I have started a series of scientific publications in which I am socializing information regarding infections, what they are, how they are expressed, and especially in this first stage dealing with what are the characteristics in humans and the pathogens that cause an infection to be expressed as a disease.
I have already shared a first part of the series Understanding Infections, in which I broke down the main characteristics related to human beings, let's continue with those that correspond to the causative agents (bacteria, viruses, fungi, parasites, etc.).
Virus and bacterial infections are by far the most frequently encountered, and therefore are the ones I will talk about in this publication, and I will leave for a third part of this series the characteristics that correspond to parasite and fungal infections.
We will begin by understanding the main characteristics that differentiate viruses and bacteria at a structural level.
Bacteria are unicellular prokaryotic organisms (they have no cell nucleus), i.e. they are basically a cell, which uses its environment to acquire nutrients. We can compare them to the cells that make up our organism. They have a cell membrane and organelles, which are responsible for keeping them alive through their cell metabolism.
They have the capacity to reproduce by themselves, in a very similar way to that used by human cells, through cell division. In the process they usually release toxic substances for the organism that serves them as host, and this is what generally produces the disease.
It should be noted that not all bacteria are harmful, for example, we have a wide variety and quantity of bacteria that are permanently living with us in different parts of the body, for example, at intestinal level they are of vital importance to absorb some nutrients.
The above in relation to bacterial structure, I don't want to say that it is the only thing, but it is what I wanted to highlight for the purpose of this publication.
As for viruses, there are some important points that differentiate them from bacteria, we could say that the main thing is that they are not a cell but rather a fragment of DNA or RNA, which have a special coding with specific orders to execute.
These fragments of genetic material are particularly sensitive, so they require a special coating so that they do not suffer any damage, this coating is called Capsid and is basically composed of protein.
There is still a discussion as to whether viruses are living beings or not, since they possess genetic material and can evolve. But they require cellular help from living organisms in order to reproduce.
Viruses are much smaller than bacteria, they can enter bacteria and use their organelles to reproduce, just as they can enter an animal cell.
The difficulties to determine without laboratory tests whether an infection is bacterial or viral is related to the similarity in the expression of symptoms, for example, in a respiratory infection (produced by either agent) there will be presence of fever, cough, expectoration, sore throat, and general malaise.
Based on these symptoms there is no certainty as to what the agent might be, but even so one can have a notion based on the evolution. For example, a very important data is the color of the mucus that is generated. Generically but not definitively- it is known that bacterial infections tend to be greenish, but viral infections tend to be more crystalline.
The latter can be confusing, as the process may start with a viral infection and "over-add " a bacterial one.
Also the presentation and duration of fever is something that we can use to have a first diagnostic impression. Fever produced by bacterial infection usually tends to appear and does not reach such high peaks so quickly, contrary to what happens with viral infections.
If we observe the patient's throat, we could find reddening of the area only when the infection is caused by virus, but when it is caused by bacteria, whitish or greenish plaques will be seen frequently-.
As can be seen in the above, guided by the symptomatology we could get a good idea of what is the causative agent, but it is not always definitive, to have a more accurate diagnosis it is necessary to perform paraclinical tests such as complete hematology, ESR, chest X-rays.
The main thing in this case is the Hematology, since there we can find a quick answer to what we are looking for, especially in the leukocyte count (white blood cells), that depending on the interpretation we make of these we could determine the origin of the infection.
Example:
- Viral infections have the tendency to lower the leukocyte count, unlike bacterial infections, which cause them to rise.
- Among the different types of white blood cells are neutrophils (fight bacteria) and lymphocytes (fight viruses); When the infection is viral, lymphocytes are elevated and neutrophils are decreased. And when the infection is bacterial, the opposite happens.
And so, only with a hematology added to the clinical examination we can have a more accurate diagnosis, and of course, a notion of the treatment that the patient deserves.
As for the treatment, it differs greatly, because the bacteria treated with the corresponding antibiotic are eliminated, but the viruses are not affected by treatments.
In general, the immune system stops the advance of the virus and eliminates it from the organism, so rest, water intake, good nutrition and prevention are recommended. Antibiotics are not recommended, unless there is a subsequent over-infection.
This point of the treatment is very important, because usually people always want to be prescribed antibiotics, even when it is not necessary.
Conclusion
Infections will always be present, regardless of the cause, and it is something we must keep in mind. Vaccines are excellent in preventing infections, because they provoke an immune response that generates immunological memory and prevents future infections or their severe expressions.
The same structural characteristics of both pathogens are the ones that mark their mechanism of infection. Therefore, the treatment will be very different in each case.
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