Concept and Etiology: The influenza virus primarily attacks your
respiratory tract: your nose, throat, and the tubes that lead to your
lungs. It is an acute viral infection of the upper or lower respiratory
tract. Influenza has been focused on in the past as a seasonal disease
that is caused by the RNA virus
, generally spread via airborne
droplets, which easily affect people during breathing and swallowing,
and which can become severe. The influenza virus
is spherical and
belongs to the family Orthomyxoviridae
. The influenza virus deviates
from the definition of health discussed in Module One, because
the influenza virus is an acute contagious infection of the airways
and lungs, so influenza can affect a person’s health physically.
Classification: Influenza is caused by any of several closely related
viruses in the family Orthomyxoviridae
(a group of RNA
viruses).
Influenza viruses are categorized as types A, B, C, and D. The A
viruses
cause the great influenza epidemics
, and the B viruses
cause
smaller localized outbreaks. The C viruses
cause only mild
respiratory illnesses
in humans. Influenza D viruses are not known to
infect humans and have been observed only in pigs and cattle.
Clinical Manifestations (Symptoms and Signs): Flu signs and
symptoms usually come on suddenly. People who are sick with flu
often feel some or all of these symptoms:
Fever or feeling feverish/chills
Cough
Sore throat
Runny or stuffy nose
Muscle or body aches
Headaches
Fatigue (tiredness)
Some people may have vomiting and diarrhea, though this is
more common in children than adults.
Not everyone with the flu will have a fever.
Diagnostic Tests: A number of tests are available to detect flu viruses
in respiratory specimens. The most common are called “rapid
influenza diagnostic tests (RIDTs).” RIDTs work by detecting the
parts of the virus (antigens) that stimulate an immune response.
These tests can provide results within approximately 10-15 minutes
but may not be as accurate as other flu tests. Even if the rapid test
came back negative, you can still have the flu. Other flu tests called
“rapid molecular assays” detect genetic material of the flu virus.
Rapid molecular assays produce results in 15-20 minutes and are
more accurate than RIDTs. There are several more accurate flu tests
available that must be performed in specialized laboratories, such as
those found in hospitals or public health laboratories. These tests
include reverse transcription polymerase chain reaction (RT-PCR),
viral culture, and immunofluorescence assays.
I hope I was able to provide everyone with a better understanding
and better details related to the influenza virus,
References
Centres for Disease Control and Prevention. (2021, October 7). Flu
symptoms & diagnosis. Centres for Disease Control and Prevention.
Retrieved November 8, 2021,
from https://www.cdc.gov/flu/symptoms/index.html.
Centres for Disease Control and Prevention. (2021, September
14). Diagnosing flu. Centres for Disease Control and Prevention.
Retrieved November 8, 2021,
from https://www.cdc.gov/flu/symptoms/testing.htm.
Gopinath, S. C. B., Lakshmipriya, T., Hashim, U., Arshad, M. K. M.,
Ayub, R. M., & Adam, T. (2016, August 5). Influenza viral infection in
the respiratory system-potential ways of monitoring. The Microbiology
of Respiratory System Infections. Retrieved November 8, 2021,
from https://www.sciencedirect.com/science/article/pii/B97801280
45435000026
.
Module 1 : Influenza - what is it and how do you get it? (n.d.). Retrieved
November 8, 2021,
from https://www.who.int/diseasecontrol_emergencies/training/PI_
M1_transmission_jan07.pdf?ua=1
.
Story, L. (2018). Influenza. In Pathophysiology: A practical
approach (pp. 134–136). Jones & Bartlett Learning.
