Unit 3 Case 3: Influenza Flashcards
virus of flu
influenza
virus of common cold
rhinoviruses
parainfluenza
seasonal coronaviruses
primary infection
first time body is exposed to and infected by a pathogen
secondary infection
when a primary infection has made a person more susceptible to disease
how can someone become more susceptible to disease
changes to immune system
comprised skin
consequences of treatment
changes to immune system
diseases can lower the immune systems ability to fight off harmful pathogens
comprised skin
skin infections can compromise the skins ability to act as a barrier especially when breaks or sores, can act as entry points for new infections
consequences of treatment
common with antibiotics
can kill good bacteria aswell as harmful bacteria
examples of secondary infections
pneumonia
symptoms of flu
sudden high temperature
aching
fatigue
dry cough
sore throat
headache
difficulty sleeping
loss of appetite
emergency flu symptoms
difficulty breathing
chest pain
dizziness
seizures
worsening of existing conditions
severe muscle pain
dehydration
pale grey or blue skin
sneezing mechanism
stimulation of trigeminal sensory nerves in the nasal epithelium
triggers sneeze centre in the medulla to trigger reflex activation of nasal and lacrimal glands
causes rhinorrhoea
facial muscles cause closure of eyes and grimace
respiratory muscles cause inspiration followed by explosive expiration
coughing mechanism
aspiration of food or fluid in the airway and stimulates sensory receptors supplied by vagus nerve
cough associated with URTIs caused by hyper-reactivity of the response and cough occurs spontaneously
cough can also be initiated and inhibited by voluntary control, indicating some control of cough from cerebral cortex
fever and chills mechanism
fever caused bycytokine released from macrophages and other immune cells
cytokines may act on vagal nerve endings or enter the brain to cause resetting of temperature control centre in hypothalamus
hypothalamus causes shivering and constriction of skin blood vessels and initiates sensation of chilliness perceived at level of cerebral cortex
lifestyle treatments of flu
rest and sleep
stay hydrated
pain relievers
keep warm
prescription treatments of flu
oseltamivir, orally
zanamivir, inhaled
peramivir, intravenous
baloxivir, orally
when are anti-viral drugs prescribed to patients with influenza
if hospitalised
severe/complicated/progressed illness
higher risk for flu
antigenic drift
consists of small mutations in the genes of influenza virus that can lead to changes of surface proteins HA and NA
HA and NA are antigens recognised by immune system
what is HA
hemagglutinin
what is NA
neuraminidase
antigenic shift
abrupt major change in flu A virus
resulting in new HA/ new HA and NA proteins
why do we need annual flu vaccines
due to antigenic drift and shift
new variants means older vaccines will be less effective
6 types of vaccines
live-attenuated
inactivated
subunit, recombinant, polisaccaride and conjugate
toxoid
mRNA
viral vector
live attenuated
use weakened form of germ that causes disease
life long immunity as they create strong and long-lasting immune response
chicken pox/small pox
inactivated vaccines
used to kill the version of the germ that causes the disease
don’t provide immunity like live vaccines so require several doses over a Long period of time
flu vaccine