1. Investigación

Leishmaniosis is a zoonosis caused by Leishmania spp., an intracellular protozoan parasite. This parasite is transmitted by sandflies, and the disease is endemic in the Mediterranean basin. In recent years, the number of species which could be a reservoir of the parasite is increased. One of the most relevant species is the horse, due to their contact with humans and ability to control the disease, thus being a possible silent reservoir. In this study, we have analyzed the prevalence and factors related to L. infantum infection in healthy horses in the Mediterranean region. Epidemiological data and serum samples were obtained from 167 apparently healthy horses, and the presence of L. infantum was evaluated via the ELISA method and real-time PCR. The results show 27.5% of prevalence and that the main factors related to infection are equine breed, morphotype, outdoor living, use, and season. In conclusion, the prevalence of L. infantum infection in apparently healthy horses from eastern Spain (Mediterranean basin) is elevated. To control this zoonosis, it would be advisable to carry out more studies on this and other species that could be silent reservoirs of the parasite, as well as carry out measures such as the use of repellents on a regular basis.

Background: Real-time PCR is the diagnostic technique of choice for the diagnosis and control of equine herpesvirus-1 (EHV-1) in an outbreak setting. The presence of EHV-1 in nasal swabs (NS), whole blood, brain and spinal cord samples has been extensively described; however, there are no reports on the excretion of EHV-1 in urine, its DNA detection patterns, and the role of urine in viral spread during an outbreak. Objectives: To determine the presence of EHV-1 DNA in urine during natural infection and to compare the DNA detection patterns of EHV-1 in urine, buffy coat (BC) and NS. Study design: Descriptive study of natural infection. Methods: Urine and whole blood/NS samples were collected at different time points during the hospitalisation of 21 horses involved in two EHV-1 myeloencephalopathy outbreaks in 2021 and 2023 in Spain. Quantitative real-time PCR was performed to compare the viral DNA load between BC-urine samples in 2021 and NS-urine samples in 2023. Sex, age, breed, presence of neurological signs, EHV-1 vaccination status and treatment data were recorded for all horses. Results: A total of 18 hospitalised horses during the 2021 and 2023 outbreaks were positive for EHV-1, and viral DNA was detected in urine samples from a total of 11 horses in both outbreaks. Compared with BC samples, DNA presence was detected in urine samples for longer duration and with slightly higher concentration; however, compared with NS, detection of EHV-1 in urine was similar in duration with lower DNA concentrations. Main limitations: Limited sample size, different sampling times and protocols (BC vs. NS) in two natural infection outbreak settings. Conclusions: EHV-1 was detected in the urine from naturally infected horses. Urine should be considered as complimentary to blood and NS in diagnosis of EHV-1 infection.

Microsporidia are widely spread obligate intracellular fungal pathogens from vertebrate and invertebrate organisms, mainly transmitted by contaminated food and water. This study aims to detect the presence of major human-pathogenic microsporidia, i.e., Enterocytozoon bieneusi, Encephalitozoon intestinalis, Encephalitozoon hellem, and Encephalitozoon cuniculi, in the gastrointestinal tract of commercially harvested marine fish from Mediterranean coast of the Comunidad Valenciana, Eastern Spain. A total of 251 fish, 138 farmed fish and 113 wild fish from commercial fishing were tested by SYBR Green real-time PCR, enabling the simultaneous detection of the four targeted species. E. intestinalis/hellem was found in 1.45% of farmed fish and 7.96% of wild fish, while Enterocytozoonidae was detected in 2.90% and 18.58% of farmed and wild fish, respectively. E. cuniculi was not detected in any of the analyzed specimens. To the authors’ knowledge, this is the first report of E. intestinalis/hellem in fish, particularly in marine fish. Although the role of fish in these species’ epidemiology remains unknown, this finding points out a potential public health risk linked to fish consumption. Further studies are necessary to characterize these microsporidia in fish hosts better and to elucidate their epidemiological role.