AuCoin 5: - strand enveloped RNA viruses Flashcards by Megan Foggia

What do - sense RNA viruses REQUIRE for replication in the cytoplasm?

RNA-dependent RNA polymerase

How well did you know this?

Not at all

Perfectly

What is the only important Rhabdovirus? What does it infect? How is it transmitted?

Rabies virus (Lyssavirus); broad range of hosts - infects all mammals; transmitted via bite of rabid animal (bats, racoons, skunks)

How well did you know this?

Not at all

Perfectly

What are the three stages of rabies virus infection?

incubation period for 2 weeks to a year
prodrome phase: fever, nausea, headache, spreads to CNS
neurologic phase: hydrophobia, anxiety, paralysis, coma

How well did you know this?

Not at all

Perfectly

How do you treat a rabies virus patient?

give vaccine and human rabies IgG following animal bite

How well did you know this?

Not at all

Perfectly

How do you clinically diagnose rabies virus?

cytological detection of inclusion bodies or identify viral antigen in brain tissue

How well did you know this?

Not at all

Perfectly

Ebola are Marburg viruses are filoviruses. What do they cause?

severe hemorrhagic fever

How well did you know this?

Not at all

Perfectly

How are ebola and marburg viruses transmitted? What is the reservoir? What happens after initial infection?

by direct contact with contaminated body fluids; bats; infects macrophages and spreads via blood causing tissue destruction due to release of cytokines causing vascular permeability, hemorrhage, shock

How well did you know this?

Not at all

Perfectly

Describe how ebola and marburg virus presents clinically leading up to death.

severe hemorrhagic fever:
sudden fever
headache
joint and muscle pain
vomiting diarrhea
**bleeding into skin, mucous membranes and visceral organs
death by multiorgan failure and shock

How well did you know this?

Not at all

Perfectly

What is another name for orthomyxovirus?

influenza virus

How well did you know this?

Not at all

Perfectly

What is on the surface of the influenza virus? What does this bind to on respiratory epithelial cells?

HA (hemagluttinin) - surface glycoproteins bind to sialic acid receptors on respiratory epithelial cells

How well did you know this?

Not at all

Perfectly

Describe the process of influenza virus endocytosis and ultimately budding from the plasma membrane of the host cell.

receptor mediated endocytosis of virus via HA binding to sialic acid receptors on respiratory epithelium
segmented ribonucleoproteins are released into the cytoplasm
genome is transported to the NUCLEUS where replication and transcription occurs
viral mRNAs are transported to the cytoplasm for translation
early viral replication proteins are transported back to the nucleus
assembly and budding occurs at the plasma membrane

How well did you know this?

Not at all

Perfectly

Why does influenza kill thousands per year?! How is it transmitted?

transmitted by respiratory droplets - infects birds, chickens, pigs; there are 3 strains A, B, C. Type A alone has 16 antigenic types of HA and 9 types of NA. Antigenic changes to HA and NA cause epidemics and pandemics.

How well did you know this?

Not at all

Perfectly

What is this?

reassortment of segments of the genome RNA

small mutations in the genome RNA

antigenic shift; antigenic drift

How well did you know this?

Not at all

Perfectly

How does influenza typically present? When does it resolve?

incubation period of 24-48 hours, followed by:
fever
myalgia
headache
sore throat
cough

**symptoms resolve in 4-7 days, but it may be complicated by pneumonia

How well did you know this?

Not at all

Perfectly

Who is especially at risk of influenza?

elderly

patients with cardiac and pulmonary disease

How well did you know this?

Not at all

Perfectly

How is the flu treated? How is it prevented?

prevented by new antigenic vaccine each year; immunity depends on IgA to specific HA in the respiratory tract; treated with tamiflu and relenza

How well did you know this?

Not at all

Perfectly

This is a paramyxovirus characterized by a maculopapular rash

morbillivirus - measles virus

How well did you know this?

Not at all

Perfectly

How is measles virus transmitted? How does it spread in the body?

transmitted via respiratory droplets; infects resp tract then spreads to blood via phagocytic cells

How well did you know this?

Not at all

Perfectly

How does measles virus present?

incubation phase of 10-14 days, followed by:
fever
conjunctivitis
runny nose and cough
RASH that spreads from face to extremities
KOPLICK spots (small white spots on inflamed buccal mucosa)
encephalitis may occur

How well did you know this?

Not at all

Perfectly

What are two characteristic features of measles?

Koplick spots
**white spots in mouth
rash from face to trunk

How well did you know this?

Not at all

Perfectly

How do we currently prevent measles?

Study These Flashcards

live, attenuated vaccine

Another paramyxovirus is the parainfluenza virus. What does this virus cause? How is it transmitted?

Study These Flashcards

In children:
croup
laryngitis/pharyngitis
bronchiolitis
pneumonia
otitis media
**disease resembles a common cold in adults;
transmitted via respiratory droplets

Which strains of parainfluenza virus are the main cause of croup in children younger than 5? What is croup?!

Study These Flashcards

PIV 1 & 2; croup is a harsh, barking cough and hoarseness caused by swelling of the trachea and larynx

**PIV 3 is in lower respiratory infections in children

Another paramyxovirus is mumps virus. What does this cause? How is it transmitted?

Study These Flashcards

causes painful swelling of the PAROTID gland; transmitted via respiratory droplets

**occurs in childhood, only a single serotype

Once in the respiratory tract, where else can mumps virus spread?

can spread via blood to parotid glands, testes, ovaries, pancreas, meninges

This paramyxovirus is the most common cause of pneumonia and bronchitis and infants; transmitted via respiratory droplets

RSV - respiratory syncytial virus

What does RSV cause in infants? In adults?

pronounced cough and expiratory wheezing in infants; common cold, bronchitis in adults; pneumonia in elderly

What is one medication used for severely ill hospitalized infants with RSV?

ribavirin

Who is specifically at risk of RSV infection?

neonates premature infants infants with CARDIOPULMONARY disease

This paramyxovirus is the second leading cause of bronchiolitis behind RSV; its illness is comparable to that caused by RSV; most likely spread via respiratory droplets

metapneumovirus

What does metapneumovirus cause in infants and children?

acute respiratory distress - mild resp tract infections

How does metapneumovirus differ from RSV?

it occurs in slightly older children and causes less severe disease **if it's not RSV, think metapneumovirus

What kind of virus is hantavirus?

bunyavirus

What does hantavirus cause?

hantavirus fever with renal syndrome | hantavirus pulmonary syndrome

Where is hantavirus pulmonary syndrome seen in the US? How is it acquired?

In Western US in DEER MICE; acquired by inhalation of aerosols of rodent feces and urine **hanta the mouse

What are the symptoms of hantavirus pulmonary syndrome?

influenza like symptoms followed by respiratory failure **very high mortality rate

How do you diagnose hantavirus clinically?

you detect viral RNA in lung tissue | PCR

Another bunyavirus is California encephalitis virus. What causes this? What is the most common subtype of this virus that causes disease?

it is an arbovirus - mosquito; La Crosse virus

What are the symptoms of California encephalitis virus or LCVA?

``` severe headache fever vomiting/convulsions seizures 1% die from aseptic meningitis ```

If an individual tests positive for IgM or IgG to California encephalitis virus antigen, what does this mean?

seropositive individuals are protected from re-infection

This is a disease caused by bunyavirus; it is a TICK-borne viral disease common in Africa, Eastern Europe and Asia

Crimean congo hemorrhagic fever

What causes Crimean congo hemorrhagic fever?

handling infected mammals or humans

What are the symptoms of Crimean congo hemorrhagic fever?

``` initially: fever headache aches dizziness mental confusion next: hemorrhagic phase bleeding from nose GI uterus ``` causes hepatomegaly

This is another Bunyavirus; mosquito borne; infects domestic LIVESTOCK; mostly in sub-Saharan Africa and Egypt

Rift Valley fever virus

What are the symptoms of Rift Valley fever virus?

mild febrile illness | can cause retinitis and permanent vision loss

Lymphocytic choriomeningitis is caused by an arenavirus. How is it transmitted? What is the most common reservoir?

aerosol inhalation or ingestion of contaminated food; HAMSTERS (secretions and excretions)

What do infections with arenavirus causing lymphocytic choriomeningitis present like? Do many patients with this disease die?

most are asymptomatic influenza like symptoms aseptic meningitis; no - low case fatality rate

So when you think lymphocytic choriomeningitis, what do you think of?

HAMSTERS

Another arenavirus is Lassa fever virus. How is this transmitted? How does it spread from person to person? How does it enter the body?

aerosol or contact with rodent excretions; spreads via contact with blood, secretions, and excretions; enters through inhalation or through skin abrasion

Where is Lassa fever virus endemic?

in West Africa | Lassa, Nigeria

What symptoms does Lassa fever virus cause?

severe hemorrhagic fever myalgia severe prostration viremia can develop and it can spread systemically via macrophages

List the 6 helical - ssRNA strand viruses

``` arenavirus bunyavirus: bunya and hanta filovirus orthomyxovirus paramyxovirus rhabdovirus ``` ABFOPR

AuCoin 5: - strand enveloped RNA viruses Flashcards

(52 cards)