Geographical Distribution of Ljungan Virus in Small Mammals in Europe

Abstract

Ljungan virus (LV), which belongs to the Parechovirus genus in the Picornaviridae family, was first isolated from bank voles (Myodes glareolus) in Sweden in 1998 and proposed as a zoonotic agent. To improve knowledge of the host association and geographical distribution of LV, tissues from 1685 animals belonging to multiple rodent and insectivore species from 12 European countries were screened for LV-RNA using reverse transcriptase (RT-)PCR. In addition, we investigated how the prevalence of LV-RNA in bank voles is associated with various intrinsic and extrinsic factors. We show that LV is widespread geographically, having been detected in at least one host species in nine European countries. Twelve out of 21 species screened were LV-RNA PCR-positive, including for the first time the red vole (Myodes rutilus), and the root or tundra vole (Alexandromys formerly Microtus oeconomus), as well as in insectivores, including the bicolored white-toothed shrew (Crocidura leucodon) and the Valais shrew (Sorex antinorii). Results indicated that bank voles are the main rodent host for this virus (overall RT-PCR-prevalence: 15.2%). Linear modeling of intrinsic and extrinsic factors that could impact LV prevalence showed a concave-down relationship between body mass and LV occurrence, so that subadults had the highest LV positivity, but LV in older animals was less prevalent. Also, LV prevalence was higher in autumn and lower in spring, and the amount of precipitation recorded during the six months preceding the trapping date was negatively correlated with the presence of the virus. Phylogenetic analysis on the 185 base pair species-specific sequence of the 5' untranslated region identified high genetic diversity (46.5%) between 80 haplotypes, although no geographical or host-specific patterns of diversity were detected.

Neutralizing Ljungan virus antibodies in children with newly diagnosed type 1 diabetes

“…Ljungan virus (LV), first isolated from a bank vole (Myodes glareolus) by the river Ljungan in Northern Sweden, was defined as a Parechovirus in the family Picornaviridae [1,2]. The isolation of the 87-012 virus was followed by characterization of several different LV strains from humans, voles, other rodents, and birds [3][4][5][6][7][8]. However, it is unclear to what extent LV infection in humans causes symptoms characteristic of Parechovirus.…”

Geographical Distribution and Genetic Diversity of Bank Vole Hepaciviruses in Europe

“…Rodents and other small mammals were sampled in 14 European countries within the EU FP7 project EDENext and several national research projects [ 23 , 25 , 26 , 27 , 28 , 29 ] ( Table 1 ; Figure 1 ). Rodent necropsy and tissue samplings followed previously established standard protocols.…”

“…RNA extraction was performed using a phenol–chloroform protocol for liver or lung tissue samples of a large part of the sample collection, as previously described [ 25 ]. Another part of liver samples was homogenized in 500 µL phosphate-buffered saline (PBS).…”

“…Small mammal trapping was performed with permission from the ethical committees in the respective countries according to their national laws [ 25 ]: Czech Republic: authorized in the protocol PP 27/2007 (institutional and state committees of the Czech Academy of Sciences in 2007); France: authorized under French and European regulations on care and protection of laboratory animals: French Law 2001-486 issued on 6 June 2001 and Directive 2010/63/EU issued on 22 September 2010; all animal procedures (trapping and euthanasia) were preapproved by the Direction des Services Vétérinaires of the Herault Department under Agreement B 34-169-1; Finland: snap trapping does not require ethical permits under the Finnish Act on Animal Experimentation 62/2006 and by the decision of Finnish Animal Experiment Board 16 May 2007. A permit (23/5713/2001) for capturing protected species ( Sorex spp., Myodes rufocanus and Myopus schisticolor ) was granted by the Finnish Ministry of the Environment; Germany: Small mammals were trapped using Sherman©live animal traps according to relevant legislation (H. B. Sherman Traps Inc., Tallahassee, FL, USA) (official permit Site R1: Regierung der Oberpfalz 55.1-8646.4-140, Site T: Regierung von Schwaben 55.1-8646-2/30, Site S: AZ 36.11-36.45.12/4/12-001).…”

Extending the Enterovirus Lead: Could a Related Picornavirus be Responsible for Diabetes in Humans?

“…The success rate of virus isolation attempts is low even from infected clinical specimens generated under experimental conditions [ 10 , 13 , 14 ]. Ljungan virus has been detected/isolated in several European countries, the USA, and Japan [ 10 , 15 , 16 , 17 , 18 , 19 ]. Genetic analyses of the virus strains showed that LVs can be divided into four genotypes [ 16 , 17 , 20 ].…”