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50 Cards in this Set

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How are orthomyxoviridae and paramyxoviridae similar?
Similar structures and ability to adsorb glycoprotein receptors, particularly in the upper respiratory tract.
How are the flu and cold similar and different?
Both cause dry cough, sore throat, and rhinorrhea.

They difference, is that the flue occurs with painful muscle aches, high fevers, and headaches.
When does the epidemic influenza occur?
Each winter, from late December to early March.
What can the influenzavirus cause other than the flu?
Primary pneumonia or secondary bacterial pneumonia or otitis media.

Secondary bacterial infection occurs from necrosis of respiratory epithelium causing loss of primary host defense.

Secondary infection: Staphylococcus aureas, Haemophilus influenzae, or Streptococcus pneumoniae.
How is influenzavirus spread?

Who is mainly effected?
Respiratory aerosols.

Elderly, immunocompromised, and those with lung disease.
What is the morphology of Orthomyxoviridae? Of Paramyxoviridae?
Orthomyxoviridae: -ss segmented RNA, helical nucleocapsid, enveloped.

They have a spherical shape.

Paramyxoviridae: -ss NON-segmented RNA, helical nucleocapsid, enveloped
What are the two glycoproteins involved in Orthomyxoviridae?
Hemagglutinin: attaches to host sialic acid receptors, located on RBCs and upper respiratory tract.

Neuraminidase: cleaves neuraminic acid that disrupts the mucin barrier exposing sialic acid. Neuraminidase is also needed for the release of newly formed virion from infected host cell.s

Note: also with some paramyxoviridae.
How do ABs prevent infection from Orthomyxoviridae?
By blocking binding of HA
What is antigenic drift?
During viral replication mutations can occur in the HA or NA, leading to changes in the antigenic nature of these glycoprotein; this results in a milder disease in adults who previously had ABs.
What is antigenic shift?
Complete change of HA, NA, or both.

This only occurs with type A since it involves trading between animal and human strains during co-infection of the same cell by two different strains allowing the RNA package to be mispackaged into another virus.
What is the morphology of orthomyxoviridae?
-ss RNA, helical nucleocapsid, enveloped.

They have a spherical shape.
What are the two glycoproteins involved in Orthomyxoviridae?
Hemagglutinin: attaches to host sialic acid receptors, located on RBCs and upper respiratory tract.

Neuraminidase: cleaves neuraminic acid that disrupts the mucin barrier exposing sialic acid. Neuraminidase is also needed for the release of newly formed virion from infected host cell.s

Note: also with some paramyxoviridae.
How do ABs prevent infection from Orthomyxoviridae?
By blocking binding of HA
What is antigenic drift?
During viral replication mutations can occur in the HA or NA, leading to changes in the antigenic nature of these glycoprotein; this results in a milder disease in adults who previously had ABs.
What is antigenic shift?
Complete change of HA, NA, or both.

This only occurs with type A since it involves trading between animal and human strains during co-infection of the same cell by two different strains allowing the RNA package to be mispackaged into another virus.

Note: Strain B and C only occurs in humans, while A affects humans and other mammals.
What is Reye's syndrome?
Liver damage, encephalomyelitis associated with salicylate (eg., aspirin) treatment for influenza in children.

Nath says occurs predominantly in influenza B.
What are two drugs used to treat Influenza A?

Two neuraminidase inhibitors for Influenza A and B?
Amantadine or rimantadine.

Zanamivir and oseltamivir
Other than the influenza virus types A, B, and C, how are they further subtyped?
Based on their surface H and N antigens (e.g., A H1N1).
Influenza replications?

Immunization occurs with?
In mucus-secreting, ciliated cells.

Killed virus vaccines.
Parainfluenza posses what that results in multinucleated giant cells (similar to those caused by herpesviridae and retroviridae infections)?

Does it have HA and NA activity?

What is its full name?
Fusion (F) protein.

Paramyxoviridae paramyxovirus: type 1 and 3
Paramyxoviridae rubulavirus: type 2 and 4

It has combined HA and NA activity.
What are the 4 paramyxoviridae that cause human diseases?

What are some common characteristics of them?
Parainfluenza virus, respiratory syncytial virus, mumps virus, and measles.

Lungs: all adsorb to and replicate in the upper respiratory tract.

Most infections occur in children.

Viremia: dissemination of virions in the blood to distant sites.
What does the Parainfluenza virus cause?
Adults: common cold.

Children: croup (laryngotracheobronchitis) and pneumonia (also in the elderly and immunocompromised).
What is croup?
Laryngotracheobronchitis that results in swelling and produces airway narrowing. Results in inspiratory stridor and a barking cough (seal like).

There is edema of the vocal cords and subglottic larynx leads to hoarsness and barking cough.

Note: occurs in children.
How does Parainfluenza virus present differently in adults versus children?
Adults: upper respiratory tract infection as a bad cold.

Children: lower respiratory tract infection as pneumonia.
How do you treat Parainfluenza?
No specific antiviral therapy.

Treatment can include: humidification, epinephrine administration via nebulizer, and glucocorticoids.
Although respiratory syncytial virus (RSV) contains a F protein as with other paramyxoviridae, what does it lack?
HA and NA glycoproteins.
How was paramyxoviridae pneumovirus named?
It was named respiratory syncytial virus because of viral fusion (F) surface proteins cause infected cells to fuse and form syncytia.
Who is most commonly affected by Paramyxoviridae pneumovirus?

What is protein G?
Respiratory syncytial virus mostly effects infants between 2 - 6 months of age.

Allows virus to attach to cells (note: does not have NA or HA)
Infection of respiratory syncytial virus causes what?
Adults: common cold.

Children: pneumonia and bronchiolitis.

Bronchiolitis is a result of inflammation of the terminal bronchioles, necrosis and sloughing of the epithelial cells.

When swollen, can lead to wheezing and hyperinflation.
How do you treat Paramyxoviridae pneumovirus?
Mild: no specific, treat symptoms (acetaminophen for fever).

Severe: O2 therapy, ventilation, ribavirin.
How is Paramyxoviridae pneumovirus spread?
Respiratory synctyial virus is easily spread by hands or aerosol.

Washing hands helps significantly.
Paramyxoviridae rubulavirus is AKA?

What occurs? Does it have HA and NA?
Mumps virus

Replicates in the upper respiratory tract in regional lymph nodes. The parotid is frequently involved. The testes are also involved, resulting in orchitis.

Note: Orchitis can rarely result in sterility.

Meningitis and encephalitis can also occur.

It has combined HA and NA activity.
What is the only live vaccine that can be given to HIV+ PTs?

Nath's book says this is contraindicated in immunosuppressed, pregnant women, and high-risk individuals.
MMR: mumps, measles, rubella.
Paramyxoviridae morbillivirus AKA?

Does it have HA and NA?
Measles AKA Rubeola

Only HA
What is the exposure of paramyxoviridae morbillivirus like?
Highly contagious and spreads via nasopharyngeal secretions.

Once replicated in epithelial cells of upper respiratory, it enters the blood stream to replicate in reticuloendothelial cells to be disseminated else where.
What is the prodrome of measles?
Prior to the appearance of the rash:

Conjunctivitis, coryza, swelling of the eyelids, photophobia, high fevers (105d F), hacking cough, rhinitis, and malaise, and Koplik's spots (small red-based lesions with blue-white centers in the mouth.
Describe the rash of measles.
Red, flat, slightly bumpy (maculopapular).

Spreads from forehead to the face, neck, and torso, and hits the feet by the third day. The rash disappears in the same sequence as it developed.
What is a complication from Measles?
Subacute sclerosing panencephalitis: chronic low infection of the CNS, resulting in encephalitis

Giant cell pneumonia
What is a characteristic Measles infection?
Warthin-Finkeldey cells: giant cells with inclusion bodies.
How do you diagnosis Orthomuyxoviridae and Paramyxoviridae?
Orthomyxoviridae: symptoms, rapid antigen test on nasopharyngeal swab; detect HA vira RBC agglutination test.

Paramyxoviridae: all with serology; morbillivirus also with Warthin-Finkeldey cells; parainfluenza viruses with hemagglutination; Morbillivirus and Rubulavirus with detection of virus in urine; all with respiratory secretions.
What are the five most common pediatric diseases with rash?
Measles (measles virus), Rubella (rubella virus), Scarlet fever (S. pyogenes), Roseola (HHV 6), Erythema infectiosum (Parvovirus B19)
Most common causes of aspetic meningitis?
Coxsackievirus, echovirus, mumps
Most common causes of pneumonia in young children?
1) RSV
2) Parainfluenza virus
Most common causes of meningitis in children 6 mos - 6 yrs?
S. pneumoniae, N. meningitids, H. influenzae type B
Causes of common cold?
Rhinovirus, coronavirus, adenovirus, influenza C virus, coxsackievirus
Multinucleated gaint cells suggest?
Paramyxovirus, which includes parainfluenza, mumps, measles (rubeola), and RSV.
Most mumps infections occur in what age bracket? Is transmitted how?
Children younger than 2.

Respiratory secretion.
Where does mumps multiply?
Epithelial cells of the oropharynx. Secondary multiplication and viremia can extend into glands and nervous tissue.

Post viremic invasion occurs in parotid and submaxillary glands.

Affected glands show edema, necrosis with perivascular mononuclear and lymphocytic infiltrates.
How do you treat mumps, and what are further complications?
No antiviral treatment. MMR (Mumps, Measles, Rubella)--live, attenuated viruses.

Hematologic dissemination (POM): parotitis, orchitis, meningitis
What does the mumps virus have on its surface glycoproteins?
HA/NA (binds sialic acid/cleaves sialic acid interaction)

Fusion protein (F protein) (causes infected cells to fuse)