History Of The Influenza Virus Biology Essay

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A stubborn and persistent pathogen, the Influenza virus has plagued mankind throughout history with its enduring characteristics of constant transformation and adaptation. However, consistencies between strains recorded over time have made it possible for scientists and health professionals to predict spreading trends, such as seasonal epidemic patterns, and promote and pre-warn of times of risk through Public Health Interventions. This report is going to highlight the influenza pandemics in the past, biological factors, environmental factors and health sector responses.

Influenza pandemics in the past

In 1918 the world fell victim to the most devastating pandemic known to mankind resulting in over 40 million deaths in less than a year. Whilst many theories to where this spread of the Spanish influenza began have been made, there is no consensus on its origin. What is clear is that the mass movement of people post WWI contributed immensely to the spread of the influenza pandemic (Kolawole, 2010). Sea vessels carrying returning soldiers were docking at major ports all over the world.

How it was spread

Pandemics in the past have higher mortality rates than any recent pandemic because health professionals of the time were not actually aware of how the influenza virus was caused. The United States Department of Health and Social Services (2008) stated that in the nineteenth century it was a medical belief that dirt and air particles, generally characterised by a bad smell, were the cause of illness rather than microorganisms. This was known as the Miasma theory, however it was quickly dismissed as scientific discoveries such as microbiology were made.

Through these discoveries we now know that there are two main ways of transmission of the influenza virus; through airborne particles and body fluid transfer from coughing and sneezing. Symptoms of the Spanish Influenza, "... include high fever as well as body aches, muscle and joint pain, headache, sore throat, and productive cough. Shortly after this, delirium, shortness of breath, hemorrhaging [sic] and cyanosis may occur. Thus, indicating the presence of pneumonia. In short, the disease was sudden and often times fatal." (Kolawole, 2010).

How it was managed

One major effect of WWI on the pandemic was the lack of doctors and nurses as they were abroad tending the wounded soldiers. To compensate for this, medical students were required to postpone their course in order to act as temporary nurses. In addition to this, managing the pandemic demanded large scale health response measures in an attempt to combat the spread (Kolawole, 2010). The government implemented educational procedures in which the emphasis was on teaching people personal and community hygiene as an instrumental tool in preventing infection. (The United States Department of Health and Human Services, 2008). Infectious disease control was vital during this epidemic, "... there were campaigns against sneezing, spitting and coughing and people were required to wear masks when in public to control the spread of the disease" (Kolawole, 2010).

How we should respond now

As we reflect on the past, it is evident that the best possible way to minimise morbidity and mortality rates is through early detection. Early detection promotes early intervention and plans can be implemented for quarantine and control. Immunizations must be provided if they are available, as this has proven an instrumental tool against rapid spread of the influenza virus.

Biological factors

There are a variety of biological causes of illness, including viral, bacterial and fungal infections. Influenza, however, is only present as a viral strain. A common misconception is that influenza can be treated using antibiotics. However, antibiotics are only effective against bacterial infections and therefore cannot be used to treat influenza. Viruses are microscopic micro-organisms that are unable to replicate independently. Therefore, a virus must attach to and invade a host cell to survive. Once inside the cell, viruses alter the genetic material within the nucleus, causing the cell to produce more viral cells. The influenza virus is divided into three strains; A, B and C. Strains type A and B are responsible for annual influenza epidemics and associated hospitalisations and death. Type C infection usually causes more mild respiratory effects or no symptoms at all. (Davis, 2011, para. 5) Each year variation in existing influenza viral strains arise, as a result of processes known as antigenic drift and antigenic shift. "Antigenic drift refers to small, gradual changes that occur through point mutations in the two genes that contain the genetic material to produce the main surface proteins of the influenza virus, hemagglutinin (H), and neuraminidase (N)," ("How Influenza Viruses Change," 2005). These mutations occur randomly and cause minor changes to these surface proteins, producing a new influenza strain that the immune system may not recognize. Pandemic viral strains arise through a process known as antigenic shift. "In this process, the existing viral H and N proteins are not modified, but are replaced by significantly different H and Ns," ("Antigenic Drift vs. Antigenic Shift," 2009). Antigenic shift can occur if influenza is contracted from animals, or if animal and human strains are mixed to create a new influenza strain. For example, swine flu (H1N1) and bird flu (H5N1) arose from antigenic shift. ("How Influenza Viruses Change," 2005). Again, this process develops a strain of influenza that is not recognized by the immune system. The alteration in the genetic material of the influenza virus is one of the main causes of the dramatic impact of influenza on the health of individuals.

Environmental factors

Proactive control procedures and strict observation and maintenance of environmental hazards are essential within the management of communicable diseases, such as the Influenza virus. Preventative and harm-minimisation techniques that have been passed down and refined through time all stem from a common principle: sanitation. Conventional control techniques, such as quarantine, direct sanitation through disinfection and treatment, as well as repellent procedures and necessary extermination of infected animal vectors, are all sanitary measures still employed today within control of the Influenza virus. However, modern advances within the understanding of microbial disease show that particles of a pathogen lodge and preserve themselves within bodily mucus and fluids, using birds and mammals, including humans, as necessary transmission vehicles for their spread (Thomas, et al; 2008). This knowledge entails more precise control of vectors, through the means of more specifically applied disinfection and sanitation techniques, as well as preventative measures, such as simply covering the nose and mouth to avoid transmission through common bodily procedures, such as coughing and sneezing. Large scale Public Health Interventions have therefore become crucial to relay prevention messages, often very simple and practical, especially within crowded city areas of low socioeconomic status, as well as to the broader community. The many overwhelming successes of Public Health Intervention within the field of communicable disease include: immunisation programs, sewerage systems, proper rubbish disposal and collection, pest repel and control, promotion of frequent hand washing and drying, and the aforementioned promotion of covering of facial outlets whilst coughing and sneezing (Feery, 1997, p.61-63). Despite this, as stated previously, there is still an increased risk for epidemic within poorer metropolitan populations across the world, and this must be constantly monitored (Rosenthal, 1990). On top of lower levels of general hygiene, high levels of pollutions and reduced abundance of flora within these areas creates higher levels of harmful gases within living environments, leading to depressed immune systems and higher rates of general morbidity (Nadeau, et al; 2010). These issues are, and will continue to be, of paramount importance to a vigilant and responsive environmental health sector for years to come.

Health Sector Response

Disease susceptibility

Communities that are from remote areas, or are classed as a low socio-economic status community are more susceptible to the disease, as they may also experience overcrowded living conditions. Overcrowded living conditions allow the disease to spread rapidly, due to close proximity to infected individuals. Socio-economic status may impact the level of education that the community has had access to, as they are less likely to have had an immunisation program put in place (Response, 2011). Education in communities firstly emphasises how to prevent the disease, and secondly how to minimise the spread to the wider community. An epidemic can rapidly turn into a pandemic due to the easy access to public transport and global transport. This allows the disease to spread more rapidly than ever seen before. In the future it is likely that there will be new strands of the disease which will arise and our bodies will not be able to fight. This may lead to an epidemic and possibly a pandemic if a vaccine cannot be found before it has the opportunity to spread throughout communities (Response, 2011).

Public Health Intervention

Public health organisations have put in place many procedures and programs which help educate communities to prevent the onset of the disease and how the disease is to be managed so that it then prevents an epidemic and possibly a pandemic (Response, 2011).

Minimising the spread

Immunisation programs have been put in place, which then makes the number of susceptible people in a community greatly lower. Health professionals are expected to report any possible new strands of influenza to the WHO (Response, 2011). Since preventative measures have been put in place there has been a dramatic decrease in the number of deaths due to the influenza virus. Throughout 2010 in Australia there were only twenty-two deaths with a median age of fifty-two. The total of deaths due to influenza worldwide from April 2009 to August 1 2010 was 18,449 (Aging, 2010)

Control Policies

There have been policies and legislations put in place which enable health professionals and the government to monitor diseases and their prevalence and impact on certain communities, which then give an idea on where resources need to be placed which will prevent an epidemic occurring. Timely disease detection is a major part of this.

Plans that are in place to prepare health services if an epidemic/pandemic ever occurred in Australia include; preventative vaccinations, awareness campaigns (television, radio posters or bill boards), encouragement of personal hygiene, quarantine centres and curative procedures (Cameron, 2010).

The above confounding factors display the complex and ongoing battle society will continue to fight against communicable disease. Through what we have learnt in past pandemics, microbial diseases such as the influenza virus can be controlled through health promotion strategies, maintenance of environmental hazards and public health interventions such as immunisation programs. The best way to minimise the impact of influenza on communities is through early detection and early intervention strategies; thus reducing morbidity and mortality rates.