Microbiology: Viruses Flashcards
1
Q
What virus causes smallpox?
A
Variola virus
2
Q
How was smallpox transmitted
A
Transmitted via respiratory route but movement through the circulatory system leads to infection of the skin (lesions)
3
Q
What was the first disease to which immunity was artificially induced?
A
smallpox
4
Q
What was the first disease to be eradicated it from the human population?
A
Smallpox
5
Q
There are only two lab sites that are able to maintain the smallpox virus. What countries?
A
- Russia
- USA
6
Q
What virus was recently thought to become a biological weapon?
A
smallpox
7
Q
What are the side effects for the smallpox vaccine?
A
Caused several fatal heart attacks
8
Q
What virus causes the chickenpox?
A
Varicella
9
Q
What virus causes shingles?
A
Herpes-zoster
10
Q
What is chickenpox?
A
Relatively mild childhood disease
Low mortality rate
11
Q
What happens once someone recovers from chickenpox?
A
They have immunity to it
12
Q
When is chickenpox more serious?
A
If contracted as an adult or during pregnancy
13
Q
What happens if a pregnant person a gets chickenpox?
A
Could cause serious fetal damage
14
Q
How does somebody get chickenpox?
A
Results from initial infection with herpes virus varicella- zoster
15
Q
How does the chickenpox virus enter the body?
A
Enters the body via respiratory system
16
Q
Where does the chickenpox virus spread to?
A
Skin cells after about two weeks
17
Q
If you have chickenpox, your skin will be vesicular for how long?
A
3-4 days
18
Q
What happens to skin vesicles after 3 to 4 days?
A
They filled with pus, rupture, and form a scab before healing
19
Q
Where can lesions from the chickenpox virus be found?
A
- face
- throat
- lower back
- chest
- shoulders
20
Q
What are all herpesviruses capable of?
A
Remaining latent within the body
21
Q
How does somebody get shingles?
A
Following a primary infection of the chickenpox virus that enters the peripheral nervous system and moves to the dorsal root ganglion near the spine where it persists as viral DNA
22
Q
Why is there no immune response to shingles?
A
Circulating antibodies cannot penetrate into the nerve cell and no viral antigens are expressed on the cell surface
23
Q
How is the shingles virus reactivated?
A
Due to stress or lowered immune system
24
Q
When the shingles virus is reactivated where does it move?
A
Moves along peripheral nerves to cutaneous sensory nerves of the skin
25
What kind of vaccine is available for shingles?
Live attenuated vaccine
26
When was the shingles vaccine first available?
1995
27
What does the shingles vaccine provide?
Long-term protection against chickenpox and shingles
28
What viruses cause the common cold?
50% rhinoviruses
| 15-20% coronaviruses
29
Why do older people tend to get fewer colds?
We tend to accumulate immunities against cold viruses during our lifetime
30
How many identified agents are there for colds?
More than 200
31
What are the symptoms for a cold?
- sneezing
- nasal secretions
- congestion
32
How many viruses is enough to cause it cold
A single rhinovirus
33
What are the symptoms for influenza?
- fever
- chills
- headache
- General muscle aches
34
How long does it take to recover from the flu?
In a few days and cold like symptoms appear as the fever subsides
35
What is the influenza virus capable of?
Capable of recombining RNA, creating antigenic shift, mutations that prevent immunity and memory of that strain
36
Is influenza zoonotic?
Yes
37
What type of vaccine is the flu shot?
Multivalent
| - multiple strains
38
What are the reservoirs for Hantavirus Pulmonary Syndrome?
rodents
| - deer mouse
39
What does Hantavirus Pulmonary Syndrome cause? (symptoms)
- fever
- muscle pain
- chills
- nausea
- headache
- diarrhea
- leads to respiratory distress
- hypotension
- death
40
How long does it take the Hantavirus Pulmonary Syndrome to progress?
a few days to 6 weeks
41
How is Hantavirus Pulmonary Syndrome transmitted?
inhalation of dried or dusty rodent dropping or urine
42
What is the direct route of transmission for Hantavirus Pulmonary Syndrome?
infected rodent bites human
43
What is the indirect route of transmission for Hantavirus Pulmonary Syndrome?
person touches area containing virus then touches their own face, nose, mouth
44
How is Hantavirus Pulmonary Syndrome treated?
- supportive care
| - ventilators
45
What is crucial for survival for Hantavirus Pulmonary Syndrome?
early diagnosis
46
How fatal is Hantavirus Pulmonary Syndrome?
50% even with treatment
47
How is Hantavirus Pulmonary Syndrome prevented?
- rodent control
| - wear face masks or ventilators when going into known rodent infestations
48
What kind of disease is Hantavirus Pulmonary Syndrome?
zoonotic
49
What type of disease is Eastern/Western Equine Encephalitis?
- zoonotic
- viral diseases that affect humans and horses
- arborvirus
50
What is the vector for Eastern/Western Equine Encephalitis?
mosquito vectors
51
Where does Eastern Equine Encephalitis (EEEV) occur?
in eastern and northern central USA
52
Where does Western Equine Encephalitis (WEEV) occur?
in western and central US
53
What is an arborvirus?
arthropod-born virus
54
How does eastern/western equine encephalitis affect the body?
1. The virus attacks the lymphatic system
2. Replicating in neutrophils and macrophages
3. Travels to other tissues, specifically nervous tissue
4. Causes damage via lesions that compromise its function (lymphatic system)
55
How is Eastern/western equine encephalitis transmitted?
Mosquito bites infected bird then bites a horse or a human
56
What are the human symptoms for Eastern/western equine encephalitis?
- asymptomatic
- headache, fever, muscular stiffness
- disorientation, lethargy, tremors, convulsions, coma
57
What is the mortality rate for humans who are infected with Eastern/Wester an equine encephalitis?
35% mortality rate
58
What are the symptoms for birds who have eastern or western equine encephalitis?
Mild or inapparent infections
59
What are the symptoms for horses who have Eastern/western equine encephalitis?
- Central nervous system inflammation
- fever, impaired vision, and coordination, drowsiness, grinding teeth, sawhorse stance, head pricing, sensitivity to light, convulsions, paralysis
60
What is the mortality rate for horses who are infected with Eastern/western equine encephalitis?
75-90% mortality rate
61
What could happen if a person or horse recovers from Eastern/western equine encephalitis?
High chance of brain damage
62
How is Eastern/western equine encephalitis diagnosed?
– Brain tissue analysis on fatal cases
| - history, season, serology, geographical location in life cases
63
What is the treatment for Western/Eastern equine encephalitis?
- None
| - supportive care
64
How is Eastern/western equine encephalitis prevented/controlled?
– Vaccinate your horse
- mosquito control
- try to keep your horse away from mosquitoes
65
What is another name for contagious ecthyma?
- orf
| - sore mouth
66
What is contagious ecthyma?
Infectious dermatitis that affects primarily sheep, goats, and cattle
67
What percentage of blacks in the US are affected by contagious ecthyma?
40% within the last three years
68
What virus from contagious ecthyma causes lesions and sores around the mouth?
Parapox virus
69
How does contagious ecthyma survive in the environment?
Scabs with virus what's in them can fall off and survive in the environment for years
Highly resistant in environment
70
What are the symptoms for animals that have contagious ecthyma?
- papules will form around lips, nostril, I live and ears of lambs and Kids
- utters of older animals
- progress to vesicles, pustules, scabs
71
What are the symptoms for humans who have contagious ecthyma?
Papules on face, arms, hands
72
How is contagious ecthyma transmitted?
- contaminated bedding or equipment
- Feed or feedlots
- Direct contact with other infected animals
73
What kind of virus is vesicular stomatitis?
- rhabdovirus
| - arborvirus
74
What does a rhabdovirus look like?
Bullet shaped
75
What does vesicular stomatitis primarily affect?
Cattle
Horses
Pigs
Occasionally sheep, goats, and llamas
76
What can vesicular stomatitis be confused with?
Foot and mouth disease
77
How is vesicular stomatitis transmitted to humans?
Direct contact between infected animals and humans
Inhalation of aerosolized droplets
78
How is vesicular stomatitis transmitted to animals?
Arthropod reservoirs
Direct contact with infected lesions
79
What are the arthropod reservoirs for vesicular stomatitis?
Mosquitoes
Sandflies
80
What are the symptoms for humans who have vesicular stomatitis?
Fever, headache, retro orbital pain, muscle aches
Vesicle formation rarely occurs in mouth, pharynx, or hands
81
How is vesicular stomatitis controlled?
- quarantine
- isolation of new animals
- insect control
- protective clothing and gloves
82
What is the vector for west Nile virus?
Mosquitoes
83
What is the reservoir for West Nile virus?
Wild birds
84
When was west Nile first scene in the US and where?
New York in 1999
85
Why is West Nile virus seasonal?
Due to mosquito transmission
From late spring to early fall
86
What are symptomatic carriers and what animals are symptomatic carriers for West Nile virus?
- will get sick with the disease
- crows
- blue jays
87
What are asymptomatic carriers and what animals asymptomatic carriers for West Nile virus?
- will not get sick with the disease
- common sparrows
- finches
- perching birds
88
How is West Nile virus transmitted?
By being bitten by infected mosquitoes
89
What are the symptoms of West Nile virus for birds?
Asymptomatic to disorientation
Muscle tremors
Death
90
What are the symptoms for horses that have West Nile virus?
- subclinical to lethargy
- hindquarter weakness
- seizures
- death
91
What are the symptoms for humans who have West Nile virus?
- subclinical to flu like symptoms
- arthralgia
- myalgia
- swollen lymph nodes
- rash
- can progress to meningoencephalitis and death
92
How is west Nile virus diagnosed?
- serology
- necropsy
- geographical location
- season
- history
93
How was west Nile virus treated?
- supportive care
- steroids to reduce inflammation of the meninges
- antibiotics to prevent secondary bacterial infections
94
How is west Nile virus prevented and controlled?
– Vaccine for horses
| – Mosquito control
95
What is bovine spongiform encephalopathy?
Mad cow disease
Progressive neurological disorder in cattle due to infectious protein particles known as prions
96
What are prions?
Modified forms of a normal protein that becomes pathogenic and cause degeneration of the brain
97
How did mad cow disease manifest?
When cattle were fed bone meal from scrapie infected sheep
98
What is bovine spongiform encephalopathy called in humans?
Creutzfeldt-Jacob Disease
99
What is bovine spongiform encephalopathy called in sheep and goats?
Scrapie
100
What is bovine spongiform encephalopathy called in cats?
Feline spongiform encephalopathy
101
How is mad cow disease transmitted?
Inherited or ingested
102
How does mad cow disease progress in cattle?
Very slow progressing disease
Rarely see this and cattle less than two years old
103
What are the symptoms of bovine spongiform encephalopathy in cattle?
- apprehensiveness
- nervousness
- reluctance to turn corners or go through doorways
- manic kicking
- Head shyness
- high stepping gait
- difficulty getting up
- skin trimmers
- loss of condition
- death
104
How does Creutzfeldt-Jacobs disease progress in humans?
gradual progressive disease may take months to years to manifest
105
What are the symptoms for Creutzfeldt-Jacobs disease and humans?
```
– Behavioral changes
– Hypersensitivity to light and touch
– Ataxia
– Dementia
– Muscle tremors two more severe contractions or spasms
– Death
```
106
How is mad cow disease treated?
- supportive care for humans
| - culling infected animals
107
What kind of virus is the rabies virus?
- zoonotic
| - Rhabdovirus
108
How is rabies virus transmitted?
Usually acquired by a bite of an infected animal
109
How does the rabies virus affect the body once it has entered the central nervous system?
Spreads rapidly throughout the nervous system and two other tissues
110
Why is the rabies virus usually spread by saliva?
The rabies virus proliferates in the salivary glands
111
What are the phases of the rabies virus in animals?
1. Initial phase
2. Excitative phase
3. Paralytic phase
112
What is the initial phase of the rabies virus?
Behavioral changes
- seeks isolation, stops eating and drinking
Drools
Lasts 1 to 3 days
113
What is the excitative phase of the rabies virus?
– Irrational and aggressive
– Loses beer and attacks without warning
– Progresses to incoordination and seizures
Death within 10 days
114
What is the paralytic phase of the rabies virus?
```
– Animal is not aggressive
– Paralysis of throat and jaw muscles
– Profuse salivation, inability to swallow
– Dropping of lower jaw
– Leads to death within 10 days
```
115
What kind of animal experiences the excitative phase?
Carnivores
116
What are the human symptoms of the rabies virus?
– Fever
- headache
- convulsions
- excessive flow of tears and saliva
- insomnia, anxiety
- maniacal behavior
117
What is clinical rabies?
Results in death of the patient usually within 2 to 6 days
118
How long should an animal that bites a human be quarantined?
8 to 10 days
119
How is the rabies virus control and prevented?
Control and domestic animals by vaccination in quarantine
Post exposure immunoprophylaxis
Vaccination of high-risk people
120
What is post exposure immunoprophylaxis?
- preformed antibodies directly to wound
| - five IM injections of rabies vaccine
