Ch. 4: Infectious Disease Flashcards
1
Q
approximately ( ) people have been infected at one time or another by hep B virus
A
2 billion people (~30% world population)
2
Q
of the 2 billion people affected by hep b virus, about ( ) remain chronically infected and are carriers of the virus
A
350 million (~5% of world pop)
3
Q
the normal or expected rate of infection in a population or geograchpic area
A
endemic rate
4
Q
When cases occur at above normal rates
A
epidemic
5
Q
the number one cause of death worthwide
A
infectious disease
6
Q
most infectious agents have what type of relationship?
A
commensal - they benefit but we are not harmed
7
Q
ifectious agents that can cause disease
A
pathogens
8
Q
Infectious agents are usually microscopic and are typically called
A
microbes
9
Q
smallest and largest microbe
A
smallest: protein molecule
largest: intestinal worms
10
Q
T/F: many agents are living things
A
False: a living thing is something that has its own metabolism and reproduces
11
Q
what’s an example of a living infectious agent? non-living?
A
living= bacteria non= virus
12
Q
mere molecules, a corrupted form of normal brain protein
A
prions (PrP)
13
Q
packets of nucleic acid encased in a protein coat (capsid)
A
virus
14
Q
how do viruses produce their RNA and DNA?
A
invade the interior or a cell and hijack the cell’s metabolism and reproductive machinery
15
Q
what do viruses not have? why is this significant to antibiotics?
A
don’t have cell wall or metabolism
this is sig bc antibiotics’ effect relies on disrupting bacterioal cell membrane or metabolism (so not effective on viruses)
16
Q
can viruses exist outside of a cell?
A
yes but can’t multiply
17
Q
can viruses transform infected cells into tumor cells?
A
yes (HPV causes cancer of cervix)
18
Q
the intestine alone contains about ( ) species of bacteria, most of which are ( )
A
400
anaerobic
19
Q
can bacteria live outside cell?
A
yes, they can live and reproduce or in any place given the right nutrients
20
Q
how are bacteria vulnerable to antibiotics?
A
they have a cell membrane and require energy to live
21
Q
what is an example of bacteria that is an exception to the rules?
A
chlamydia
22
Q
do bacteria have DNA and nucleus?
A
have DNA but no nucleus
23
Q
how are bacteria classified?
A
shape, need for oxygen, and color after a standard stain
24
Q
bacteria:
crystal-violet (deep purple)
A
gram-positive
25
bacteria: lost color after staining
gram-negative
26
bacterioa: specherical
cocci
27
bacterioa: elongated forms
bacilli
28
bacteria:corkscrew shape
spirochetes
29
two distinctive forms of fungi
molds and yeast
30
fungi: long, branching, multicellular filaments (hyphae)
molds
31
fungi: mulicellular clusters of budding round forms (spores)
yeast
32
fungi: in cool temperatures, usually grow as ( ) but at body temp deep infections occur in ( )
hyphae,
| yeast form
33
fungi: infections of skin, hair, and nails are cause by
dermatophytes (tinea)
34
parasites: motile, single cell, nucleated organisms that are capable of reproducing within cells
protozoa
35
parasites: responsible for much illness and death in developing countries
protozoa
36
parasites: inseacts spread some protozoa such as ( )
malaria
37
parasites: protozoa can be directly observed in...
blood smears, stool, or tissue sections
38
parasites: infect about 1/3 of world pop
helminths (parasitic worms)
39
most serious helminth
schistosomiasis (go through snail first then human)
40
parasites: small insect-like creatures that attach to or live in skin
ectoparasites
41
parasites: may cause local skin irritation from bites, but they also may transmit pathogens
ectoparasites
42
3 ways organisms cause damage after infection
1) invasion
2) release of toxins
3) provocation of an immune response
43
the degree of harmfulness of a microbe
virulence
44
most microbes (including viruses) exhibit a preference for a particular type of cell
tropism
45
toxin: from bacterial cell membranes as they die
endotoxin
46
toxin: prouced and excreted from bacteria
exotoxins
47
most endotoxins come from what types of bacteria?
gram-negative
48
viruses generally incite what?
chronic inflammation
49
some viruses (like herpes) causes ( )and others (like human papillomavirus) causes ( )
- cytopathic reaction
| - cytoproliferative reation
50
pus-forming reaction (pyogenic) is usually produced by gram-positive cocci such as ( ) or gram-negative bacilli such as ( )
- staphylococcus or stepococcus
| - E. col or H. influenza
51
if infection acquired outside of a hospital it is a ( ) infection, it it's acquired in a hospital it's a ( ) infection
- community-spread
| - nosocomial
52
mode of transmission from reservoir to new host: sexual intercourse, syphilis, herpes
-most organisms penetrate through breaks in skin or sexual mucosa
direct contact
53
mode of transmission from reservoir to new host: hep A, parasites
ingestion
54
mode of transmission from reservoir to new host: fomites (inanimate objects)- doorknob, clostridium
indirect contact
55
mode of transmission from reservoir to new host: sneezing, rhinovirus
droplets
56
mode of transmission from reservoir to new host: mosquitos, Zika virus
vectors
57
when blood is the main infected tissue, the condition is called ( )
septicemia or sepsis
58
T/F: gram positive organisms are purple while gram negative are red-pink
True
59
T/F: virulence is the ability to cause disease
true
60
T/F: host immunity always decreases virulence
False: host immunity does not always decrease virulence and the host response may actually induce additional inflammation and damage
61
T/F: the incubation time varies b/w diseas
True
62
what are the major categories of infectious agents?
- Prions
- Viruses
- Bacteria
- Fungi
- Parasites
63
Name the crucial differences b/w viruses and bacteria
viruses are obligate intracellular parasites. Bacteria can live outside of cells. Viruses are packers of protein w/o a cell wall. Bacteria are more complex with a cell wall
64
An organism called Bacillus cereus grows in reheated rice and can cause food poisoning very quickly within four hours. It is more likely that endotoxin or exotoxin causes this disease?
exotoxin, performed, similar to that os Staphyloccus aureus
65
granulomas are most likely caused by what two types of organisms?
fungi and mycobacterium (TB)
66
the time b/w invasion and appearance of signs or symptoms, during which the organism attempts to proliferate
incubation period
67
may occur in which the patient suffers from mild, nonspecific symptoms
prodromal period
68
a time of maximum acute, typical clinicial signs and symptoms
actue phase
69
time during which symptoms fade
convalescence
70
time during which no symptoms are present but the patient may feel fatigued
recovery period
71
what causes malaria?
plasmodium
72
what causes rocky mountain spotted fever? (wood ticks, dog ticks)
rickettsiae
73
what causes lyme disease? (deer ticks)
borrelia burgorferi
74
what causes plague? (rodent fleas)
bacterium Yersinia pestis
75
agent: bacteria, response:
neutrophils
76
agent: viruses, response:
LYMPHOCYTES, monocytes, few neutrophils
77
agent: mycobacteria and fungi
GRANULOMAS, lymphocytes, monocytes
78
agent: parasitic worms, response:
eosinophils
79
agent: protozoa, response:
lymphocytes, monocytes
80
usual result of acute virus infection
an effective host immune response that eliminates the virus
81
usually infects upper respiratory tact, causing tonsillitis and often presents in combo with conjunctivitis
adenovirus
82
a mjor cause of lower respiratory tract infections during infancy and childhood
respiratory syncytial virus (RSV)
83
influenza type: less common and causes mild disease
Type B
84
influenza type: severe respiratory infection
Type A
85
the most common cause of severe diarrhea among infants and young children
rotavirus
86
virus infection type: rhinovirus, norovirus, measles, hep A, influenza
Acute
87
virus infection type: herpes, hep B and C, HIV, HPV
chronic (persistent)
88
virus infection type: can stimulate the development of neoplasia (HPV, EBV, KSHV)
transformative
89
causes about 90% of nonbacterial outbreaks of epidemic gastroenteritis around the world
norovirus
90
the most common cause of vaccine-preventable illness worldwide
measles
91
virus infections in which the immune system does not eliminate the virus
chronic (persistent)
92
chronic viral infection: virus persists in noninfectious form but can periodically reactivated to cause recurrent disease and new infections
latent virus infections
93
chronic viral infection: Herpes simplex virus (HSV) is usually associated with...
oral cold sores and genital herpes
94
a variety of herpesvirus that infects blood monocytes and related cells and causes a wide array of illnesses depending on host age and immune status
cytomegalovirus (CMV)
95
T/F: vaccination against viruses has decreased the incidence of many virus diseases
true
96
T/F: vaccination against viruses increases cancer risk
Fasle: it decreases it
97
what virus is responsible for cold sores? shinles? infection mononucleosis?
- HSV 1 and 2
- VZV
- EBV
98
what virus is most likely to cause gastroenteritis on a cruise ship? the common cold during school year? involve parotids and gonads?
- noroviris
- rhinovirus
- mumps
99
why are influenza vaccines recommended anually?
because the virus mutates
100
gram-positive cocci that cause acute pyogenic infections
staphylococci
101
gram positive cocci: varities of S. aureus that are resistant to treatment with late antibiotics
methicillian-resistant styphylococcus aureus
102
gram positive cocci: S. pneumoniae, S. pyogenes
streptococci
103
bacterial infections: very common aerobic pathogens that cause acute, intense, pyogenic infection
gram positive cocci
104
bacterial infections: cause illnesses closely identified with each species
gram positive bacilli
105
gram positive bacilli: diptheria is an acute pharyngeal or skin infection caused by ( )
corynebacterium dyptheriae
106
gram positive bacillus: growns at fridge temp and causes food-borned infections through contaminated dairy products, raw veggies, and raw chicken and other meats
listeria
107
gram positive bacillus: large, toxin producing, encapsulated, aerobic or anaerobic...produces spores capable of lying dormant in soil for decades or longer
bacillus anthracis
108
gram positive bacillus: grow in distinctive branched chains similar to fungal hyphae and are widely found in soil
norcadia
109
gram positive bacillus: anaerobe that grow in animal feces and sol
clostridia
110
gram positive bacillus: clostridium difficile causes ( )
pseudomembranous colitis
111
4 types of clostridia:
1) C. difficile
2) C. perfringens
3) C. tetani
4) C. botulinum
112
the only important gram negative cocci
neisseria
113
2 types of neisseria
N. gonorrhea and N. meningitidis
114
gram negative bacilli: E coli, salmonella, shigella, vibrio cholera, helicobacter pylori
intestinal infections
115
gram negative bacilli: H. influenza, legionella, bordatella pertussis
respiratory infections
116
gram negative bacilli: opportunistic or nosocomial infections
pseudomonas
117
bacterial infections: transmitted by insect bites
rickettsiae and borrelia
118
rickettisia: RMSF,
Borrelia:
lyme disease
119
bacterial infections: corkscrew-shaped
spirochetes
120
ex. of spirochetes
syphilis
121
bacterial infections: often a mixture of organisms
anaerobic infections
122
myobacteria TB is the agent of ( ) while myobacteria leprae is the agent of ( )
- human TB
| - human leprosy
123
TB incites distinctive chronic granulomatous inflammation, which features a central area of semi-solid criumbly, necrotic tissue called ( )
caseous necrosis
124
pathogenesis of TB: many infected but few are diseased
primary TB
125
pathogenesis of TB: in about 5% of initial infections, the immune system cannot control spread and infection immediately progresses to active disease
primary progressive TB
126
pathogenesis of TB: arises from dormant primary TB bc the patient has developed a chronic, debilitating disease such as diabetes, chronic lung disease, or malignancy
reactivation TB
127
skin test for infection
purified protein derivative (PPD) test-- aka Mantoux test
128
T/F: anaerobic bacteria are present in the mouth and are responsible for aspiration pneumonia
True
129
T/F: staphylociccus and step are gram postive bacteria that can infect a number of different organs
true
130
T/F: in testing for TB, a purified protein derivative test of less than 15 mm is always considered negative
False: in high risk or immunocompromised patients, it would be considered positive
131
T/F: myobacterium leprae is the most virulent myobacterium
False: this virus only uncommonly infects and causes disease
