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Flashcards in Viral Zooneses Deck (39):

Arboviruses are defined as viruses that are...?

Viruses that are transmitted via arthropods to humans.


The arboviruses that fit into the Flaviviruses are?

Dengue fever, Yellow fever, and Zika viruses.


What arboviruses are within the Togavirus family?



What arboviruses are found within the bunyaviruses?

La Crosse


What arboviruses are found within the Reovirus family?

Colorado Tick Fever


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



Bunyaviruses from mammals includes what virus type?

Hantaviruses (Sin Nombre Virus)


What are the three clinical syndromes of Denue Virus?

Dengue fever
Dengue Hemmorrhagic Fever
Dengue Shock Syndrome


Where does Dengue fever incubate within mosquitos?

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


What does an infection by dengue fever look like?

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


What is dengue hemorrhagic fever/ dengue shock syndrome?

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.


Why does DHF/DSS occur?

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.


How does Yellow fever present?

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


What is Yellow Fever?

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.


How is yellow fever diagnosed?

Detection of anti-YFV antibodies via PCR


How is Yellow fever treated?

Supportive therapy, rehydration.


Does Yellow fever have a vaccine?

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.


What are the clinical features of the Zika virus?

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


What is the treatment for Zika virus/ vaccine?

There is none.


What are three complications associated with the zika virus?

Sexually transmitted
Microencephaly in pregnancys
Gillion Barre Syndrome.


What is the key word associated with what chikungunya causes?

A bent over stooped appearance due to painful arthralgia.


How is chikengunya transfered?

Transferred via mosquitos!


What is the primary resevoir for chikungunya?

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


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

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.


How is Chikungunya distinguished from Dengue fever?

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


This virus is known to cause hemorrhagic fever with renal syndrome

Hanta Virus


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

Rodents are the main apparent host of the Hanta viruses.


How is the Hanta virus transmitted?

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


What is hantavirus pulmonary syndrome?

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


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

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


What resevoirs are Colorado Tick Virus kept within?

Ground squirrels, chipmunks, rabbits and deer.


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

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


How does the acute form of colorado tick fever appear?

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.


What symptoms are present with Colorado tick fever?

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


What is considered a hallmark symptom for Colorado tick fever?



How is Colorado Tick fever virus diagnosed?

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


What does Ebola virus cause?

Severe, fatal, hemorrhagic fever


What are the natural resevoir for Ebola virus?

Bats or possibly rodents, NO insect host!


How does the Ebola virus cause infection?

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.