Immunity and Infection

Question 1

global determinants of infectious disease in a herd/flock

Answer 1

exposure to infection, spread of infection within group, resistant to infection, and treatment of sick animals

Question 2

exposure to infection

Answer 2

biosecurity and eradication

Question 3

resistance to infection

Answer 3

genetic resistance to disease, colostral immunity, vaccination, environment, and nutrition

Question 4

spread of infection within group

Answer 4

stocking density, reoval of sources of contamination, isolation of sick animals

Question 5

treatment of sick animals

Answer 5

individual animal treatment, group treatment, antibiotics

Question 6

infection and immunity balance

Answer 6

factors promoting infection balance with factors promoting immunity

Question 7

factors promoting immunity

Answer 7

vaccines, limiting stress, biosecurity

Question 8

opportunistic pathogens

Answer 8

not common infection but common in weak animal groups

Question 9

highly pathogenic agents

Answer 9

cause disease in immune competent animals (EX: salmonella, pathogenic E. coli, influenza, anthrax)

Question 10

less pathogenic agents

Answer 10

cause sever infections in immune deficient, immune competent may carry infection (EX: cryptosporidium, non-pathogenic E. coli)

Question 11

what groups would be susceptible to opportunistic infections?

Answer 11

young animals, immunosuppressive drugs, pregnant animals

Question 12

the major components of defense

Answer 12

physical and chemical barriers to infection, innate immune responses, and acquired immune responses

Question 13

first line of defense

Answer 13

physical and chemical barriers

Question 14

physical and chemical barriers examples

Answer 14

nasal cavity traps inhaled microorganisms, antimicrobial protein in saliva and tears, trachea and lung epithelial barrier, skin barrier, intestinal epithelial barrier

Question 15

respiratory barriers

Answer 15

nasal cavity and muco-ciliary escalator

Question 16

respiratory barriers: nasal cavity

Answer 16

nasal turbinate bones have lots of surface area and trap large particles of dust and bacteria, viruses and fungi

Question 17

respiratory barriers: muco-ciliary escalator

Answer 17

lining of the airway has lots of mucous, mucous catches the bacteria and cilia move the bacteria up to be coughed out

Question 18

what environmental conditions influence the efficacy of the muco-cilary escalator?

Answer 18

drop in humidity and drop in temperature decrease transport velocity and impair muco-ciliary clearance

Question 19

viruses can damage physical barriers

Answer 19

bovine respiratory disease complex, viruses damage respiratory epithelium and impair muco-ciliary clearance increasing the risk of bacterial pneumonia.

Question 20

innate immunity specificity

Answer 20

non-specific responses

Question 21

adaptive immunity specificity

Answer 21

pathogen specific responses

Question 22

innate immunity adaptability

Answer 22

response is not more effective on second exposure to pathogen

Question 23

adaptive immunity adaptability

Answer 23

improved response on second exposure to pathogen

Question 24

innate immunity speed

Answer 24

activated in minutes, important during initial/early infection

Question 25

adaptive immunity speed

Answer 25

days to weeks for full immunity

Question 26

innate immunity defense

Answer 26

complement proteins, lysozyme in milk, saliva, and tears, lactoferrin in saliva

Question 27

adaptive immunity defense

Answer 27

antibody dependent, cell mediated immunity

Question 28

acute

Answer 28

short duration or sudden onset

Question 29

itis

Answer 29

inflammation

Question 30

innate immunity: acute inflammation

Answer 30

acute mastitis from staphylococcal infection, acute pneumonia from mannheimiosis, acute enteritis from salmonella

Question 31

what are 5 signs of acute inflammation?

Answer 31

redness, swelling, heat, pain, and loss of function

Question 32

what are the key phagocyte cell types involved in innate immunity?

Answer 32

neutrophils and macrophages

Question 33

what do neutrophils do?

Answer 33

isolate and destroy disease causing microorganisms

Question 34

innate immunity neutrophil defense

Answer 34

draining of pus onto surface of site of inflammation, focal accumulation of pus in tissue cavities (abscessation), phagocytize bacteria

Question 35

outcomes of acute infection in individual animals

Answer 35

local acute inflammation can lead to recovery and reduced productivity and tissue damage or systemic inflammation and death

Question 36

what are examples of reduced productivity?

Answer 36

growth, milk yield, fertility

Question 37

adaptive immunity key cells

Answer 37

lymphocytes

Question 38

humoral immunity

Answer 38

antibodies bind to pathogens in body fluids

Question 39

cell mediated immunity

Answer 39

immunity against intracellular pathogens

Question 40

humoral immunity defined

Answer 40

production of antibodies by plasma cells, antibody mediated, B lymphocytes differentiate into antibody mediating cells

Question 41

B cells

Answer 41

named from the bursa of fabricius in the bird, made in bone marrow of mammals and develop into plasma cells

Question 42

antibody types

Answer 42

five major classes of antibody, IgA, IgM, IgG, IgE

Question 43

IgA

Answer 43

important for mucosal immunity, respiratory and GI tracts

Question 44

IgM

Answer 44

often first to be produced following infection, early in infection, valuable for diagnostics

Question 45

IgG

Answer 45

most abundant in the body, used for quantification of antibodies in the blood

Question 46

IgE

Answer 46

important for immunity to multicellular parasites

Question 47

what do antibodies do?

Answer 47

bind extracellular pathogens and mediate destruction, promote phagocytosis by bringing antigens close to phagocytes

Question 48

passively acquired immunity

Answer 48

maternal transfer and injection of antibodies

Question 49

passive maternal transfer

Answer 49

placental transfer of antibodies and colostral transfer of antibodies

Question 50

passive injection of antibodies

Answer 50

antitoxins are used during outbreaks of enterotoxemia types C and D, generally doesn't work well, used as treatment rather than prevention

Question 51

relationship between serum IgG and survival in calves

Answer 51

higher IgG leads to greater survival rates of calves

Question 52

passive transfer of antibodies via placenta is species dependent

Answer 52

ruminants and pigs are born without any IgG in the blood, mothers do not pass IgG through the placenta, humans and rodents have placental crossover of IgG due to fewer layers of placenta to maternal antibodies

Question 53

colostral antibody absorption is time dependent

Answer 53

the sooner the better, first 24 hours of life IgG can be absorbed, IgG broken down if given late

Question 54

how are antibodies absorbed from colostrum into the blood stream?

Answer 54

endocytosis of the intestinal epithelium

Question 55

failure of passive transfer

Answer 55

important predisposing factor to infectious disease in neonatal ruminants, piglets, and foals, major risk for neonatal disease

Question 56

colostrum failure of passive transfer predisposing factors

Answer 56

insufficient colostrum, ingested too late resulting in poor absorption, mother not exposed to relevant pathogens, mother in poor condition not producing milk, unhealthy neonate not wanting to drink milk

Question 57

passive immunity wanes

Answer 57

in the first weeks of life

Question 58

how long does passive immunity need to last?

Answer 58

it needs to last until adaptive immunity has to developed so an animal is not susceptible disease

Question 59

why is initial intake of colostrum important?

Answer 59

sufficient intake is important, if initial intake is low there will be a gap where antibody is low before the animal develops adaptive immunity

Question 60

T lymphocytes

Answer 60

develop in the thymus, key role in cell mediated immunity

Question 61

cell mediated immunity and killing

Answer 61

mediated by T cells, antibody independent, important for defense against intracellular pathogens

Question 62

diagnostic use of adaptive immune responses

Answer 62

useful when infectious agent is difficult to detect or tissue samples are unavailable, serological diagnosis of disease, skin testing for tuberculosis

Question 63

leptospira in cattle disease sign

Answer 63

anemia, jaundice, red urine, nephritis

Question 64

rising antibody titer in graphs

Answer 64

demonstrates exposure to the pathogen and body producing antibodies, or building antibodies from vaccine

Question 65

single antibody titers

Answer 65

of limited use for acute infections

Question 66

paired titers

Answer 66

important for diagnosis of infectious diseases, enables confirmation of recent infection when initial results were negative, takes 2 weeks to obtain

Question 67

single titers are valuable for

Answer 67

detecting disease where there has been no vaccination, like surveillance of foreign animal diseases