title: Orthopox virus infections in Eurasian wild rodents.
abstract: The genus Orthopoxvirus includes variola (smallpox) virus and zoonotic cowpox virus (CPXV). All orthopoxviruses (OPV) are serologically cross-reactive and cross-protective, and after the cessation of smallpox vaccination, CPXV and other OPV infections represent an emerging threat to human health. In this respect CPXV, with its reservoir in asymptomatically infected wild rodents, is of special importance. In Europe, clinical cowpox has been diagnosed in both humans and animals. The main objective of this study was to elucidate the prevalence of OPV infections in wild rodents in different parts of Eurasia and to compare the performance of three real-time polymerase chain reaction (PCR) methods in detecting OPV DNA in wildlife samples. We investigated 962 wild rodents from Northern Europe (Finland), Central Europe (Germany), and Northern Asia (Siberia, Russia) for the presence of OPV antibodies. According to a CPXV antigen-based immunofluorescence assay, animals from 13 of the 17 locations (76%) showed antibodies. Mean seroprevalence was 33% in Finland (variation between locations 0%-69%), 32% in Germany (0%-43%), and 3.2% (0%-15%) in Siberia. We further screened tissue samples from 513 of the rodents for OPV DNA using up to three real-time PCRs. Three rodents from two German and one Finnish location were OPV DNA positive. The amplicons were 96% to 100% identical to available CPXV sequences. Further, we demonstrated OPV infections as far east as the Baikal region and occurring in hamster and two other rodent species, ones previously unnoticed as possible reservoir hosts. Based on serological and PCR findings, Eurasian wild rodents are frequently but nonpersistently infected with OPVs. Results from three real-time PCR methods were highly concordant. This study extends the geographic range and wildlife species diversity in which OPV (or CPXV) viruses are naturally circulating.
authors: Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland. Paula.Kinnunen@helsinki.fi
authors: Paula M
authors: PM
authors: Kinnunen
authors: Heikki
authors: H
authors: Henttonen
authors: Bernd
authors: B
authors: Hoffmann
authors: Eva R
authors: ER
authors: Kallio
authors: Christian
authors: C
authors: Korthase
authors: Juha
authors: J
authors: Laakkonen
authors: Jukka
authors: J
authors: Niemimaa
authors: Airi
authors: A
authors: Palva
authors: Mathias
authors: M
authors: Schlegel
authors: Hanan Sheikh
authors: HS
authors: Ali
authors: Paula
authors: P
authors: Suominen
authors: Rainer G
authors: RG
authors: Ulrich
authors: Antti
authors: A
authors: Vaheri
authors: Olli
authors: O
authors: Vapalahti
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000097:blood; D005260:Female; D005387:Finland / Q000453:epidemiology; D005858:Germany / Q000453:epidemiology; D008297:Male; D018155:Orthopoxvirus / Q000276:immunology*; D011213:Poxviridae Infections / Q000097:blood / Q000453:epidemiology*; D060888:Real-Time Polymerase Chain Reaction; D012377:Rodentia / Q000097:blood / Q000821:virology*; D017421:Sequence Analysis; D012800:Siberia / Q000453:epidemiology
chemical_list: D000956:Antigens, Viral