The document discusses how diseases are transmitted from infected hosts to healthy individuals via pathogens like bacteria, viruses, and fungi. It explains that pathogens can spread through various modes of transmission such as food/water, airborne transmission, and vectors like mosquitoes. The document also outlines principles of treatment for infectious diseases, including reducing symptoms and targeting the root cause. Preventive measures like vaccination, immunization, and general public hygiene are emphasized as better approaches than treatment of illness.

1. TOPIC
TRANSMISSION OF DISEASES

2. LEARNING OUTCOME
To study in detail about diseases, pathogens and
Immunity terminologies
To look into principles of treatment, Inflammation,
Antibiotics and Anti-viral drugs
To elaborate on preventive measures, Vaccination and
Immunization

3. LEARNING OBJECTIVE
Why prevention is better than cure?

4. WHY DO WE FALL ILL
Diseases are transmitted from one person to
another from an animal to human.

5. WHY DO WE FALL ILL

6. WHY DO WE FALL ILL
In both the cases, both the diseased human as well as the
animal act as hosts carrying the pathogens that cause the
disease.

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Example:
You can catch a cold if you come into to contact with a
person already suffering from it.

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Example:
A mosquito biting a malarial patient can pass on the
pathogen into a healthy human causing the disease to
spread.

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Pathogens
Agents which causes infectious diseases are called
pathogens.

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Pathogens
Pathogens are broadly classified into bacteria, virus, and
fungi.

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Pathogens
They are commonly transmitted by food or water.
Example,
Salmonella is commonly found in partially cooked eggs
or chicken.

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Pathogens
AIDS can be spread during pregnancy or through breast
milk from infected mother to child.

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Pathogens
Airborne pathogens are transmitted by air and travel via
the nose (mucus) and throat (saliva).
Example,
viruses that cause cold.

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Pathogens
Vector-borne pathogens are transmitted by insects, birds
or animals that act as hosts for the pathogen.

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Pathogens
Example,
Mosquitoes are the most common vectors and spread
diseases like dengue, malaria, filarial and Japanese
encephalitis.

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IMMUNITY

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Immunity
Immunity is the biological defence systems that fight
infection and disease, tolerate allergies and autoimmune
diseases in multicellular organisms.

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Immunity
The immune system is a major factor that determines the
number of microbes surviving in the body.

24. LEARNING OUTCOME
To study in detail about diseases, pathogens and
Immunity terminologies
To look into principles of treatment, Inflammation,
Antibiotics and Anti-viral drugs
To elaborate on preventive measures, Vaccination and
Immunization

25. WHY DO WE FALL ILL
Principles of Treatment

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Principles of Treatment
There are two ways to treat on infectious disease:

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Reduce the effects of the disease
The effects of a disease can be reduced by identifying
symptoms, taking relevant medicines and resting to allow
the body to heal.

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Treating the root cause of the disease
Treating the symptoms will not cure you of a disease.

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Treating the root cause of the disease
To cure the body completely of the disease needs to focus
on killing the microbes that originally caused the
infection.

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INFLAMMATION

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Inflammation
The symptoms are usually caused by inflammation.

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Inflammation
Inflammation is the process by which the active immune
system recruits cells to fight infections that are killing the
pathogens in the diseased area.

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Antibiotics
To kill microbes that cause diseases like bacteria or virus,
the medicine needs to target their biochemical life
process, that is, the medicine while targeting the cells of
the microbe should not attack the cells of the diseased
human.

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Antibiotics

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Antibiotics
The drugs that kill the cells of a bacteria and hence an
infection are called antibiotics.

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Antibiotics
Example,
A bacterium has a cell wall and the penicillin blocks the
cell wall formation in bacteria.

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Antibiotics
Example,
Since humans do not have a cell wall, penicillin can act on
bacteria without affecting human cells.
This is how antibiotics act on microbes.

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Anti-viral drugs

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Anti-viral drugs
An antibiotic which blocks bacterial biochemical pathway
is ineffective on a virus because they have different
metabolic processes and biological pathways.

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Anti-viral drugs
Viruses use human cells for their life processes as they do
not have biochemical mechanisms in their body.

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Anti-viral drugs
Therefore it is difficult to make drugs that will target
viruses, as human cells also get killed in the process.

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Anti-viral drugs
Medicines or drugs used to kill viruses are called anti-viral
drugs.

44. LEARNING OUTCOME
To study in detail about diseases, pathogens and
Immunity terminologies
To look into principles of treatment, Inflammation,
Antibiotics and Anti-viral drugs
To elaborate on preventive measures, Vaccination and
Immunization

45. WHY DO WE FALL ILL
Why is prevention better than cure?

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Why is prevention better than cure?
A disease can make a person weak and bedridden for a
long time.

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Why is prevention better than cure?
It can affect and damage body functions.

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Why is prevention better than cure?
It can spread from one person to another.

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Why is prevention better than cure?
It can affect the mental health of the patient as well as
caregivers.

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Ways to Prevent a Disease:

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General Methods
Proper sanitation, disposal of garbage, preventing flies
and mosquitoes from breeding

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General Methods
Healthy habits like washing hands, covering food items
and drinking boiled water

53. GENERAL METHODS
PUBLIC HYGIENE

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General Methods
Isolation and quarantine of a sick person

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Specific Methods
Natural Immunity

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Specific Methods
Natural Immunity
WBCs present in our blood produces antibodies to
fight against disease-causing microbes or antigens.
Each antibody can fight only a specific antigen.

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Specific Methods
Natural Immunity
The specialty is that once an antibody is produced
against an antigen, it can be produced instantly at the
time of another invasion by the same antigen.

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VACCINATION

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Vaccination
The weakened form of a microbe introduced into our
body by inoculation or vaccination is called a vaccine.

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Vaccination
A vaccine is a biological preparation that improves
immunity to a particular disease after inoculation.

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Vaccination
Vaccination plays a major role in the prevention of
diseases.

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IMMUNIZATION

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Immunization
Immunization is the protection of individuals from
communicable diseases by administration of a suspension
of dead micro-organisms.

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Immunization
Our bodies may become immune to some diseases due to
exposure to a certain microbe.
Example,
Most children in India are immune to hepatitis A.

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Immunization
It is important to follow public health programmes of
childhood immunization to prevent infectious diseases.

67. LEARNING OUTCOME
To study in detail about diseases, pathogens and
Immunity terminologies
To look into principles of treatment, Inflammation,
Antibiotics and Anti-viral drugs
To elaborate on preventive measures, Vaccination and
Immunization

68. WHITEBOARD