Myxomatosis is an infectious disease caused by the myxoma virus (MYXV), which has very high mortality rates in European wild rabbits (Oryctolagus cuniculus). While sporadic cases of myxomatosis have also been reported in some hare species, these lagomorphs are considered to have a low susceptibility to MYXV infection. In the present How to cite this article: García-Bocanegra I, Camacho-Sillero L,
Background
Aleutian mink disease virus (AMDV) causes major economic losses in fur-bearing animal production. The control of most AMDV outbreaks is complex due to the difficulties of establishing the source of infection based only on the available on-farm epidemiological data. In this sense, phylogenetic analysis of the strains present in a farm may help elucidate the origin of the infection and improve the control and biosecurity measures.
Objectives
This study had the following aims: characterize the AMDV strains from most outbreaks produced at Spanish farms between 2012–2019 at the molecular level, and assess the utility of the combined use of molecular and epidemiological data to track the possible routes of infection.
Methods
Thirty-seven strains from 17 farms were partially sequenced for the NS1 and VP2 genes and analyzed phylogenetically with other strains described worldwide.
Results
Spanish AMDV strains are clustered in four major clades that generally show a good geographical correlation, confirming that most had been established in Spain a long time ago. The combined study of phylogenetic results and epidemiological information of each farm suggests that most of the AMDV outbreaks since 2012 had been produced by within-farm reservoirs, while a few of them may have been due to the introduction of the virus through international trade.
Conclusions
The combination of phylogenetic inference, together with epidemiological data, helps assess the possible origin of AMDV infections in mink farms and improving the control and prevention of this disease.
Porcine circovirus type 2 (PCV2) is the aetiological agent of PCV2-Systemic Disease (PCV2-SD) and PCV2-Subclinical Infection (PCV2-SI). PCV2 is highly resistant to environmental conditions, being able to remain in the farm environment and thus represent a risk for infection maintenance. The aim of this study was to identify, under field conditions, the possible critical points in the environment of non-vaccinated farrow-to-weaning swine farms where PCV2 could accumulate and persist. For that, environmental samples from five swine farms with PCV2-SD or PCV2-SI were taken and analysed by qPCR, including different farm areas, farm personnel and management implements. PCV2 DNA was detected in the environment of all farms (42.9% of positive samples). Overall, the PCV2-SD herd seemed to present more positive samples and higher viral loads than the PCV2-SI herds. At individual farm level, weaning areas appeared to be the most contaminated facilities. In addition, PCV2 was found at high levels in most samples from farm workers, especially work boots, suggesting that they may play a role in within-farm transmission. In addition, PCV2 was detected in areas without animals the like warehouses, offices and farm perimeter. Therefore, this study is helpful to improve measures to reduce within-farm PCV2 dissemination.
In order to provide up-to-date information about the prevalence of infectious and parasitic agents in Spanish roe deer (Capreolus capreolus), samples from 93 animals hunted from January 2013 to April 2015 were collected and analysed by parasitological, serological and molecular techniques. Sampled animals came from four roe deer populations corresponding to Oceanic, Continental, Mediterranean and Mountainous ecosystems of Spain. Data regarding sex, age and year were also considered. A high percentage of roe deer (95.7%) resulted positive for at least one agent. Sarcocystis spp. was the most frequently diagnosed genus (88.8%), followed by gastrointestinal nematodes (62.9%) and Schmallenberg virus (53.5%). Varestrongylus capreoli (38%), Anaplasma phagocitophylum (34.2%), Eimeria spp. (29.2%), Toxoplasma gondii (25%) and Cephenemyia stimulator (23.8%) displayed medium prevalences and, finally low percentages were registered for Moniezia spp. (6.7%), Dictyocaulus noerneri (2.4%) and Mycobacterium avium subsp. paratuberculosis (1.5%). No infections by Neospora caninum, Bovine herpesvirus, pestivirus or Coxiella burnetii were found. Climate was significantly associated with the prevalence of T. gondii, C. stimulator and A. phagocitophylum, with higher prevalences in animals from Oceanic and Mediterranean areas. Our results suggest that infections affecting Spanish roe deer, especially those of parasitic aetiology, represent one of the causes of the descent in the abundance of this ungulate in the last years. Moreover, the high prevalence of zoonotic agents such as T. gondii and A. phagocitophylum could also have a great relevance in the environmental and/or Public Health.
ARTICLE HISTORY
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