Infectious disease

Question 1

define infectious disease

Answer 1

disease caused by bacterium, virus, protozoan, or fungus

Question 2

define infection

Answer 2

occurs when infectious agent enters the body and begins to reproduce

Question 3

define pathogen

Answer 3

infectious agent that causes disease

Question 4

define host

Answer 4

an organism infected by another organism

Question 5

define virulence

Answer 5

relative ability of agent to cause rapid and severe disease

Question 6

categories of infectious agents

Answer 6

-prion
-viruses
-bacteria
-fungi
-protozoa
-helminths
-ectoparasites

Question 7

prions are characterized by …

Answer 7

spongiform change caused intracellular vacuoles in neurons and glia

Question 8

prions are composed of

Answer 8

abnormal forms of host protein

Question 9

prions cause what type of disease

Answer 9

transmissible spongiform encephalopathies (neurodegenerative disorder)

Question 10

creutzfeldt Jakob disease has symptoms of

Answer 10

loss of cognitive ability, decrease in ability to move and memory loss

Question 11

what is seen in Creutzfeldt Jakob disease

Answer 11

prions build up and cause brain to shrink and tissue fills with holes

Question 12

viruses are defined as

Answer 12

obligate cellular parasites that replicate inside living cells

Question 13

viruses replicate by doing what

Answer 13

by replicating nucleic acid and synthesis of viral protein

Question 14

how are bacteria classified

Answer 14

• by gram staining
• by shape
• by need of O2

Question 15

gram positive bacteria have

Answer 15

thick wall that retains crystal violet stain

Question 16

gram negative bacteria have

Answer 16

thin cell wall surrounded by an outer membrane

Question 17

types of bacteria are

Answer 17

• cocci
• bacilli
• spiral

Question 18

characteristics of cocci bacteria

Answer 18

• round shaped and cause pneumonia and sepsis

Question 19

characteristics of bacilli bacteria

Answer 19

• rod shaped
• single, pairs, or in chains
• causes serious diseases

Question 20

characteristics of spirila bacteria

Answer 20

• shaped like spirals
• very motile
• need moist atmosphere
• live in reproductive tract
• leptospirosis

Question 21

what different methods can bacteria damage hosts

Answer 21

1. producing enzymes that destroy tissue
2. producing poisonous toxins
3. exotoxins released into surroundings

Question 22

what can exotoxins cause

Answer 22

1. inhibit protein synthesis
2. damage cell membrane
3. interfere with normal nerve function

Question 23

what are the different types of fungal infections (Mycoses)

Answer 23

• superficial mycoses
• subcutaneous mycoses
• systemic mycoses
• allergic mycoses
• endemic mycoses

Question 24

what area do superficial mycoses affect

Answer 24

affect skin, hair, nails

Question 25

what area do subcutaneous mycoses affect

Answer 25

affect muscle and connective tissue below skin

Question 26

what area do systemic mycoses affect

Answer 26

involve internal organs

Question 27

what area do allergic mycoses affect

Answer 27

affect lungs or sinuses - have chronic asthma, cystic fibrosis or sinusitis

Question 28

what are endemic mycosis

Answer 28

infections restricted to certain areas (histoplasma in Ohio river valley)

Question 29

histoplasmosis and blastomycosis are endemic to which region

Answer 29

Mississippi river

Question 30

paracoccidiodes brasiliensis endemic to which region

Answer 30

south america especially Brazil

Question 31

coccidiodes immitis is endemic in which region

Answer 31

southwestern USA and north mexico

Question 32

what are the morphological classification of protozoa

Answer 32

- amoebas - flagellates - cliliophroa - coccidian

Question 33

diseases caused by protozoans include

Answer 33

-malaria, dysentery, giardiasis, sleeping sickness, toxoplasmosis

Question 34

characteristics of helminths

Answer 34

- macroscopic, multicellular and eukaryotic - lack digestive system and locomotion - reduced nervous system

Question 35

two major phyla of helminths are

Answer 35

- nemathelminthes (roundworms) - Platyhelminthes (flatworms) - Trematoda (flukes) - Cestoda (tapeworms)

Question 36

what location in the body are helminths common and what places

Answer 36

common in intestinal tract and places with poor sanitation

Question 37

ectoparasites are what

Answer 37

insects or arachnids that attach to and live on the skin

Question 38

what can ectoparasites cause

Answer 38

itching and excoriations

Question 39

patterns of infection include

Answer 39

- localized infection - systemic infection - focal infection

Question 40

patterns of transmission are

Answer 40

- horizontal (infected person to person) - vertical transmission (parent to offspring)

Question 41

define localized, systemic, and focal infection

Answer 41

localized: microbes enter body and stay at confined space systemic: infection spreads by the bloodstream focal: infectious agent breaks and from local infection and carried to other tissues

Question 42

bacteria damage to host cells depends on what

Answer 42

ability to adhere to host cells, invade cells, or deliver toxins

Question 43

LPS is what

Answer 43

toxin found in gram negative bacteria

Question 44

MTB causes what

Answer 44

granulomatous inflammation -> delayed hypersensitivity to prevent spread of bacilli

Question 45

HBV and HCV cause what

Answer 45

liver damage due to infected hepatocyte

Question 46

what are the mechanisms that help microorganisms resist immune system

Answer 46

- antigenic variation - resistance to innate defenses - impairment of T cell response - resistance to phagocytosis - resistance to ROS - resistance to complement activation - resistance to antibiotics

Question 47

what are the five major histological patterns tissue reaction to infections

Answer 47

- suppurative inflammation - mononuclear/granulmatous - cytopathic cytoproliferative reaction - tissue necrosis - chronic inflammation and scarring

Question 48

suppurative or purulent inflammation is characterized by

Answer 48

production of large amounts of pus consisting of neutrophils, necrotic cells and edema fluid

Question 49

what bacteria induces suppurative inflammation

Answer 49

staphylococci