Animal mortality

About: Animal mortality is a research topic. Over the lifetime, 526 publications have been published within this topic receiving 14887 citations.

Fine-scale determinants of vertebrate roadkills across a biodiversity hotspot in Southern Spain

Abstract: An increasing number of wildlife-vehicle collisions occur each year worldwide, which involves extensive economic costs and constitutes one of the main anthropogenic causes of animal mortality. Because of this, there is an urgent need to identify the factors leading to collision hotspots and thus implementing effective mitigation measures. By using a stratified random sampling survey, we investigated the fine-scale determinants of roadkill probability in small and medium-sized birds and mammals across a country-size region of Southern Spain, Andalusia (87,000 km2), located within a global biodiversity hotspot. During two consecutive seasons, we regularly surveyed 45 road transects of 10 km each and characterized the site-specific attributes of both roadkill and random points, including traffic density, road design (embankments, medians, fences, roadside vegetation and distance to curves), and adjacent landscape matrix. Based on this information, we investigated variation in collision risk according to landscape and road features, and the life history of the affected taxa. Mortality rates of mammals and birds increased with traffic density, and were also significantly affected by the distance to the nearest curve, slope of embankments, height of roadside vegetation, and land use adjacent to roads. Road mortality of both birds and mammals was related to the presence and typology of fences and center medians, so more densely vegetated medians and smaller mesh sizes reduced roadkill probability. Overall, our results indicate that roadkill risk may vary at exceedingly small spatial scales. The information provided by this extensive survey may be used to identify taxa-specific factors associated to roadkill risk and priority points for action. Our findings will therefore be relevant for the design of safer roads for both drivers and wildlife through the application of effective mitigation measures.

Environmental determinants correlated to Vibrio harveyi-mediated death of marine gastropods.

Abstract: Summary Vibrio harveyi is an emerging pathogen that causes mass mortality in a wide variety of marine animal species; however, it is still unclear which environmental determinants correlate V. harveyi dynamics and the bacterium-mediated death of marine animal life. We conducted a correlation analysis over a 5-year period (2003–2007) analysing the following data: V. harveyi abundance, marine animal mortality and environmental variables (seawater temperature, salinity, pH, chlorophyll a, rainfall and total viable bacterial counts). The samples were collected from a coastal area in northern Japan, where deaths of a marine gastropod species (Haliotis discus hannai) have been reported. Our analysis revealed significant positive correlations between average seawater temperature and average V. harveyi abundance (R = 0.955; P < 0.05), and between average seawater temperature and V. harveyi-mediated abalone death (R = 0.931; P < 0.05). Based on the regression model, n°C rise in seawater temperature gave rise to a 21n-fold increase in the risk of mortality caused by V. harveyi infection. This is the first report providing evidence of the strong positive correlation between seawater temperature and V. harveyi-mediated death of marine species.

Morphological, biological and molecular characterization of three strains of Trypanosoma cruzi Chagas, 1909 (Kinetoplastida, Trypanosomatidae) isolated from Triatoma sordida (Stal) 1859 (Hemiptera, Reduviidae) and a domestic cat

Abstract: A study was conducted of the biological, morphological and molecular characters of 3 strains of Trypanosoma cruzi (SI5, SI8 and SIGR3) isolated from specimens of Triatoma sordida collected in Santo Inacio and a domestic cat. In order to carry out the study, the following parameters were evaluated: pre-patent period, parasitaemia curves, morphology of the parasites, mortality rates, histopathological lesions and molecular typing. The strains presented variable pre-patent periods, low parasitaemia and no animal mortality. The morphological study of trypomastigotes showed a predominance of intermediate-width and short-length forms, as well as low nuclear index. Epimastigotes presented a low nuclear index, intermediate-width forms in strains SI5 and SI8, and large-width forms in SIGR3. A shorter length could be noted in strains SI8 and SIGR3, whereas SI5 displayed an intermediate length. The histopathological study did not detect amastigote nests in tissues. The amplification of the divergent domain of 24Sα rRNA, HSP60 and GPI genes of strains SI5, SI8 and SIGR3 classified the 3 strains into Group II. Biological parameters made it possible to classify the strains isolated in Santo Inacio (BA) into Biodeme III, Zymodeme 1 and Group II of T. cruzi.

An outbreak of lethal toxoplasmosis in pigs in the Gansu province of China

Abstract: In October 2004, a swine farm in Jinchang, Gansu Province, China, experienced an outbreak of toxoplasmosis. Most of the affected pigs had a rectal temperature greater than 40 degrees C and gradually lost their appetite. Morbidity reached 57%, and mortality was approximately 2%. Analysis of blood samples from affected pigs using hemagglutination inhibition (HI) assay, immunoglobulin G-enzyme-linked immunosorbent assay (IgG-ELISA), and IgM-ELISA tests showed high titers of anti-Toxoplasma gondii antibody. Tachyzoites of T. gondii were found in body fluids of mice inoculated intraperitoneally with ground samples from the heart, liver, spleen, and brain of 2 sick pigs. In addition, the inoculation of 5 pigs with T. gondii tachyzoites caused death in 2 of the pigs. The origin of this outbreak was concluded to be food-borne T. gondii infection.

Rabies DNA Vaccines: Current Status and Future

Abstract: Rabies continues to be a significant cause of human and animal mortality, despite the availability of safe and effective prophylactics Apart from limited access, the cost and complex schedules of rabies biologics often impact on the success of post-exposure prophylaxis in humans in the endemic countries Mass vaccination of dogs, critical in rabies control, often fails to achieve its goal in rabies-endemic countries due to logistic, animal and vaccine-related issues DNA vaccination has been proposed as a cheaper and efficient strategy for rabies prophylaxis, and its feasibility has been demonstrated in a number of animal models including companion animals, since 1994 Despite the proven efficacy, the technology suffers from a few drawbacks that limit its large-scale application, such as delayed and weaker immune responses in larger animals Recent advances in the field of vector design and delivery hold promise for enhancement of rabies DNA vaccine efficacy The present article provides an overview of developments in the field of DNA rabies vaccination and its future prospects