Environmental Health and Communicable Disease: Avian Influenza Virus and Its Impact

Running Head: ENVIRONMENTAL HEALTH AND COMMUNICABLE DISEASE 0
Environmental Health and Communicable Disease
9/5/2018

ENVIRONMENTAL HEALTH AND COMMUNICABLE DISEASE 1
Introduction
The essay brings about the discussion on the topic, ‘environmental health and
communicable diseases, and the related aspects. Environmental health and communicable
disease, is one of the major concern in today’s scenario that impacts on the health of the
environment and the society. Environmental health is the branch of the public health which
includes the natural and built environmental aspects affecting the human health. Therefore,
with context to the essay, it can be stated that the communicable diseases are spread from one
person to other or from an animal to the person. There are a number of factors which
influence the spread of the communicable disease leading to the epidemics. Therefore, one of
the communicable disease or Flu is taken under research i.e. Avian Influenza, which is a bird
Flu and the related aspects and concepts determining the level of health and disease (Ding et
al, 2016).
Origin of the virus
Avian Influenza was recorded for the first time, in Italy 1878, and the disease at that
time was known as Fowl Plague. The continuous spread of this disease led to the situation of
outbreaks in poultry, consisting of two in the United States. It has been found that the virus
leading to Fowl Plague is an influenza virus. In the year 1997, highly pathogenic avian
influenza (HPAI), was discovered. H5N1 was found in the humans in Hong Kong which
received a great publicity (Yu et al, 2014).
The virus had been reported and held responsible for a number of confirmed bird flu
infections in the humans and their impact. It killed 60 people in the year 1997, when the virus
was first detected in humans. Avian influenza spreads sporadically throughout the world, and
the diseases had severe impact on the poultry industry, harming millions of chickens, and
geese. The virus is similar to the other viruses acting as illness caused due to the strains of
influenza virus, which adapts itself to a particular host. Amongst all three types of virus, i.e.
(A, B, and C), virus A refers to the zoonotic infection that contains a natural reservoir in
birds, and specifically Avian influenza is referred to the influenza ‘A’ virus (Chan et al.,
2015).

ENVIRONMENTAL HEALTH AND COMMUNICABLE DISEASE 2
Avian Influenza virus and various subtypes
Discussing about the pathways or the transmission of the influenza virus includes that
the influenza ‘A’ virus is adapted to the birds, but it affects the humans as well. It is spread
or transmitted to humans by contact with the infected birds or the contaminated surfaces. It
has been found that transmission from person to person to rare, and risk of infections in
humans is low. The contact with the infected birds usually takes place during the home
slaughter and plucking of infected poultry. Therefore, avian influenza viruses rarely affect the
health of the humans, and such cases have been rarely reported (Ip et al, 2015).
Subtypes of Avian influenza virus
Avian influenza has many subtypes or sub-categories, but not all affect humans, i.e.
there are only 5 subtypes or strains of the virus which are considered affecting humans. These
are H5N1, H7N3, H7N9, and H9N2. Most cases of the human illness due to this virus is due
to the handling of the infected birds. There have been 4 types of influenza virus, i.e. A, B, C,
and D; the influenza virus of ‘A’ types is then divided into other sub-categories based on the
two proteins on the surface of the virus. It has been found that there are 18 known HA virus
and 11 known NA subtypes virus. There are distinct types of combinations of the HA and
NA proteins, for an instance an “H7N2” is the influenza virus that designates an influenza A
virus subtype that contains HA7 protein and NA2 protein. Each subtype of the influenza ‘A’
virus can affect the birds except H17N10, and H18N11, as it is found affecting bats.
Currently, it has been analysed that only two types of viruses i.e. H1N1, and H3N2 are
prevailing amongst people. Moreover, avian influenza virus is denoted as highly pathogenic
avian influenza (HPAI) and low pathogenicity avian influenza (LPAI). It is based on the
capability of the virus to cause diseases with high mortality rate (Chen et al, 2014).
Signs and Symptoms
There are some clinically diagnosed signs and symptoms of the avian influenza virus,
which ranges from mild to the severe conjunctivitis, and the other symptoms. The person
experiencing the H5N1virus is identified with the symptoms or the influenza type illness,
such as fever, cough, sore throat, and muscle aches. It sometimes also includes nausea, severe
abdominal pain, vomiting, and diarrhoea. These symptoms also lead to the serious illness
when not taken care of properly, i.e. respiratory issues; short of breath, difficulty in breathing,
pneumonia, and the respiratory failure. The virus has the symptoms over the neurology