NRC 261 1st Edition Lecture 6 Outline of Last Lecture I Causes of Population Changes Constituents of Food Energy Flow i Kinds of Energy Water Minerals Vitamins Limitations on Food Intake Behavioral Morphological Physiological Environmental Limitations IV Adaptations Morphological Behavioral Outline of Current Lecture Conditions of Wildlife Diseases Disease Definition Continuum IV Infectious Diseases Diseases in New England VI Rabies Raccoon Rabies in the Eastern U S Raccoon Rabies in Pennsylvania Raccoon Rabies Research Rabies Vaccine These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Landscapes Rural Urban Suburban Trapping Protocol Habitat Use Models Current Lecture Diseases of Wildlife Conditions for Wildlife Diseases can be devastating for wildlife populations and people devastating when there are high populations of people overcrowding unhealthy conditions when interaction with dead or alive wildlife species human encroachment on wildlife habitat animals have been living and evolving with diseases and with the changes humans can make to the landscape environment the wildlife and their diseases have more interaction with humans humans changing landscape in major ways environmental destruction has altered the balance and interactions between humans diseases wildlife Wildlife Diseases Interface realm of human medicine and public health some related directly to wildlife aspect of veterinary medicine and agriculture agriculture is a major landscape change where all these things intersect is where we get a confluence of wildlife diseases this is where it becomes a real concern for wildlife and for people too Important Note if something is viewed as bad for people and comes from wildlife people often fix the problem by getting rid of the wildlife Disease Definition any impairment that interferes with or modifies the performance of the normal function includes responses to environmental factors infectious agents they cause the disease but are not the disease themselves or a combination of these factors Disease Continuum absolute health relatively healthy disease death relatively healthy animals are reproducing maintaining themselves a disease might be present but is not affecting the population growth disease lower on the continuum not all lead to death but many can lead to poor growth and or reproduction disease isn t an all or nothing phenomenon there are many of ways it can affect an organism Epidemiological Triangle the relationships between the environment and agent and a host NOT a linear relationship triangle means there is an interaction of the three causative agent animal not always disease interactive relationship among causative agent animal and environmental factors causes the disease Infectious Diseases they don t occur equally across the globe looking at the map it clearly shows that disease is transmissible wherever there are both humans and animals high density of disease occurrence where there is a high density of people lots in India and China certain place in Africa with high population density interactions between these population centers and wildlife is what causes lots of diseases Diseases in New England rabies Lyme disease raccoon roundworm intestinal parasite west nile virus eastern equine encephalitis avian influenza Rabies fatal viral disease left untreated it will kill you one of the oldest recognized diseases 4 000 years old behaviors of infected animals hydrophobia turning vicious aggressive active at odd times of day causes 40 000 to 60 000 deaths worldwide each year people who don t have access to shots In the U S in last 25 years 24 deaths since 1990 only 2 nationwide reported in people in U S in 2010 status of rabies in North America changed over the last 30 years because of distribution of the disease Map from the CDC shows animals most likely to carry rabies in different parts of the country mostly skunks in northwest midwest and west raccoon in east fox in Alaska mongoose in puerto rico The infectious path of Raccoon Rabies raccoon is bitten rabies virus enters the bitten animal via saliva and enters the tissues such as the blood stream to the coon virus spreads throughout the body virus incubates keeps growing inside the body reaches the brain and multiplies rapidly 3 week period before this happens once its in the brain the animal ends up dying Raccoon Rabies in Eastern United States first case was in Florida in 1954 it then spread through Georgia Alabama South Carolina spread to Virginia in 1970 s and moved through the population natural spread of this disease there was an outbreak in the mid atlantic states high density of animals lots of interaction between humans and animals that have rabies so they were more likely to pass it on the population of rabid animals the died off and since populations were low for a while the disease didn t get spread because there were less creatures to bite and spread the infection then an outbreak in the New England states ended up occurring in unexpected places and spread very fast not how it had been spreading in the south Theory rabid raccoons were brought from mid atlantic states on trucks that were carrying supplies food they enticed the coons so they hitched a ride part of the rabies spread was human assisted and not just a natural spread of disease through the population although humans were unaware of their contribution Raccoon Rabies in Pennsylvania first documented cases occurred in 1982 enzootic throughout the commonwealth by 1994 millions of raccoons now lived there greater than 58 of the positive rabies cases every year were because of raccoons started to worry people Raccoon Rabies Research studied how to restrict the extension of the range of rabid raccoons interested on landscape effects on disease dynamics in raccoons wanted to look at raccoon bacteria and parasite loads with respect to landscape and human health Vaccination Strategies thought about trying to vaccinate the raccoons ahead of time so that when the disease came to the area and tried to bite the vaccinated ones then they would be safe and the already rabid raccoons would die and hopefully the disease would die with them wanted to try to contain the rabies not let it spread to the west let it burn out so the overall levels of rabies would go down along with levels of bad raccoon human interactions wanted the vaccine to be given to