Theories of disease &its causation and levels of prevention

1. PATHOPHYSIOLOGY AND
PSYCHODYNAMICS OF DISEASE
CAUSATION
PRESENTOR
TAJINDER KAUR

5. RISK FACTORS:
• A risk factor is nay situation, habit, and social or environmental condition
physiological condition, developmental or intellectual condition or spiritual
or other variable that increases the vulnerability of an individual or group to
an illness or accident.
• The presence of risk factors do not mean that a disease will develop, risk
factors increases the chances that the individual will experience a particular
disease or dysfuntion.the risk factors can be divided into:

6. 1. Genetic and physiologic factors: physiological risk factors involve the
physical functions of the body. Certain physical condition such as being
pregnant or overweight place increased stress on physiological system
increasing susceptibility to illness in that areas.
Heredity or genetic predisposition to specific illness is a major physical risk
factors.eg: a person with a family history of diabetes mellitus is at risk for
developing the disease later in life.
2. Age: age increases or decreases susceptibility to get illness.eg: an infant
born prematurely and neonates are more susceptible to infection. The risk
of heart disease increases with the increase in age for both sex.

7. 3. Environment: where we live and the condition of that area determines
how we live what we eat. The disease agents to which we are exposed, our
state of health and our ability to adapt. The physical environment in which
a person works or lives increases likelihood that certain illness will
occur.eg: some type of cancer and disease are more prevalent in industrial
works.
4. Life style: many activities, habits and practices involve risk factors. Life
style practices can be positive or negative effect on health. Life style with
potential negative effects are sedentary life style over eating or poor
nutrition, insufficient rest and sleep, poor personal hygiene. Other habit
process negative effects are use of tobacco, alcohol, drug abuse, unsafe
sex, multiple sex partners etc.

8. ETIOLOGY
• It is defined as a specific part of the disease which act as
the main cause for the occurrence of the disease.
Etiology along with risk factors and other triggering
mechanism of the body as well as the environment
causes a disease. These are specific etiological features or
every disease. There may be some times only one or the
group of etiology which causes the disease:

9. 1. Hereditary: this is the disease causing features that comes from parents. The
disease like diabetes mellitus, hypertension etc.can be identified as hereditary if
parents are having the disease, then there is a higher chance to get them for their
children: sickle cell anemia, hemophilia.
2. Congenital: it is mostly not related with the chromosomal or the genetic features
which causes the disease. The X-linked hemophilia and other congenital birth
anomalies are the best examples. They appear shortly after birth. These are results
from some failures in development during pregnancy for first two months of
pregnancy. Contributing factors are dietary lacking, drugs and exposure to any
radiations.
3. Inflammatory: inflammatory disease are the causative factors for the many
diseases. The cell wall destruction or any inflammation occurring o cell acts as the
disease origin. Here the body reacts to the causative agents with an inflammatory
response e.g.: bronchitis and pharyngitis.

10. 4. Degenerative: this is destruction of specific activity or the
power of group of cells. The degeneration of group of cells
results in disease.e.g. Osteoarthritis.
5. Infection: infectious disease are caused any invasion of
specific pathogens or bacteria into the human body. The
infectious are caused mainly because of bacteria, virus, fungus,
etc. e.g. tuberculosis, AIDS etc.
6. Deficiency: deficiency results from a specific lack of a group
of protein, carbohydrates, minerals or lack of food constituents
in nutrition of the human body.

11. 7. Metabolic: metabolic causes of the disease are the disturbance in the
normal function of the body or the specific routine.it is caused by a
dysfunction that result in a loss of metabolic control of homeostasis.
8. Neoplastic: it occurs because of the increased number of cell division or
any abnormal call growth. Neoplasm is the causation of cancer.it may be
benign or malignant. Malignant neoplasm is a serious threat to health.
9. Traumatic: this is caused by the external environment or any force which
act or overcome the body function and results to later
disorientationeg.accidents.it can be both physical and emotional trauma e.g.
loss of loved ones.

12. Dynamic balance: steady state
Physiologic mechanism must be understood in the context of
body as a whole. Each person as living system has both internal
and external environment between which information and
matter are continuously exchanged. Within the internal
environment each organ, tissue and cell is also a system or
subsystem of the whole each with its own internal and external
environment, each exchange information and matter.

13. Stress and adaption:
Stress is a state produced by a change in the environment that is
perceived as challenging, threatening or damaging to a person is
dynamic or equilibrium.
Adaptation is constant, ongoing process that requires a change
in structure, function or behaviour so that a person is better
suited to the environment.it involves an interaction between the
person and the environment.
Both stress and adaption may exist at different levels of a
system, it is possible to study this reaction at the cellular, tissue
and organ levels.

14. Psychological response to stress: • Appraisal of stressful event: primary
appraisal result in the situation being identified as either non stressful. A non-
stressful situation is irrelevant or benign.
A stressful situation may be one of these kinds:
# One which is harm or loss has occurred.
# One that is threatening, in that harm or loss is anticipated.
# One that is challenging, in that some opportunity or gain is anticipated.
Secondary appraisal is an evaluation of what might can be done about situation.
Action includes assigning blame to person responsible for a frustrating event,
thinking about whether it is possible to do something about whether it is possible to
do something about the situation.
• Copying with the stressful event: copying consists of the cognitive and behavioral
efforts made to manage the specific external and internal demands that tax a person’s
resource and may be emotion focused or problem focused. Copying that is emotion
focused seeks to make the person feel better by listening the emotional distress..

15. Physiological response to stress: the physiological response to stressors, whether it is
physical or physiological, is a protective and adaptive mechanism to maintain the
homeostatic and adaptive mechanism to maintain the homeostatic balance of the body.
When a response occurs, it triggers a number of neurologic and hormonal processes
that is too activated within the brain and body.
• Alarm reaction or alarm phase: the sympathetic “flight-or-fight” response is
activated with release of catechol amines and the onset of the adrenocorticotropic
hormone (ACTH).this reaction is defensive and anti-inflammatory but self-limited
because living I a continuous state of alarm would result in death.
• Stage of resistance: adaptation to the noxious stresses occur and cortisol activity is
still increased.
• Stage of exhaustion: this stage occurs only if the exposure to stressors are
prolonged.in this endocrine activity increases thereby cause a negative effect on body.
System especially digestive and circulatory.

16. Sympathetic nervous system response: this response is rapid and short
lived. Norepinephrine is release at nerve endings that are in direct
contact with their respective end organs to cause and increase in
function of the vital organs and states of general body arousal. The
heart rate is increased and vasoconstriction occurs, raising the blood
pressure. The purpose of this response is to provide better tissue
perfusion of vital organs.
Sympathetic adrenal modular response: it stimulates the medulla of the
adrenal gland to release hormone epinephrine and norepinephrine into
the blood stream and stimulates the nervous system and produce
metabolic effect that increase the blood glucose level and increase the
metabolic rate.

17. Hypothalamic pituitary response: the hypothalamus secrets corticotrophin
releasing factor which stimulates the anterior pituitary to produce ACTH
which in turn stimulates the adrenal cotex.cortisol stimulates protein
catabolism releasing amino acids, stimulates liver uptake of amino acids
and their conversion to glucose and inhibit glucose uptake by many body
cells but not those of brain and heart. Other hormones are also playing a
major role as ADH and aldosterone promotes sodium and water
retention which is an adaptive mechanism in the event of hemorrhage or
loss of fluid.
Immunological response: immune system is connected to neuroendocrine
and autonomic syatems.lymphoid tissue is richly supplied with autonomic
nerves capable of releasing a number of neuropeptides that can have a
direct effect on leukocyte regulation and the inflammatory response.

37. 1. Prepathogenesis phase: this is the period preliminary to the onset of
disease in man. The disease agent has not yet entered man, but the factors
which favor its interaction with the human host already exist in the
environment. This situation is frequently referred to as ―man in the midst
of disease‖ or ―man exposed to the risk of disease‖. The causative factors
of disease may be classified as AGENT, HOST and
ENVIORNMENT. These three factors are referred to as
epidemiological triad. The mere presence of agent, host and favorable
environmental factors in the Prepathogenesis period is not sufficient to
start the disease in man. What is required is the interaction of these three
factors to initiate the disease process in man.

38. 2. Pathogenesis phase: The pathogenesis phase begins with the
entry of disease ―agent‖ in the susceptible human host. The
disease agent multiplies and induces tissue and physiological
changes, the disease progresses through a period of
incubation and later
through early and late pathogenesis. The final outcome of the
disease may be recovery, disability or death. The pathogenesis
phase may be modified by intervention measures such as
immunization and chemotherapy.

39. METHODS OF DISEASE TRANSMISSION:
• DIRECT
TRANSMISSION
• INDIRECT
TRANSMISSION

40. Direct transmission:
Direct contact: direct contact may be transmitted by direct contact from skin to skin, mucosa or mucous
membrane of the same person of the different person.e.g. in AIDS and leprosy.
Droplet infection: this direct projection of a spray of droplets of saliva and naso-pharyngeal secretions
during coughing, sneezing or speaking and spitting, talking in to the surrounding atmosphere. The potential
for droplet spread is increased in conditions of close proximity, overcrowding and lack of ventilation.e.g.
Tuberculosis is caused by droplet infection.
Contact with soil: the disease agent may be acquired by direct exposure of susceptible tissue to the disease
agent in soil, compost or decaying vegetable matter in which it normally leads a saprolytic existence e.g.
Hookworm, tetanus etc.
Inoculation into skin: the disease agent may directly inoculated into the skin or mucosa e.g. rabies virus by
a dog bite, hepatitis B.
Trans placental transmission: disease agent can be directly transmitted thru mother to baby by
placenta.e.g. TORCH and AIDS.

41. Vector borne: vector is defined as an arthropod or any living carrier that transport and infectious agent
to a susceptible individual. Transmission by a vector may be mechanical or biological.in mechanical
transmission infectious agent is mechanically transmitted by crawling or flying. But in biological
transmission infectious agent is undergoing replication and development or both in vector and requires
an incubation period before vector can transmit. Some disease which are transmitted by vectors are;
• Diphtheria – flies and mosquito
• Sihonaptera – fleas
• Orthopnea – cockroaches
• Hemiputra – bugs
INDIRECT TRANSMISSION

42. CONT…
• Airborne: it is transmitted through droplet nuclei and dust. Dust is inhaled
during talking, sneezing, coughing etc. Disease spread from airborne route
are chickenpox, measles-fever and many respiratory infections.
• Fomite borne: fomites are inanimate articles or substances other than water
or food contaminated by the infectious discharges from a patient agent to a
healthy person. Fomites include soled clothes, towel, linen, handkerchiefs,
cups, spoons, books and chain e.g.diptheria, typhoid fever, bacillary dysentery
etc.

43. CONT…
• Vehicle borne: it implies transmission of the infectious
agent through the agency of water, food, ice, blood,
serum, plasma or other biological products such as tissues
and organs. Of these water and food are the most
frequent route of transmission as they are consume by
everyone. e.g. acute diarrehea,polio,cholera,hepatitis A,
food poisoning etc.

44. CONT….
• Unclean hands and fingers: hands are the most
common medium by which pathogenic agents are
transferred to food from the skin, nose, bowel etc. as well
as from other foods. The transmission takes place both
directly and indirectly. Examples include staphylococcal
and streptococcal infections, typhoid fever, dysentery,
hepatitis A and intestinal parasite

45. LEVEL OF PREVENTION
PRIMORDIAL
PREVENTION
PRIMARY
PREVENTION
SECONDARY
PREVENTION
TERTIARY
PREVENTION

46. PRIMORDIAL PREVENTION
it is a new concept, is receiving special attention in the prevention of chronic
disease. This is primary prevention in its purest sense, that is, prevention of the
emergence or development of risk factors in countries or population group in
which they are not yet appeared.eg: many adult problems (hypertension and
obesity) have their origin because this is the time when lifestyle are formed.in
primordial prevention children are to be discouraged from adopting harmful
lifestyle.it is done with the help of mass media and through individuals.

47. PRIMARY PREVENTION
• it can be defined as action taken prior to the onset of disease which removes
the possibility that a disease will ever occur.it signifies intervention in the
prepathogenesis phase of the disease or health problem.it is accomplished by
measures designed to promote general health and well-being and the quality
of life by specific protective measures.
In primary prevention holistic approach is used.it relies on measures used to
promote health or to protect against specific disease agents and hazards in the
environment. Primary prevention is achieved with the help of health education
through mass media and camps or some other means.

48. SECONDARY PREVENTION
• it can be defined as action which halts the progress of a disease at its incipient stage
and prevents complications. The specific interventions are early diagnosis(
eg:screening,case findings programs) and adequate treatment.by early diagnosis and
adequate treatment secondary prevention attempts to arrest the disease process;
restore health by seeking out unrecognized disease and treating it before irreversible
pathology will takes place; and reverse communicability of infectious diseases.it may
also protect others in community from acquiring infection and thus provides
secondary prevention for the infected people and primary prevention for the
potential contacts.

49. TERTIARY PREVENTION
• when the disease process has advanced beyond its early stages, it is still
possible to accomplish prevention by what might be tertiary prevention.it
signifies intervention in the late pathogenesis phase. Tertiary prevention can
be defined as the all measures available to reduce or limit impairment and
disabilities, minimizes suffering caused by existing departures from good
health and to promote the patient’s adjustment to irremediable condition
tertiary prevention extends the concept of prevention into the field of
rehabilitation.

50. RESEARCH ARTICLE:
Theunissen SC, Rieffe C, Netten AP, Briaire JJ, Soede W, Schoones JW, Frijns JH.Psychopathology and Its Risk and
Protective Factors in Hearing-Impaired Children and Adolescents: A Systematic Review. JAMA Pediatrics. 2013 Dec 2.
(10-12-2013)
FINDINGS Literature consistently demonstrated that hearing-impaired children and adolescents were more prone to
developing depression, aggression, oppositional defiant disorder, conduct disorder, and psychopathy than their
normally hearing peers. Levels of anxiety, somatization, and delinquency were elevated in some, but not all, hearing-
impaired participants, for reasons related to sex, age, and type of school. Divergent results were obtained for the level
of attention-deficit/hyperactivity disorder and the influence of type of hearing device on psychopathology. Possible
risk and protective factors were identified, including age at detection and intervention of hearing loss, additional
disabilities, communication skills, intelligence, type of school, and number of siblings.
CONCLUSIONS AND RELEVANCE Literature on psychopathology in hearing-impaired children and adolescents is
scarce and sometimes inconsistent. To define a more precise occurrence of psychopathology, more studies are needed.
These studies should have a longitudinal design to draw firmer conclusions on causality. Hopefully, this will lead to
more knowledge in the future to help and support each hearing-impaired individual

51. REFERENCES:
O Park.k. textbook of preventive and social medicine. 21st ed. Banarsidas bhanot
publishers. p. 31-41
O Khan S. Yaseen and Basheer. Shebeer.P. Text book of Advanced Nursing Practice. 1st
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O Basavanthapa BT. Essential of community health nursing. 1st ed; jaypee publishers
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O Kamalam .S. Essential in community health nursing practice. 2nd ed; Jaypee
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ONLINE REFRENCES
O Available from url-http://www.ncbi.nlm.nih.gov/pubmed/24296921
O Available from url-http://www.hps.cam.ac.uk/people/broadbent/models_of_disease.
JOURNAL REFERENCES:
Theunissen SC, Rieffe C, Netten AP, Briaire JJ, Soede W, Schoones JW, Frijns
JH.Psychopathology and Its Risk and Protective Factors in Hearing-Impaired Children
and Adolescents: A Systematic Review. JAMA Pediatrics. 2013 Dec 2. (10-12-2013)