Dobrava-Belgrade Virus in Apodemus flavicollis and A. uralensis Mice, Turkey

I. Mehmet Ali Oktem, Yavuz Uyar, Ender Dincer, Aysegul Gozalan, Mathias Schlegel, Cahit Babur, Bekir Celebi, Mustafa Sozen, Ahmet Karatas, Nuri Kaan Ozkazanc, Ferhat Matur, Gulay Korukluoglu, Rainer G. Ulrich, Mustafa Ertek, and Aykut Ozkul

Author affiliations: Faculty of Medicine, Dokuz Eylul University, Izmir, Turkey (I.M.A. Oktem); Cerrahpasa Faculty of Medicine, Istanbul University, Istanbul, Turkey (Y. Uyar); Ankara University, Ankara, Turkey (E. Dincer); Refik Saydam National Public Health Agency, Ankara (A. Gozalan, C. Babur, B. Celebi, G. Korukluoglu, M. Ertek); Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany (M. Schlegel, R.G. Ulrich); Karaelmas University, Zonguldak, Turkey (M. Sozen, F. Matur); Nigde University, Nigde, Turkey (A. Karatas); Bartin University, Bartin, Turkey (N.K. Ozkazanc); Faculty of Veterinary Medicine, Ankara University, Ankara (A. Ozkul)

Abstract

In 2009, human Dobrava-Belgrade virus (DOBV) infections were reported on the Black Sea coast of Turkey. Serologic and molecular studies of potential rodent reservoirs demonstrated DOBV infections in Apodemus flavicollis and A. uralensis mice. Phylogenetic analysis of DOBV strains showed their similarity to A. flavicollis mice–borne DOBV in Greece, Slovenia, and Slovakia.

The genus Hantavirus, family Bunyaviridae, contains human pathogenic viruses that cause hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome (1). HFRS in Europe is caused mainly by Puumala virus and different genotypes of Dobrava-Belgrade virus (DOBV) (2). In Asia, Hantaan virus and Seoul virus cause most HFRS cases. Hantaviruses are enveloped viruses with a single-stranded 3-segmented RNA genome of negative polarity. The small (S), medium, and large genome segments encode the nucleocapsid protein, the glycoproteins Gn and Gc, and an RNA-dependent RNA polymerase, respectively.

Hantaviruses have been detected in various rodent, shrew, mole, and bat species (3). They are transmitted to humans by inhalation of aerosols that are contaminated with urine, feces, and saliva of infected reservoir hosts. The human pathogenic DOBV was first isolated from a yellow-necked field mouse (Apodemus flavicollis) and, subsequently, from a striped field mouse (A. agrarius) and a Caucasian wood mouse (A. ponticus) (1). The association of DOBV with these different Apodemus species seems to determine its human pathogenicity, with the A. flavicollis–associated genotype Dobrava being the most life threatening (1).

Figure 1

Thumbnail of Regional map of Turkey showing the Bartin province (41°38′9′′N, 32°20′15′′E), where trapping of small mammals was conducted. Abbreviations indicate locations at which captures were performed: A, Akbas; B, Bogaz; H1, Hanyeri; H2, Hasankadi; G, Guzelcehisar; K, Kumluca; R, Region 49. Panel A corresponds to the region (Bartin Province) indicated by box in panel B.

Figure 1. [[caption]]

Few reports about hantavirus seroprevalence in human and rodent populations in Turkey occurred before 2009 (4,5). In February 2009, the first hantavirus outbreak among humans in this country was described in 2 provinces in the western Black Sea region (6; Figure 1). DOBV-reactive antibodies were reported for 7 of 200 patients who had renal symptoms in a region near the Aegean Sea (7). In 2010, DOBV RNA was detected by a nucleic acid test in urine from a person in Istanbul Province who was experiencing fatigue, diffuse pain, nausea, and vomiting (8). The reservoir host(s) and virus strain(s) causing human infections on the Black Sea coast of Turkey remained unknown.