Molecular epidemiology of Aleutian mink disease virus causing outbreaks in mink farms from Southwestern Europe: a retrospective study from 2012 to 2019

Abstract

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.

AMDV Vaccine: Challenges and Perspectives

“…When taken together, early diagnostic approaches of AMDV-positive mink could provide reinforcing tools to help limit viral spread. Indeed, these have been somewhat effective in several countries, including Spain, where farms with AD have been reduced from 100% in 1980 to around 25% in 2019 [ 68 ].…”

“…Despite this encouraging statistic, however, the eradication of the disease remains challenging and has failed in many countries, including Canada, Denmark, and others [ 57 , 63 , 68 , 80 ]. This can be explained by the reinfection of farms due to viral persistence and by contaminated human individuals visiting farms, leading to a failure of eradication systems [ 81 ].…”

“…Another strategy to prevent the harmful effects of AMDV is to select mink having low titers of anti-AMDV-protein antibodies in their blood, which is a common practice in many countries [ 58 , 66 , 67 , 68 , 69 ]. Besides this classical selection method, an alternative approach has been recently studied by Karimi et al which is based on characterizing host-genomic patterns of AD-tolerant mink with the intention to select those that could be tolerant or resistant to AMDV.…”

“…A drawback of this method is that it does not detect all virus strains since AMDV has a great genetic diversity and is constantly mutating [ 64 , 65 ]. Another strategy to eliminate the harmful effects of AMDV is by selecting mink that are tolerant to this virus and this can be performed by identifying mink with a low antibody titer, which is performed in Europe and North America [ 58 , 66 , 67 , 68 , 69 ]. The selection for tolerance can also be performed by characterizing genomic regions of AD-tolerant mink [ 70 ].…”

“…aReduction in the prevalence of infected mink in Nova Scotia Canada[57] and in Spain[68]; more accurate than ELISA[75] Farid et al (2012) [57], Pietro et al (2020) [68], Farid and Hussain [75] Diagnostic method: ELISA b Estimated sensitivity and specificity of 96.2% and 98.4%, respectively, for AMDV-VP2-recombinant antigen [60]; greater sensitivity than CIEP [61] but lower accuracy [61,62] Knuuttila et al (2014) [60], Dam Tuxen et al…”