LRT Viruses

Question 0

Respiratory syncytial virus

RSV

Answer 0

LRT virus
Paramyxoviridae
-large, -sense ssRNA
-helical, enveloped, spherical
-replicates in *cytoplasm
-2 serotypes (subtype A(bad) and B)
Transmission
-respiratory secretions
-*winter!
-highly contagious, causes nosocomial infx
Disease
-**Bronchiolitis
-cold, otitis meida, croup, acute bronchitis, pneumonia, acute respiratory failure, apnea
Virulence
-*F protein
-*immune mediated damage to ciliary fx
Diagnostic
-RT-PCR
Treatment
-supportive mainly
-ribavirin if severe
Prevention
-no vaccine
-handwashing
-gloves
-palivizumab

Question 1

Parainfluenza virus

HPIV

Answer 1

LRT virus
Paramyxoviridae
-large, -sense ssRNA
-helical, enveloped, spherical
-replicates in *cytoplasm
-4 diff. types (HPIV 1-4)
Transmission
-respiratory secretions
-*Fall
Disease
-*leading cause of croup
-can also cause cold, bronchitis, bronchiolitis and pneumonia
Virulence
-*hemagglutinin-neuraminidase (HN) (entry/budding)
-*Fusion protein (entry/giant cell formation)
-*RNA-dep RNA polymerase
Diagnosis
-RT-PCR
Treatment
-humidifier plus pain reliever
Prevention
-no vaccine
-breastfeeding is protective
-hand washing

Question 2

Mumps virus

Answer 2

LRT virus
Paramyxoviridae
-large, -sense ssRNA
-helical, enveloped, spherical
-replicates in *cytoplasm
-single serotype
Transmission
-respiratory secretions
-*late winter/spring
Virulence
-*hemagglutin-neuramindase (HN) activity
-*Fusion acitivity
Disease
-initially, low fever, malaise, HA, myalgias, and anorexia
-*bilateral/unilateral parotitis
-Complications: meningitis, encephalitis, orchitis, ooophoritis, pancreatitis, mastitis and myocarditis
Diagnostic
-RT-PCR
Treatment
-aspirin/acetaminophen
-warm/cold pack for parotid swelling
Prevention
-MMR vaccine
-breastfeeding is protective

Question 3

Human metapneumovirus

Answer 3

LRT virus
Paramyxoviridae
-large, -sense ssRNA
-helical, enveloped, spherical
-replicates in *cytoplasm
-found worldwide
-Winter/early spring
-causes mild URTI to severe LRTI like bronchiolitis and pneumonia in kids

Question 4

Nipah virus

Answer 4

LRT virus
Paramyxoviridae
-large, -sense ssRNA
-helical, enveloped, spherical
-replicates in cytoplasm
-bats: primary reservoir
-*pigs: amplification host
-transmitted to those in close contact w/ infected pigs
-found in *Malaysia, Singapore, Bangladesh, and India
-caused sever febrile encephalitis or respiratory disease

Question 5

Hendra virus

Answer 5

LRT virus
Paramyxoviridae
-large, -sense ssRNA
-helical, enveloped, spherical
-replicates in *cytoplasm
-*bats: reservoir
-*horses: amplification host
-in Australia
-caused sever respiratory disease

Question 6

Hantavirus

Answer 6

LRT virus
Bunyavirus
-a robovirus=rodent-borne virus
-enveloped, circular -sense ssRNA
-caused *hemorrhagic fever w/ renal syndrome (HFRS) in old world
-caused *hantavirus pulmonary syndrome (HPS) in *NM, CA, AZ, and Co (“4 corners virus”)

Question 7

Influenza virus

Answer 7

LRT virus
Orthomxyoviridae
-segmented, single-strande, -sense RNA
-helical, enveloped
-*replicates in the nucleus
-3 types (A,B, and C)
Transmission
-respiratory droplets
-Winter!
Virulence
-*Hemagglutinin and neuraminidase activity
-*M2 proton channel
Disease
-sudden onset
-fever/chills, cough, sore throat, rhinitis, aches, HA, fatigue, vomiting and diarrhea
-complications: ear infx, bronchitis, pneumonia, death
-*cytokine storm
Diagnosis
-rapid flu test
Treatment
-oseltamivir (tamiflu) and zanamivil (relenza)
Prevention
-"trivalent" "quadrivalent" vaccines