Surveillance of Hantaviruses in Poland: A Study of Animal Reservoirs and Human Hantavirus Disease in Subcarpathia

Abstract

The first cluster of hemorrhagic fever with renal syndrome (HFRS) in Poland was identified in 2007 in the Subcarpathian region. The natural environment of this area is a key habitat for hantavirus vectors. The animal reservoir of existing human HFRS clusters was studied to assess the occurrence of viruses (including Tula virus, Puumala virus, and Dobrava-Belgrade virus) among rodents. We examined 70 suspected human cases with symptoms corresponding to the clinical picture of HFRS. Serological analysis (indirect immunofluorescence assay and immunoblot) confirmed the presence of anti-hantavirus antibodies in 18 patients, which were surveyed with regard to developed symptoms and presumed rodent contact. Seroepidemiological analysis of newly confirmed human cases was performed, putative areas of human exposure were studied, and 194 rodents were subsequently captured from identified areas. Internal organs (lungs, heart, spleen, bladder, and kidneys) were collected from 64 Apodemus flavicollis, 55 Apodemus agrarius, 40 Myodes glareolus, 21 Mus musculus, and 14 Microtus arvalis and tested for the presence of hantavirus RNA by reverse transcription and subsequent real-time PCR. Positive samples were also tested by indirect immunofluorescence. Animal reservoir surveillance enabled the first detection of Puumala virus and Dobrava-Belgrade virus among animals in Poland. Furthermore, some places where rodents were captured correlated with areas of residence of laboratory-confirmed human cases and likely detected virus species. Moreover, three species of hantaviruses coexisting in a relatively small area were identified.

Puumala Virus in Bank Voles, Lithuania

“…Recent investigations confirmed the presence of PUUV in certain parts of Poland ( 5 , 6 ). A molecular study of bank voles in Latvia identified 2 PUUV lineages (Russian and Latvian) ( 7 ).…”

“…In contrast to the Fennoscandian Peninsula and parts of central Europe ( 4 , 5 ), little is known about the epidemiology of PUUV in Poland and the Baltic States. Recent investigations confirmed the presence of PUUV in certain parts of Poland ( 5 , 6 ).…”

Hemorrhagic fever with renal syndrome (HFRS) in Poland

“…The 13 patients had antibodies of both classes, that is the IgM and IgG, and 5 patients had the IgG class. The examination of the 194 caught rodents, the genetic material of the virus was identified in 17 (in 10 rodents of the Dobrava species, in 5 Tula, and in 2 cases of Puumala) (17).…”

“…13 pacjentów posiadało p-w ciala w obu klasach -IgM i IgG, natomiast 5 osób w klasie IgG. Spośród 194 odłowionych gryzoni u 17-u osobników zidentyfikowano materiał genetyczny wirusa (u 10 gryzoni gatunku Dobrava, u 5 Tula, a w 2 przypadkach Puumala) (17). from the whole group, which constituted 5.7% of the examined population, while anti-Hantaan antibodies were present in the IgG class in 2 people (2.9%) (20).…”

First molecular characterization of Dobrava-Belgrade virus found in Apodemus flavicollis in Poland

“…DOBV can be hosted by mice from the sub-family Murinae: yellow-necked mice (Apodemus flavicollis), striped field mice (A. agrarius), or Black Sea field mice (A. ponticus). Humans are only accidental hosts of DOBV -they usually become infected by inhaling aerosolized dried rodent excreta [3]. Horizontal transmission of DOBV from person-to-person has not been observed.…”