CiteULike: neteler's wildlife

Wildlife as source of zoonotic infections.

H Kruse — 2008-05-09T20:47:13-00:00

Emerging infectious diseases, Vol. 10, No. 12. (December 2004), pp. 2067-2072.

Zoonoses with a wildlife reservoir represent a major public health problem, affecting all continents. Hundreds of pathogens and many different transmission modes are involved, and many factors influence the epidemiology of the various zoonoses. The importance and recognition of wildlife as a reservoir of zoonoses are increasing. Cost-effective prevention and control of these zoonoses necessitate an interdisciplinary and holistic approach and international cooperation. Surveillance, laboratory capability, research, training and education, and communication are key elements.

Emerging infectious diseases in wildlife.

ES Williams — 2007-12-17T21:39:14-00:00

Rev Sci Tech, Vol. 21, No. 1. (April 2002), pp. 139-157.

The processes which give rise to emerging infectious diseases of wildlife can be categorised as follows: ecosystem alterations of anthropogenic or natural origin; movement of pathogens or vectors, via human or natural agency; and changes in microbes or in the recognition of emerging pathogens due to advances in the techniques of epidemiology. These are simplistic divisions because factors influencing the emergence of diseases of wild animals generally fall into more than one category. Mycoplasmosis among passerines is related to habitat changes and artificial feeding resulting in increased bird densities and subsequent disease transmission. The origin of this strain of Mycoplasma gallisepticum is not known. Hantavirus infections in rodents have emerged due to human-induced landscape alterations and/or climatic changes influencing population dynamics of hantavirus reservoir hosts, with disease consequences for humans. Movement of pathogens or vectors is a very important process by which diseases of wildlife expand geographic range. Although the origin of caliciviruses of rabbits and hares is somewhat obscure, their movement by humans, either deliberately or accidentally, has greatly expanded the distribution of these viruses. Rabies is an ancient disease, but geographic expansion has occurred by both natural and anthropogenic movements of wild animals. Human movement of amphibians may explain the distribution of the highly pathogenic chytrid fungus around the world. Newly recognised paramyxoviruses may reflect both changes in these pathogens and the development of techniques of identification and classification. Many more such examples of emerging diseases will arise in the future, given the extensive alterations in landscapes world-wide and movements of animals, vectors and pathogens. Those who study and diagnose diseases of wildlife must be alert for emerging diseases so that the impact of such diseases on wild animals, domestic animals and humans can be minimised.

Wildlife, environment and (re)-emerging zoonoses, with special reference to sylvatic tick-borne zoonoses in North-Western Italy.

D De Meneghi — 2008-01-11T09:34:43-00:00

Ann Ist Super Sanita, Vol. 42, No. 4. (2006), pp. 405-409.

Over the last century, changes in land-use, modification of agriculture-livestock production systems, disruption of wildlife habitats, increase of human activities, higher frequency of international and intercontinental travels, wider circulation of animals and animal products have contributed to alter the distribution, presence and density of hosts and vectors. As a result, the number of emerging and reemerging diseases, including zoonoses, have greatly increased. Some infectious pathogens, originated in wild animals and/or maintained in sylvatic environments, have become increasingly important worldwide for their impact on wildlife, human health, livestock and agricultural production systems. In this paper, a synthesis of the information available on selected zoonoses of wildlife origin is given, with special reference to sylvatic tick-borne zoonoses in North-western Italy.

Surveillance and monitoring of wildlife diseases.

T Mörner — 2008-01-04T12:31:30-00:00

Rev Sci Tech, Vol. 21, No. 1. (April 2002), pp. 67-76.

It is now recognised that those countries which conduct disease surveillance of their wild animal populations are more likely to detect the presence of infectious and zoonotic diseases and to swiftly adopt counter measures. The surveillance and monitoring of disease outbreaks in wildlife populations are particularly relevant in these days of rapid human and animal translocation, when the contact between wild and domestic animals is close and the threat of a bioterrorist attack is very real. The authors describe the problems inherent in wildlife disease surveillance and stress the importance of the establishment of national strategies for disease detection. The various sampling methods employed for monitoring outbreaks of disease and mortality in wildlife populations are discussed and their strengths and weaknesses described. A major advantage of an efficient disease monitoring programme for wildlife is the early detection of new and 'emerging' diseases, some of which may have serious zoonotic and economic implications. The authors conclude that wildlife disease monitoring programmes that are integrated within national animal health surveillance infrastructures should have the capacity to respond promptly to the detection of unusual wildlife mortality and to institute epizootiological research into new and emerging wildlife diseases.

PUBLIC HEALTH: Pathogen Surveillance in Animals

T Kuiken — 2007-12-19T10:35:14-00:00

Science, Vol. 309, No. 5741. (9 September 2005), pp. 1680-1681.

10.1126/science.1113310

Emerging infectious diseases in wildlife

ES Williams — 2007-12-17T21:25:08-00:00

Revue Scientifique et Technique de l'Office International des Epizooties, Vol. 21, No. 1. (April 2002), pp. 139-157.

The processes which give rise to emerging infectious diseases of wildlife can be categorised as follows: ecosystem alterations of anthropogenic or natural origin; movement of pathogens or vectors, via human or natural agency; and changes in microbes or in the recognition of emerging pathogens due to advances in the techniques of epidemiology. These are simplistic divisions because factors influencing the emergence of diseases of wild animals generally fall into more than one category. Mycoplasmosis among passerines is related to habitat changes and artificial feeding resulting in increased bird densities and subsequent disease transmission. The origin of this strain of Mycoplasma gallisepticum is not known. Hantavirus infections in rodents have emerged due to human-induced landscape alterations and/or climatic changes influencing population dynamics of hantavirus reservoir hosts, with disease consequences for humans. Movement of pathogens or vectors is a very important process by which diseases of wildlife expand geographic range. Although the origin of caliciviruses of rabbits and hares is somewhat obscure, their movement by humans, either deliberately or accidentally, has greatly expanded the distribution of these viruses. Rabies is an ancient disease, but geographic expansion has occurred by both natural and anthropogenic movements of wild animals. Human movement of amphibians may explain the distribution of the highly pathogenic chytrid fungus around the world. Newly recognised paramyxoviruses may reflect both changes in these pathogens and the development of techniques of identification and classification. Many more such examples of emerging diseases will arise in the future, given the extensive alterations in landscapes world-wide and movements of animals, vectors and pathogens. Those who study and diagnose diseases of wildlife must be alert for emerging diseases so that the impact of such diseases on wild animals, domestic animals and humans can be minimised.

Spatial aspects of disease dynamics

G Hess — 2007-01-24T17:34:47-00:00

(2002), pp. 102-118.

Human Granulocytic Anaplasmosis in Northeastern Italy

Anna Beltrame — 2006-10-27T09:57:39-00:00

Annals of the New York Academy of Sciences, Vol. 1078, No. 1. (October 2006), pp. 106-109.

Sporadic cases of human granulocytic anaplasmosis (HGA) have been reported in areas with a high prevalence of tick-borne diseases (TBDs) in Europe. We aimed at estimating the sero-prevalance of A. phagocytophilum and other TBDs in northeastern Italy in outpatients with a history of recent tick bite or suspected TBD. In the 1-year study, 79 patients were enrolled and 30 (38%) received a diagnosis of TBD: 24 (30%) with Lyme desease and 5 (6%) with HGE. Our findings indicate the presence of HGA in northernsterm Italy; so, since co-infection with Lyme disease appeared to be frequent, physicians assessing patients after a tick bite should consider HGA in the diagnosis.

The ecology of tick-borne infections in wildlife reservoirs

SE Randolph — 2006-04-02T21:57:25-00:00

(2002), pp. 119-138.

Can climate data from METEOSAT improve wildlife distribution models?

S Suárez-Seoane — 2006-01-25T15:07:26-00:00

ECOGRAPHY, Vol. 27 (2004), pp. 629-636.

Global climate change generated by human activities is likely to affect agroecosystems in several ways: reinforcing intensification in northern and western Europe, and extensification in the Mediterranean countries. If we are to predict the consequences of global warming for wildlife, distribution models have to include climate data. The METEOSAT temporal series from EWBMS offers an attractive alternative to using climatic surfaces derived from ground stations. The aim of this paper is to test whether this climatic satellite data can improve the distribution models obtained previously by Suarez-Seoane et al. using habitat variables for three agro-steppe bird species: great bustard, little bustard and calandra lark in Spain. Rainfall, radiation balance, evapotranspiration and soil moisture images were incorporated together with the other variables used as predictors in the published stepwise GAM models. Changes in the predicted distributions from the habitat only and climate-habitats models were assessed by reference to the CORINE land cover categories. Inclusion of climatic variables from METEOSAT led to statistically superior models for all three species. There were large differences in the climatic variables selected and the original variables dropped among the species. Evapotranspiration variables were the most frequently selected. Maps of the differences between the habitat and climate-habitat models showed very different patterns for the three species. Inclusion of climate variables led to a wider range of land cover types being deemed suitable. Despite the statistical superiority of models, care is needed in deciding whether to use climatic variables because they may emphasize the fundamental rather than the realized niche. Used together, however, habitat and climate models can provide new insights into factors limiting species distributions and how they may respond to climate change.

The role of wildlife in emerging and re-emerging zoonoses.

RG Bengis — 2005-11-05T08:37:16-00:00

Rev Sci Tech, Vol. 23, No. 2. (August 2004), pp. 497-511.

There are huge numbers of wild animals distributed throughout the world and the diversity of wildlife species is immense. Each landscape and habitat has a kaleidoscope of niches supporting an enormous variety of vertebrate and invertebrate species, and each species or taxon supports an even more impressive array of macro- and micro-parasites. Infectious pathogens that originate in wild animals have become increasingly important throughout the world in recent decades, as they have had substantial impacts on human health, agricultural production, wildlife-based economies and wildlife conservation. The emergence of these pathogens as significant health issues is associated with a range of causal factors, most of them linked to the sharp and exponential rise of global human activity. Among these causal factors are the burgeoning human population, the increased frequency and speed of local and international travel, the increase in human-assisted movement of animals and animal products, changing agricultural practices that favour the transfer of pathogens between wild and domestic animals, and a range of environmental changes that alter the distribution of wild hosts and vectors and thus facilitate the transmission of infectious agents. Two different patterns of transmission of pathogens from wild animals to humans are evident among these emerging zoonotic diseases. In one pattern, actual transmission of the pathogen to humans is a rare event but, once it has occurred, human-to-human transmission maintains the infection for some period of time or permanently. Some examples of pathogens with this pattern of transmission are human immunodeficiency virus/acquired immune deficiency syndrome, influenza A, Ebola virus and severe acute respiratory syndrome. In the second pattern, direct or vector-mediated animal-to-human transmission is the usual source of human infection. Wild animal populations are the principal reservoirs of the pathogen and human-to-human disease transmission is rare. Examples of pathogens with this pattern of transmission include rabies and other lyssaviruses, Nipah virus, West Nile virus, Hantavirus, and the agents of Lyme borreliosis, plague, tularemia, leptospirosis and ehrlichiosis. These zoonotic diseases from wild animal sources all have trends that are rising sharply upwards. In this paper, the authors discuss the causal factors associated with the emergence or re-emergence of these zoonoses, and highlight a selection to provide a composite view of their range, variety and origins. However, most of these diseases are covered in more detail in dedicated papers elsewhere in this Review.

Using the spatial and spectral precision of satellite imagery to predict wildlife occurrence patterns

Edward Laurent — 2005-07-29T16:35:53-00:00

Remote Sensing of Environment, Vol. 97, No. 2. (30 July 2005), pp. 249-262.

We investigated the potential of using unclassified spectral data for predicting the distribution of three bird species over a ~400,000 ha region of Michigan's Upper Peninsula using Landsat ETM+ imagery and 433 locations sampled for birds through point count surveys. These species, Black-throated Green Warbler, Nashville Warbler, and Ovenbird, were known to be associated with forest understory features during breeding. We examined the influences of varying two spatially explicit classification parameters on prediction accuracy: 1) the window size used to average spectral values in signature creation and 2) the threshold distance required for bird detections to be counted as present. Two accuracy measurements, proportion correctly classified (PCC) and Kappa, of maps predicting species' occurrences were calculated with ground data not used during classification. Maps were validated for all three species with Kappa values > 0.3 and PCC > 0.6. However, PCC provided little information other than a summary of sample plot frequencies used to classify species' presence and absence. Comparisons with rule-based maps created using the approach of Gap Analysis showed that spectral information predicted the occurrence of these species that use forest subcanopy components better than could be done using known land cover associations (Kappa values 0.1 to 0.3 higher than Gap Analysis maps). Accuracy statistics for each species were affected in different ways by the detection distance of point count surveys used to stratify plots into presence and absence classes. Moderate-to-large detection distances (100 m and 180 m) best classified maps of Black-throated Green Warbler and Nashville Warbler occurrences, while moderate detection distances (50 m and 100 m), which ignored remote observations, provided the best source of information for classification of Ovenbird occurrence. Window sizes used in signature creation also influenced accuracy statistics but to a lesser extent. Highest Kappa values of majority maps were typically obtained using moderate window sizes of 9 to 13 pixels (0.8 to 1.2 ha), which are representative of the study species territory sizes. The accuracy of wildlife occurrence maps classified from spectral data will therefore differ given the species of interest, the spatial precision of occurrence records used as ground references and the number of pixels included in spectral signatures. For these reasons, a quantitative examination is warranted to determine how subjective decisions made during image classifications affect prediction accuracies.

Ixodes ricinus, transmitted diseases and reservoirs

A Rizzoli — 2005-04-27T19:51:32-00:00

Parassitologia, Vol. 46, No. 1-2. (June 2004), pp. 119-122.

The tick Ixodes ricinus has been recorded in most Italian regions especially in thermo-mesophilous woods and shrubby habitats where the relative humidity allow the tick to complete its 3 year developmental cycle, as predicted for the European climatic ranges. This tick acts both as vector and reservoir for a series of wildlife zoonotic pathogens, especially the agents of Lyme diseases, Tick borne encephalitis and Human Granulocytic Ehrlichiosis, which are emerging in most of Europe. To assess the spatial distribution of these pathogens and the infection risk for humans and animals within the territory of the Province of Trento, we carried out a long term study using a combination of eco-epidemiological surveys and mathematical modelling. An extensive tick collection with a GIS based habitat suitability analysis allowed us to identify the areas where tick occurs at various density. To identify the areas with higher infection risk, we estimated the values of R0 for Borrelia burgdorferi s.l., TBE virus and Anaplasma phagocytophila under different ecological conditions. We assessed the infection prevalence in the vector and in the wildlife reservoir species that play a central role in the persistence of these infections, ie the small mammals A. flavicollis and C. glareolus. We also considered the double effect of roe deer (Capreolus capreolus) which act as reservoir for A. phagocytophila but is an incompetent host for B. burgdorferi and TBE virus, thus reducing the infection prevalence in ticks of these last two pathogens. Infection prevalence with B. burgdorferi and A. phagocytophila in the vector was assessed by PCR screening 1212 I. ricinus nymphs collected by dragging in six main study areas during 2002. The mean infection prevalence recorded was 1.32% for B. burgdorferi s.l. and 9.84% for A. phagocytophila. Infection prevalence in nymphs with TBE virus, as assessed in a previous study was 0.03%. Infection prevalence in rodents was assessed by screening (with ELISA and PCR) tissues and blood samples collected from 367 rodent individuals trapped extensively during 2002 within 6 main study areas. A. flavicollis (N=238) was found to be infected with all three pathogens investigated, with infection prevalence ranging from 3.3% for TBE virus to 11.7% for A. phagocytophila, and 16.6% with B. burgdorferi s.l. C. glareolus (N=108) showed an infection prevalence of 6.5% with A. phagocytophila and 12.7% with B. burgdorferi s.l., while no individuals were infected with TBE virus. We also screened 98 spleen samples collected from roe deer with PCR, resulting in a mean prevalence of infection with A. phagocytophila of 19.8%. Using a deterministic model we explored the condition for diseases persistence under different rodent and roe deer densities. R0 values resulted largely above 1 for B. burgdorferi s.l. in the vast majority of the areas classified as suitable for I. ricinus occurrence in Trentino, while the condition for TBE persistence appeared to be more restricted by a combination of climatic condition and host densities.