[6] Viral Disease Lower Respi Flashcards
causative agents fo influenza
virus types A and B
influneza; enzymes, which produce new strains. This
occurs by antigenic drift and antigenic shift
hemagglutinin (HA) and
neuraminidase (NA)
type A or type b influenza: Can cause significant disease
type A
type A or type b influenza: Infects humans and other
species (e.g. birds; H5N1)
type A
type A or type b influenza: Can cause epidemics and
pandemics (worldwide
epidemics)
type A
type A or type b influenza: Generally causes milder disease
but may also cause severe disease
type B
type A or type b influenza: Limited to humans
type B
type A or type b influenza: Generally causes milder epidemics
type B
Mutations in the genes coding for these glycoprotein spikes are
responsible for the production of new strains of influenza virus, via
processes known as
antigenic drift and antigenic shift.
Mild outbreaks
- Process:
1. Influenzavirus enters host cell
2. Upon entering, the virus eventually
mutates/mutation in antigen gene, occurs
during replication within host cell
3. It will now release another virus.
Influenzavirus 1: differing slightly from virus
1 (virus that entered the host cell), exits the
cell and infect different host cells
antigenic drift
Occasional outbreaks, but very severe influenza
is seen
- Process:
1. Influenzaviruses 1 and 2 enter host cell
2. Genes and antigens from both viral types are
incorporated into new virions
3. The new virions will produce a third kind of
influenzavirus. Influenzavirus 3, which is very
different from viruses 1 and 2, exits cell
antigenic shift
In ?, they discovered the MERS in humans and
reported that the reservoir are camels
2012
First case of MERS was in ? and the
following year in Europe, Jordan, Qatar, Indonesia,
United Kingdoms
Saudi Arabia
Most common childhood respiratory disease (newborn and young
children)
- Usually seen 4-6 days following infection
RESPIRATORY SYNCYTIAL VIRUS INFECTION (RSV)
? is the leading cause of bronchiolitis (inflammation of the
bronchioles) and pneumonia among children less than one year
of age and the leading respiratory killer of infants worldwide.
RESPIRATORY SYNCYTIAL VIRUS INFECTION (RSV)
Some children develop ?, known commonly as
“croup”, which is inflammation of the trachea and bronchi,
resulting in breathing difficulty accompanied by a barking
cough
tracheobronchitis
pathogen; genus Pneumovirus, family Paramyxoviridae
○ An enveloped, helical, -ssRNA virus
○ It is relatively unstable outside the body, surviving only
about five hours in the environment or two hours on skin
or used facial tissues
Respiratory Syncytial Virus (RSV)
RSV Virus causes ? to form in the lungs
syncytia
● Immune response to RSV further damages the ?
lungs
is a giant, multinucleated cell formed from the fusion
of virally infected cells to neighboring cells
Syncytium
● Muscle aches (particularly in the large muscles of the thighs,
hips, and back)
● Symptoms progress to cough, shock, and labored breathing
● Elevated WBC count and a low or falling platelet count
HANTAVIRUS PULMONARY SYNDROME (HPS)
A genus of enveloped, segmented, -ssRNA viruses in the family
Bunyaviridae
● Infect various species of mice, particularly deer mice without
causing disease to the mice🐀
● Two American strains of Hantavirus are transmitted via
inhalation in dried mouse urine, feces, or saliva to infect the
lungs of humans
● Transmitted from mice via inhalation
Hantavirus
Hantavirustravels throughout the body via the
blood
