Viral Zooneses

Question 1

Arboviruses are defined as viruses that are…?

Answer 1

Viruses that are transmitted via arthropods to humans.

Question 2

The arboviruses that fit into the Flaviviruses are?

Answer 2

Dengue fever, Yellow fever, and Zika viruses.

Question 3

What arboviruses are within the Togavirus family?

Answer 3

Chikungunya

Question 4

What arboviruses are found within the bunyaviruses?

Answer 4

La Crosse

Question 5

What arboviruses are found within the Reovirus family?

Answer 5

Colorado Tick Fever

Question 6

Filoviruses that are spread from other mamalls gives rise to what disease?

Answer 6

Ebola!

Question 7

Bunyaviruses from mammals includes what virus type?

Answer 7

Hantaviruses (Sin Nombre Virus)

Question 8

What are the three clinical syndromes of Denue Virus?

Answer 8

Dengue fever
Dengue Hemmorrhagic Fever
Dengue Shock Syndrome

Question 9

Where does Dengue fever incubate within mosquitos?

Answer 9

Within the salivary glands and stomach. Can then be passed directly to humans (urban route) or to monkeys then to humans (non urban)

Question 10

What does an infection by dengue fever look like?

Answer 10

Initial fever/ head ache/ periorbital pressure etc lasting up to a week followed by a 1-2 week convalescense period.

Question 11

What is dengue hemorrhagic fever/ dengue shock syndrome?

Answer 11

5% of individuals with dengue virus will develop DHF
Presents initially like dengue fever then as fever subsudes pt becomes restless/lethargic and develops skin hemorrhages and epistaxis, bleeding gums, hematemesis, and melena.

Question 12

Why does DHF/DSS occur?

Answer 12

Two theories:

1) DHF is from hyper vrulent strain of dengue.
2) DHF develops following previous dengue infection leading to easier ability for dengue to replicate in macrophages and cause vascular leakage.

Question 13

How does Yellow fever present?

Answer 13

75% of cases are asymptomatic but some will present with an acute phase similar to dengue but will improve within a few days.

Question 14

What is Yellow Fever?

Answer 14

Yellow fever occurs within 15% of patients when they enter a toxic phase within 24 hours of infection.
Pt has a reappearing fever and jaundice of the skin withh bleeding from the mouth nose, eyes and or stomach.
Kidney fct deteriorates.
20-50% of pt die within 10-14 days.

Question 15

How is yellow fever diagnosed?

Answer 15

Detection of anti-YFV antibodies via PCR

Question 16

How is Yellow fever treated?

Answer 16

Supportive therapy, rehydration.

Question 17

Does Yellow fever have a vaccine?

Answer 17

Yes, it allows protection for at least 10 years and is recommended for travelers to high-risk areas. It is also required for entry to many countries.

Question 18

What are the clinical features of the Zika virus?

Answer 18

The zika virus develops in less than 20% of infected individuals with symptoms including headache, fever, rash, muscle and joint pain and conjunctitis.

Question 19

What is the treatment for Zika virus/ vaccine?

Answer 19

There is none.

Question 20

What are three complications associated with the zika virus?

Answer 20

Sexually transmitted
Microencephaly in pregnancys
Gillion Barre Syndrome.

Question 21

What is the key word associated with what chikungunya causes?

Answer 21

A bent over stooped appearance due to painful arthralgia.

Question 22

How is chikengunya transfered?

Answer 22

Transferred via mosquitos!

Question 23

What is the primary resevoir for chikungunya?

Answer 23

Humans are the primary resevoir although other animals have been infected with it as well.

Question 24

What is the acute presentation of a patient infected with chikungunya?

Answer 24

3-10 days pt will display very high fever, severe joint pain and swelling, headache and diffuse back pain amongst others.

After 1 week pt will feel improvements, others will have joint pain for months.

Question 25

How is Chikungunya distinguished from Dengue fever?

Answer 25

Antibodies specific to this virus can be detected! | It is believed long lasting immunity can be developed against this virus.

Question 26

This virus is known to cause hemorrhagic fever with renal syndrome

Answer 26

Hanta Virus

Question 27

Hanta viruses are named based on the host. What is the typical host for this virus?

Answer 27

Rodents are the main apparent host of the Hanta viruses.

Question 28

How is the Hanta virus transmitted?

Answer 28

It is passed from rodents to humans horizontally via aerolized excreta, particularly urine.

Question 29

What is hantavirus pulmonary syndrome?

Answer 29

Pt will present at first with a febrile illness that develops into an acute pulmonary edema stimulating acute respiratory distress syndrome (ARDS)

Question 30

How soon does Hanta virus pulmonary syndrome rear its ugly head?

Answer 30

Usually within 24 hours most pt will develop hypotension with evidence of pulmonary edema and hypoxia.

Question 31

What resevoirs are Colorado Tick Virus kept within?

Answer 31

Ground squirrels, chipmunks, rabbits and deer.

Question 32

What time of the year does Colorado Tick Virus typically occur?

Answer 32

May thru September which is representative of seasonal activity of ticks and their hosts.

Question 33

How does the acute form of colorado tick fever appear?

Answer 33

It is biphasic in that within 1 week of exposure the fever may last for 2-3 days followed by a few days of afebrile and a returning fever for a few days.

Question 34

What symptoms are present with Colorado tick fever?

Answer 34

Biphasic fever, Lymhodenopathy, hepatosplenemegaly, and rash. Leukopenia is considered a hallmark of the disease?

Question 35

What is considered a hallmark symptom for Colorado tick fever?

Answer 35

Leukopenia.

Question 36

How is Colorado Tick fever virus diagnosed?

Answer 36

It is diagnosed by serological or molecular testing to confirm infection.

Question 37

What does Ebola virus cause?

Answer 37

Severe, fatal, hemorrhagic fever

Question 38

What are the natural resevoir for Ebola virus?

Answer 38

Bats or possibly rodents, NO insect host!

Question 39

How does the Ebola virus cause infection?

Answer 39

The ebola virus replicates in and destroys parencyhmal cells of the liver, lungs, spleen, and lymph nodes. Destruction of vascular endothelial cells leads to massive rupturing.