Introduction to General Hygiene and Physical Contributors to Environmental Health

Introduction to General Hygiene and Physical Contributors to Environmental Health

General and applied Hygiene #1 - Prof. Ciccacci - Intro and contributors to environmental health Page 1 of 27 General and applied Hygiene #1 Introduction To General Hygiene and Physical Contributors to Environmental Health Prof. Ciccacci - 01/03/22 Patacchiola - Pellegrino

Introduction to the Course

E-mail address: fausto.ciccacci@unicamillus.org Book: Basic Epidemiology (uploaded on the web app)

Objectives of the Course

It won't be focused on clinical medicine that studies the health status of single or multiple individuals (as you study in other subjects) but will be addressed to hygiene, epidemiology, and public health study the health status of communities: in other words what happens in a population in terms of health status. This is the main difference with Clinical Medicine. Of course, this approach could lead to changes in the status of a single individual, but still, our focus will be on communities.

Useful Definitions in Health

First, we need to define again what health is, even if you already studied it in other subjects since we are about to study communities/population health. > HEALTH: it is a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity (WHO, 1948) -> in this subject "state of complete, mental and social well-being in a population/community" >DISEASE: a physiological or psychological dysfunction >ILLNESS: a subjective state of not being well >SICKNESS: a state of social dysfunction

Helpful Questions for Health Concept Complexity

Some questions can help us to see how complex the concept of health is. These are all alterations of physical, psychological, and social well-being. All of these could be defined as diseases or health.

• A 34-year-old male with a broken leg?
• An undergraduate student suffering from clinically diagnosed depression.
• A 17-year-old heroin addict currently on a methadone program)
• A middle-aged single mother with 2 children and about of flu?
• A 63-year-old male with ischaemic heart disease? 1General and applied Hygiene #1 - Prof. Ciccacci - Intro and contributors to environmental health Page 2 of 27
• A 29-year-old female with BMI>35? - > severe obesity
• A 57-year-old unemployed alcoholic?
• A pregnant 20-year-old woman suffering from "morning sickness"?
• A successful businessman who is HIV positive?
• A successful businessman with AIDS?
• A blind person?

Each one of these could make up things if our idea of healthy is right/good or not but in the end in the clinical medicine we have this way out that is that we can have the patient to whom we can ask "Do you feel healthy or not? Do you have any complaint? Do you feel pain?". It can also happen; you can have a blind person who is not fully healthy in our perception, but he/she could tell you he/she feels healthy.

Studying Health at a Population Level

How do evaluate the health status of a population? Regarding Epidemiology, we cannot have a patient since we only have a community/population. To have answers to these questions we could use for example surveys, but it's not always easy to analyze data and interpret results. This is just to say that health is always something complex to define, way more especially at a community level. We will see during our course how we can evaluate health, which measures we can have, and which indicator we use to define the health status of a population. Each of these indicators could have some limits, we can use maternal mortality ratio and if we look at this indicator, we will obtain some information; we could look at life expectancy at birth which would give us other information. So, in our course, we will study also how to see health at a population level which is something more complex since we cannot directly ask the patients.

Defining Health

The WHO definition of health as complete wellbeing is no longer fit for purpose given the rise of chronic disease. Since the definition of Health was made by WHO in 1948, we have had many discussions about the real definition of health also in changing scenarios as we are seeing in our Western World but not only also in other countries in which the epidemiological scenario is changing, especially for the rise of chronic diseases or we could have people maybe that seems to be in a complete state of wellbeing but maybe they are hypertensive patients that just take one pill per day but they don't suffer any pain or any problem for this disease for example. So, we have several definitions of health, here I just show you one published in the British Medical Journal in 2011 by Machteld Huber and colleagues who propose changing the emphasis towards the ability to adapt and self-manage in the face of social, physical, and emotional challenges (Huber, Machteld, et all. "How should we define health?" Bmj 343 (2011): d4163). So here we see 2General and applied Hygiene #1 - Prof. Ciccacci - Intro and contributors to environmental health Page 3 of 27 that there is another added factor that is the environment, or in other words the challenges that an individual will face. So, the health status of an individual and/or a population is not only an internal feature, but it's also depending on external conditions. The same man with a broken leg could have a different perception of the conditions if he is living in London or Kampala, in Uganda because his daily activities could be highly reduced maybe in Kampala, not so much in London. So, the challenges he faces could impact the way the same disease could be perceived. The ability to manage to adapt to these challenges is also something important to finding the degree of health status.

The Disease Process

The disease process Causes Disease Treatment Here I just show you some simplistic schemes of what usually happens with diseases. We usually have causes of a disease, we have a disease and then the treatment (when it is possible). Normally for example we could say that we have Mycobacterium Tuberculosis that is the cause, the disease is Tuberculosis and then we have the treatment. So, this is what we normally have. We have some causes, some diseases to diagnose and describe to the patient, and the treatment administered to him. The same thing we can do at a community level is the articulation also of our course.

Studying Health on a Community Level

Studying health on a community level Hygene · Causes and determinants Epidemiology · Distributions and frequency Public health · Treatment We have hygiene that is mostly focused on causes and determinants of health or disease. So, in Hygiene we are going to discuss factors in our life that could be bacteria, viruses, or also lifestyles, what we eat, if we do exercise or not, etc .. , so all those factors can someway cause or determine 3General and applied Hygiene #1 - Prof. Ciccacci - Intro and contributors to environmental health Page 4 of 27 health and we will also discuss the difference between cause and determinants. This is the focus of Hygiene -> we study the etiology of diseases at a population level. Epidemiology is more related to clinical medicine, so how we could describe a disease how to understand who will be infected, which are the symptoms, the signs of a disease in a population. So, epidemiology it's something like clinical medicine, the diagnostics faced when we meet the patient, is made at a population level by epidemiology. We have many tools we can use that we are going to study, how we can see the distribution of diseases, their frequency in a population. Then we have Public Health, which is something like the treatment, the intervention we can do on our patient that is in our case the population/community. So, an intervention that in some ways can improve the status of our population. So, this is the schematic description of the three main areas of our course, but we are going to deepen their divisions, actions, many fields, and many studies where these three categories are merging. This is useful just to understand that the same process that you do as a clinical doctor with a patient, is the same we do with the community with Hygiene, Epidemiology, and Public Health. Normally sometimes especially in the Anglo-Saxon language we use epidemiology to just cover the three areas of interest, so could happen during our course I'm speaking about epidemiology, but I mean the three categories just explained, like from now on in this lesson.

Epidemiology

Scope of Epidemiology

• Originally: epidemiology was concerned with the investigation and management of epidemics of communicable diseases even though in those times they didn't know the causes of them, but what happened was that they started to see many cases of diseases, so they started to think about why they were developing diseases among the population. This was the first step in all the history of epidemiology but also in the normal research process
• Lately: epidemiology was extended to endemic communicable diseases and non-communicable infectious diseases
• Recently: epidemiology can be applied to all diseases and other health-related events that can impact our health status.

So, epidemiology studies non-communicable diseases as well, obesity, hypertension, and so on, and epidemics are often used for non-communicable diseases a few years ago the WHO defined that we have an epidemic of obesity in the world. Epidemics are not only related to non-communicable diseases, just meaning the unusual occurrence of a disease in a population.

Purpose of Epidemiology

The purpose of epidemiology is the prevention of diseases and promotion of health.

• How? 4General and applied Hygiene #1 - Prof. Ciccacci - Intro and contributors to environmental health Page 5 of 27

1. Elucidation of the natural history of diseases
2. Description of the health status of the population
3. Establishing determinants of disease
4. Evaluation of intervention

Basic Epidemiological Assumptions

We have two important basic epidemiological assumptions:

1. The first one was the idea that was present since the beginning of men because I think it is also related specifically to the way human beings see the world that is "Human diseases don't occur at random or by chance". So, you know as humans try always to look for causality even where there isn't, even when there is a good, useful thing. This first assumption is the basic idea of epidemiology because at that time they used to think diseases were caused by Gods for example which was the reason why "diseases don't occur at random or by chance".
2. The second one is more related to a modern view of medicine, and it is that causes and determinants can be studied to prevent diseases. "Human diseases have casual and preventive factors"

Basic Features of Epidemiology

These are other features of epidemiology:

• Studies are conducted on the human population
• It examines patterns of events in people (REALLY IMPORTANT). This is common, very important, and strictly related to the way of thinking of humans because we tend to see patterns behind events. During our lessons we are going to talk for example about John Snow, that described cholera in London in 1854 and saw a pattern of cases diffusion on a map -> he understood the cause of cholera just by looking for patterns.
• Can establish a cause-effect relationship without the knowledge of biological mechanism (based on patterns !!! )
• It covers a wide range of conditions. It is important to examine every single aspect of the lives of people, trying not to miss a single piece since all of them act in some way on the insurgence, development, end of disease (how cities are planned, urban health, global change, radiations, pollution, economics, and income of our country, how many markets there are in a city). That is why we should include in our area of interest almost everything.
• It is an advancing science

Definition of Epidemiology

• It is the study of frequency, distribution, and determinants of diseases and other health-related conditions in a human population
• the application of this study to the prevention of disease and promotion of health 5