Influenza: Epidemiology, Physiology, and Pathophysiology Analysis

This report delves into the physiology and pathophysiology of influenza, examining the normal functioning of organ systems and the abnormalities caused by the virus. It explores the epidemiology of influenza, particularly in New Zealand, and discusses the virus's impact on the respiratory system, including the signs, symptoms, and diagnostic tests. The report also analyzes existing prevention and management strategies, with recommendations for improvement. It covers the digestive, respiratory, circulatory, and excretory systems, explaining how influenza disrupts normal physiological processes. The discussion includes the effects of the virus on the respiratory tract and the subsequent immune response. Overall, the report aims to provide a comprehensive understanding of influenza to aid in better prevention and management.

Physiology
And
Pathophysiology

ABSTRACT
The given reports is based on the physiology including functioning of organs systems of
living being and pathophysiology that consist abnormalities in functions of organs due to disease
or injury to analyse actual cause of specific health problem. It includes the particular health
condition of Influenza along with its social reasons such as poverty and cultural aspects.
However, the pathophysiology of Influenza in New Zealand will be present in the given
assignment including related signs and symptoms which provide support to make appropriate
decision of providing correct medication for their welfare. The purpose of this report is to
evaluate the causes and existing preventing strategies of Influenza in order to improve them.

Table of Contents
ABSTRACT.....................................................................................................................................2
INTRODUCTION...........................................................................................................................1
DISCUSSION..................................................................................................................................1
Epidemiology of Influenza.....................................................................................................1
Describe normal physiology of systems.................................................................................2
Describe pathophysiology of the disease i.e., influenza.........................................................5
Pathophysiological changes linked to clinical manifestations...............................................6
Explain relevant diagnostic tests and assessments with rationale..........................................7
Analysis of existing prevention or management strategies of influenza................................9
RECOMMENDATIONS...............................................................................................................10
Changes in prevention and management of Influenza by analysing existing strategies......10
SUMMARY...................................................................................................................................11
REFERENCES..............................................................................................................................12

INTRODUCTION
The physiology can be described as a branch of science that deals with study of normal
functions of living organisms and their different body parts (Nelson and Frohman, 2015).
Basically, it includes analysing overall normal functions of different organs systems present in
body of a living being. However, pathophysiology can be explained as to determine abnormal
functioning of organs and other body parts due to presence of any particular health disorder or
injury. In addition to this, it is necessary to carrying out pathophysiology of an individual
regarding identification of specific cause behind any kind of particular health problems or injury
in order to make correct decision for wellness of an individual. The present report is based on
health condition known as Influenza which can be described as a Flu which is a respiratory
illness mainly caused by a virus. Flu is an extremely infectious and usually spread by sneezes
and coughs of an septic person. This assignment will focus on epidemiology, normal physiology
and pathophysiology regarding the selected health problem. It will also include the objective of
pathophysiological changes due to Influenza including signs and symptoms of the same along
with diagnostic tests. The existing prevention and management strategies related to Influenza are
given below.
DISCUSSION
Epidemiology of Influenza
Epidemiology can be described as study about health issues take place in different groups
along with causes of diseases. It involves epidemiological information used to plan and evaluate
strategies in order to prevent illness. However, it is necessary to make apply effective as well as
efficient strategies in order to conduct proper management of patients suffering from specific
health issues in terms of making them disease free. Moreover, it is necessary to analyse actual
causes of Influenza and in occurrence in different group of people because it will facilitate to
make appropriate strategies and practices in order to make people disease free.
Influenza is a very severe condition which is a illness occurred in respiratory system and are
caused by influenza viruses. Mainly Influenza is of two types including Influenza viruses ( A and
B). In addition to this, the epidemiological features of Influenza consists A and B viruses which
is mainly responsible for seasonable flu epidemics (Blanc & et. al., 2016). As A viruses of
Influenza is found in animal such as, pigs, whales, seals, ducks and horses this acts as an one the

major reason for transmitting viruses of Influenza form animal to people. It is required to
determine real causes of commonness of Influenza in Zeeland and globally along with adopting
trends which should be prevented by applying effective practices and strategies in respect of
reducing the problem from society for their well-being.
Influenza viruses H1N1 can be considered as one of the major of cause of Influenza in
New Zealand. It is a respiratory illness which is mainly caused by influenza viruses. There are
different types of symptoms that emerge suddenly. These symptoms include, headaches,
coughing, fever, chills, sore throat, achiness and fatigue. Along with this, in children diarrhoea
and vomiting are common symptoms. In severe conditions of Influenza physicians dictate
antiviral medication and recommend infected persons to drink proper liquid. In addition with
this, Influenza surveillance centre also help them to monitor the factors that circulate Influenza
strains. Influenza vaccination was added in the childhood immunization schedule. Along with
this, there are different type of antivirals are prescribed by doctors, some of that antivirals
include, zanamivir and oseltamivir which is used for some circumstances. In addition to this,
pain relief medications are also available that can able to alleviate some symptoms that include,
body pains and headache. There are different types of painkillers that can be purchased by an
individual via online. But in this it is important to appropriately compare those products and take
proper medical professional advices. Most experts determine that flu viruses is spread by small
tiny droplets which is made when a inflected people with flue sneeze, cough and talk. These
droplets can spread via air and land in the nose and mouth of individual who is nearby. Thus,
when this flu attacked on New Zealand people are advised to stay at home, keep warm and rest,
consume plenty of liquids and eats is possible.
Describe normal physiology of systems
Physiology can be described to understand the normal function of overall organs and
organs systems in living being. However, human physiology can be considered as branch of
science to study about mechanical, physical and biochemical functions in humans along with
serving a foundation of modern medicine. Physiology is helpful to determine normal functions
which facilitate to conduct difference between abnormalities occurred in condition of specific
disease with the help of carrying out pathophysiology. In addition to this, human physiological
consist different types of organs systems present in human body such as digestive, respiratory,
circulatory, excretory, nervous, endocrine & immune and musculoskeletal system which has

their own functions in order to maintain balance in functioning human body to remain healthy
(Gregory and Kobzik, 2015). These organs systems conduct their functions and interconnected to
each other for conducting overall metabolic and other activities of human body in proper
manner.
Digestive system – This systems is composed of various organs which basically carrying
out function of digesting food which facilitate to provide desired nutrients to whole body. It
consist several organs such as mouth, pharynx, oesophagus, stomach, small intestine, accessory
organs and large intestine. Initially, it includes mouth which ingests & chews food, chemical
breakdown of carbohydrates, moves food into pharynx and begins breakdown of lipids with help
of lingual lipase along with moistens & dissolves food and conduct some antimicrobial activity.
However, pharynx is responsible to propels food from oral cavity to oesophagus and lubricates
the same along with passageways. In addition to this, oesophagus also lubricates food and
propels food to stomach and that food is known as bolus. Moreover, stomach is helpful to churns
nutrition with gastric juice in order to form chyme, start breakdown of proteins, release chyme
into duodenum, absorbs some fat soluble substances and possesses antimicrobial functions. It is
also responsible stimulating protein digesting enzymes and secretes intrinsic factor required for
vitamin B12 absorption in small intestine. Meanwhile, small intestine mixes chime with
digestive juices, propels food at a rate slow enough for digestion & absorption, absorb
breakdown products including proteins, lipids, vitamins, minerals, nucleic acid & water and
conduct physical digestion through segmentation. It provides an optimal medium for enzymatic
activity. Large intestine plays role of absorbs most residual water, electrolytes and vitamins
produced by enteric bacteria and propels faeces towards rectum.
Respiratory system – This organ system is helpful in exchange of gases in order to
maintain required concentration of oxygen in tissues and exhale carbon dioxide. It is a
combination of several organs including nasal cavity, pharynx, trachea, larynx, lungs and
bronchioles. However, trachea plays an important role of connecting throat to bronchi and
divides bronchi two bronchi- tubes which lead to both lungs in left and right sides. Pulmonary
alveoli is also known as small air sac that delineated by a single layer membrane with blood
capillaries at other end. Meanwhile, the exchange of gases occur through membrane of
pulmonary alveolus which always consist oxygen is absorbed from the air into blood capillaries
which is further transfer to all tissue of body by function of heart. In the same way, carbon

dioxide gets transferred from blood capillaries to alveoli and expelled out via bronchi & upper
respiratory. Lungs consists bronchial tree i.e., air tubes branching off from bronchi into smaller
air tubes in which each one ends with pulmonary alveolus. Main function of respiratory system is
breathing including inhalation and exhalation.
Circulatory system – The circulatory systems is also known as cardio vascular system
including number of organs like heart, arteries & veins, coronary and portal vessels. Basically,
this system has s function flow of blood, nutrients, oxygen, hormones and other gases from and
to cells. Initially heart has a function of pumping blood via network of arteries and veins which is
called as cardiovascular system. In addition to this, systematic circulation is major function of
circulatory systems which has been carried out by arteries, veins and blood vessels. Moreover,
they are responsible for transporting oxygenated blood from heart, delivers oxygen and nutrients
to the cells of human body and then returns back deoxygenated blood to heart (Lee & et. al.,
2015). At the other hand, it has been analysed that arteries carry oxygen rick blood from heart
through the body whereas veins carry oxygen poor blood from body tissues back to the heart.
Furthermore, superior vena cava is responsible carries oxygen poor blood into heart and aorta
carries oxygenated blood from the heart to organs as well as tissues respectively.
Excretory system – This system is composed of kidneys, ureters, urinary bladder and
urethra. The basic function of excretory system is filter blood and remove wastes and produce
urine for excrete out from the body because these substances very toxic for human body. Firstly,
kidneys are bean shaped organ in a pair and carrying out function of filtering metabolic wastes,
excess ions and chemicals from the blood to form urine. Secondly, ureters are a pair of tubes
which plays an important role of carrying urine from kidneys to urinary bladder. Ureters are
getting sealed at the point of entry to bladder by ureterovesical valves and these valves prevent
urine from flowing back towards kidneys. Thirdly, urinary bladder is a kind of hollow sac organs
which conduct function of storage of urine and it cab allow to stretch to hold anywhere from 600
to 800 millilitres of urine. In addition to this, urethra can be considered as tube via that urine
passes from passes to the exterior body. However, the female urethra is around 2 inches long and
ends inferior to clitoris & superior to the vaginal opening. In contrary to this, male urethra is
around 8 to 10 inches long and ends at the tip of penis and it is also helpful to male reproductive
system as it carries sperm out of the body through penis for insemination. Kidneys help to
maintain homeostasis of certain internal condition by balancing ions, pH, osmolarity, blood

pressure and filtration with help of nephrons. Kidneys also produce several hormones such as
calcitriol, erythropoietin and renin.
Describe pathophysiology of the disease i.e., influenza
Influenza viruses are important human respiratory pathogen which causes preriodic,
endemic infection and seasonal, unpredictable pandemics. When influenza virus introduced into
respiratory tract, by contact or by aerosol with other respiratory secretions or saliva from infected
person, it attaches to and then replicates in epithelial cells (Gotts, Abbott and Matthay, 2014).
This virus replicates in cells of lower and upper respiratory tract. The viral replication joins with
immune response to infection which lead to loss of cells lining and destruction respiratory tract.
Infection subsides, epithelium is regenerated, mechanism which can take up to one month.
Weakness and cough may persist up to two weeks after the infection. Influenza complication of
lower and upper respiratory tract are most common. These include sinusitis, croup, bronchitis
and otitis media. Pneumonia has severe complications to get influenza infection, which can be
observed in children and adults. This virus replicates in the alveolar epithelial cells, which leads
rupturing of wall of bronchioles and alveoli.
Influenza virus travel through air in droplets, in the case someone has infection sneezes,
talk and cough. And these droplets can be inhaled directly by the other healthy person and the
object which has germs can be picked like computer keyboard and telephone and that transfer
germs to nose, mouth and eyes. Individuals with virus are contagious from day and sometimes
the symptoms appear later like after 5 days. Individuals and children with weak immune system
can be contagious for slightly longer time. This virus is constantly changing with the new strains
which appears regularly.
Causes of Influenza
Influenza is mainly caused by influenza virus which infects throat, lungs and nose. This
virus can be spread one person to other. As this virus is airborne and spread through droplets
which produces from sneeze and cough. It can also spread from one person to others. As children
come in the contact of things which have germs and viruses which cause the influenza infection
more in children. The adults who work, those cal also spread the virus to others. Main causes of
influenza virus is not maintaining hygiene and cleanness. Not washing hands often can cause the
influenza.

The major causes of Influenza are influenza viruses. Mainly there are two type of
influenza that includes influenza viruses (A and B). It can further transmitted by air, sneezing
and coughing by an infected person via air (Pan & et. al., 2014). A main cause of influenza is
influenza virus which leads towards infecting throat, lungs and nose. In addition to this, can also
infect a person by touching a surface and a object that already consists flu viruses. Viruses of
type A and B generally cause large seasonable outbreaks and it resulted in a highly contagious
disease. Influenza is mainly spread when an individual come into the contact of an infected
person or a stuff which already consists flu viruses. It is entered in a person if they touch a
surface and use that same to touch their mouth, nose and eyes. This flu mainly attach during
winters as they live longer in cold places because winter contains less humid environment. In
New Zealand major causes of Influenza was avain flue (H5N1) and H1N1(swine flu). There are
different type of symptoms that include, runny nose, chills, muscle aches, cough, congestion,
headaches and fatigue. In this an individual may face pain in their areas like muscle and get dry
cough with phlegm. Viruses of Influenza keep on constantly changing. Thus, flu viruses of
Influenza travel through the medium of air as a tiny droplet by an infected person. This can affect
a person as they may inhale those droplets directly or they can get contact with germs by
touching an object like, keyboard or telephone. This will further transfer into a person body by
transferring in their nose, mouth or eyes. Influenza can be easily spread through a person to other
person in a direct or indirect way. Along with this, droplets by other if contaminated on surfaces
like, clothing, dishes, and utensils can also effect a person if he touched that and made contact
with their nose or mouth.
Pathophysiological changes linked to clinical manifestations
Clinical representation of influenza which ranges between mild to severe condition that is
depend on vaccination status, natural immunity to virus, age and co- morbidities. Normally,
patients who have received seasonal vaccine existing with milder symptoms and they develop
less complications. Symptoms and signs of influenza in mild cases like fever, cough, myalgia,
runny nose, congested eyes, headache and sore throat. A frontal is normal presentation with the
selected ocular symptoms which include photobhobia and also pain with different qualities.
Cause of ocular pain is associated to viral tropism which is related to certain types and also
subtypes. Some severe cases can progress to hypotension, tachycardia, shortness of breath and
other respiratory interventions.

Epithelial of bronchioli: When body infected with influenza virus it changes the
epithelial linings which are erythematous and filled with the thin blood stained fluid. Epithelial
are necrotic, simpler structure of bronchiolar epithelium, flattening and thinning of the cells can
be much pronounced that those in larger airways. And this case complete loss of epithelial layer
which can seen and often associated with information of hyaline membranes.
Duct of mucus glands: Degeneration of epithelial cells in bronchial and tracheal mucus
glands in the infection of influenza. And overlaying epithelial and changes consists of
desquamation and cynonecrosis.
Tracheobronchial changes: This involves epithelial cell lining upper respiratory tract
which is recognised and correspondence to clinical symptoms and signs of traceobronchitis and
pharyngitis. The major changes occur particularly severe tracheitis (Vlahos and Selemidis,
2014). In acute stage, desquamation and multi-focal destruction of pseudostratified columanar
epithelial of bronchi and trachea are characteristic. Sometimes only basal layer of epithelium
remains.
And early structural changes can caused by influenza virus in epithelial of upper airway
are changeable, it include cytonecrosis primarily involving vacuolization and shrinkage which is
followed by desquamation of these cells in luminar space. The necrotic cells can also undergo
phagocytosis by the microphages. These changes in structure to epithelium are irregular
distributed as well as pathology regions can abut areas which is appearing hislologically normal.
These physiological changes may risk to other physiological diseases. Influenza virus
also increases the risk of pneumonia. It also can infect with the other respiratory problems which
can be dangerous to individual health. Such type of physiological changes interrupt the other
body mechanisms and important process of body. Internal destructions of cells and tissues can
also cause the internal part's injury. Influenza virus also cause other respiratory and infections
which can be severe for individuals. This virus is airborne and can be get inside the body through
small droplets which create severe cause in individual.
Explain relevant diagnostic tests and assessments with rationale
Diagnosis test are required to decrease influenza in individuals. Influenza virus testing
is not necessary to make clinical diagnosis of influenza in patients with suspected influenza,
specifically during increased influenza activity during seasonal influenza A and B viruses which
are circulating in local community. There are two types of influenza virus those are A and B

which causes annual flu most epidemic and pandemics. Influenza type C may cause mild
respiratory illness. There are several subtypes of influenza A viruses. A number of tests may help
diagnosis of influenza (Woods & et. al., 2015). These test are not required for the every person
who is suspected. Diagnostic tests available this infection include serology, viral culture, reverse
transcription polymerase chain reaction, rapid antigen testing, molecular assay and
immunofluoscence. Specificity and sensitivity of any test for influenza can be vary by laboratory
which performs test, type of tests which are used, time from illness start to the specimen
collection and types of specimen tested. Among respiratory specimen for the vital rapid or
isolation detection of human influenza viruses but nasopharyngeal specimen mainly have high
yield compare to throat or nasal swab specimen. Screening of people who are suffering from
influenza is the first step for diagnosis. There are diagnostic tests which are done to check the
severity of the disease and to give appropriate treatment according to diseases.
Immunofluorescence: These assays are an antigen detection assay which is require use
of fluorescent microscope, which produces results in 2-4 hours approximately with high
specificity and moderate sensitivity. Indirect and direct fluorescent antibody staining assay detect
influenza A and B viral antigens in the respiratory tract specimens. This assay also used in New
Zealand to detect the infection virus so treatment can be provide to the people of New Zealand
country.
Rapid molecular assays: These Assay are new type of molecular influenza diagnostic
test. These are used for upper respiratory tract with specificity and sensitivity. In these assay
isothermal nucleic acid amplification which has high specificity and hifg sensitivity and give
results within 5 minutes. To get early results for the influenza infection this assay is used in New
Zealand, to get results in lesser time.
Serological testing: This is a type of routine testing which is used for influenza which
requires convalescent sera and paired acute, does not gives results to help with the clinical
decision making, only accessible at limited number of research laboratories or public health and
not commonly recommended except for public health and research investigations. Serological
testing results for the antibodies to the human influenza viruses on single serum specimens which
is not interpretable or not recommended (Gotts and Matthay, 2014.). These type of tests are
generally do not recommended to influenza suspected patients in New Zealand because of some
limitation in clinical field so it is only used in research field for investigations.

Other molecular assay: Other molecular assay and reverse transcription polymerase
chain reaction can identify presence of influenza viral RNA in the respiration specimens who are
with specificity and high sensitivity.
These diagnostic tests and assays are used to detect the severity of infection in New
Zealand which helps to understand influenza infection properly and gives an idea of treatment
which can be given to patient.
Analysis of existing prevention or management strategies of influenza
There are several simple steps which can be use to to prevent individual's health and
also from influenza during the season. There are several preventive measures and management to
prevent and control influenza in New Zealand.
Personal protective measures are important to prevent influenza infection. This
infection is mainly season specific and symptoms are quite normal so hard to predicted the
infection. And usually individual get affected in absence of specific vaccine which is required to
get earlier (Li & et. al., 2016). Children can be prevented by giving influenza vaccine which
reduces the risk of getting influenza. An individual has to take vaccination every year, but some
health habits such as washing hands often and covering mouth while coughing. There are flu
antiviral drugs are available which can prevent influenza.
Avoid close contact: Avoiding contact with people who are infected, distance should
be maintained which can prevent influenza in New Zealand. The influenza virus is normally
seasonally so in that season individuals have to avoid contact with those people who are infected
it can prevent from spreading from one to others.
Cover mouth and nose: While sneezing and coughing, an individual has to cover
mouth and nose. It can prevent the initial infection of influenza in New Zealand.
Clean hands: Hand wash and sanitizer has to be used to clean hands. Alcohol based
hand rub can be also used to clean hands which prevent the infection of influenza which is
airborne.
Immunization in working adults and school children: Working adults and school
children are major spreaders of the influenza in community. There are health workers whose are
trained to give vaccine, those can provide vaccination to adults as well as children which will
reduce the risk of influenza (Wang, Yao and Yao, D., 2015). They will be already immunized so