Chapter 29: other RNA viruses

Question 1

What are the Arboviruses?

Answer 1

These are arthropod borne viruses that include the togaviruses, bunyaviruses, flaviviruses.

Question 2

What are the categories of togaviruses?

Answer 2

alpha viruses and rubivirus

Question 3

What are the alpha viruses?

Answer 3

WEE, EEE, VEE and chikungunya virus which are named after where they are found and they cause encephalitis (not chikungunya most of the time).
this leads to headache, altered consciousness, and focal neurologic problems.
Chikungunya virus leads to fever, rash, joint pain followed by chronic arthritis.
They are all spread by mosquitos.

Question 4

What is rubella what what family is it from?

Answer 4

Rubella is a disease that causes fever and flu-like symptoms as well as rash from the forehead down the trunk to the extremities.
It is also a part of TORCH meaning it can spread from mother to child through blood-placental barrier.
It is part of the Togaviruses.

Question 5

What is one thing that sets rubivirus apart from the other togaviruses?

Answer 5

It does not have an insect vector

Question 6

What are the diseases caused by flaviviruses?

Answer 6

yellow fever
dengue virus
St. louis and japaneses encephalitis
West Nile virus
Hepatitis C

Question 7

What organs affected by congenital rubella?

Answer 7

Heart, eyes and CNS

leading to patent ductus, cataracts, mental retardation and deafness

Question 8

What does yellow fever lead to?

Answer 8

It causes hepatits, fever, and backache.

Question 9

What is bone break fever?

Answer 9

This is also called Dengue fever and it is caused by a flavivirus. The disorder causes painful fever, headache, muscle aches, joint aches, and back aches.

Question 10

If Dengue fever persists what does it lead to?

Answer 10

IT can cause hemorrhages, thrombocytopenia, and septic shock in a disease known as Dengue hemorrhagic fever

Question 11

What is special about St. Louis encephalitis?

Answer 11

This is the second most common viral cause of encephalitis in the US.

Question 12

What are the associated symptoms of West Nile?

Answer 12

Fever, headache, and possible maculopapular rash, before leading to weakness and difficulty concentrating. the elderly and immunocompromised are most likely to have neuroinvasive symptoms like encephalitis, myelitis, and meningitis

Question 13

How do you diagnose West Nile?

Answer 13

1. Detection of virus by isolation through PCR
2. Serum IgM or IgG
3. CSF fluid IgM against WNV
4. fourfold rise in serum antibody titers

Question 14

Bunyaviridae causes what three diseases?

Answer 14

California encephalitis and Rift valley fever as well as Hantavirus

Question 15

What is the major difference between Rift valley and California encephalitis?

Answer 15

Rift valley can also lead to a hemorrhagic disorder.

Question 16

What is Hantavirus pulmonary syndrome?

Answer 16

This is an influenza like illness with fever, muscle aches, nausea, and vomiting
Most commonly found in the four corners.
The damage commonly leads to pulmonary edema and respiratory failure in 40%
The original Hantavirus that is associated with Asia cause a hemorrhagic fever with renal failure.

Question 17

Who should be considered most for Hantavirus?

Answer 17

Young adults that are in the area of the Four corners that have influenza-like symptoms with pulmonary edema.

Question 18

What are the major groups of picornaviruses?

Answer 18

Enterovirus, rhinovirus, hepatovirus, and parechovirus.

Question 19

What are the supgroups of enteroviruses?

Answer 19

poliovirus
coxsackie A
coxsackie B
Echovirus
New enteroviruses

Question 20

What do enteroviruses affect and how are they spread?

Answer 20

Enteroviruses = intestinal epithelial cells and lymphoid tissue like Peyer’s patches and they are excreted in feces and spread in the fecal-oral route with replication and shedding to GI from the tonsils.

Question 21

what are the three disease manifestations of Polio?

Answer 21

Mild illness = asymptomatic or mild febrile viral illness which is most common in infants of underdeveloped nations.
Aseptic meningitis = fever and meningismus with quick recovery.
Paralytic poliiomyelitis = viral infection of the motor neurons of the anterior horn of spinal cords. Leads to peripheral neuron deficits.

Question 22

compare and contrast Coxsackie A and B.

Answer 22

The each can be asymptomatic, mild febrile, cause respiratory symptoms, rashes, and aseptic meningitis. These are actually the most common causes of aseptic meningitis
A causes paralysis and necrosis of skeletal muscle.
Herpangina = small red vesicle over back of throat.
Hand, foot, mouth disease that causes oral vesicles and small tender lesions on hands feet and butt.
B is less severe but can affect heart, brain, liver, pancreas and skeletal muscle.
Pleurodynia = pleuritic pain with respiratory infection
Myo/pericarditis = arrhythmias, cardiomyopathy and heart failure.

Question 23

What are the two causes of the common cold?

Answer 23

Rhinovirus and coronavirus

Question 24

What is SARS and how is it spread?

Answer 24

SARS stands for severe acute respiratory syndrome which is specifically from a coronavirus. Patients present with fevers, myalgias, chills and dry coughs. Leads to chest pain and difficult breathing caused by alveolar consolidation. This can lead to acute respiratory distress syndrome which can lead to respiratory failure.

Question 25

What RNA viruses cause diarrhea?

Answer 25

Caliciviruse, rotavirus, adenovirus, and astroviruses

Question 26

Which two viruses are indistinguishable from each other besides the age of presentation?

Answer 26

Calicivirus and rotavirus
calici = young children and infants
Rotavirus = infects all ages but it is a major cause of infant mortality due to infectious diarrhea and dehydration.

Question 27

What are the symptoms of Norwalk and Noroviruses and what are possible causes?

Answer 27

Norwalk and noroviruses both lead to infectious diarrhea but Norwalk is also associated with severe vomiting. The Noroviruses is spread by infected water sources in a selected population like on cruiseships or after environmental disasters.

Question 28

what age groups are affected by astroviruses?

Answer 28

infants, children and elderly patients

Question 29

What sets the morphology of Rhadboviruses apart from the other viruses?

Answer 29

It is bullet shaped.

Question 30

What is the prodrome for rabies?

Answer 30

fever, headache, sore throat, fatigue, nausea and intense pain due to very sensitive nerves near bite wound.

Question 31

What are the two types of encephalopathies in rabies?

Answer 31

Acute encephalitis = hyperactive and agitated states that lead to confusion, meningismus and seizures = madness
Classic brainstem encephalitis = cranial nerve dysfunctions leading to very painful swallowing = foaming at the mouth

Question 32

What are the two main filoviruses?

Answer 32

Marburg and Ebola virus

Question 33

What are Marburg and Ebola and example of?

Answer 33

They are examples of an acute viral hemorrhagic fever.
This disorder is heterogeneous in symptoms but usually includes fever, diarrhea, weakness, dysphagia, hiccups and bleeding from all mucous membranes.

Question 34

What is the transmission of viral hemorrhagic fever?

Answer 34

Any direct contact with any bodily fluids of the living infected or of the deceased. Airborne transmission cannot be ruled out.
This means that the most common people infected are people in the healthcare industry.

Question 35

What are the major potential bioweapons that cause hemorrhagic fever?

Answer 35

Filoviruses, arenaviruses, rift valley fever, and yellow fever virus.