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DISEASE CONTROL (DEMT 2433)

DIPLOMA IN ENVIRONMENTAL HEALTHVICTORIA INTERNATIONAL COLLEGE

BY: MR KHAIRUL NIZAM MOHD ISADEPARTMENT OF ENVIRONMENTAL HEALTH

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ObjectivesObjectives

1. To understand the classification of diseases2. To understand the concept of signs, symptoms and syndromes

3. To elaborate the stages of infection

4. To discuss the diseases controlling strategies

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Classification of DiseaseClassification of DiseaseInherited disease

Inherited disease are caused by errors in genetic information.The resulting developmental disorders may be caused byabnormalities in the number and distribution of chromosomesor by the interaction of genetic and environmental factors.

Example: Sickle cell anaemia

Congenital diseaseCongenital diseases are structural and functional defectspresent at birth, caused by drugs, excessive X-ray exposureor certain infections.

Examples: Rubella, syphilis infection

Degenerative diseaseDegenerative disease are disorders that develop in one ormore body system as aging occurs.

Patients with degenerative disease such as emphysema orimpaired kidney function are susceptible to infections.

Conversely, infectious agents can cause tissue damage that

lead to degenerative disease.

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Classification of DiseaseClassification of DiseaseNutritional deficiency disease

Nutritional deficiency diseases lower resistance to infectiousdisease and contribution to the severity of infections.

Examples: Corynebacterium diptheriae produces more toxinin people with iron deficiencies than in those with normalamount of iron.

Endocrine diseaseEndocrine diseases are due to the excessive or deficiencies ofhormones.

Viral infection has been linked to pancreatic damages thatlead to insulin-dependent diabetes.

Mental diseaseCan be caused by a variety of factors, including those of anemotional or psychogenic nature as well as certain infections.

Examples: psychological stress may give rise to severalgastrointestinal disorders, skin irritation and breathdifficulties. Result from brain infections such as in case of

neuropsyphilias and Creutzfeld-Jakob disease.

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Classification of DiseaseClassification of Disease

Immunological diseaseImmunological disease such as allergies, autoimmune disease andimmunodeficiencies caused by malfunction of the immune systems.

Examples: AIDS is a consequence of viral infection and destruction ofcertain cells of immune system.

Neoplastic disease

Involve abnormal cell growth that leads to the formation of varioustypes of general harmless or cancerous growths or tumors.

Causes of such disease include chemicals, physicals, radiation andmicroorganisms.

Example: Papillomavirus which cause cervical cancer.

Iatrogenic diseaseIatrogenic disease are caused by medical procedures and/ortreatments.

Examples: surgical errors, drug reactions and infections acquiredfrom hospital treatment.

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Classification of DiseaseClassification of Disease

Idiopathic diseasesIdiopathic diseases are disease whose cause is unknown.

Some researchers believe that Alzheimers disease whichcause mental deterioration.

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Classification of DiseaseClassification of Disease

Noncommunicable disease (NCD)NCD is a disease which is not infectious.

Such diseases may result from genetic or lifestyle factors.

A non-communicable disease is an illness that is causedby something other than a pathogen.

It might result from hereditary factors, improper diet,smoking, or other factors.

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Non-communicableNon-communicableDiseaseDisease

A non-communicable disease or NCD is a diseasewhich is not infectious. Such diseases may result fromgenetic or lifestyle factors.

A non-communicable disease is an illness that iscaused by something other than a pathogen.

It might result from hereditary factors, improper diet,smoking, or other factors. Those resulting from lifestylefactors are sometimes called diseases of affluence.

Examples include hypertension, diabetes,cardiovascular disease, cancer, and mental health

problems, asthma, atherosclerosis,allergy etc.The non-communicable diseases are spread by:heredity, surroundings and behavior.

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Communicable DiseaseCommunicable Disease

Communicable disease:Is defined as an illness that is capable of beingspread to a susceptible host through the direct orindirect transmission of an infectious agent or toxicproduct by an infected person, animal, arthropod,

or through the agency of an intermediate host, or avector or through the inanimate environment.

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INFECTIOUS DISEASEINFECTIOUS DISEASE

Infectious disease: illness caused by thepresence of a pathogen

Pathogens: disease causing organisms

Examples: bacteria, protozoa, fungi, viruses

Pathogens are found in the soil, contaminatedwater, and infected animals (including

humans)

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Types of Infectious diseaseTypes of Infectious disease

Term Characteristic of infection

Acute disease Disease in which symptoms develop rapidly and thatruns its course quickly

Chronic disease Disease in which symptoms develop slowly and diseaseis slow to appear

Subacute disease Disease with symptoms intermediate between acute andchronic

Latent disease Disease in which symptoms appear and/or reappear longafter infection

Local infection Infection confined to a small region of the body, such asa boil or bladder infection

Focal infection Infection in a confined region from which pathogenstravel to other regions of the body, such as abscessed

tooth or infected sinuses

Systemic infection Infection in which the pathogen is spread throughout thebody, often by traveling through blood or lymph

Primary infection Infection in a previously healthy person

Secondary infection Infection that immediately follows a primary infection

Super infection Secondary infection that is usually caused by an agentresistant to the treatment for the primary infection

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Signs, Symptoms &Signs, Symptoms &SyndromesSyndromes

SignA sign is a characteristic of a disease that can be observed byexamining the patient.

Signs of disease include such things as swelling, redness, rashes,coughing, pus formation, runny nose, fever, vomiting anddiarrhea.

SymptomsA symptom is a characteristic of a disease that can be observedor felt only by the patient.

Symptoms includes such thing as pain, shortness of breath,nausea, sore throat, headache, malaise (discomfort).

SyndromeSyndrome is a combination of signs and symptoms that occurtogether and are indicative of a particular disease or abnormalcondition.

For example, most infectious disease cause the body to mountan acute inflammatory response.

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Stages of InfectiousStages of InfectiousDiseaseDisease

The incubation periodThe incubation period for an infectious is the time betweeninfection and the appearance of signs and symptoms.

Although the infected person is not aware of the presence ofan infectious agents.

He or she can spread the disease to others.

Each infectious disease has a typical incubation period.

The length of the incubation period is determined by theproperties of the pathogen and the response of the host tothe organism.

Properties that affect the incubation period include:

The nature of the organismIts virulence

How many organism enter the body

Where they enter in relation to the tissues they affect

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Stages of InfectiousStages of InfectiousDiseaseDisease

The prodromal PhaseThe prodromal phase of disease is a short period during whichnonspecific, often mild, symptoms such malaise and headachesometimes appear.

Example: you wake up one morning feeling bad, and you knowyou are coming down with something, but you dont know yet

whether you will break out in spots, start to cough, develop asore throat or experience other signs or symptoms.

Many disease lack of prodomal phase and begin with a suddenonset of symptoms such as fever and chills.

During the prodomal phase, infected individuals are contagiousand can spread the disease to others.

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Stages of InfectiousStages of InfectiousDiseaseDisease

The Invasive PhaseThe invasive phase is the period during which the individual experiences thetypical signs and symptoms of the disease.

These may include fever, nausea, headache, rash and swollen lymph nodes.

During this phase, the time when the sign and the symptoms reach theirgreatest intensity is known as acme.

During the acme, pathogens invade and damage tissues.

A period of chills followed by fever marks the acme of many disease.As sign and symptoms appear, the form of infection will take become clear.

Individual at this critical stage are still contagious.

The battle between pathogens and host defenses is at its height.

If treatment is not available or provided in time, death can result.

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Stages of InfectiousStages of InfectiousDiseaseDisease

The Decline phaseAs symptoms begin to subside, the disease enters the declinephase.

The period of illness during which host defense and the effects oftreatment finally overcome the pathogen.

The body activities gradually return to normal.

Secondary infections may occur during this phase.

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Stages of InfectiousStages of InfectiousDiseaseDisease

The Convalescence PeriodDuring the convalescence period, tissues are repaired, healingtakes place and the body regains strength and recovers.

Individuals no longer have disease symptoms.

In some disease, however, especially those in which scabs formover lesions, person recovering from the disease can still

transmit pathogens to others.

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Stages of InfectiousStages of InfectiousDiseaseDisease

Invasive

phaseDecline

phase

Most severe signs

and symptomsDeclining signs

and symptoms

Time

Acme

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Controlling DiseaseControlling DiseaseTransmissionTransmission

Several methods are currently available for full orpartial control of communicable disease. Includes:Isolation

Quarantine

Immunization

Vector control

IsolationA patient with a communicable disease is prevented fromhaving contact with the general population.

Generally accomplished in a hospital.There are appropriate procedures can be carried out toreduce the spread of disease among susceptible individualand to prevent the spread of disease in general population.

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Controlling DiseaseControlling DiseaseTransmissionTransmission

QuarantineQuarantine is the separation of healthy human or animal carriersfrom the general population when they have been exposed to acommunicable disease.

Quarantine prevents spread of the disease during its incubationperiod.

Mainly used for serious disease such as cholera and yellow fever.

Immunization programExtremely effective means of controlling communicable diseasefor which safe vaccines are available.

This program greatly increase herd immunity and thus greatlydecrease human suffering and death from infectious diseases.

Examples: polio, measles, mumps.

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Controlling DiseaseControlling DiseaseTransmissionTransmission

Vector controlEffective means of controlling infectious disease if the vector,such as an insect or rodent, can be identified and its habitat,breeding habits and feeding behaviour determined.

Place where a vector lives and breeds can be treated withinsecticides or rodenticides.

Window screen, mosquito netting, insect repellents and otherbarriers can be used to protect human from becoming victimsof the bites of feeding vectors.

Unfortunately, vectors have their own defenses. Some escapeor become resistant to pesticides.

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