Epidemiology: What It Is And How It Studies Diseases
For a few weeks now, a certain virus that many of us thought was not going to be a big deal has ended up giving us a “pleasant” surprise, inviting us to stay home. Not because of laziness or because it hasn’t been a good day, but because it turns out that the street is, right now, potentially contagious.
Given the alarming situation we find ourselves in, it is not surprising that people are wondering about the symptoms, incidence, progression of infection, incubation and elimination period and other factors of the COVID-19 virus.
These questions have their own field of study. Epidemiology is the biomedical science that is responsible for studying the distribution frequency and conditions for the appearance and progression of a disease, and below we are going to see in more depth what it is about.
Epidemiology (from the Greek “epi”, “about; “demos”, “people”; and “logos”, “science”) is the study of the appearance and distribution of events, states and processes related to health in the population. That is to say, It is the medical science that studies diseases and their evolution in the entire population Epidemiologists study the distribution, frequency and factors that influence and determine the progression of diseases in a group of people.
The position that epidemiology occupies in the biomedical sciences is very important, given that serves as a bridge between health sciences and social sciences It integrates both biomedical and social methods and principles to study health, control diseases in the population and study their socioeconomic and biomedical effects.
Although originally epidemiology arose to study epidemics of infectious diseases, such as cholera, the Spanish flu or the plague, today it also includes diseases not necessarily due to bacteria and viruses, such as lung cancer. cause of smoking, addictions, in addition to the appearance of mental disorders such as bipolar, anorexia nervosa or depression, among others.
What is taken into account when studying diseases?
Epidemiologists, when studying a disease, whether caused by a live pathogen such as a bacteria or by habits in the population, such as a sedentary lifestyle and smoking, take into account a series of patterns of the medical condition or psychiatric to study:
1. Time
With time reference is made to when it arises, especially if it is a disease with a possible contagious cause and may have its highest points at a certain time of the year.
2. Place
It is the physical place, like a city, a country, the characteristics of the area where there have been the most cases …
3 people
People refer to those who are more likely to manifest a certain biomedical condition, that is, the risk group.
Normally, in contagious diseases, the groups most at risk are newborns and the elderly.
Epidemiological methodology
The epidemiological methodology uses the observational scientific method because this discipline, to increase its knowledge, has to use real cases that have occurred in the population. That is, look at how many new cases of the disease there are, what individual characteristics make those cases have manifested the disease, what has meant that there has not been such an incidence elsewhere…
The epidemiological method uses fundamentally quantitative techniques. Epidemiological studies do not alter or manipulate the factors that act on people unlike a laboratory experiment, in which the characteristics of the person, the type of stimuli or environmental factors to which they are subjected, among others, are controlled.
Goals
Epidemiology is a fundamental area of biomedical sciences, since it allows us to understand the development of medical conditions, whether or not they are caused by infectious agents. This discipline has the following objectives.
1. Establish the magnitude of the disease
Aims to measure what happens in the population, what are the mortality rates, incidence and prevalence of diseases in addition to the prevalence of risk factors.
All of this serves to know the specific characteristics of health or illness in a population, in addition to being able to monitor over time how changes in these characteristics are occurring.
For example, epidemiology would study why in a certain region there is more mortality than in another, what genetic and environmental factors make a population more vulnerable or what eating habits or habits that imply risk would explain the incidence of the medical condition.
As we have already seen, since its beginnings, epidemiology has tried to discover the reason for the appearance of a certain health state and what causes affect the pathological process.
In essence, It is responsible for identifying factors that imply risk when it comes to manifesting a medical illness or psychological disorder
3. Complete clinical charts
In clinical medicine, epidemiology has a very useful application, since it allows us to specify, through epidemiological and statistical criteria, what the patient is suffering from.
An example of this was the case of rapeseed oil poisoning Through epidemiological research, it was possible to discover that the illness that thousands of people were experiencing was caused by having consumed that specific oil.
4. Detect new diseases
The appearance of new cases of a disease that was not known is studied using the epidemiological method.
This was the case of HIV/AIDS Patients were discovered to have a rare pneumonia, which only affected people who had symptoms of immunosuppression.
5. Evaluate the effectiveness of the health intervention
The epidemiology It is applied to know the effectiveness of any type of health intervention whether prevention or treatment.
6. Contribute to health planning
Although the previous applications already contribute to health planning, epidemiology is also used, specifically, to understand the specific needs of health services, for example, designing health plans.
Furthermore, also It is used to evaluate results after health intervention policies analyzing the objectives set in the previous plans.
7. Contribute to training
Epidemiology not only aims to find out how a disease occurs, what its prevention is, which population is at risk and other aspects directly related to the biomedical condition.
Also aims to train health professionals so that, in the event that the disease appears, they know, by consulting biomedical literature and knowing the symptoms of a health condition in question, what they should do and how to prepare.
Some fundamental terms
Within the language of epidemiology, some terms are included that have a specific meaning when talking about pathological processes. Below we will look at some of them in more depth.
1. Epidemic
A disease is considered an epidemic when There is a very high number of people who have this medical condition simultaneously
A pandemic is a large epidemic that spreads widely, becoming present throughout the world. An example of this is the case of COVID-19 in March 2020.
3. Endemic disease
An endemic disease is one that occurs in greater numbers in a given population although it does not necessarily imply that it has manifested itself in all individuals.
An example of an endemic disease is the case of thalassemia, a type of anemia found in many Mediterranean countries, with more cases found in southern Spain and Italy.
4. Incidence of a disease
This term refers to the number of new cases of an individual disease in a population over a given period of time.
5. Prevalence
The prevalence of a disease is given by the total number of new cases and existing cases detected in a specific population also for a certain period of time.
6. Sprout
An outbreak is understood as the appearance of new cases in a specific region, usually over a short period of time.
When we talk about an outbreak, it means that there are more cases than before, although it does not necessarily have to refer to the appearance of a new disease. It may be that this same disease occurred before, but very sporadically.
About contagious diseases
To cause a disease, a pathogen, such as a bacteria or virus, needs to find an individual to host. Over there, grows and reproduces, affecting the health of the individual and producing the symptoms of the disease
It should be said that, although there are diseases that are fatal, in most contagious diseases, if the host dies, so does his tenant, which is not beneficial to him. If they have to kill the host, these organisms must first be able to reproduce and pass on to another organism, because, otherwise, they will end up becoming extinct.
It is for this reason that the majority of Host-dependent pathogens need to adapt and coexist with the individual on which they host This is not a symbiotic relationship, but rather parasitism, since the host individual, even if it does not die, will be harmed.
The pathogen, when it is already well adapted in the individual, takes what it needs to be able to continue living and uses the host’s own biological structures to nourish itself or reproduce, as would be the case of viruses with cells during viral reproduction. The damage that these pathogens can cause is various, ranging from simple temporary symptoms to chronic infections that must be treated urgently and intensely.
