umu.sePublications
Change search
Link to record
Permanent link

Direct link
BETA
Hörnfeldt, Birger
Alternative names
Publications (10 of 22) Show all publications
Khalil, H., Hörnfeldt, B., Evander, M., Magnusson, M., Olsson, G. & Ecke, F. (2014). Dynamics and Drivers of Hantavirus Prevalence in Rodent Populations. Vector Borne and Zoonotic Diseases, 14(8), 537-551
Open this publication in new window or tab >>Dynamics and Drivers of Hantavirus Prevalence in Rodent Populations
Show others...
2014 (English)In: Vector Borne and Zoonotic Diseases, ISSN 1530-3667, E-ISSN 1557-7759, Vol. 14, no 8, p. 537-551Article, review/survey (Refereed) Published
Abstract [en]

Human encroachment on wildlife habitats has contributed to the emergence of several zoonoses. Pathogenic hantaviruses are hosted by rodents and cause severe diseases in the Americas and Eurasia. We reviewed several factors that potentially drive prevalence (the proportion of infected rodents) in host populations. These include demography, behavior, host density, small mammal diversity, predation, and habitat and landscape characteristics. This review is the first to include a quantitative summary of the literature investigating hantavirus prevalence in rodents. Demographic structure and density were investigated the most and predation the least. Reported effects of demographic structure and small mammal diversity were consistent, whereby reproductive males were most likely to be infected and prevalence decreased with small mammal diversity. The influences of habitat and landscape properties are often complex and indirect. The relationship between density and prevalence merits more investigation. Most hantavirus hosts are habitat generalists and their control is challenging. Incorporating all potential factors and their interactions is essential to understanding and controlling infection in host populations.

Place, publisher, year, edition, pages
Mary Ann Liebert, Inc. publishers, 2014
Keywords
Biodiversity, Density dependence, Habitat, Hantavirus, Predation, Prevalence, Rodent, Transmission
National Category
Microbiology in the medical area
Identifiers
urn:nbn:se:umu:diva-94929 (URN)10.1089/vbz.2013.1562 (DOI)000342146800002 ()
Available from: 2014-11-10 Created: 2014-10-20 Last updated: 2018-06-07Bibliographically approved
Khalil, H., Olsson, G., Ecke, F., Evander, M., Hjertqvist, M., Magnusson, M., . . . Hörnfeldt, B. (2014). The importance of bank vole density and rainy winters in predicting nephropathia epidemica incidence in Northern Sweden.. PLoS ONE, 9(11), Article ID e111663.
Open this publication in new window or tab >>The importance of bank vole density and rainy winters in predicting nephropathia epidemica incidence in Northern Sweden.
Show others...
2014 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 11, article id e111663Article in journal (Refereed) Published
Abstract [en]

Pathogenic hantaviruses (family Bunyaviridae, genus Hantavirus) are rodent-borne viruses causing hemorrhagic fever with renal syndrome (HFRS) in Eurasia. In Europe, there are more than 10,000 yearly cases of nephropathia epidemica (NE), a mild form of HFRS caused by Puumala virus (PUUV). The common and widely distributed bank vole (Myodes glareolus) is the host of PUUV. In this study, we aim to explain and predict NE incidence in boreal Sweden using bank vole densities. We tested whether the number of rainy days in winter contributed to variation in NE incidence. We forecast NE incidence in July 2013-June 2014 using projected autumn vole density, and then considering two climatic scenarios: 1) rain-free winter and 2) winter with many rainy days. Autumn vole density was a strong explanatory variable of NE incidence in boreal Sweden in 1990-2012 (R2 = 79%, p<0.001). Adding the number of rainy winter days improved the model (R2 = 84%, p<0.05). We report for the first time that risk of NE is higher in winters with many rainy days. Rain on snow and ground icing may block vole access to subnivean space. Seeking refuge from adverse conditions and shelter from predators, voles may infest buildings, increasing infection risk. In a rainy winter scenario, we predicted 812 NE cases in boreal Sweden, triple the number of cases predicted in a rain-free winter in 2013/2014. Our model enables identification of high risk years when preparedness in the public health sector is crucial, as a rainy winter would accentuate risk.

National Category
Microbiology in the medical area
Identifiers
urn:nbn:se:umu:diva-100516 (URN)10.1371/journal.pone.0111663 (DOI)000349144400028 ()25391132 (PubMedID)
Available from: 2015-03-04 Created: 2015-03-04 Last updated: 2018-06-07Bibliographically approved
Rodushkin, I., Engstrom, E., Sorlin, D., Baxter, D., Hörnfeldt, B., Nyholm, E. & Ecke, F. (2011). Uptake and Accumulation of Anthropogenic Os in Free-Living Bank Voles (Myodes glareolus). Water, Air and Soil Pollution, 218(1-4), 603-610
Open this publication in new window or tab >>Uptake and Accumulation of Anthropogenic Os in Free-Living Bank Voles (Myodes glareolus)
Show others...
2011 (English)In: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 218, no 1-4, p. 603-610Article in journal (Refereed) Published
Abstract [en]

Osmium tetroxide (OsO4) is one of the most toxic air contaminants but its environmental effects are poorly understood. Here, for the first time, we present evidence of osmium uptake in a common herbivore (bank vole, Myodes glareolus) in boreal forests of northern Sweden. Voles (n = 22) and fruticose arboreal pendular lichens, the potential main winter food source of the vole, were collected along a spatial gradient to the west of a steelwork in Tornio, Finland at the Finnish-Swedish border. Os-187/Os-188 isotope ratios increased and osmium concentrations decreased in lichens and voles along the gradient. Osmium concentrations in lichens were 10,000-fold higher than those in voles. Closest to the steelwork, concentrations were highest in kidneys rather than skin/fur that are directly exposed to airborne OsO4. The kidney-to-body weight ratio was higher at the two localities close to the steelwork. Even though based on a small sample size, our results for the first time demonstrate that osmium is taken up, partitioned, and accumulated in mammal tissue, and indicate that high kidney-to-body weight ratios might be induced by anthropogenic osmium.

Keywords
Boreal forest, Herbivore, Kidney-to-body weight ratio, Metal uptake, Spatial gradient
National Category
Ecology Agricultural Science, Forestry and Fisheries
Identifiers
urn:nbn:se:umu:diva-104860 (URN)10.1007/s11270-010-0671-y (DOI)000290724400053 ()
Available from: 2015-06-16 Created: 2015-06-15 Last updated: 2018-06-07Bibliographically approved
Ecke, F., Christensen, P., Rentz, R., Nilsson, M., Sandström, P. & Hörnfeldt, B. (2010). Landscape structure and the long-term decline of cyclic grey-sided voles in Fennoscandia. Landscape Ecology, 25(4), 551-560
Open this publication in new window or tab >>Landscape structure and the long-term decline of cyclic grey-sided voles in Fennoscandia
Show others...
2010 (English)In: Landscape Ecology, ISSN 0921-2973, E-ISSN 1572-9761, Vol. 25, no 4, p. 551-560Article in journal (Refereed) Published
Abstract [en]

Changes in forest landscape structure have been suggested as a likely contributing factor behind the long-term decline in the numbers of cyclic grey-sided voles (Clethrionomys rufocanus) in northern Fennoscandian lowland regions in contrast to mountain regions due to the absence of forest management in the mountains. This study, for the first time, formally explored landscape structure in 29 lowland (LF) and 14 mountain forest (MF) landscapes (each 2.5 x 2.5 km) in northern Sweden, and related the results to the cumulated spring trapping index of the grey-sided vole in 2002-2006. The grey-sided vole showed striking contrasts in dynamics close in space and time. The MF landscapes were characterized by larger patches and less fragmentation of preferred forest types. The grey-sided vole was trapped in all of 14 analyzed MF landscapes but only in three out of 29 of the LF landscapes. MF and LF landscapes with grey-sided vole occurrence were characterized by similar focal forest patch size (mean 357 ha, minimum 82 ha and mean 360 ha, minimum 79 ha, respectively). In contrast, these MF compared to the LF landscapes were characterized by larger patches of preferred forest types and less fragmented preferred forest types and by a lower proportion of clear-cut areas. The present results suggest that landscape structure is important for the abundance of grey-sided voles in both regions. However, in the mountains the change from more or less seasonal dynamics to high-amplitude cycles between the mid 1990s and 2000s cannot be explained by changes in landscape structure.

Place, publisher, year, edition, pages
Springer, 2010
Keywords
Boreal forest, Clethrionomys rufocanus, Contrasting dynamics, Fragmentation, Habitat preferences, Metapopulation, Mountain forest, Patch size, Small mammals, Sweden
National Category
Environmental Sciences Ecology Geology
Identifiers
urn:nbn:se:umu:diva-109631 (URN)10.1007/s10980-009-9441-x (DOI)000275444100005 ()
Available from: 2015-10-02 Created: 2015-10-02 Last updated: 2018-06-07Bibliographically approved
Olsson , G., Hjertqvist , M., Lundkvist , Å. & Hörnfeldt , B. (2009). Predicting High Risk for Human Hantavirus Infections, Sweden. Emerging Infectious Diseases, 15(1), 104-106
Open this publication in new window or tab >>Predicting High Risk for Human Hantavirus Infections, Sweden
2009 (English)In: Emerging Infectious Diseases, ISSN 1080-6040, E-ISSN 1080-6059, Vol. 15, no 1, p. 104-106Article in journal (Refereed) Published
Abstract [en]

An increased risk for hemorrhagic fever with renal syndrome caused by Puumala hantavirus was forecast for Sweden in 2007. The forecast was based on a predicted increase in the number of Myodes glareolus rodents (reservoir hosts). Despite raised awareness and preparedness, the number of human cases during July 2007-June 2008 was 1,483, a new high.

Identifiers
urn:nbn:se:umu:diva-23300 (URN)10.3201/eid1501.080502 (DOI)
Available from: 2009-06-09 Created: 2009-06-09 Last updated: 2018-06-08
Niklasson, B., Råsten Almqvist, P., Hörnfeldt, B. & Klitz, W. (2009). Sudden infant death syndrome and Ljungan virus. Forensic Science, Medicine, and Pathology, 5(4), 274-279
Open this publication in new window or tab >>Sudden infant death syndrome and Ljungan virus
2009 (English)In: Forensic Science, Medicine, and Pathology, ISSN 1547-769X, E-ISSN 1556-2891, Vol. 5, no 4, p. 274-279Article in journal (Refereed) Published
Abstract [en]

Ljungan virus (LV) has recently been associated with perinatal death in its natural rodent reservoir and also with developmental disorders of reproduction in laboratory mice. A strong epidemiological association has been found between small rodent abundance in Sweden and the incidence of intrauterine fetal death (IUFD) in humans. LV antigen has been detected in half of the IUFD cases tested. The question was therefore raised whether sudden infant death syndrome (SIDS) might be associated with rodent abundance, and whether the virus is present in cases of SIDS. Variation in the incidence of SIDS using the Swedish cause-of-death database tracked the changes in the population fluctuations of native rodents. Formalin-fixed tissues from the brain, heart, and lung were investigated from cases of SIDS, SIDS with lymphocytic infiltration of the myocardium (myocarditis) and myocarditis cases using LV specific immunohistochemistry (IHC). Ljungan virus was detected in the brain, heart, and lung tissue from all three of the patient categories investigated using IHC. These studies suggest that LV may play a prominent role in infant death, and that IUFD and SIDS may have common etiological underpinnings.

Place, publisher, year, edition, pages
Totowa: Humana Press, 2009
Keywords
Forensic science, Sudden infant death, Sudden unexplained death in infants, Myocarditis, Ljungan virus, Zoonosis, Rodent virus, Immunohistochemistry
National Category
Forensic Science
Identifiers
urn:nbn:se:umu:diva-115947 (URN)10.1007/s12024-009-9086-8 (DOI)000273261000005 ()19408134 (PubMedID)
Available from: 2016-02-29 Created: 2016-02-08 Last updated: 2018-06-07Bibliographically approved
Christensen, P., Ecke, F., Sandström, P., Nilsson, M. & Hörnfeldt, B. (2008). Can landscape properties predict occurrence of grey-sided voles?. Population Ecology, 50(2), 169-179
Open this publication in new window or tab >>Can landscape properties predict occurrence of grey-sided voles?
Show others...
2008 (English)In: Population Ecology, Vol. 50, no 2, p. 169-179Article in journal (Refereed) Published
Abstract [en]

There has been a long-term decline in spring and fall numbers of Clethrionomys rufocanus in boreal Sweden in 1971-2005. Previous studies on permanent sampling plots in the centre of 2.5 x 2.5 km landscapes suggested that habitat fragmentation (sensu destruction) could have contributed to the decline. Therefore, we tested these findings in a field study and compared trapping results on the central sampling plots of landscapes with a low degree of fragmentation (LDF) and of "hot spot" type with trapping results in managed forest landscapes with a high degree of fragmentation (HDF). We predicted that C. rufocanus would be more common on the LDF plots. We used our permanent plots supplemented with a new sample of plots, mainly of the rare LDF type, inside or just outside the long-term study area. Very few voles were trapped on both plot types, and no difference was found. However, a subsequent pilot study with trapping in a national park with large areas of pristine, unfragmented forest yielded more voles than in the managed, more fragmented, areas. Consequently, the initial field study data and some other recent data were also re-analysed from a "local patch quality" perspective. This alternative approach revealed the positive importance of large focal patches of forest > 60 years old and their content of old-growth (pine) forest (> 100 years). Interestingly, at the landscape level, the frequency distribution of patches of forest > 60 years old, old-growth (> 100 years), and especially of old-growth pine forest (> 100 years), relative to the properties of plots with C. rufocanus, suggested that there are few forest patches left that are suitable for C. rufocanus. Our current results suggest that habitat fragmentation cannot be excluded as a contributing cause to the long-term decline of C. rufocanus in boreal Sweden.

Identifiers
urn:nbn:se:umu:diva-11501 (URN)doi:10.1007/s10144-008-0077-5 (DOI)
Available from: 2009-01-13 Created: 2009-01-13 Last updated: 2018-06-09Bibliographically approved
Hipkiss, T., Stefansson, O. & Hörnfeldt, B. (2008). Effect of cyclic and declining food supply on great grey owls in boreal Sweden. Canadian Journal of Zoology, 86, 1426-1431
Open this publication in new window or tab >>Effect of cyclic and declining food supply on great grey owls in boreal Sweden
2008 (English)In: Canadian Journal of Zoology, Vol. 86, p. 1426-1431Article in journal (Refereed) Published
Abstract [en]

In this study of 35 years of data, we examine the short-term (cyclic) and long-term relationship between breeding success of great grey owls (Strix nebulosa Forster, 1772) and their food supply (bank voles (Clethrionomys glareolus (Schreber, 1780)), grey-sided voles (Clethrionomys rufocanus (Sundevall, 1846)), and field voles (Microtus agrestis (L., 1761))) in northern Sweden. Annual number of owl nests showed a 3 year cyclicity, which as predicted, corresponded to the length of the vole cycle in the region. Mean annual brood size also fluctuated and was positively dependent on the vole supply during the same spring. In this region, there has also been a decline in vole numbers in recent decades, from high-amplitude cycles in the 1970s to subsequent low-amplitude cycles. Correspondingly, and as predicted, mean annual brood size of the owls also declined, although only during the third years of the vole cycle when vole supply in spring and brood size of the owls is at its highest level in high-amplitude cycles. We predict that in the long run the vole decline, associated with increasingly milder winters, and the reduction of the brood size of the owls, especially in years of high owl breeding success, will have serious implications for the population of great grey owls in Scandinavia.

Identifiers
urn:nbn:se:umu:diva-11568 (URN)doi:10.1139/Z08-131 (DOI)
Available from: 2009-01-15 Created: 2009-01-15 Last updated: 2018-06-09Bibliographically approved
Niklasson, B., Samsioe, A., Papadogiannakis, N., Kawecki, A., Hörnfeldt, B., Saade, G. R. & Klitz, W. (2007). Association of zoonotic Ljungan virus with intrauterine fetal deaths. Birth Defects Res (Part A), 79, 488-493
Open this publication in new window or tab >>Association of zoonotic Ljungan virus with intrauterine fetal deaths
Show others...
2007 (English)In: Birth Defects Res (Part A), Vol. 79, p. 488-493Article in journal (Refereed) Published
Identifiers
urn:nbn:se:umu:diva-6208 (URN)
Available from: 2007-12-07 Created: 2007-12-07 Last updated: 2018-06-09Bibliographically approved
Niklasson, B., Nyholm, E., Feinstein, R. E., Samsioe, A. & Hörnfeldt, B. (2006). Diabetes and myocarditis in voles and lemmings at cyclic peak densities--induced by Ljungan virus?. Oecologia, 150(1), 1-7
Open this publication in new window or tab >>Diabetes and myocarditis in voles and lemmings at cyclic peak densities--induced by Ljungan virus?
Show others...
2006 (English)In: Oecologia, ISSN 0029-8549, Vol. 150, no 1, p. 1-7Article in journal (Refereed) Published
Keywords
Animals, Arvicolinae, Blood Glucose, Diabetes Mellitus/epidemiology/*veterinary, Myocarditis/epidemiology/*veterinary, Parechovirus/*isolation & purification, Picornaviridae Infections/epidemiology/*veterinary, Population Density, Population Dynamics, Rodent Diseases/*epidemiology/*virology, Scandinavia/epidemiology
Identifiers
urn:nbn:se:umu:diva-6240 (URN)16868760 (PubMedID)
Available from: 2007-12-07 Created: 2007-12-07 Last updated: 2018-06-09Bibliographically approved
Organisations

Search in DiVA

Show all publications