Inger Hamnes | Norwegian Veterinary Institute (original) (raw)
Papers by Inger Hamnes
Norsk Veterinærtidsskrift, 2012
Norsk Veterinærtidsskrift, 2010
Veterinary Parasitology, Oct 1, 2006
Faecal samples were collected from 1190 wild cervids in Norway and analyzed for cysts/oocysts of ... more Faecal samples were collected from 1190 wild cervids in Norway and analyzed for cysts/oocysts of the protozoan parasites Giardia and Cryptosporidium. Samples were from calves, yearlings and adults of moose (Alces alces), red deer (Cervus elaphus), roe deer (Capreolus capreolus) and reindeer (Rangifer tarandus) shot during the hunting season. Cryptosporidium was found in 15 (3.3%) of 455 moose, 1 (0.3%) of 289 red deer, 18 (6.2%) of 291 roe deer, but was not found in any of 155 reindeer. Giardia was found in 56 (12.3%) moose, 5 (1.7%) red deer, 45 (15.5%) roe deer and 11 (7.1%) reindeer. The calves had the highest prevalence of infection, but this was only statistically significant for Giardia in moose and for Cryptosporidium and Giardia in roe deer. Calves generally had the highest intensity of infection, but this difference was only statistically significant for calves with Giarda and the highest intensity of infection. Both Giardia and Cryptosporidium were found in samples from several geographical areas, indicating that these parasites are distributed among the cervid population in all parts of Norway, especially in moose and roe deer. This is the first published report of Cryptosporidium in moose and of Giardia in reindeer.
International Journal for Parasitology: Parasites and Wildlife
High host density combined with climate change may lead to invasion of harmful parasites in cervi... more High host density combined with climate change may lead to invasion of harmful parasites in cervid (host) populations. Bot flies (Diptera: Oestridae) are a group of ectoparasites that may have strong impact on their hosts, but data on the current distribution, prevalence and intensity of the moose nose bot fly (Cephenemyia ulrichii) in Scandinavia are lacking. We estimated prevalence and intensity of nose bot fly larvae in 30 moose from southern and 79 moose from central Norway. All larvae detected were identified as the moose nose bot fly. We found surprisingly high prevalence in these areas, which are up to 1300 km south-southwest of the first published location in Norway and west of the distribution in Sweden. Prevalence (0.44-1.00) was higher in areas with higher moose density. Parasite intensity in hunter killed moose was higher in central Norway (mean 5.7) than southern Norway (mean 2.9), and in both regions higher in calves and yearlings than adults. Fallen moose had higher parasite intensity (mean 9.8) compared to hunter killed moose in the subsample from central Norway, suggesting a link to host condition or behavior. Our study provides evidence of parasite range expansion, and establishing monitoring appears urgent to better understand impact on host populations.
International journal for parasitology. Parasites and wildlife, Aug 1, 2021
The Oestrid flies Cephemyia trompe and Hypoderma tarandi and the nematode Elaphostrongylus rangif... more The Oestrid flies Cephemyia trompe and Hypoderma tarandi and the nematode Elaphostrongylus rangiferi are important parasites of Rangifer spp. The larvae of Oestrid flies develop in the throat (C. trompe) and skin (H. tarandi) of their host during winter while E. rangiferi develop in the CNS. Oestrid pupation, and development of E. rangiferi larvae from first-(L1) to infective third-stage in the environment during summer are highly temperature dependent. We investigated the possible negative effects of these parasites on the winter bodycondition of wild reindeer calves. Two year-classes (generations) of calf, born in a warm (2014) and cold (2015) summer respectively, were examined for changes in body condition between autumn and spring, in relation to the parasite load determined in the spring. The body condition in the autumn was assessed as carcass weight, while the body condition in the spring was assessed as carcass weight, supplemented by an evaluation of fat reserves in various bodily locations. Oestrids were counted directly whereas the E. rangiferi quantification was based on faecal counts of L1 larvae. The abundance of infections for Oestrids and E. rangiferi were significantly greater in the 2014 generation than in the 2015 generation. The mean carcass weight decreased between autumn and spring for the 2014 generation but increased in the 2015 generation. Emaciation in the spring was documented (fat reserve evaluation) in 42% and 7% of calves in the 2014 and 2015 cohorts, respectively. There was a significant correlation between high parasite load and the probability of emaciation. The mean summer temperature in 2014 was 2.6 • C higher than the mean for 2015, and 1.0 • C higher than the mean for the last 30years. Our findings suggest that following a warm summer, high loads of Oestrids and E. rangiferi may cause emaciation and potentially deaths among the calves.
Additional file 1: Figure S1. Yearly variation of the mean abundance for each country. The abunda... more Additional file 1: Figure S1. Yearly variation of the mean abundance for each country. The abundance (y axis) was calculated as the mean all the observations (log transformed) from each country. Figure S2. QQ-plots of the residuals per month for the Obsoletus ensemble. Figure S3. QQ-plots of the residuals per month for the Pulicaris ensemble. Figure S4. Comparison of the abundance maps for each month using Random Forest (RF) and Interpolations for the Obsoletus ensemble. a Maps from January to June. b maps from July to December. Figure S5. Comparison of the abundance maps for each month using Random Forest (RF) and Interpolations for the Pulicaris ensemble. a Maps from January to June. b Maps from July to December. Figure S6. Comparison of the abundance maps for each month using Random Forest (RF) and Interpolations for Culicoides imicola. a Maps from January to June. b Maps from July to December. Figure S7. At a local scale, interpolation maps produce a smother surface between the ...
Additional file 4. Data supporting conclusions on the ability to differentiate statistically betw... more Additional file 4. Data supporting conclusions on the ability to differentiate statistically between levels of study variables when using three different outcome variables.
Additional file 3. Data supporting conclusions regarding impact of study variables on OPG counts.
Additional file 2. Data supporting conclusions regarding impact of study variables on frequency o... more Additional file 2. Data supporting conclusions regarding impact of study variables on frequency of turkeys with severe intestinal lesions.
Additional file 1. Additional photos of intestinal lesions. Folder with 47 additional photos in J... more Additional file 1. Additional photos of intestinal lesions. Folder with 47 additional photos in JPG format illustrating turkeys with intestinal lesions that were assigned to scores 0, 1, 2 or 3.
Background: Culicoides biting midges are hematophagous insects of veterinary importance able to t... more Background: Culicoides biting midges are hematophagous insects of veterinary importance able to transmit viruses such as bluetongue virus and Schmallenberg virus to livestock. The aim of this work was to describe the average temporal abundance of biting midges at a continental scale, by comparing the seasonal variation at six different latitude ranges from southern Spain to northern Sweden. Materials and methods: We gathered Culicoides obsoletus group trap data collected by national surveillance programs in nine European countries (Spain, France Germany, Switzerland, Austria, Denmark, Sweden, Norway, Poland) from 2007-2013. In total, 904 farms were sampled for Culicoides midges using UV light traps. We divided Europe into 6 latitudinal bands of 5° width and calculated the average weekly midge abundance as well as the average annual cumulative sum of biting midges for each of these bands. We plotted the results to visualize the spatial and temporal patterns at a continental scale. Re...
Monthly availability of Culicoides trap data in the participating countries during the selected s... more Monthly availability of Culicoides trap data in the participating countries during the selected seven-year study period (2007–2013). X symbol indicates months when data were available. (XLSX 12 kb)
Table S1. The top five of the most important variables by species group for each month. The varia... more Table S1. The top five of the most important variables by species group for each month. The variable importance is scaled from 0 to 100. Within each month (columns), the most important variable has a value of 100. (XLSX 67 kb)
A longitudinal study on the occurrence of Cryptosporidium and
<b>Copyright information:</b>Taken from "A longitudinal study on the occurrence ... more <b>Copyright information:</b>Taken from "A longitudinal study on the occurrence of and in dogs during their first year of life"http://www.actavetscand.com/content/49/1/22Acta Veterinaria Scandinavica 2007;49(1):22-22.Published online 11 Sep 2007PMCID:PMC2040143.age, or at more than one sampling.
Transboundary and Emerging Diseases
Parasites & Vectors
Background Culicoides biting midges transmit viruses resulting in disease in ruminants and equids... more Background Culicoides biting midges transmit viruses resulting in disease in ruminants and equids such as bluetongue, Schmallenberg disease and African horse sickness. In the past decades, these diseases have led to important economic losses for farmers in Europe. Vector abundance is a key factor in determining the risk of vector-borne disease spread and it is, therefore, important to predict the abundance of Culicoides species involved in the transmission of these pathogens. The objectives of this study were to model and map the monthly abundances of Culicoides in Europe. Methods We obtained entomological data from 904 farms in nine European countries (Spain, France, Germany, Switzerland, Austria, Poland, Denmark, Sweden and Norway) from 2007 to 2013. Using environmental and climatic predictors from satellite imagery and the machine learning technique Random Forests, we predicted the monthly average abundance at a 1 km2 resolution. We used independent test sets for validation and t...
Ecological Solutions and Evidence
Norsk Veterinærtidsskrift, 2012
Norsk Veterinærtidsskrift, 2010
Veterinary Parasitology, Oct 1, 2006
Faecal samples were collected from 1190 wild cervids in Norway and analyzed for cysts/oocysts of ... more Faecal samples were collected from 1190 wild cervids in Norway and analyzed for cysts/oocysts of the protozoan parasites Giardia and Cryptosporidium. Samples were from calves, yearlings and adults of moose (Alces alces), red deer (Cervus elaphus), roe deer (Capreolus capreolus) and reindeer (Rangifer tarandus) shot during the hunting season. Cryptosporidium was found in 15 (3.3%) of 455 moose, 1 (0.3%) of 289 red deer, 18 (6.2%) of 291 roe deer, but was not found in any of 155 reindeer. Giardia was found in 56 (12.3%) moose, 5 (1.7%) red deer, 45 (15.5%) roe deer and 11 (7.1%) reindeer. The calves had the highest prevalence of infection, but this was only statistically significant for Giardia in moose and for Cryptosporidium and Giardia in roe deer. Calves generally had the highest intensity of infection, but this difference was only statistically significant for calves with Giarda and the highest intensity of infection. Both Giardia and Cryptosporidium were found in samples from several geographical areas, indicating that these parasites are distributed among the cervid population in all parts of Norway, especially in moose and roe deer. This is the first published report of Cryptosporidium in moose and of Giardia in reindeer.
International Journal for Parasitology: Parasites and Wildlife
High host density combined with climate change may lead to invasion of harmful parasites in cervi... more High host density combined with climate change may lead to invasion of harmful parasites in cervid (host) populations. Bot flies (Diptera: Oestridae) are a group of ectoparasites that may have strong impact on their hosts, but data on the current distribution, prevalence and intensity of the moose nose bot fly (Cephenemyia ulrichii) in Scandinavia are lacking. We estimated prevalence and intensity of nose bot fly larvae in 30 moose from southern and 79 moose from central Norway. All larvae detected were identified as the moose nose bot fly. We found surprisingly high prevalence in these areas, which are up to 1300 km south-southwest of the first published location in Norway and west of the distribution in Sweden. Prevalence (0.44-1.00) was higher in areas with higher moose density. Parasite intensity in hunter killed moose was higher in central Norway (mean 5.7) than southern Norway (mean 2.9), and in both regions higher in calves and yearlings than adults. Fallen moose had higher parasite intensity (mean 9.8) compared to hunter killed moose in the subsample from central Norway, suggesting a link to host condition or behavior. Our study provides evidence of parasite range expansion, and establishing monitoring appears urgent to better understand impact on host populations.
International journal for parasitology. Parasites and wildlife, Aug 1, 2021
The Oestrid flies Cephemyia trompe and Hypoderma tarandi and the nematode Elaphostrongylus rangif... more The Oestrid flies Cephemyia trompe and Hypoderma tarandi and the nematode Elaphostrongylus rangiferi are important parasites of Rangifer spp. The larvae of Oestrid flies develop in the throat (C. trompe) and skin (H. tarandi) of their host during winter while E. rangiferi develop in the CNS. Oestrid pupation, and development of E. rangiferi larvae from first-(L1) to infective third-stage in the environment during summer are highly temperature dependent. We investigated the possible negative effects of these parasites on the winter bodycondition of wild reindeer calves. Two year-classes (generations) of calf, born in a warm (2014) and cold (2015) summer respectively, were examined for changes in body condition between autumn and spring, in relation to the parasite load determined in the spring. The body condition in the autumn was assessed as carcass weight, while the body condition in the spring was assessed as carcass weight, supplemented by an evaluation of fat reserves in various bodily locations. Oestrids were counted directly whereas the E. rangiferi quantification was based on faecal counts of L1 larvae. The abundance of infections for Oestrids and E. rangiferi were significantly greater in the 2014 generation than in the 2015 generation. The mean carcass weight decreased between autumn and spring for the 2014 generation but increased in the 2015 generation. Emaciation in the spring was documented (fat reserve evaluation) in 42% and 7% of calves in the 2014 and 2015 cohorts, respectively. There was a significant correlation between high parasite load and the probability of emaciation. The mean summer temperature in 2014 was 2.6 • C higher than the mean for 2015, and 1.0 • C higher than the mean for the last 30years. Our findings suggest that following a warm summer, high loads of Oestrids and E. rangiferi may cause emaciation and potentially deaths among the calves.
Additional file 1: Figure S1. Yearly variation of the mean abundance for each country. The abunda... more Additional file 1: Figure S1. Yearly variation of the mean abundance for each country. The abundance (y axis) was calculated as the mean all the observations (log transformed) from each country. Figure S2. QQ-plots of the residuals per month for the Obsoletus ensemble. Figure S3. QQ-plots of the residuals per month for the Pulicaris ensemble. Figure S4. Comparison of the abundance maps for each month using Random Forest (RF) and Interpolations for the Obsoletus ensemble. a Maps from January to June. b maps from July to December. Figure S5. Comparison of the abundance maps for each month using Random Forest (RF) and Interpolations for the Pulicaris ensemble. a Maps from January to June. b Maps from July to December. Figure S6. Comparison of the abundance maps for each month using Random Forest (RF) and Interpolations for Culicoides imicola. a Maps from January to June. b Maps from July to December. Figure S7. At a local scale, interpolation maps produce a smother surface between the ...
Additional file 4. Data supporting conclusions on the ability to differentiate statistically betw... more Additional file 4. Data supporting conclusions on the ability to differentiate statistically between levels of study variables when using three different outcome variables.
Additional file 3. Data supporting conclusions regarding impact of study variables on OPG counts.
Additional file 2. Data supporting conclusions regarding impact of study variables on frequency o... more Additional file 2. Data supporting conclusions regarding impact of study variables on frequency of turkeys with severe intestinal lesions.
Additional file 1. Additional photos of intestinal lesions. Folder with 47 additional photos in J... more Additional file 1. Additional photos of intestinal lesions. Folder with 47 additional photos in JPG format illustrating turkeys with intestinal lesions that were assigned to scores 0, 1, 2 or 3.
Background: Culicoides biting midges are hematophagous insects of veterinary importance able to t... more Background: Culicoides biting midges are hematophagous insects of veterinary importance able to transmit viruses such as bluetongue virus and Schmallenberg virus to livestock. The aim of this work was to describe the average temporal abundance of biting midges at a continental scale, by comparing the seasonal variation at six different latitude ranges from southern Spain to northern Sweden. Materials and methods: We gathered Culicoides obsoletus group trap data collected by national surveillance programs in nine European countries (Spain, France Germany, Switzerland, Austria, Denmark, Sweden, Norway, Poland) from 2007-2013. In total, 904 farms were sampled for Culicoides midges using UV light traps. We divided Europe into 6 latitudinal bands of 5° width and calculated the average weekly midge abundance as well as the average annual cumulative sum of biting midges for each of these bands. We plotted the results to visualize the spatial and temporal patterns at a continental scale. Re...
Monthly availability of Culicoides trap data in the participating countries during the selected s... more Monthly availability of Culicoides trap data in the participating countries during the selected seven-year study period (2007–2013). X symbol indicates months when data were available. (XLSX 12 kb)
Table S1. The top five of the most important variables by species group for each month. The varia... more Table S1. The top five of the most important variables by species group for each month. The variable importance is scaled from 0 to 100. Within each month (columns), the most important variable has a value of 100. (XLSX 67 kb)
A longitudinal study on the occurrence of Cryptosporidium and
<b>Copyright information:</b>Taken from "A longitudinal study on the occurrence ... more <b>Copyright information:</b>Taken from "A longitudinal study on the occurrence of and in dogs during their first year of life"http://www.actavetscand.com/content/49/1/22Acta Veterinaria Scandinavica 2007;49(1):22-22.Published online 11 Sep 2007PMCID:PMC2040143.age, or at more than one sampling.
Transboundary and Emerging Diseases
Parasites & Vectors
Background Culicoides biting midges transmit viruses resulting in disease in ruminants and equids... more Background Culicoides biting midges transmit viruses resulting in disease in ruminants and equids such as bluetongue, Schmallenberg disease and African horse sickness. In the past decades, these diseases have led to important economic losses for farmers in Europe. Vector abundance is a key factor in determining the risk of vector-borne disease spread and it is, therefore, important to predict the abundance of Culicoides species involved in the transmission of these pathogens. The objectives of this study were to model and map the monthly abundances of Culicoides in Europe. Methods We obtained entomological data from 904 farms in nine European countries (Spain, France, Germany, Switzerland, Austria, Poland, Denmark, Sweden and Norway) from 2007 to 2013. Using environmental and climatic predictors from satellite imagery and the machine learning technique Random Forests, we predicted the monthly average abundance at a 1 km2 resolution. We used independent test sets for validation and t...
Ecological Solutions and Evidence