Disease definition	Any negative change from normal health, condition interfering with normal functions Response to environmental factors Toxins Nutrition Climate Infectious agents Trauma/injury Inherent/congenital defects Combination of these
What condition are most wild animals in?	Perfect health Apparently healthy Minor signs Sick Visibly sick death
Why are diseases becoming a more important factor	More knowledge Increased technology Diseases thrive in unstable systems: Increased pollution High population densities Climate change Species introductions / range expansions - More contact between wildlife, humans and domestic animals
Two main groups of causes for disease and some examples	Internal: Genetic sisceptibility Congenital (birth) defects Stress (pregnancy, rut,…) External: Nutrition, Toxins, Infectious agents, environmental, weather, other species, air and water quality, population density,…
4 factors of disease agent that influence disease in animal	Strain Dose Route of exposure Duration of exposure
Multifactoriality of diseases and exceptions	Usually exposure alone is not enough, to get sick there often have to be predisposing causes and secondary causes However, there are exceptions: Botulism, Rabies, Anthrax,…
Effects of diseases	Don’t assume there is no effect, just because it is not visible. But also don’t assume there is an effect. True effect is usually only determined after eliminating the disease.
Should wildlife disease be managed?	- Humans have caused many changes in the environment that result in increasing wildlife health problems - Health risk to humans (zoonosis) - Health risk to livestock - Risk to the whole wildlife population - Risk to other wildlife species - Who is the management for? Most wildlife disease are monitored, not managed.
Potential benefits of diseases in wildlife	Population might increase without disease  could lead to crash Decreased reproduction and survival can cause improved fitness of the remaining individuals
3 Management objectives	Prevention: - Prevent relevant contact (human/livestock) - Prevent introduction through translocations, imports,… Control: - Reduce effects/spread of disease (for example remove feeding stations) Eradication: - usually impossible - very expensive - mostly for political diseases ( affecting humans or livestock) - rearely for the benefit of wildlife
6 stages of making a management plan	1. Cause/ecology of disease 2. Biology of disease in the population 3. Identify players 4. Target species to benefit 5. How cause gets to target 6. Reservoirs?
What is an outbreak?	Increase in the number of cases above the regular baseline of cases
3 Approaches to identify taxa in an eDNA sample	PCR (Presence/absence of single species) Metabarcoding (Identification of many taxa in the same sample) Metagenomics (Targets all DNA in a sample
Symbionts	We have a huge microbiota in and on us. About 1.5kg of bacteria per person.
Commensalism	A relationship where one species profits, while not causing harm to its host/another species
Symbiosis	Coexistence of two or more species where all profit
Parasitic	Species living off another species where the host is harmed
Infection	Colonialism of an organism by an infectious agent that can cause disease
Opportunistic pathogen	An agent that under the right circumstances can cause disease (for example because of reduced immunity)
Pathogen	Infectious agent that causes disease
Pathogenicity / virulence	Ability and “power” to cause disease
Disease	A pathological condition of a part, organ, or system of an organism resulting from various causes, such as ingection, genetic defect, environmental stress. Is characterized by an identifiable group of signs or symptoms.
How is a virus built?	Genetic material is protected by a protein shell (capsid) Capsid must be able to recognize susceptible host cells to be able to start an infection
Virus replication cycle (8 Steps)	- Attachment - Penetration - Uncoating - Replication - Transcription/Translation - Assembly - Maturation - Release
What defines the host range of a virus?	Each virus depends on a specific binding of the virus proteins to the surface of a cell (receptor molecules)
What is a bacteria?	Bacteria are cells (with cell wall, produce energy, reproduce by cell division, can grow on cell-free media) 2-100 times larger than viruses
What is a parasite?	Any agent/organism living on the expence of the host organism Ectoparasites = on the host Endoparasites = in the host
5 types of infectious agents	Parasites Bacteria Viruses Fungi Prions
What is a Pathogenic parasites?	A parasite that carries an infectious agent (such as a tick carrying TBE, or mosquitos with malaria)
Individual and population factors that impact the susceptibility and outcome of an infection (8)	Immunity Genetics Age Nutrition Stress Pregnancy Other diseases Medical treatment
Defence mechanisms against pathogens (6)	Hard skin / tree bark Exoskeleton of insects Mucus covering mucus membranes Symbionts Biochemical defence Immune system
Innate and adaptive immunity	Innate immunity is the immediate response Adaptive immune response follow later (lymphocytes)
Antibody	Protein molecule which attaches to the antigen on a pathogen and then either: -causes pathogen to be unable to enter body cells - Attracts white blood cells to engulf the pathogen
Balance & co-evolution between infectious agents and host/victim	Balance between pathogenicity (ability to cause disease) and the immunity of the host Balance can be changed when: 7. Agents are introduced to new hosts 8. Relocations of hosts 9. Changes in the host (stress, other infections,…) 10. Mutations, genetic shifts
Effect of climate change on disease vectors	Increased temperatures and increase precipitation affect distribution and population size of insects and other vectors
Definition necropsy	Examination of an animal/human after death, usually to determine the cause of death or the extent of the disease
How to protect for necropsy (4 steps)	- Pack equipment and think what you will need - Get background on the clinical history of the animal if possible - Contact other experts beforehand - Consider your safety  protective clothes and other protective gear
How to assess the body condition of an animal	- Pack equipment and think what you will need - Get background on the clinical history of the animal if possible - Contact other experts beforehand - Consider your safety  protective clothes and other protective gear
What are primary and secondary injuries?	Primary injuries: happened before death (indicated by bloody wounds, bruising) Secondary injuries: happened after death (scavenger marks, missing body parts)
Why do we do necropsy?	- Contributes to science and understanding of anatomy and physiology - Complements clinical medicine - Disease detection and surveillance tool - Legal reasons (detect poaching, poisoning,…)
Necrobacillosis	- Bacteria - Common in rumen content - Digital necrobacillosis was common in semi-domesticated reindeer for milking, disappeared when milking of reindeers ended, but now new outbreaks in wild reindeer - swollen (bloody) feet - Oral necrobacillosis is more common now than in the past - fucked up inside of mouth
Papillomavirus	Found in a wide variety of host species like deer or moose - creates tumors which can lead to weakness, shows as hairless crusts - tumors can lead to secondary bacterial infections
What groups are most at risk for zoonosis	Farmers, pet owners Slaughterhouse workers Veterinarians Biologists/field workers Laboratory personell Hunters Zoo and aquarium personnel
Rabies	Rabies can affect almost any mammal, but mainly carnivores with high population density (fox, dog, racoon, racoon dog) Always fatal if untreated Rabies-eradication theoretically possible if (stray) dogs are vaccinated About 50’000 fatal human cases per year
Pathogenesis Rabies (4 steps)	1. Virus transmitted by bite 2. Virus moves from cell to cell until it reaches brain 3. Virus is distributed from brain to salivary glands. The animal is now infectious. 4. Animal’s brain has become infected enough to alter the behavior
3 stages of symptoms in rabies	Prodromal stage: 1-3 days, minor behavioural changes such as loss of fear from humans, increased aggressiveness, daytime activities for nocturnal animals, abnormalities in appetite Excitative phase: Animal bites anything, very aggressive, may day in this stage Paralytic phase: Inability to swallow  foaming of mouth, paralysis, death
Echinococcosis	Parasite Endhost: carnivores: fox, dogs Intermediate host: Rodents, People Can be found in reindeer meat sometimes Incubation time 5-15 years Infection via eggs (fecal material, water, dogs,…) Causes cysts in liver and other organs Patients die from liver insufficiency
Toxoplasma gondii	Parasite very common in humans and other mammals (>2 billion people have it) Usually no symptoms (maybe fever, enlarged lymph nodes, nausea) Dangerous if first time infection is during pregnancy (abortion can happen) Infection through cat feces (cats are finite host), or not sufficiently cooked meat
Trichinellosis	Parasite Lives in muscles Can be in raw (pig) meat, other meat possible Symptoms in humans: nausea, fever, muscle pain Present in arctic fox, polar bears, wolverine,…
Sarcoptic mange (Scabies) (Räude/Krätze)	Caused by mites Many animals (mainly carnivores) affected Highly contagious Can survive in warm dens Circulates in red fox population Usually not deadly by itself for animals
Implications of diseases on carnivore populations in Scandinavia compared to human hunting	For most carnivore species in Scandinavia hunting is a much much bigger threat for healthy population sizes than disease
Some problems for wildlife with climate change	Temperature dependent sex determination in reptiles Mismatch (for example between reproduction cycle and vegetation period) Drought Struggles to regulate bodytemperature Decrease in temperature fluctuations in the arctic
Three stages of disease control	- Prevention (primary prevention) Inhibiting the introduction of a disease into an area, herd or shelter - Control (secondary prevention) Disease is already present, but we try to reduce the problem to a tolerable level - Eradictaion Complete eradication of the pathogen from the geographic area
Three approaches to prevention (no details)	- Target the host - Target the transmission - Target the reservoir
Targeting the reservoir	Removal of (reservoir animals) - Test and slaughter - Stamping out: (slaughter infected, potentially infected and contact animals) - Traceability systems: Identify infected animals in the trading and movement chain - Population reduction: avoid contact frequency Removal of contact points, waste management, rotational grazing to reduce danger of parasites
Targeting the vector	5. Target the vector Biological control oft he vector, by reducing the natural population of it by using natural predators and other means 6. Target the vehicle Neutralize pathogens in vehicle and prevent introduction into vehicle (pasteurization of milk, food safety and hygiene) 7. Reduce contact potential (mosquito repellent, enough space for livestock, reduce livestock-wildlife contact,..)
Targeting the host	Increase host resistance Through immunization
4 phases of eradication	Phase 1: planning, training, infrastructure development etc. Phase 2: actual disease reduction including active surveillance Phase 3: “mopping up” the last few cases, huge effort to find the last cases Phase 4:implementing procedures to prevent re-introduction and develop systems for early warning
African swine fever	Enveloped DNA virus with high robustness -No vaccination, only prevention is biosafety -Affects all pig species -Deadly for domestic pigs, lower mortality in wild boars -Symptoms in house pigs: high fever, diarrhea, vomiting, abortion, bleeding, reddening of the skin, sudden death -Transmission through direct contact, tick bites, garbage, contaminated boots/tools,… -virus in blood, urine, feces, saliva,…(all body fluids) -high environmental resistance of virus -huge economic impact -spreading in Europe and asia (long distance jumps) -very much a human driven disease
Avian influenza	caused by the Influenca A virus - highly contagious and infectious - high mutation rate - no vaccination yet, only prevention is biosafety - high and low pathogenic variants: low cause lower egg production and misshapen eggs, respiratory signs, lethargy, decreased feed and water consumption; high causes respiratory/neurological signs, sudden death, oral and nasal discharge, skin issues - wild birds usually asymptomatic or mild disease, mainly waterbirds ( however, threat for some species/populations) - spread through global trade and migratory birds - seasonality - large zoonotic potential
5 stages of crisis management cycle	Prevention, Mitigation, Preparedness, Response, Recovery
Blue tongue virus (BTV)	viral infection transmitted by biting midges - virus reproduces in midges, then spreads - affects all ruminants - most dangerous to sheep, not very dangerous to cows (can be deadly in few cases) - symptoms: fever, oral and nasal erosions ulcerations - lameness, weakness, depression, weight loss, excessive salivation, nasal discharge, abortions,.. - vaccine is available - not dangerous to humans, can still eat meat and drink milk - can be detected by analyzing milk and blood samples and midge surveillance
Tularemia	- caused by bacteria - rodents, rabbits and hares are the main reservoir hosts - can infect humans, mainly through insect/tick bites and infected water (but also dust, blood, uncooked meat…) - highly contagious - symptoms: skin rashes, flu-like symptoms, pneumonia, swelling of lymph nodes
TBE	- Virus transmitted by ticks - Many times, no symptoms - Flu like symptoms - Can affect central nervous system (in 5-15% of cases) headache, dizziness, can lead to (long lasting) paralysis and death - Vaccination available
Hantavirus	- Viral disease (zoonosis) - Symptoms: in humans often without symptoms, however possible: high fever, muscle aches, severe fatigue, trouble breathing - Symptoms usually 1-5 weeks after exposure - Transmittion by rodents (bites), their saliva, urin and the dust from their feces

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Wildlife In The Anthropocene One Health

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