Essay: Body’s defence against disease / Polio

Infectious diseases are ailments and illnesses that spread rapidly and can result in the death of millions if not brought under control. (Study.com, 2016) They are caused by micro-organisms such as bacteria, viruses, fungi and parasites and are easily transmitted by bites, air, contaminated water and food sources and being exposed to infected living beings. (Study.com, 2016)
To defend itself from infectious diseases, the human body has various barriers that fight the harmful micro-organisms that try to enter our body. (Bbc.co.uk, 2016) Some of these defences include physical barriers like the skin, mucus and tears, whereas others are internal, like the immune system. (Answers.yahoo.com, 2016) The skin is slightly acidic, defending and killing large bacteria, however some small viruses can still get past. The stomach is another defence. Some harmful bacteria will have been trapped in the mucus in the throat and will end up in the stomach, eventually being killed from the stomach acids. (Answers.yahoo.com, 2016) Some other defences are more complex, such as fever and inflammation. (Bbc.co.uk, 2016) An inflamed area will inform the immune system of the situation, and the immune system takes immediate actions against it. It isolates the area, disposes of dead cells and tissue, kills the invaders and heals the area. (Bbc.co.uk, 2016) Another way that the body fights invaders, is by increasing the temperature of the body, enhancing its ability to protect itself. (Bbc.co.uk, 2016) The body also has protection against airborne diseases. Lining the walls of the airways is mucus and cilia which trap the micro-organisms to the sides. (Bbc.co.uk, 2016) These micro-organisms are then flushed out of the body when sneezing, coughing or blown out of the nose.
The most prominent intervention in public health in the last 200 years, vaccines prevent the spread of micro-organisms and diseases that can cause serious issues and in some cases, death. Infectious diseases killed huge amounts at the beginning of the 20th century, and few treatments and preventions existed. (Cdc.gov, 2016) After the use of vaccines for a century, smallpox has been completely eradicated and many others have almost been completely wiped out. (Cdc.gov, 2016) After taking a vaccination, the body can become immune to specific diseases, hence the term ‘immunisation’. The vaccines train the body to fight diseases by releasing dead or weakened antigens, forcing the body into action. (Cdc.gov, 2016) The body senses these antigens and produces antibodies to eliminate the threats. In the future if the body encounters the same antigen, it will kill the invaders faster.
A highly infectious disease, poliomyelitis mainly occurs in children and induces a variety of symptoms that include headache, vomiting, fever, fatigue, stiffness in the neck and pain in the limbs. (Anon, 2016) In some rare cases, symptoms can progress further and the virus can cause often permanent paralysis. Polio currently has no cure; however, some treatments can help an infected person recover. Some treatments include antibiotics, physiotherapy and heat treatments. (Health line, 2016) However, polio can be avoided and prevented with immunisation, and is recommended for everyone. The National Immunisation Program offers polio vaccinations for free for babies at two, four and six months of age, children of 4 years and Aboriginal and Torres Strait Islanders. (Health line, 2016)
Poliovirus can be caused by poor hygiene and is spread when water, hands or food have been contaminated by bodily secretions of an infected person (Poliotoday.org, 2016). Once someone has become infected by the virus, they will begin to show the symptoms within 3 to 21 days and will (Mayoclinic.org, 2016) usually remain infected for a few weeks (Anon, 2016). Some people will experience weaknesses, joint pain, fatigue and muscle pain years or in some cases, decades after being infected with poliovirus. This is known as post-polio syndrome (Anon, 2016), and is most common in people who experienced paralysis in the first stage of poliomyelitis.
Post-polio syndrome is not caused by the body contracting the virus again, but the body struggling to recover from the first attack from poliovirus (Anon, 2016). Scientists believe that post-polio syndrome is caused by the damage of the nerve cells that control the body’s movements. (Mayoclinic.org, 2016) This is believed to cause some nerve cells to create new nerve fibres (Poliotoday.org, 2016) that are overworked as they try to compensate for the damage and loss of nerve cells, and over time, the overload on these new nerve fibres begin to die, creating muscle weakness. (Mayoclinic.org, 2016) Like polio, there are no specific cures or treatments for post-polio syndrome, however it has been shown in affected patients that avoiding physical stress, exposure to cold temperatures and conserving energy helps with the syndrome. (Anon, 2016)
The first clinical description of polio was “a debility of the lower extremities” in 1789, provided by Michael Underwood, an English physician. Jakob Heine and Karl Oskar’s work on the disease led to polio being known as Heine-Medin disease and was later known as infantile paralysis, due to the majority of infected people being children. (Healthline, 2016)
In Europe and the United States around 1900, paralytic polio epidemics start to occur in localized areas, and the epidemic (Healthline, 2016) became such a large problem around 1900, it began to reach a pandemic scale in Europe, Australia, North America and New Zealand, and by 1952, polio became the worst outbreak of disease in the United States in history. (En.wikipedia.org, 2016) In 1952, over 58 thousand cases were reported and over 3000 died and 21 thousand suffered from paralysis and muscle weaknesses. (En.wikipedia.org, 2016)
In 1955, the first polio vaccine that was both effective and safe to use was created by Dr. Jonas Salk and the March of Dimes. (En.wikipedia.org, 2016) Before the vaccine was put into use, the number of people infected with polio was approximately 45,000, but within 5 years, that number had dropped below one thousand. (En.wikipedia.org, 2016)
The vaccine polio changed both the epidemic and the cultural view of diseases affecting the population, giving rise to medical philanthropy and fund-raising organisation and campaigns.