Epidemiology of Influenza

This article provides an overview of the epidemiology of influenza, including its causes, symptoms, and prevention methods. It discusses the role of community health nurses in managing and reporting cases of influenza and highlights the importance of public education in combating the virus. Study material and solved assignments on this topic can be found on Desklib.

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Epidemiology of Influenza
Name
Institution

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Introduction
The Centre for Disease Control and Prevention (CDC) defines influenza or 'the flu' as a
virus composed of various strains that attack or infect the upper side of the respiratory system in
human beings and that usually uses animals as the carriers. This virus is known to mutate very
fast that vaccines for it are normally produced every year. This is because every year the strains
of virus are not technically the same as those from the previous year. The influenza virus
commonly infects people during the cold seasons and reaches the peak in winter. The period of
surged or increased infection is what is normally called the flu season during which about two
hundred and fifty thousand people die. Public health nurses can however reduce these effects and
deaths of the virus if preventive care and promotional campaigns for vaccination.
Description of the Disease
The influenza virus is described by symptoms like cough, sore throat, nasal congestion,
headaches, fatigue and muscle pains. When the virus spreads to the stomach, gastrointestinal
distress is also noticed. After four to seven days, the flu is not infectious although the above
symptoms usually persist for about fourteen days before the onset. The influenza virus usually
spreads through airborne particles of moisture which come from an infected individual through
coughing, sneezing and breathing. Risk of infection is increased when a person inhales the
infectious particles and for this reason people who have not been inoculated against the virus are
supposed to put on facial masks when they are with infected persons.
Data from the Centre for Disease Control and Prevention (CDC) and Communicable
Disease Chain states that the most effective way of combating the influenza virus is through

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preventive medicine. This therefore requires annual update of the influenza vaccine and timely
distribution to the population. In addition there should be extensive sensitization campaigns on
the benefits of vaccination against the virus to the people. The main advantage of widespread
vaccination is that the inoculated ones are protected and potential hosts are removed hence
impeding the spread (Chen, Yuan, Gao, Zhang, Wang, Xiong and Zou 2014). There is also
secondary care of the influenza disease which involves the use of antiviral medicines even if they
do not cure the disease nor are they effective as the prevention measures.
There has been an increase in the rate of deaths from influenza in the past decade. This is
after the emergence and discovery of two particular strains of the virus which are H5N1 known
as “bird flu” and H1N1 commonly called “swine flu. H5N1 virus usually infects a range of
animal species like human beings, horses, birds and pigs. On the other hand, H1N1 virus or
swine flu only infects human beings. Bird flu is usually more lethal but less contagious whereas
swine flu is highly contagious but less lethal. In combination, the two influenza strains have led
to a rise in the morbidity and mortality rates of influenza all over the world. According to the
CDC report of 2016, the influenza season of 2014 - 2015 had over 35% of the patients tested for
respiratory conditions testing positive for the influenza virus (Krämer, Kretzschmar and
Krickeberg 2010).
Determinants of Health
The most important environmental factor that determines the spread of the influenza virus
is the animal carriers. This is because both the H1N1 virus and the H5N1 virus are capable of
having reservoirs in swine and birds respectively. When a human being is exposed to the animals
as a result of geographical or demographical conditions, they highly risk getting the infection. As

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such, it is the duty of health workers to take precaution since they are the ones mostly exposed
and can easily contact the virus due to the poor environmental determinant. The moisture
particles through which the virus is transmitted amongst people is known as the agent. This
determinant of health can be affected easily by simple hygienic practices like covering the mouth
when coughing, sneezing or washing hands. In order to influence the risk of infection and spread,
people should also be educated well about the preventive measures and adherence to the
protocols prescribed (Wang, Li and Li, 2010).
Finally the other determinant of health is the period of incubation and the symptomatic
period of the disease. The virus usually stops being infectious after about 6 days within the host
although the host sometimes continues to show symptoms for up to the second week. The
element of time is quite important and therefore a determinant of health in the development of
the disease.
Epidemiological Triangle
There has been extensive research on the epidemiological triangle of influenza and
according to Maurer and Smith it is composed of the host, the environment and the agent.
Human beings are the hosts of the influenza virus as they are the animals that are capable of full
blown infections. A weaker immune system means a higher or increased risk of infection.
Immuno-compromised human beings are the ones that are extremely at high risk of contacting
the influenza virus. The agent is the environment through which the virus is spread that is the
particles.

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Demographics
According Novel Swine-Origin Influenza A (H1N1) Virus Investigation Team (2009), in
the United States, the average number of deaths caused by influenza is about 20,000. Of these
deaths, 90% occur among people who are over 65 years of age. Deaths attributable to influenza
have been increasing substantially in the US since the 1980s because of the increasing aging
population. Hospitalization as a result of complications of the influenza disease is often seen
with children. Demographically, for every 100,000 children, 500 children with chronic illnesses
between the age of zero and four are hospitalized annually. Additionally, about 100 children
without chronic illnesses for every 100,000 children are hospitalized every year.
Causes and Symptoms
Communicable Disease Chain notes that for the first five days after infection with the
influenza virus, the patient is hit with sudden and harsh symptoms like abrupt headaches, dry
coughs, fever with very high temperatures of over 40 degrees Celsius. Nasal congestions and
sore throats are also common symptoms as the flu subsides. There are complications that arise

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from bacterial infections in the lower parts of the respiratory tract. Children and teenagers are
normally required to be cautious of Reye's syndrome like nausea, vomiting and other
neurological problems. The influenza virus causes serious complications in the lower respiratory
system like pneumonia and bronchitis. Neurological conditions like Guillain-Barre syndrome
and cerebral edema are also witnessed in severe cases. Although the neurological involvement is
rare, influenza virus normally causes death through compromising the lower respiratory system
excessively resulting in impeding the ability of the body to receive oxygen (Krämer,
Kretzschmar and Krickeberg 2010). This results in weakening of the body which creates a cycle
that cannot be fought by the body's immune system.
Diagnosis
There exists various specific viral culture tests that are used in identification of the
influenza virus strain from the respiratory samples collected. However, the results usually take
some days before they can be accessed. As such, the doctors usually depend on various
symptoms related to influenza in the community to administer treatment. There are special tests
that are done in order to determine the type of influenza virus in the community.
There are also commercially available tests that take about 30 minutes for the influenza
virus. The tests are mostly useful with children as they allow the doctors to administer treatment
faster. The symptoms can normally be relieved through bed rests as well as ensuring the patient
is properly hydrated. In instances where the patient has breathing complications, a steam
vaporizer is usually recommended to ease their breathing while aches and pains are relieved by
taking pain killers (Alexander 2017). Infection by influenza virus has usually resulted in loss of

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appetite and as such efforts should be made to eat food that is well nourished (Ferguson, Fraser,
Donnelly, Ghani and Anderson 2014).
Role of the Community Health Nurse
A community health nurse plays a vital role in the management and reporting of
influenza virus infection cases. According to Maurer and Smith investigations and reports on the
rates and cases of any communicable disease like influenza are one of the major responsibilities
of a community health nurse. It is the duty of the community health nurse to that gather data,
findings and statistics on communicable diseases like influenza and shares these reports with the
CDC. As such, the main role of a community health nurse in any region is to collect information
and ensuring that the community is well versed and prepared in case of any influenza outbreak or
infection. This information collected and shared with CDC enables a comprehensive and precise
assessment of the risks as well as enabling a proper tracking of the progress in the interventions
administered. The effectiveness of the vaccines administered is also based and rated on the data
collected and presented by the community nurses while the vaccine prepared and produced for
the following year is referenced with this same data (Hope-Simpson, 2013). As such, the data
collected by the community nurses plays a key role in assisting researchers and scientists in
producing the vaccine that is most suitable.
In addition to data collection, the community health nurses also plan and implement
public sensitization campaigns and community workshops to educate and update the populace on
the risks associated with the influenza virus, protective measures as well as the benefits of
getting vaccinated on time against the virus. Organization of the policy reforms in schools,
charitable funding as well as direct communication with the community is a duty that falls under

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the purview of community health nurses in order to address influenza (Chen, Yuan, Gao, Zhang,
Wang, Xiong and Zou 2014).
Role of International Organizations
The World Health Organization (WHO) is the international organization that provides
information and literature about the prevention of influenza infections. The body further assists
in advocating for and organizing of funding for the production and distribution of the influenza
vaccine all parts of the world, up to the community level. The WHO also has an important role in
the fight against spread of the influenza virus globally. From the early 1980s, WHO has been in
the frontline in the research about influenza and its dynamic strains. As the main health body
under the United Nations, WHO has been providing the companies that produce the influenza
vaccine with the information required in the determination of the composition of the vaccine and
the strains that should be target by the vaccine (Stallknecht and Brown, 2017).
Prevention
The Centers for Disease Control and Prevention alongside other local bodies that support
the fight against influenza have always recommended that all people should be vaccinated with
the influenza vaccine annually before the onset of the flu season. For instance, in the United
States, the flu season starts from December and runs through March. As such, America people
should be vaccinated two to five weeks before the flu season starts, which ideally means between
November and early December in order to give the body system ample time to develop
immunity. The vaccine usually contains about three strains which the scientists have established
are most likely to be found the following season and in cases where there is a good match, the

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success rate of the vaccine is usually between 80% - 90% for people under the age of sixty five
(Maltezou 2018).
Conclusion
The most successful tool that can be used in the medical system to combat the influenza
virus is public education. Both the population and the scientists researching about the disease
will be better placed when they access all the necessary information related to the virus.
However, the permanent dynamic nature of the strains of the influenza virus mean that the
disease may never be completely 'cured' but instead every year there has to be a battle fought in
trying to minimize the negative impacts the disease has on the population. The role of the
community health nurses in this battle should never be undermined nor neglected as they are the
main agents of data collection as well as disseminators of information that relates to influenza in
the process of providing effective preventive care to the people.

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