Infectious Disease and Primate Conservation

Question 1

What are pathogens classified as ?

Answer 1

Microparasites and Macroparasites

Question 2

What is an infectious disease ?

Answer 2

PPT definition - Illness due to a pathogen or its toxic product , which arises through transmission from an infected person, an infected animal, or a contaminated inanimate object to a susceptible host

Simplified - there has to be a pathogen or another organism carrying the disease

Question 3

Are all organisms harmful?

Answer 3

Many organisms live in and on our bodies. Normally harmless or even helpful, but under certain conditions some organisms may cause disease

Question 4

Are infectious diseases spread directly or indirectly?

Answer 4

Infectious diseases can spread directly or indirectly from one individual to another

Question 5

What is a parasite ? What are two examples found in the wild?

Answer 5

A parasite is an organism that lives in or on another host. A parasite gets its food from the host or at the expense of the host. It can cause damage to the host.

Examples
1. Bears have tapeworms attached to them
2. A howler monkey has butt flies that burrow in their skin and hatch after

Question 6

What are 4 types of microparasites ?

Answer 6

4 types of microparasites are
1. Virus
2. Bacteria
3. Fungi
4. Protozoa

Question 7

What are examples of the 4 microparasites?

Answer 7

Examples in the same order
1. Virus
- Ebola
- COVID
- Flu (Influenza)
2. Bacteria
- Black plague
- Hansen’s Disease (Leprosy)
3. Fungi
- Yeast Infections
4. Protozoa
- Malaria
- Giardia
- Toxoplasmosis

Question 8

What are two important facts about microparasites?

Answer 8

• They reproduce inside their hosts on rapid timescales, much shorter than their hosts’ lifespans
• Short term infections that can result in death or development of immunity

Question 9

What are two facts about protozoa?

Answer 9

• Go through different hosts at different life stages
• Protozoa has a very complex life cycle

Question 10

What are two types of Macroparasited?

Answer 10

These are parasites we can see.
1. Helminths (flatworms, roundworms)
2. Anthropods* (more important as vectors)
- Anthropods are vectors and are not the disease, they
are the ones carrying the disease to the host

Question 11

What are two important facts about Macroparasites?

Answer 11

• They are larger, longer-lived, and rarely complete their
  life cycle within a single host
  *THEY HAVE TO GO THROUGH DIFFERENT
  HOSTS
• For these pathogens, the host’s immune response is
  often incomplete or short-lived, resulting in persistent
  infections and continuous re-infection
  *Body will try to fight it but it will keep coming back

Question 12

What disease is caused by Trematodes?
What do you know about the life cycle about Trematodes (flatworms)?

Answer 12

• Schistosomiasis, also known as bilharzia, is a disease caused by parasitic worms.
• The life cycle starts when eggs are in human feces/urine. It is when people use the lake for excretory purposes and the eggs are hatched in water.
• It is then released from the snail in water. If you spend too much time in the water it can get absorbed into the skin. You’d have to spend 30 seconds in the water.
  -This is very common in Madagascar

Question 13

How are zoonotic diseases transferred?

Answer 13

There are two ways

Zoonosis/ anthropozoonosis : infectious disease that has jumped from a non-human animal to humans
- animals –> humans
- Example: COVID

Zooanthroponosis : Disease transfer from humans to other animals
- humans –>other animals
- Example: Leprosy in primates came from human
transmission

Question 14

What form can Zoonotic diseases be in ?

Answer 14

Pathogens may be bacterial , viral or parasitic, or may involve unconventional agents

Question 15

Why are zoonotic diseases a major public heath problem ?

Answer 15

They represent a major public health problem around the world due to out close relationship with animals in agriculture , as companions and in the natural environment

Question 16

What are the 4 ways zoonotic diseases are transmitted and examples of each ?

Answer 16

Airborne diseases
- caused by pathogenic microbes small enough to be
discharged from an infected person via coughing ,
sneezing , laughing, and close personal contact or
aerosolization of the microbe
- Simplified : cough, speak or sneeze to expel saliva
particles

Vector borne diseases
- infections transmitted by the bite of infected arthropod
species
- Simplified : bug carries the disease to the host

Food-borne diseases
- can be transmitted via consumption of animal products,
e.g. chicken or fish
- simplified : food poisoning because the food was
contaminated with bacteria or protozoa

Direct contact
- with animals, such as animal bites or touching of infected
animals
- how a lot of diseases started. Ex: rabies, SARS, COVID,
HIV

Question 17

What are 4 reasons why emerging zoonotic diseases occur?

Answer 17

-live animal markets
ex: SARS,COVID-19,Avian influenza
-wildlife hunting
ex: HIV, Ebola
-intensive wildlife farming
ex: COVID-19 , Rabies, Avian Influenza
-domestic animals
ex: Hendra, Nipah, Avian Influenza

Question 18

Chain of Infection- What is a reservoir ?

Answer 18

A reservoir is the habitat in which the agent normally lives ,grows, and multiplies.

Reservoirs include humans ,animals , and the environment.

Simplified - Transmission ???

Pathogen lives in another species or a host and will leave the reservoir which is conveyed by some mode of transmission like a cough.

Disease has to leave somewhere and has to go somewhere to cause the disease via transmission to make it to another host. It has to be the right port of entry. Example : HIV is sexually transmitted therefore transmission would not occur via a cough.

Question 19

Chain of infection- what is an amplifier?

Answer 19

Individuals or systems that provide the necessary conditions for pathogens to multiply rapidly and to become major sources of transmission to the wider community

Once the pathogen gets to the amplifier it multiplies rapidly

Question 20

Chain of infection - What is a susceptible host? What does susceptibility depend on ?

Answer 20

A susceptible host is the final link in the chain of infection.

Susceptibility depends on 3 things which are : genetics, specific immunity (antibodies) and non specific factors.

Specific immunity - susceptibility depends on available antibodies that can result in lower susceptibility. For example a person who is immunocompromised has higher susceptibility

Non-specific factors are skin, mucous membranes, cough reflex , alcoholism and malnutrition.

Question 21

What are three factors involved in the chain of infection ?

Answer 21

Reservoirs, amplifier and susceptible host

Question 22

What is sickle cell disease?

Answer 22

Sickle cell disease occurs when there is a change in the amino acid sequence.
Red blood cells in patients with this disease will result in long red blood cells.
This can cause clotting in the blood.

Written on the slide “ The change in amino acid sequence causes hemoglobin molecules to crystallize when oxygen levels in the blood are low. As a result, red blood cells sickle and get stuck in small blood vessels.

Question 23

Is sickle cell disease infectious? What is an advantage of sickle cell disease ?

Answer 23

Sickle cell disease is not an infectious diseases, it is a genetic blood disorder.

People with sickle cell disease provides protection against malaria.

Question 24

Does the reservoir of a pathogen get ill and explain why?

Answer 24

Monkeys are reservoirs where they carry the disease but the disease has no effect on them .

As reservoirs there is a long evolutionary relationship with pathogen.
Rarely gets ill because it has evolved antibodies

Question 25

What is a spill over event? how does it occur?

Answer 25

A spill over event goes from one species to the next. The cause is poorly understood. Sometimes " amplifier host": infectious agents/ pathogens multiply to high concentration

Question 26

What is the consequence in a new host?

Answer 26

The consequence is more severe in a new host because it has not evolved resistance. In a spill over event it moves from one species to another. Ex: Wildlife to humans - infection is more sever in humans as a new host because the body does not know what it is and has no antibodies to work against it. This situation occurs in both ways meaning it can go from humans to wildlife

Question 27

Why are zooanthroponosis particularly problematic for primates?

Answer 27

Through hunting or research , humans can travel further . Because we are genetically related it is most likely that the same diseases affect non-human primates as well . If non-human primates have never been exposed before they have no way to fight it

Question 28

What is density dependent disease transmission?

Answer 28

DD: the per capita contact rate between susceptible (S) and infected (I) individuals depends on the population density *transmission rates increase with density Density dependent means that if the population density is high then rate of contact will be higher

Question 29

What is frequency dependent disease transmission?

Answer 29

FD: The per capita contact rate between S (Susceptible) and I (Infected) does not depend on the population density *transmission rates do not change with density Frequency dependent disease transmission is THE SAME regardless of density

Question 30

What are examples of density dependent and frequency dependent disease transmission?

Answer 30

An example of density dependent would be COVID. If area 1 has 5 people and area 2 has 10 people it is best to go to area 1 because there is less contact. An example of frequency dependent which is =same amount of transmission regardless of density is HIV or any STI It doesn't matter how many people there are, same probability of transmission in area 1 and 2

Question 31

Can parasites drive hosts to extinction? Explain the 5 reasons why

Answer 31

It is very unlikely! * Parasites vary in their effects on primate hosts - some primates do well whereas other do not - ex : gorillas can get ebola from humans * Some infectious agents have devastating impacts on their primate hosts eg : ebola, anthrax, yellow fever * Pathogens can "spill over" from humans to wild primates and cause substantial mortality * Virus and bacteria can cause sudden die-offs - newly introduced microparasites can cause die-offs * Macroparasites can impact host population dynamics -Ex : if it affects females or younger primates it can cause a disruption in population dynamics

Question 32

Under what conditions could a parasite cause host extinction?

Answer 32

Host would be naive * if the host has never been exposed to the disease * If only a small population remains for that species, a parasite could lead to its extinction * Reduced genetic diversity - their bodies do not know how to fight it

Question 33

Can the host population decline substantially enough that other factors lead to its extinction?

Answer 33

Yes? E.g - effects of reduced genetic diversity or demographic stochasticity

Question 34

What are the threats of infectious disease to biodiversity ?

Answer 34

Infectious diseases have been implicated in a number of species declines and extinctions * 4% extinction * 8% critically endanger Diseases are usually one of multiple factors influencing extinction risk. IUCN lists 22 frog species are becoming extinct due to chytridiomycosis . This is fungal infection that is transmitted by frogs spending time in water

Question 35

Why are infectious diseases a particular threat to primates?

Answer 35

Because primates live in close proximity and live in a big group. If someone has a parasite or a disease everyone is in close contact.

Question 36

What are the 6 conditions infectious diseases are more likely to be a threat to primate hosts ?

Answer 36

1. Overall host genetic diversity = low -Low genetic diversity 2. Few barriers exist that stop the spread of an infectious agent/pathogen -Not many barriers meaning ? 3. Introduction of infectious diseases for which hosts lack immune responses 4. Group-living , social behaviours -Aggressive behavior or any interaction of physical touch - social behaviours or group living 5. Infectious agent exists in a reservoir host that is relatively less affected by the organism -Reservoir hosts carry a pathogen and they either evolve or get use to it. Organisms carry the disease but are not affected. The pathogen will become pathogenic in a new host 6. Infectious organism can survive in the environment ( and remain infectious) for long periods of time.

Question 37

What is the consequence of infectious disease?

Answer 37

* When there is a disease , it is natural for population to decline * density dependent transmission rarely leads to extinction * Density dependent - keeps high density populations at check. With too many individuals = likely that disease will cause a decline in population * infectious diseases are part of a healthy ecosystem

Question 38

Why is density dependent transmission less likely to lead to host extinction than frequency dependent transmission?

Answer 38

* Lots of individuals will die due to density dependent transmission because of close contact * Because density will decrease less interaction will occur.

Question 39

A density dependent disease transmission occurs in a population that declined from 100 to 10 individuals. What will happen to the risk of contracting the disease?

Answer 39

It will decrease.

Question 40

What about if those 10 remaining individuals lived in the same social group - will the risk of contracting the disease increase, decrease or stay the same?

Answer 40

The risk of contracting the disease will increase.

Question 41

What are two views of disease transmission that may affect evolution of sociality ? Explain both

Answer 41

Traditional view : selects for evolution of solitary lifestyle , smaller group size or fission-fusion ( when a big group divides into a smaller group. * To avoid disease - it is best to live alone, have small group sizes or fission fusion Recent view : some microbe transmission is beneficial. Ex - social transmission of gut microbiome improves digestion of leaves. * Not all microbes are bad for example gut microbiome improves digestion of leaves

Question 42

How did the Ebola virus disease spread?

Answer 42

Spreads via direct contact (through broken skin or mucous membranes)

Question 43

What was the source of the Ebola Virus Disease?

Answer 43

Source = African fruit bats.

Question 44

What population acts as: 1. Reservoir 2. Amplifier 3. Final host

Answer 44

1. Reservoir =African fruit bats 2. Amplifier = Chimpanzees, Sooty mangabey and Gorillas - When a fruit bat eats a fruit and it drops to the ground. The ape can eat the fruit and obtain Ebola 3. Final Host = humans got it from the 3? - Through activities like hunting, touching a dead gorilla could cause transmission of Ebola because of skin contact.

Question 45

What are the two main hypotheses of ebola transmission in apes? Are these two mutually exclusive?

Answer 45

Two main hypotheses Social hypothesis : ebola virus is transmitted socially and spreads in a wave-like fashion among hosts. Close social contact. Reservoir hypothesis : the virus is primarily maintained and spreads in a reservoir host, with occasional spill-overs to apes (and some other mammals They are NOT mutually exclusive meaning these two events cannot occur simultaneously it is either one or the other.

Question 46

Ebola and apes - how many gorillas died from ebola? What was the population decline? Is it still occuring?

Answer 46

* 2006 report --> 5000 lowland gorillas died from the Ebola virus at 2 sites in Congo * Up to 1/3 of the gorilla and chimp population declined * the disease has continued to sweep across Africa

Question 47

What is the solution for the Ebola Virus affecting apes?

Answer 47

Solution : vaccination but this is costly/expensive and logistically challeging Vaccine against ebola is expensive and hard to do Other people think that money can go towards other conservation actions

Question 48

What did Caillaud et al, 2006 notice in regards to Gorilla susceptibility to Ebola virus?

Answer 48

He noticed a drop in gorilla population then there was an outbreak in disease in villages nearby.

Question 49

Caillaud et al, 2006 -How many human Ebola outbreaks were there and where? How did they occur ?

Answer 49

* Since 1994, 9 human Ebola virus outbreaks in East Gabon (Central Africa) and NW Congo * Most originated from handling carcasses found by local hunters

Question 50

What species did Cauillaud et al., 2006 monitor and where ? How many gorillas died ? Where was the death rate the highest ?

Answer 50

* Monitored Gorilla gorilla gorilla population at National Park in Congo * 95% gorillas in the population died in 2004 * The death rate WAS HIGHEST AMONGST GORILLAS LIVING IN GROUPS (97%) * Solitary male gorillas were at least two times more resistant to infection (77%) . - Females will live in groups. Only Adult Male gorillas disperse. - Solitary males were unaffected because of no close contact and transmission took longer

Question 51

In the study done by Cauillaud et al , 2006 "Gorilla susceptibility to Ebola virus : The cost of sociality " what are the implications for conservation?

Answer 51

It disproportionately afects females and young individuals , which are essential for population recovery, * Females and young individuals are important for population.

Question 52

What is HIV? What was the origin of the strain ?

Answer 52

* HIV stands for Human Immunodeficiency Virus * It attacks the body's immune system * HIV infects the CD4+ T cells responsible for regulating immune response Simplified : Virus kills the cells in the body that are responsible for the immune system * Origin of strain came from Chimpanzee - Strain 1

Question 53

What is SIV? Which primate group were affected and displayed similar symptoms of AIDS? Who was the natural host ?

Answer 53

* SIV stands for Simian Immunodeficiency Virus (very similar to HIV) * There are monkeys that acts as reservoirs - meaning they are not affected by HIV * Rhesus macaques have a clinical syndrome similar to AIDS * Sooty mangabeys were the natural host

Question 54

Which primates were involved in the 3 spillover events of SIV? Who acted as the reservoirs for SIV?

Answer 54

3 spillover events Once Sooty Mangabey (SIV smm) Twice from Chimpanzees (Origin of HIV) [SIVcpz] Once from Gorilla (SIVgor) * All 4 turn into HIV just different strains * Old world monkeys act as reservoirs

Question 55

Origins of human HIV viruses - Who is naturally infected with SIVS? How did these cross over events occur?

Answer 55

* Old world monkeys are naturally infected with >40 different lentiviruses= SIVS - most wild species do okay with SIV -most primates are okay with the virus - it is just the case of rhesus macaques where the did NOT do okay * Humans and the mona monkey for HIV from Sooty Mangabey * Chimpanzee ate the mona monkey and red capped managabey which then transferred HIV to humans * Gorillas got SIV from the chimpanzees - maybe there was a dead chimp that had SIV, by exploring the body they may have obtained the strain of SIV

Question 56

What happens when SIVs cross the species barrier?

Answer 56

Several of these SIVs crossed the species barrier to affect great apes and humans, generating new pathogens

Question 57

What is yellow fever ? How is yellow fever transmitted?

Answer 57

* Yellow fever is a virus * it is transmitted through mosquito bites aka mosquito as the vector

Question 58

Where did yellow fever originate from ? How and where was Yellow fever introduced ?

Answer 58

* Yellow fever originated in mainland Africa * Slave trade introduced Yellow Fever to the Americas

Question 59

What is the mortality rate of yellow fever in humans and howler monkeys ? Where have there been recent outbreaks f?

Answer 59

* 15% mortality in humans * 90% mortality in howler monkeys. Most howler monkeys that get yellow fever will die from it. * In recent years there are outbreaks in Argentina and Brazil

Question 60

When a yellow fever outbreak occurs why are howler monkeys killed by humans?

Answer 60

* People think that monkeys are the one transmitting Yellow Fever and so people kill monkeys out of fear * They don't just kill howler monkeys, they also kill Tamarins as well

Question 61

What is the purpose of making campaigns for yellow fever?

Answer 61

* Campaigns were made to educate the community about transmission and that monkey population can signify the health of the ecosystem (INDICATORS!). * Instead use the monkeys as an early warning system. - If monkeys are dying it indicates yellow fever is in the area .

Question 62

How can you link disease with habitat disturbance?

Answer 62

* Humans are going into areas we've never gone before at an increasing rate * Transmission between species is more likely to happen when you got ot a new environment

Question 63

What are 4 reasons "Spill over events" are more likely to happen with habitat disturbances?

Answer 63

* Increased contact with animal species * Bring in human diseases * Put ourselves in contact with new pathogens * Disrupt long evolved systems - Ex: Monkeys with SIV are natural reservoirs that are unaffected because they have evolved with it. If humans bring new pathogens to monkeys it can produce a new reaction.

Question 64

Chapman et al, 2006 did a study on parasite abundance from the forest edge and interior primate groups. 1. which primates did they study? 2. how did they sample them ?

Answer 64

1. black and white colobus monkeys and red colobus monkeys . Colobus species in Kibale National Park (Uganda) 2. Analyzed 822 fecal samples

Question 65

What were the results of the Chapman et al, 2006 study on parasite abundance from the forest edge and interior primate groups?

Answer 65

* Although all monkeys all had parasites [common in wild species]. - common to have more than 1 parasite in both populations * Edge groups had more species of parasites known as **"Multi-species parasite infections" ** * Significant difference when comparing populations that lived on the edge

Question 66

Why do you think urban primates are more likelt to get pathogens versus forest edge primates ? 4 reasons

Answer 66

Urban primates are even more at risk than those at the forest edge because * Exposed to different pathogens from dogs, cats, humans and garbage. [Exposed to other animals and other animal waste] * More contact with human waste * Lots of cases of monkeys such as baboons and macaques foraging and eating garbage in South Africa and Vietnam. - Macaques are losing their fur because the garbage they eat has high conc of salt so as a result they lose their fur. * The monkeys could have higher stress living in this environment as well.

Question 67

What is the general reason how researchers and tourists are increasing the risk of disease to primates?

Answer 67

Humans transmit pathogens to primates or vice versa

Question 68

List 4 reasons how research and ecotourism are linked risk of disease to primates and explain each circumstance

Answer 68

* Close proximity for observation : Close contact with animals can produce spilover events. Occurs for research and tourists taking pictures. * Provisioning for habituation : Humans will supply primates with food so primates get use to them and eventually don't get scared which is a big problem. * Reintroduction for repopulation: When monkeys are confiscated by the police, organizations will try to reintroduce them into the wild. - Good for genetic gene flow but hard to do because primates are social animals - If you are not testing the disease the primate has or the social group has there can be transmission as well * Inadequate waste dispersal : When researchers go into the forest and leave trash. Or if people take their dogs or cows into the forest and excrete they can create an avenue for transmission, - We have to have adequate waste disposal .

Question 69

Wallis and Lee, 1999 did a study called " Primate conservation : the prevention of disease transmission". What happened ?

Answer 69

Case: Field assistant handed bananas to chimpanzees. Chimpanzees produced twins which is rare. Then all chimps died afterwards. * Chimpanzees were habituated to get use to the research assistant. * To observe how monkeys are eating you have to follow them and observe their behaviour. Most monkeys run away. * Early 1996- everyone was getting the cold/flu and chimpanzees do not do well with respiratory diseases. - 11 chimpanzees died from this group

Question 70

Wallis and Lee, 1999 did a study called " Primate conservation : the prevention of disease transmission" at Gombe National park . What happened ?

Answer 70

Case: Field assistant handed bananas to chimpanzees. Chimpanzees produced twins which is rare. Then all chimps died afterwards. * Chimpanzees were habituated to get use to the research assistant. * To observe how monkeys are eating you have to follow them and observe their behaviour. Most monkeys run away. * Early 1996- everyone was getting the cold/flu and chimpanzees do not do well with respiratory diseases. - 11 chimpanzees died from this group

Question 71

What type of disease did the link the death of chimps from the Wallis and Lee , 1999 study? How were they able to conclude that?

Answer 71

* Respiratory disease * Did not get proof that they died from respiratory disease -but knew it was related to respiratory disease * They know they are not in contact with anyone else other than sick humans. * These chimps were not scared of research assistants * Everything indicated that these chimps died from respiratory disease

Question 72

Melin et al.,2020 did a study on COVID- 19 Susceptibility on primates. Who has high susceptibility? Who had low susceptibility?

Answer 72

* Demonstrated high or predicted high susceptibility: All of the apes, African monkeys-cebaca (ALL Catarhines), and brown lemurs, Aye-Aye , sifaka * Low Susceptibility : Howler monkey, night monkey, squirrel monkey, capuchin, Mouse lemurs, Lorises and Tarsiers , galigo

Question 73

What are 4 things that can be done to make research and ecotourism safe for primates?

Answer 73

* proper handling of waste * Use masks * Avoid contact and being in close proximity * Vigilance and testing people before contact with primates. Take caution of interaction with primates. Ensure you are not sick.

Question 74

A campaign was made to keep distance from primates. Which primates were used as a measure of distance? How many were used?

Answer 74

* Pygmy marmosets are the smallest monkeys * 36 pygmy marmosets

Question 75

What are the 4 effects of biodiversity changes on disease risk?

Answer 75

* The Dilution Effect * The reverse -dilution effect * The Density effect * The amplification effect

Question 76

What is the dilution effect? Where is it not well studied?

Answer 76

* The dilution effects suggests that diverse ecological communities limit disease via several mechanisms. **The risk of disease decreases with increasing species diversity ** * More species there are mean less chances the individual has of getting it * Not well studied in tropical areas.

Question 77

Compare what happens in biodiversity rich and biodiversity poor habitats with the dilution effect.

Answer 77

* Biodiversity rich habitats: lots of host species, some do not transmit disease well, slow (Speed of ) transmission. When it is biodiversity rich there is bad transmission - less likely to get disease. * Biodiversity poor habitats: few host species with fast life histories and poor immune defense (competent hosts), fast transmission. Poor = species have short lives so these become competent hosts (good at spreading disease)

Question 78

What is the issue with the dilution effect ?

Answer 78

* This is a hypothesis how biodiversity affects transmission * More diversity- better chances the pathogen will be stopped somewhere else in high biodiversity * If disturbance occurs -organisms that are good at stopping pathogen can die * As diversity gets lower then you have higher chances of getting the disease * Issue- whatever is left is good with dealing with disturbance and disease. Less species (Biodiversity poor habitats )doesn't support the dilution effect

Question 79

What is the reversed dilution effect?

Answer 79

* The risk of disease increases with biodiversity * More biodiversity there is =higher chance of disease spread

Question 80

Compare what happens in biodiversity rich and biodiversity poor habitats with the reversed dilution effect.

Answer 80

* Biodiversity rich: lots of competent hosts which increases the speed of transmission. More biodiversity there is = higher chance of disease spread * Biodiversity poor habitats: Few host species that are resistant. As a result this slows the speed of transmission.

Question 81

What is the amplification effect

Answer 81

* The risk of disease increases with biodiversity * Amplification- more species meaning more diversity of pathogens and hosts

Question 82

What happens in biodiversity rich habitats with the amplification effect?

Answer 82

* Higher number of organisms , including those causing disease - Lots of opportunities for different hosts * More spill-over between species

Question 83

The amplification effect - what conditions increased with what type of species richness?

Answer 83

* Ape malaria increased with mammal richness * Primate parasite richness increased with primate richness

Question 83

The amplification effect - what conditions increased with what type of species richness?

Answer 83

* Ape malaria increased with mammal richness * Primate parasite richness increased with primate richness

Question 84

What are issues with the Amplification effect?

Question 85

What is the density effect ? What is an example of a condition that follows the density effect?

Answer 85

The risk of disease may vary with biodiversity depending on whether there is a : * High vector population density / high abundance of pathogen =higher disease risk * Low vector population density / low abundance of pathogen =low disease risk * Ex: Malaria - pathogen is transmitted by the mosquito (vector).

Question 86

What are 4 take home messages of Infectious diseases and Primate conservation ?

Answer 86

1. Conditions under which parasites can cause extinction are rare but they exist! Ex: Different frog species have disappeared due to fungal infection 2. There are negative effects of parasites on host populations- which depends on susceptibility , genetics and habitat 3. Close contact between humand and primates increases the chance of disease transmission both ways 4. Loss of individuals lead to :negative impact on future research , loss of income for local people and negative effects on conservation efforts.