinegético se encuentren en franca expansión en la península Ibérica. Este hecho ha dado lugar a escenarios epidemiológicos complejos, que limitan la implantación eficaz de los programas de control de diversas enfermedades en las especies domésticas, favoreciendo un incremento significativo en la prevalencia de distintos procesos patológicos con importancia en sanidad animal y en salud pública (Górtazar et al., 2006). Todo ello, ha supuesto una mayor demanda por parte de la sociedad de profesionales cualificados en relación a la gestión y sanidad de las especies silvestres

Andalusia (Southern Spain) is considered one of the main routes of introduction of bluetongue virus (BTV) into Europe, evidenced by a devastating epidemic caused by BTV-1 in 2007. Understanding the pattern and the drivers of BTV-1 spread in Andalusia is critical for effective detection and control of future epidemics. A long-standing metric for quantifying the behaviour of infectious diseases is the case-reproduction ratio (Rt), defined as the average number of secondary cases arising from a single infected case at time t (for t>0). Here we apply a method using epidemic trees to estimate the between-herd case reproduction ratio directly from epidemic data allowing the spatial and temporal variability in transmission to be described. We then relate this variability to predictors describing the hosts, vectors and the environment to better understand why the epidemic spread more quickly in some regions or periods. The Rt value for the BTV-1 epidemic in Andalusia peaked in July at 4.6, at the start of the epidemic, then decreased to 2.2 by August, dropped below 1 by September (0.8), and by October it had decreased to 0.02. BTV spread was the consequence of both local transmission within established disease foci and BTV expansion to distant new areas (i.e. new foci), which resulted in a high variability in BTV transmission, not only among different areas, but particularly through time, which suggests that general control measures applied at broad spatial scales are unlikely to be effective. This high variability through time was probably due to the impact of temperature on BTV transmission, as evidenced by a reduction in the value of Rt by 0.0041 for every unit increase (day) in the extrinsic incubation period (EIP), which is itself directly dependent on temperature. Moreover, within the range of values at which BTV-1 transmission occurred in Andalusia (20.6°C to 29.5°C) there was a positive correlation between temperature and Rt values, although the relationship was not