SM_179a: Viral Infections Flashcards by Nathan Shlobin

Which viruses infect the respiratory tract?

Influenza virus
Respiratory syncytial virus
Human metapneumovirus
Parainfluenza virus
Rhinovirus
Coronavirus
Adenovirus
Bocavirus

(other viruses utilize but do not infect the respiratory tract)

How well did you know this?

Not at all

Perfectly

List the respiratory viruses and their family and genetic material

Influenza virus: orthomyxoviridae, (-)ssRNA, segmented
RSV: respiroviridae, (-)ssRNA
Metapneumovirus: respiroviridae, (-)ssRNA
Parainfluenza virus: paramyxoviridae, (-)ssRNA
Rhinovirusa: picornaviridae, (+)ssRNA
Coronavirus: coronaviridae, (+/-)ssRNA
Adenovirus: adenoviridae, dsDNA
Bocavirus: parvoviridae, (+/-)ssDNA

How well did you know this?

Not at all

Perfectly

Pharyngitis is most commonly caused by ______

Pharynigitis is most commonly caused by adenovirus

How well did you know this?

Not at all

Perfectly

Croup is most often caused by ____ and _____

Croup is most often caused by PIV1 and PIV2

How well did you know this?

Not at all

Perfectly

Bronchiolitis is most commonly caused by ___

Bronchiolitis is most commonly caused by RSV

How well did you know this?

Not at all

Perfectly

Pneumonia in adults is most commonly caused by ______

Pneumonia in adults is most commonly caused by influenza

How well did you know this?

Not at all

Perfectly

_____ cause the common cold

Multiple viral pathogens cause the common cold

(rhinitis, nasal congestion, sneezing, pharyngitis, cough, hoarseness)

How well did you know this?

Not at all

Perfectly

A respiratory virus is usually the cause of pharyngitis when there is associated _____

A respiratory virus is usually the cause of pharyngitis when there is associated nasal congestion

How well did you know this?

Not at all

Perfectly

Croup is caused most often by ____ and symptoms arise from _____

Croup is caused most often by PIV1 and PIV2 and symptoms arise from inflammation and obstruction of the subglottic structures

How well did you know this?

Not at all

Perfectly

Tracheobronchitis is characterized by a ______ and is caused by _____ and _____

Tracheobronchitis is characterized by a non-productive cough and is caused by influenza and PIV

How well did you know this?

Not at all

Perfectly

Bronchiolitis is _____ characterized by _____ and is most commonly caused by _____

Bronchiolitis is viral infection of the terminal bronchiolar epithelial cells characteried by wheezing and nasal flaring and is most commonly caused by RSV

Edema and excessive mucus results in obstruction of small airways
Shortness of breath, increased work of breathing

How well did you know this?

Not at all

Perfectly

Describe the classification of influenza

Influenza

A: humans, mammals, and birds - acquatic birds are main reservoir
B: severe disease in elderly and at risk, no pandemics
C: disease in children, most adults have protective immunity

How well did you know this?

Not at all

Perfectly

Influenza A is characterized by _____ and _____

Influenza A is characterized by hemagglutinin and neuraminidase

Hemagglutinin (16 types): binds sialic acid, limits species transfer
Neuraminidase (9 types): viral release and propagation

How well did you know this?

Not at all

Perfectly

Antigenic drift in influenza is ____ and is associated with _____

Antigenic drift in influenza is minor change based on mutations in genome RNA secondary to poor fidelity of RNA polymerase and is associated with epidemics

How well did you know this?

Not at all

Perfectly

Antigenic shift in influenza is _____ and is associated with _____

Antigenic shift in influenza is a major change based on reassortment of segments of genome RNA and is associated with pandemics

How well did you know this?

Not at all

Perfectly

H1N1 was a ______ reassortment

H1N1 was a quadruple reassortment

(Asian and European influenza, avian influenza, human influenza)

How well did you know this?

Not at all

Perfectly

Describe the transmission of influenza

Influenza

Invades ciliated epitheial cells of upper respiratory tract
Spread via respiratory droplets and fomites
Droplets are large, travel short distances, and are viable for up to 24 hours on surfaces
Shed for 1-2 days prior to symptoms and up to 5 days after symptom onset

How well did you know this?

Not at all

Perfectly

Common symptoms of influenza include _____, _____, _____, and _____

Common symptoms of influenza include fever, mylagias, sore throat, and non-productive cough

All symptoms not seen in all patients
Fever of abrupt onset
Severe cases present as pneumonia

How well did you know this?

Not at all

Perfectly

Main complications of influenza are _____ and _____

Main complications of influenza are secondary bacterial pneumonia (Staph aureus and Strep pneumoniae) and exacerbation of cardiopulmonary conditions

(mortality rates higher in older age)

How well did you know this?

Not at all

Perfectly

_____ is the preferred testing method for influenza

PCR identification is the preferred testing method for influenza

Clinical syndrome and rapid antigen detection can also be used

How well did you know this?

Not at all

Perfectly

___ are NOT effective for treatment of influenza

M2 inhibitors (amantidine, rimantidine) are NOT effective for treatment of influenza

How well did you know this?

Not at all

Perfectly

_____ used to treat influenza prevent virus release from the cell and have the effect of _____

Neuraminidase inhibitors (oseltamivir, zanamivir) used to treat influenza prevent virus release from the cell and have the effect of reducing symptoms by 24 hours and transmission by 24-48 hours

How well did you know this?

Not at all

Perfectly

_____ used to treat influenza act by ____

Cap-dependent endonuclease inhibitors (Biloxivir) used to treat influenza act by stopping mRNA synthesis

About as effective as oseltamivir
One-time dose

Which factor placed her at risk for severe respiratory distress from influenza infection?

Pregnancy

Who should be treated for influenza?

* Start within 48 hours of symptoms * Severe symptoms or anyone hospitalized * Higher risk for complications * \< 19 years of age and receiving long-term aspirin therapy * Immunosuppressive conditions

\_\_\_\_ is a form of prevention for influenza virus

Influenza virus vaccine is a form of prevention for influenza virus (everyone should get it)

RSV surface proteins are _____ and \_\_\_\_\_

RSV surface proteins are SH protein and F protein * SH protein: inhibits apoptosis * F (fusion) protein: mediates fusion of infected cells together to form syncytia

\_\_\_\_\_ is the most common cause of lower respiratory tract infection in kids \< 1 year old

RSV is the most common cause of lower respiratory tract infection in kids \< 1 year old (also large cause of neonatal death)

RSV is transmitted by \_\_\_\_

RSV is transmitted by respiratory droplets

RSV infection ______ and reinfection is common because \_\_\_\_\_

RSV infection remains restricted to the lung and reinfection is common because immunity does not persist

RSV symptoms depend on _____ and \_\_\_\_\_

RSV symptoms depend on age and immunocompromised status * Older children and adults: rhinorrhea, nasal congestion, sore throat, cough, and fever * Infants and neonates: pneumonia or bronchiolitis, wheezing and apnea * Immunocompromised adults: viral pneumonia and secondary bacterial pneumonia

Mainstay of RSV management is \_\_\_\_\_

Mainstay of RSV management is supportive * Passive immunity not recommended and benefit of ribavirin is unknown

Parainfluenza virus ______ mediates \_\_\_\_\_\_

Parainfluenza virus fusion protein mediates the formation of multinucleated giant cells

Describe the illness caused by the different types of parainfluenza virus

* PIV 1 and 2: croup * PIV 3: children with lower respiratory tract disease (pneumonia) * PIV 4: common cold, pneumonia in immunocompromised people (PIVn 3 is most common)

PIV 1 and 2 cause _____ in children

PIV 1 and 2 cause croup in children (high mortality in immunocompromised adults)

PIV treatment is \_\_\_\_\_\_

PIV treatment is supportive (no available antiviral has shown efficacy for therapy)

Adenovirus has many \_\_\_\_\_, which allows it to cause many disparate diseases

Adenovirus has many antigenic serotypes (41), which allows it to cause many disparate diseases * Types 3, 4, 7, 21: respiratory disease * Types 8, 19: keratoconjunctivitis * Types 11, 21: hemorrhagic cystitis * Types 40, 41: infantile gastroenteritis

Adenovirus is primarily transmitted via the _____ route

Adenovirus is primarily transmitted via the fecal-oral route (also aerosol droplet and direct inoculation)

Adenovirus causes \_\_\_\_\_\_, which is bilateral conjunctivitis followed by development of painful corneal opacities

Adenovirus causes epidemic keratoconjunctivitis, which is bilateral conjunctivitis followed by development of painful corneal opacities

Adenovirus ___ causes sporadic outbreaks, which can be severe disease and pneumonia

Adenovirus 14 causes sporadic outbreaks, which can be severe disease and pneumonia

Most adenovirus infections are \_\_\_\_\_, so treatment is reserved for those with severe disease

Most adenovirus infections are self-limiting, so treatment is reserved for those with severe disease * Severe pneumonia or other organ invasive disease are treated * Cidofivir: nephrotoxic * Brincidofovir

Vaccine for _____ used by military, not civilians

Vaccine for adenovirus used by military, not civilians (oral type 4 and 7 vaccine for military recruits)

Rhinovirus has \_\_\_\_, which makes development of a vaccine difficult and explains why the common cold is so common

Rhinovirus has 100 serologic types, which makes development of a vaccine difficult and explains why the common cold is so common

Rhinovirus is transmitted via ____ and \_\_\_\_\_

Rhinovirus is transmitted via respiratory droplets and contaminated hands or surfaces

Rhinovirus replicates best at \_\_\_\_, so it prefers the \_\_\_\_\_

Rhinovirus replicates best at 32ºC, so it prefers the nose and conjunctiva (replicates poorly at body temperature 37ºC, which is why it DOES NOT prefer the lower airway)

There is ______ for rhinovirus

There is no specific therapy for rhinovirus * Symptom management * Vitamin C does not prevent common cold but may reduce symptoms * Zinc therapy may decrease symptoms

Coronavirus is _____ and causes the \_\_\_\_\_

Coronavirus is ubiquitous and causes the common cold (has been associated with lower tract disease but unclear if primary pathogen or co-pathogen) * Non-SARS serotypes include MERS-CoV and 2019-nCoV * SARS coronvirus: genome sequence different from existing human strains and binds to angiotensin-converting enzyme 2 receptor

The source of his infection is _____ because he has \_\_\_\_\_

The source of his infection is a civet because he has SARS

Hantavirus cardiopulmonary syndrome is \_\_\_\_\_\_

Hantavirus cardiopulmonary syndrome is initial fever followed by the abrupt onset of acute pulmonary edema and shock

SARS-CoV is spread to humans from \_\_\_\_\_, which receive the virus from \_\_\_\_\_\_

SARS-CoV is spread to humans from palm civets, which receive the virus from bats

MERS-CoV is spread to humans from \_\_\_\_\_, which receive the virus from \_\_\_\_\_\_

MERS-CoV is spread to humans from camels, which receive the virus from bats (high mortality rate)

Most common signs and symptoms of 2019-nCoV are _____ and \_\_\_\_\_

Most common signs and symptoms of 2019-nCoV are fever and cough (chest X-ray is best way to diagnose, most severe in males/older/those with comorbidities)

\_\_\_\_\_ is avian influenza A

H5N1 is avian influenza A (could be very contagious in humans)