COMMUNICABLE DISEASE• An illness caused by an infectious

agent or its toxic products that are transmitted directly or indirectly to a well person through an agency, and a vector or an inanimate object.

Two Major Types of Communicable Disease

1. INFECTIOUS – not easily transmitted by ordinary contact but require a direct inoculation through a break in the previously intact skin or mucous membrane.

2. CONTAGIOUS – easily spread directly transmitted from person to person

INFECTION- The invasion and

multiplication of microorganisms on the tissues of the host resulting t signs and symptoms as well as immunologic response

…. Microorganisms injures the patient either by:• Competing with the host’s

metabolism.

• Cellular damage produced by the microbes

• Intracellular multiplication.

PATTERNS OF A DISEASE/INFECTION

• SPORADIC DISEASES- diseases that occur occasionally and irregularly with no specific pattern.

• EPIDEMIC DISEASES- diseases that occur in a greater number than what is expected in a specific area over a specific time.

• PANDEMIC DISEASES- an epidemic that affects several countries or continents.

• ENDEMIC DISEASES- are those that are present in a population or community at times. They usually involve few people during specific periods.

Why infection occurs…..• Resistance to antibiotics• Multiple strains of microbes• Resistance of viruses to antiviral

drugs• New infectious agents occur• Microbes localize in areas of the

body that make treatment difficult.• Immunocompromised patients may

be infected by opportunistic organisms.

• Inadequate or no immunization

• Increased air travel can cause the spread of the virulent organism to a heavy populated area in hours.

• Use of biological warfare and bioterrorism with organisms

• The expanded use of immunosuppressive drugs.

THE CHAIN OF INFECTION

A. CAUSATIVE AGENT

• Any microbe capable of producing a disease.

• It can be bacteria, spirochete, virus, rickettsia, chlamydiae, fungi, parasite, protozoa.

TERMS TO REMEMBER• PATHOGENECITY- ability to cause

disease.• VIRULENCE- ability to move through

the tissue.• INFECTIVE DOSE- number of

organisms to initiate infection.

• ORGANISMS SPECIFITY- host preference; antigenic variations

• ELABORATION OF TOXINS

B. RESERVOIR OF INFECTION

• Refers to the environment and objects on which an organism survives and multiplies.• Human reservoir-CARRIERS-

Incubatory carrier Convalescent carrier Intermittent carrier Chronic or Sustained carrier

• Animals• Nonliving objects (nonanimal)

C. THE PORTAL OF EXIT

• The path or way in which the organisms leaves the reservoir.

• Common portals of exit• Respiratory system• GUT• GIT• Skin and mucous membrane• placenta

Mode of Escape from Reservoir

• Respiratory tract• Gastrointestinal tract• Genito-urinary tract• Open lesions• Mechanical escape• Blood

D. MODE OF TRANSMISSION

• Is the means by which the infectious agent passes through from the portal of exit of the reservoir to the susceptible host

• The earliest link to break the chain of infection

FOUR (4) ROUTES OF TRANSMISSION

1. CONTACT TRANSMISSION• Most common mode of transmission.

It can be in the following modes:• Direct contact- person to person

transfer• Indirect contact- a susceptible

person comes in contact with a contaminated object

• Droplet spread- contact with respiratory secretions

2. AIRBORNE TRANSMISSION

• Occurs when fine microbial particles or dust particles containing microbes remain suspended in the air for a prolonged period.

3. VEHICLE TRANSMISSION• The transmission of infectious

disease through articles or substances that harbor the organism until it is ingested or inoculated into the host.

4. VECTOR- BORNE TRANSMISSION

• Occurs when intermediate carriers such as fleas, flies and mosquitoes transfer the microbes to another living organism.

E. PORTAL OF ENTRY

• The venue where the organism gains entrance into the susceptible host.

• The infective microbes use the same avenues when they exit from the reservoir.

F. SUSCEPTIBLE HOST• An immunosuppressed

individual; weakened host

Occurrence of infection depends on the hosts’…..• Age, sex and constitution of the host• Nutritional status, fitness,

environmental factors• General condition, physical, emotional

and mental state• Absent of or abnormal immunoglobulin• Underlying diseases• Treatment with certain antimicrobials,

corticosteroids, radiation r immunosuppressive drugs.

EMERGING PROBLEMS IN INFECTIOUS DISEASE

• Increasing number of organisms

• Increasing numbers of immunosuppressed individuals

• Persons with serious diseases• The use of indwelling lines

and implanted foreign bodies.

INFECTION CONTROL MEASURES

…..” UNIVERSAL PRECAUTION means that all patients shall be assumed infected with HIV/ AIDS and other blood borne pathogens.”

LEVELS OF PREVENTION• Primary prevention

• Secondary prevention

• Tertiary prevention

ASPECTS OF CARE OF PATIENTS WITH

COMMUNICABLE DISEASEPREVENTIVE ASPECT

A. Health EducationB. Environmental SanitationC. Immunization

TYPES OF IMMUNITY1. NATURAL• Passive- acquired through placental

transfer• Active- acquired through immunization

and/or recovery from a certain disease.

2. ARTIFICIAL• Passive- acquired through the

administration of antitoxin, antiserum, convalescent serum and gamma globulins.

• Active- acquired through the administration of vaccine and toxoid

3. SUB-CLINICAL-an immunity acquired through constant exposure to a particular disease or organism.

Suggested Control Measures for Primary

Care Clinics• Masking• Hand washing• Gloving• Gowning• Eye protection• Environmental sanitation

ISOLATION- Is the separation of patients with communicable diseases from others so as to prevent or reduce transmission of infectious agent directly or indirectly

Purpose of Isolation……. To confine the infectious

agent to a circumscribed area and to prevent the escape of infection from that area.

SEVEN (7) CATEGORIES RECOMMENDED IN

ISOLATION1. STRICT ISOLATION2. CONTACT ISOLATION3. RESPIRATORY ISOLATION4. TB ISOLATION5. ENTERIC ISOLATION6. DRAINAGE/ SECRETION PRECAUTION7. UNIVERSAL PRECAUTION