Exam 3 Flashcards
White-nose syndrome in bats is a ____ pathogen.
Fungal.
White-nose syndrome is currently found in…
33 states and 5 Canadian provinces, and is still spreading at an alarming rate.
Why do we care about bats?
They are pollinators and protectors of certain crops. Also, we care because we don’t want living things to die…obviously.
What causes White-nose syndrome? How does it kill?
Pseudogymnoascus destructans, or Pd destructans for short.
Pd destructans kills by causing dehydration and rapid heat loss, and increasing arousal (thus coming into contact with other bats more, spreading the disease) and causing an inability to feed. This disrupts hibernation and wing physiology.
Pd destructans is very environmentally persistant, meaning it can stay in reservoirs in the environment pretty rigorously.
How is WNS spread? Where did it come from?
It originated somewhere in France in 1918. People think it can be spread by raccoons, moths, and even mosquitos. However, it is primarily spread across the landscape by bats.
How are some ways people are mitigating the spread of WNS?
1) Biocontrol, by spreading certain bacterias that attack or inhibit Pd destructans.
2) UV light, which has been shown to weaken Pd as it is extremely sensitive to UV light.
3) Vaccines, obviously, that gives populations resistance to the disease.
What are prions?
“Proteinaceous infectious particles”.
Explain how PRPC –> PRPBSE, PRPCWD, or PRPSC.
PRP stands for “normal prion protein”. These proteins do not have a role that has been discovered yet, but the gene is not required for survival. It is usually a glycoprotein normally found at the cell surface in the plasma membrane.
When a PRPC meets a PRPBSE, it converts it to the abnormal form.
BSE, CWD, and SC are the diseases the misfolded proteins cause.
How are prions transmitted?
Firstly, a misfolded protein shows up (we dont entirely know how, as they aren’t living and they break a lot of fundamental biological principles).
This protein bumps into another and converts it to the misfolded form, which are highly resistant to most disinfectants, UV, heat, and radiation.
What is TSE?
Transmissible Spongiform Encephalitis. It affects the CNS, and can affect even humans.
It is caused by ingestion or inoculation, and is ALWAYS fatal. Slow progression.
How is TSE studied in mice?
1) 2 mice, one with PRPc and one with the gene knocked out (PRPko) were infected with PRPsc. Only the mouse with the PRPc gene were affected, meaning that without PRPc, PRPsc cannot spread.
2) Mice were expressing ovine, human, and bovine PRPc. When infected with PRPsc, only the ovine-expressing mouse was affected. We can study species barriers to transmission this way.
How do we diagnose TSE using histopathology?
Using “post mortem definitive diagnosis” - AKA, looking at the brain. It has a spongy-like appearance, vacuolated (exploded) neurons, plaques surrounded by vacuoles.
How do we diagnose TSE using immunochemistry?
Using antibodies specific for the prion protein antigens, which bind to it and stain it a certain color in tissue sections.
What is scrapie? What are the clinical signs?
A prion disease in sheep. It causes weight loss with a ravenous appetite, behavioral changes, excessive itching, rubbing, wool pulling and lip smacking and changes in gait.
Is there a genetic predisposition to scrapie?
Yes, it seems that the several variants of the PRNP gene can affect susceptibility or resistance to scrapie, and can also affect how long the disease incubates for.
What is BSE?
Bovine spongiform encephalitis. Depending on the dose ingested, the incubation period can be anywhere from 2-8 years.
The average age of onset tends to be 5 years.
Clinical signs include excitability, nervousness and aggression, sensitivity to noise, slow movement, and tremors.
What was the timeline of BSE outbreaks in europe, US and Canada?
1986, the first case confrmed.
1988, UK banned meat and bone meal from cattle feed.
1989, USDA bans importation of meat from countries with BSE.
1997, US & Canada ban ruminant products fed back to ruminants.
2001, EU ordered mandatory tests on cattle destined for slaughter.
2003, BSE found in washington state.
As of 2018, 6 cases of BSE in US. All have been sporadic and atypical.
What is Kuru?
Identified in New Guinea in 1900s, it was found in a tribe practicing cannibalism.
Women, children, and eldery infected 5x as often as men. The incubation period is also over 30 years.
What is CJD?
Creutzfeldt-Jakob disease. Age of onset usually 65 uears and kills in 4.5 months. It tends to be sporadic, but can also be inherited.
What is variant CJD?
CJD from consuming BSE contaminated foods, with the first case appearing in the UK in 1995.
Little is known, incubation period not known, nor is dose required. 28 years average age of onset, with duration being 13 months.
Possible genetic component, as all human cases have been homozygous at codon 129 of PRPC.
Initial symptoms are depression and schizophrenia-like psychosis, unsteady movements, progressively immobile and mute. No treatment available.
What is CWD?
A prion that affects deer, found in NA, Norway, and South Korea. Orginal epicenter in northeasternish Colorado.
Affects deer, no cases of human transmission YET. Does not YET appear to infect cattle.
Incubation is 12-64 months, but varies. Ingestion of prion from dirt or grass or contact with bodily fluids believed to transmit. Also believed to remain in the environment for long periods.
Causes weight loss, lack of coordination, drooping ears, and hypersalivation.
What are the differences in CWD infections in free vs captive populations?
Free rangings had slow proliferation, stable prevalence, and slow rates of diffusion, with a 10-15% infection rate.
Captive hers had faster dispersion, with an up to 79% infection rate. They can
What are some other examples of TSE?
Mink encephalopathy in MI and WI in 1947.
Feline encephalopathy, exclusively in the UK.
Exotic ungulate encephalopathy, exclusively in UK.
What are some ways to prevent TSE?
1) the FDA “animal feed rule” which bans using mammalian proteins as a source of food for ruminants.
2) 1989 import restriction on countries with BSE.
3) BSE testing of all rendered animals.
4) Surveilance, CWD testing, Scrapie National Eradication Program
What are some current issues with TSE?
Theres no reliable antemorten test.
Its difficult to study due to long incubation times.
Its very difficult to control spread in wildlife and environment.
Its risk to humans is unclear, but has huge and widespread economic impacts.
What makes the ecology of WTD so special?
Subspecies that occupy many varied niches and habitats and the fact that they are highly adaptable.
They are edge species.
Local food supplies are fundamental to pop dynamics: forested areas w/ lots of forage species means higher densities of deer. High pops can degrade communities and destroy the habitat for other wildlife species.
What are characteristics of captive deer populations?
They are often bred for specific traits, lke large racks, meaning herds may have genetically similar animals.
They have very high stocking densities and can also still interact with free-ranging populations.
Infected with CWD at higher rates and can also spread to wild populations.
What are difficulties of controlling CWD?
Eradication once it has been established in an area is actually impossible with the current tools available.
What is bovine tuberculosis and how does it infect deer?
A respiratory infection caused by M. bovis and M. tuberculosis. Spread primarily through exchange of repiratory secretions, and can remain in the environment for weeks to months.
It is a chronic and progressive disease that causes absesses, nasal discharge, and swollen lymph nodes.
It is diagnosed with cultures, as necropsy findings are not always present. No effective vaccines or treatment available.
How is bovine TB controlled in domestic animals?
1) carcass inspections at slaughter.
2) Live animal testings
3) TB being eradicated when found in herds.
How is Bovine TB controlled in deer?
Deer can spread to uninfected cattle, so limiting shared feeding & direct contact helps.
Reducing deer density in designated TB management zones.
Elliminating baiting of deer.
Continual monitoring of bovine TB by testing hunter-harvested deer
What is Hemorrhagic disease?
An orbiviral disease of ruminants.
Transmitted by Culicoides spp. midges. Includes BTV and EHDV.
Causes infections, chronic lameness, and wasting in cervids.
They are expanding northwards and increasing in frequency.
How do orbiviruses affect domestic animals?
They cause fever and depression, nose discharge, redness and swelling of muzzle, swelling of tongue, and abortion.
Causes economic losses, such as damaged wool and decreased milk production.
What are some current issues with WTD?
1) they have suburban and urban populations that are virtually uncontrolled without human intervention.
2) current management is controversial.
3) captive deer farms are also controversial and pose regulatory difficulties.
4) deer pop can be DRAMATICALLY affected by several infectious diseases.
5) deer can be subclinically infected by other species, but spread the agents to other species.
What is happening to herpetiles?
Ectotherms are more vulnerable to certain types of diseases, and they are emerging at an alarming rate for unclear reasons.
Some of the largest disease related population declines ever have been in herps.
What is snake fungal disease?
A skin infection caused by the fungi known as O. ophiodiicola.
The majority of cases are mild, but can vary in severity. Can also be referred to as “hibernation sores”.
Only poses a threat to a few pops, and may be a native pathogen. Climate change may play a role here.
What is ranavirus?
Discovered in the 1960s, in the 1990s became a major pathogen of amphibians that causes massive population die-offs in the larvae.
The origin is unknown and may be spreading due to deteriorating environmental conditions.
Has been found in turtles in NA recently.
What is Chytrid fungus?
Caused by the fungus B. dendrobatidis and was found in the 1990s in australia, but conflicting theories of the origin.
Now has a global distribution due to humans spreading the disease.
It causes skin infections and persists for a long time in the environment. Has caused a believed 30 extinctions in species in Panama alone.
What are tumors in sea turtles caused by?
A papilloma virus that is found worldwide now, but the reasons for the emergence are unclear.
What are Perkinsus-like infections?
First discovered in 1999, they cause massive mortality events in tadpoles. They are caused by a protist.
How are diseases in aquatic animals different from terrestrial?
THINK AQUATIC!
Changes to the environments, such as water quality, can cause major acute/chronic issues.
Infections and noninfectious pathogens are more ubiquitous, meaning more widespread effects.
Habitat destruction, like urbanization, wetland elimination, and fish farms play a role.
What are some examples of chemical pollutants in aquatic habitats?
1) pesticides and herbicides, which can function as endocrine disruptions and chitin inhibitors
2) sewage and dumping
3) industrial spills, PCBs
4) changes in salinity, dissolved oxygen, and PH due to human and natural events.
How does climate change affect aquatic habitats?
1) warm water pathogens becoming transmissible to cold water aquatic species.
2) more microogranisms thriving in warmer water temps.
3) extreme weather events contribution to environmental perturbations.
What contributes to the surge in coral diseases?
1) habitat degredation, causing biological stress.
2) bleaching, or loss of zooxanthelle, due to bacterial infections, salinity changes, and increased temp/UV light.
What are examples of coral disease?
1) black band disease (caused by cyanobacteria)
2) white band disease
3) white plague (bacterial?)
4) yellow blotch (unknown cause)
What is sea star wasting disease?
A disease caused by a densovirus causing massive mortality in sea star populations, possibly encouraged by global warming.
What are the economic impacts of shrimp diseases?
Can cause 50-95% mortality in US shrimp farms, and can cause a 1 billion dollar impact annually.
What are some examples of shrimp disease?
1) Taura syndrome virus, found in the Taura river in ecuador.
2) White Spot syndrome, caused by a Baculovirus)
3) Yellow head virus, found worldwide now, but found first in the 1990s. Causes high mortality in Juveniles, and survivors are chronic carriers.
4) Vibrio species, the leading cause of death in humans related to seafood consumption.
What are lobster diseases?
In 1990, a massive mortality in lobsters (70% decrease!)
Possibly cause by Vibrio sp. or Aerococcus viridans.
Associated with warming water temps/
What are oyster diseases?
Mostly parasites:
1) Perkinsus marinus, which causes the most mortalities in warm temps.
2) Haplodporidium nelsoni, a protozoal parasite, that causes 90-100% mortality in juveniles.
What is Mycobacteriosis?
A fish disease that is zoonotic, caused by atypical Mycobacteria sp.
What is Viral Hemorrhagic septicemia?
An accute-to-chronic, highly contagious viral dfish disease which is currently expanding in range.
Caused by a rhabdovirus, an endemic european salmonid virus that has spread to 42+ non-salmonid species.
Transmitted by urine, feces, and sexual fluids, and mortality occurs at 37-50 degrees.
What are Amphibian Malformations caused by?
Ribeiroia ondatrae, a parasitic fluke that attacks limb tissues.
The 1st intermediate is in aquatic snails, where it undergoes asexual reproduction.
the 2nd is in amphibians.
the definitive host is inside of waterfowl, where it undergoes sexual reproduction
What are some effects of Eutrophication on amphibian malformations?
More nutrient loads =more snail intermediate hosts = more ribeiroia ondatrae = more liklihood of amphibian infection.
What is Salmonellosis in red-eared sliders?
It causes severe diarrhea and cramping in humans.
In 1970, was regulated by restricting the sale of sliders to those with a carapace of 4 inches.
What is fibropapillomatosis?
A herpes virus causing decreased immune response in green sea turtles.
High prevalence in disturbed ocean habitats due to red tides, pollution, etc.
How has global warming affected polar bears?
Has caused a pop. decline by about 40% since 2001.
Due in part to:
1) drowning, due to being forced to swim abnormally long distances
2) starvation, due to seals becoming more and more inaccessable. They have been moving more and more into towns and scavenging garbage.
What is Erysipelas?
Caused by the bacterium Erysipelothrix rusiopathiae, it is a disease of pigs worlwid that also affects cetaceans, primarily dolphins.
Transmission could be due to dumping slaughter house materials into the ocean.
Comes in 2 forms: peracute (high mortality) and skin (grey plaques on skin)
What are some reasons sea otter population has declined by 70%?
Infectious diseases, like toxoplasmosis gondii, or industrial chemicals like PCBs.
What are HABs?
Harmful algal blooms, caused by dinoflagellates and diatoms which secrete toxins that can become aerosolized.
What is Red Tide?
Caused by Karenia brevis, they secrete brevetoxin, which is a potent neurotoxin.
Exacerbated by agricultural runoff, such as fertilizers.
What are symptoms of Red Tide?
Inhalation can cause irritation, congestion, hemorrhage, and also cause massive fish and bird die-offs. Has killed 10% of the manatee population since 1996. Has also killed hundreds of bottlenose dolphins.
Can also cause Neurotoxic Shellfish Poisoning in humans.
How many marine animal deaths were there from Jan 1 2018 to Sept 18 2018?
- 50 dead dolphins from tampa to naples
- 350+ sea turtles
- 115 manatees
- 1 whale shark
- 100 tonnes of fish and birds
Why are endangered species prone to extinction?
- genetic issues like inbreeding and finding mates, like in the Florida panther
- disease issues, as small populations can become completely extirpated by disease, like measles in golden lion tamarins.
Why are small populations more vulnerable to disease?
- individuals in isolated populations may not contract endemic diseases.
- pop may be immunologically naive and at risk for epizootics
- diseases may depress reprocution rather than just cause deaths, causing a hidden impact on population
- lack of genetic diversity may increase disease risk
How does loss & fragmentation of habitat affect endangered species?
- conservation of wildlife primarily for human use causes human-made “island ecosystems”
- island species are more vulnerable, african wild dog as an example
- they require vast ranges for hunting prey, but human encroachment and fragmentation causes island populations and allows contact with domestic dogs, which can cause canine distemper and rabies.
- mojave desert tortises getting crushed by vehicles or shot
How does increased contact between humand and wildlife affect endagered species?
- increases zoonotic and anthropozoonotic disease transmission
- rabies, bovine TB transferred back and forth
- gray wolves on isle royale nearly wiped out by canine parvovirus
How is global warming affecting endangered species health?
warming trends can change rainfall patterns and influence epidemiology of vector borne diseases, like avian and human malaria.
How does environmental pollution affect endangered species?
- can cause low level, chronic toxin exposure.
- endocrine disruptors, PCBs (which affect reproduction), cause emerging diseases like chytrid fungus
How do you manage disease in endangered populations?
Difficult, but possible.
1) preserve/protect ecosystem
2) limit human and w=omestic wildlife interactions
3) remove causative problems like poaching and pollutions
4) vaccination is difficult but possible in small populations
5) translocation of organisms to a viable or safe habitat, but may introduce to new diseases
What are some issues associated with animal translocations?
1) diseases transmitted by asymptomatic hosts, like canine distemper in black-footed ferrets.
What are some pros and cons for captive propogation of endangered species?
Pros: -produce stock for reintroduction -preserve genetic variability -provides stock for research -public education cons: -need a successful captive pop -need to successfully reintroduce -need funds -may aquire diseases -diverts attention from long-term, in-field solutions - physiological compromise due to abnormal diets, human exposure, etc.
Why was the reintroduction of red wolves so successful?
300+ wolves were successfully bred in captivity.
In 1987, released at alligator river refuge, and the current population is 100+.
in 1991, released in smokey mountains, but the last 2 were removed in 1998. Parvovirus killed pups and human encroachment was an issue.
Increased tourism helped the area.
Current issues are interbreeding with coyotes and gunshot deaths.
Why are recoveries of bird populations rare?
Predation, power line collisions, gunshots, chemical spill risks, disease-related mortality is not well documented.
What are some health concerns for whooping cranes?
Bacterial: mycobacteriosis, salmanellosis
fungal: aspergillosis
parasitic, toxicological, antrhopogenic factors, etc.
What is Disseminated Visceral Coccidosis?
E. gruis or E. reichenowi, causes a particular risk to chicks in wild birds, can cause pneumonia, lesions in organs and tissues, etc. Treated w/ environmental management and Monensin.
What is Avian mycobacteriosis?
M. acium intracellulare comp. They are ubiquitous in soil and water, but cause debilitating infections. Can remain infective for a long time.
What are the goals of Whooper reintroduction?
- improve fitness
- do not translocate pathogens with the release of birds
- do not interfere with the hands off nature of costume rearing
- collect relevant health measures of cranes following release
How much has wisconsin warmed since 1950?
1-3 degrees F, and it will warm by 4-9 degrees by mid-21st century.
How does global warming affect mosquitos?
The warmer it gets, the shorter the development time of mosquitos, meaning that mosquitos become malaria infectious sooner.
How does global warming affect Zika/ Dengue?
Zika is optimized for high temps. So is dengue. Thats why they co-occur with el nino, which causes higher temps.
What are some ecological impacts of dams?
Mosquitos like shallow, slow moving water. Rivers and streams are too swift, and too deep & clear.
What are some diseases affected by deforestation?
1) Kyansanur Forest disease, a tick born arbovirus due to lantana thickets replacing original forest.
2) yellow fever, with a sylvatic cycle, rapid emergence in Aedes in cities poses risk for large epidemics.
3_ mycobacterium ulcerans, which is surging due to freshwater bacterial biodiversity
When was aids first documented?
1959, when a Bantu male was found to be HIV positive in a serological survey.
When did the HIV pandemic start?
Late 70s, early 80s. It was characterized and isolated in 1984, and caused more than 20 million deaths, with half the cases being in sub-saharan african.
What are the differences between HIV 1 and HIV 2?
HIV one: more virulent, east-central africa. M N O clades, with multiple subgroups
HIV two: west africa, less virulent, distantly realted to HIV1 and low sequence similarity.
How does the Sooty Mangabey relate to HIV?
They are often eaten and kept as pets, and are natural hosts to SIV, which is a very close relative of HIV-2.
What are Lentiviruses?
HIV-1 and other relatives. SIVagm are transmitted between Cercopithecus species, and have been spreading west to east.
What is SIVcps?
SIVcpzANT was the first to be characterized and looked like a divergent HIV-1.
SIVcpzGAB was found in 2 captive chimps in west africa that were positive for HIV.
SIVcpzUS from a wild chimp shipped to USA.
SIVcpzCAM from 2 captive chimps in cameroon.
How do chimp subspecies differ?
West african chimps are the most divergent. All chimp subspecies are geentically distinct.
Easter chimps are genetically homogenous, and similar to humans in their levels of diversity.
The central subspecies are infected by SIVcpz at prevalenes between 29 and 35%/
A new subspecies in Nigeria exists, and are related to the east and central subspecies.
What are the possible origins of HIV-1 M and N?
They are very closely related to SIVcpz from cameroon, with pop of chimps there harboring it at high prevalence.
Bushmeat is also rampant in Cameroon.
It could potentially be from this area of high human-primate contact.
What is SIVgor?
A new SIV found in gorillas, and closely related to HIV-1.
HIV O and P may have originated through this strain.
Why are there so many primate EIDs?
1) biological similarity in receptors and immune systems
2) ecological overlap w/ anthropogenic disturbance and shared activity spaces
What is so special about Kibale?
A fragmented forest, which mean sit affects primate behaviour, ecology, and demographics. It reduces biodiversity. Increases habitat use overlap between primates and people.
How were Human/chimp microbial transmissions studied in Kibale?
3 populations - people from local villages, kibale chimps, and people employed in tourism in Kibale.
3 fragments with different levels of disturbance.
There was found to be genetic similarity between human and primate bacteria in three forest fragments, with the most disturbed being the most similar.
What was a summary of interview findings in Kibale?
Most people didnt consider zoonotic disease a health concern. they focused on structural barriers to health, such as poverty, healthcare access, etc.
