The Presence of Toxins in the Body and the Symptoms of an Infectious Disease - Essay Example

The purpose of this essay is to critically discuss, analyse and determine the extent to which toxin(s) play the role in causing infectious diseases in the human body. By the end of this essay, I hope to conclude successfully whether toxins are indeed, the only reason for people getting infectious diseases. Before embarking upon the explanation of the role toxins play in infecting people, the concept of infections and microscopic organisms must first be understood. Infectious diseases, also known as communicable diseases, kill more people globally than any other cause (NIH: National Institutes of Health, 2012). They keep the doctors on their toes because the emergence of infectious diseases is almost always followed by their re-emergence. Despite the medical community’s best efforts, most infectious diseases are not being successfully eradicated. An infectious disease can be contracted through anything and by any means; by eating, drinking, touching, and kissing, even by breathing in an impure atmosphere. They are everywhere. Infectious diseases exist because of the existence of microscopic organisms. More commonly known as microorganisms, the ones that cause infectious diseases are known as pathogens, that is, any bacterium, fungus, virus that can cause disease (Oxford Dictionary, 2012). The main types of pathogens are; bacterium, fungus, virus and protozoa. An example of each is given below: Treponema pallidum – bacteria that causes congenital syphilis in foetus or Neonate. Rhinovirus – virus that causes the common cold. Candida albicans – fungus that causes Vaginitis. Naegleria fowleri – protozoa that causes meningoencephalitis. People get infectious diseases when microorganisms that enter our body overpower our host defences, that is, when the balance between the organism and host shifts in favour of the organism (Levinson 2008, p30). Now the host defense mechanism is our body’s innate immunity – our body’s defence system against foreign objects entering our body. There can be two possible ways in which our body becomes susceptible to diseases; when the number of microorganisms is too great for our body to bear and counter, which therefore, overwhelms our host defences, or when they are higly virulent. The virulence of an organism can be further understood by the following explanation. “Virulence is a quantitaive measure of pathogenicity and is measured by the number of organisms required to cause a disease. The 50% lethal dose is the number of organisms needed to kill half the hosts, and the 50% infectious dose is the number needed to cause infection in half the hosts. For example, Shigella and Salmonella both cause diarrhea by infecting the gastrointestinal tract, but the infectious dose of Shigella is less than 100 organisms, whereas the infectious dose of Salmonella is on the order of 100,000 organisms” (Levinson, 2008). To further elaborate on Levinson’s explanation, by quantifying microorganisms and host defences through the the measure of virulence factors, we are able to determine which microorganisms make us more vulnerable to contracting infectious diseases. By quantifying our body’s reaction to them, and their affect on our body, we are better able to understand and thus, counteract the harmful effects of them. E. coli, Botulism, Anthrax, Influenza, Hepatitis, SARS, Salmonella, Shigella, Lyme disease and countless more are examples of infectious diseases currently plaguing the world with their constant occurances and reoccurances. But how does the mechanism of these infectious diseases work? When bacteria and other microorganisms are taken in by our body, be it through the respiratory system, via blood, broken skin, or orally; they release toxins into our body. These toxins, depending on their virulence level, result in the beginning symptoms of an infection to appear. If not treated, these symptoms escalate into a full blown infectious disease. Given below is a table showing microorganisms entering our body via skin: (Mims, Nash and Stephen, 2001) Toxin is a poison of plant or animal origin, especially one produced by or derived from microorganisms and acting as an antigen in the body (Oxford Dictionary, 2012). Depending on its severity, toxin production in the body caused by bacteria can result in the body developing an infectious disease. Toxins are all around us. Our environment is filled with chemicals that produce them. Lipsticks, couches, certain juices, all of these products contain chemicals, and thus, toxins in them. Studies by the Environmental Working Group have deduced that there are large numbers of toxic chemicals, going in hundreds, that are contained in the umbilical cord blood of new-borns and these include pesticides, fire retardants and PCBs (Tortorello, 2012). Levinson (2008, p31) explains that toxins can fall into two categories; exotoxins and endotoxins. Exotoxins are polypeptides released by the cell. They are produced and released by microorganisms for example; botulinum toxin is released by Clostridium botulinum. On the other hand, endotoxins are lipopolysaccharides and are found on the cell wall of Gram-negative bacteria. Different pathogens contain different toxins that separately, or together, cause symptoms which then escalate to cause infectious diseases in the body. Once these toxins enter our body, they can overthrow our host defences and thus, make us vulnerable to infections. Toxins that cause infectious diseases are usually bacterial in nature. Bacterial toxins are microbial products, which are capable of damaging host cells and tissues, (Ahmed and Usmani, 2006). An example of bacterium given by Ahmed and Usmani (2006) is the S.Aureus. It has many toxins including Exfoliative Toxin, Enterotoxin and Toxic Shock Syndrome toxin. These toxins result in infectious diseases: Exfoliative Toxin causes the Scalded Skin Syndrome, Enterotoxin causes food poisoning and Toxic Shock Syndrome toxin causes Toxic Shock Syndrome. Scalded Skin Syndrome is when the skin affected by the toxin peels off in layers. Food poisoning is characterized by vomiting and diarrhoea. Toxic Shock Syndrome is characterized by sudden fever, vomiting, diarrhoea, myalgias, et cetera. According to Levinson (2008, p48), only toxins cause infectious diseases; but this may happen through different mechanisms. Sometimes, it is not the organism itself causing the symptoms of the disease but the immune response to the presence of the organism. Here, the role of toxins does not come into equation. Our host defences, recognizing a foreign object, start reacting even though the virulence could have been very low to be of any real danger. Even the numbering of the organisms could have been very little to be able to overpower our host defence system. This is immunopathogenesis. Our antibodies attack the foreign organism, but they become too active and in turn attack the beneficial bacteria and et cetera in our body, thus weakening it. This puts the human body at greater risk of contracting any number of infectious diseases. Then there is invasion and inflammation, which is an extension of immunopathogenesis. It is a medium through which people contract infectious diseases, [Lev08]. Let us explain this concept with examples first. An inflammatory response takes place when the body senses an invasion by some foreign substance (antigen) and attempts at protecting itself from it (A.D.A.M Copyrights, 2012). In ulcerative colitis, the body mistakes beneficial microorganisms for harmful ones and attacks them. In order to fight the infection in our body, the body releases different chemicals and white blood cells (antibodies). This reaction creates by-products which cause persistent inflammation in the intestinal lining. Gradually, this inflammation tends to damage and permanently change the intestinal lining. The inflammatory process is a by-product of the activity of the body's immune system, that is responsible for fighting infection and healing wounds and injuries (The New York Times, 2008). The relevance and relation of this with toxins and infectious diseases is that the invasion of tissues and/or bacteria with the resulting inflammation, leads to toxin production in the body because of the presence of the virulence factors in the microorganisms. This toxin production causes the starting symptoms of an infectious disease in our body, which with time will aggravate the disease to an advanced stage. The statement, “All infectious diseases are cause by toxins” cannot be refuted. Infectious diseases are indeed caused by toxins solely. The medium through which it is caused, the process with which it occurs, the mechanics of it all may be as varied as possible, but the underlying acting force does remains to be toxins. Without the presence of toxins in the body, the symptoms of an infectious disease would never manifest themselves because they will not exist. Invasion and inflammation and immunopathogenesis, both cause infectious diseases, but only because the toxins triggered the initial response from the host defence system. Reference Lev08: , (Levinson, 2008), Read More