In this essay, a description of the three most important features of an infectious disease so that it may be regarded as truly harmful and cause for great fear for the community’s health is made – the infectivity, pathogenicity and virulence.
It is also justified and explained why these should be regarded as the most important ones, being that they are the ones that cause higher numbers of diseased people with great and quick consequences.
Furthermore, it is also explored why the others – toxigenicity, resistance and antigenicity – should only be regarded secondary to the onset of the first three ones.
Keywords: infectivity, pathogenicity, virulence, toxigenicity, resistance, antigenicity, infectious, disease, most harmful, serious consequences.
- Most important characteristics of risk imposing diseases
Among the six characteristics of infectious diseases that are considered, there are three that can be the one that seem to be the cause for greater risk to the community and for greater care and fear.
The virulence would be the first, since being both associated with diseases that cause greater negative consequences for a person’s health and with the ones that are capable of causing death itself, when present in the body, such infectious diseases need greater care and prevention, in order to make sure that they do not infect a great number of people.
Following this chain of thought, these infectious diseases’ infectivity is also very important, because only those with a high infectivity pose greater risk of entering large numbers of community members.
Associated with such notion is the last characteristic to be found as most important, which is the pathogenicity. According to a high rate of this feature, an infectious disease will easily cause the considered disease in the people that are infected.
- Why are these the most important ones
The selected characteristics pose a greater risk for the community’s health, because the greatest danger is present when an infectious disease is more severe and cause of greater health risks if being easily transmitted to the people (high infectivity); when, in those infected people, it easily causes the referred illness (high pathogenicity); and when this considered infectious disease causes severe and even life-threatening consequences to the infected body (high virulence).
Without these three characteristics all together, an infectious disease is not prone to cause the biggest, most severe (and in highest number) effects that its pathogenic potential may have.
- Why the others were not considered as such
Regarding the remaining characteristics – toxigenicity, resistance and antigenicity – although they are important complementary features of an infectious disease, they are not, however, the most important ones.
The ability of producing toxins that damage the body’s function and health, the resistance of the pathogens to the treatments and the low antibody production rate in re-infection cases they cause if having low antigenicity – i.e. the poor recognition of them as pathogens by the immune system – are truly influential when the infectious diseases are set and one is regarding their ability to cause true damage (or even death).
Never the less, an infectious disease, to be dangerous and source of fear for high health risk, must first be easily set inside the bodies in high numbers, be easily able to produce the considered disease itself, and to have a high virulence, so that it is able to cause actual grave/severe damage (which may even lead to death) to the body. After these features set the infectious disease in a high number among the community, with easy onset of it and severe consequences, then the rest become important to consider; but the most important thing that makes an infectious disease so feared is exactly the high numbers of infected people and the quick severe effects.
In conclusion, what defines an infectious disease as a feared one and capable of inflicting great harm to the community when present are its ability to easily infect the body – infectivity –, the ability to easily have the onset of the disease itself on the bodies – pathogenicity – and to have quick and early severe consequences for the health – high virulence.
The other features – its toxigenicity, resistance and antigenicity – are only important after those first three ones are present.
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