LEC 4: COMMUNICABLE DISEASES PART 1

• Communicable diseases are often the leading

  causes of all illness in the country today.
• Communicable diseases are readily transferred

  from one infected person to a susceptible and

  uninfected person and maybe caused by

  microorganisms.
• Viruses- consist primarily of nucleic acid and

  therefore must enter a living cells in order to

  reproduce
• Bacteria- the most common infection-causing

  microorganisms
• Parasites-Live on other living microorganism
• Fungi- includes yeast and Molds
• ETIOLOGIC AGENT

  The extent to which any microorganisms is

  capable of producing an infectious process

  depends on the number of microorganism

  (pathogenicity).,
• ETIOLOGIC AGENT

  the ability of the microorganisms to enter the body,

  the susceptibility of the host, and the ability of

  microorganisms to live in the host’s body.
• RESERVOIR

  Common sources are the other humans, the client’s

  own microorganism, plants, animals, or the

  general environment.
• People are the most common source of infection

  for others and for themselves.
• PORTAL OF EXIT FROM THE RESERVOIR

  Before an infection can establish itself in a host, the

  microorganism must leave the reservoir.
• METHOD OF TRANSMISSION

  After the microorganisms leaves its sources reservoir,

  it requires a means of transmission to reach another

  person or host through a receptive portal of entry.
• DIRECT TRANSMISSION

  involves immediate and direct transfer of

  microorganisms from person to person through

  touching, biting, kissing, or sexual intercourse.
• INDIRECT TRANSMISSION

  may either be vehicle borne or vector borne
• VEHICLE BORNE TRANSMISSION

  a vehicle is any substance that serves as an

  intermediate means to transport and introducing

  infectious agent into susceptible host through a

  suitable portal of entry.
• FOMITES

  (inanimate objects or materials) such as

  handkerchiefs, toys, soiled clothes, cooking or

  eating utensils, and surgical instruments or

  dressing can act as vehicle.
• VECTOR

  borne transmission- a vector is an animal or flying

  or crawling insects that serves as an intermediate

  means of transporting the infectious agents.
• VECTOR

  Transmission may occur by injecting salivary gland

  fluid during biting or by depositing feces or other

  materials on the skin through the bite wound or a

  traumatized skin area.
• PORTAL OF ENTRY TO THE SUSCEPTIBLE HOST

  Before a person can became infected,

  microorganisms must enter the body.
• The skin is a barrier to infectious agents; however,

  any break in the skin can readily serve as portal of

  entry.
• PORTAL OF ENTRY TO THE SUSCEPTIBLE HOST

  Often, microorganisms enter the body of the host by

  the same route they used to leave the source.
• A susceptible host is any person who is at risk for

  infection.
• SUSCEPTIBLE HOST

  A compromised host is a person “at increased risk:,

  an individual who for one or more reasons is more

  likely than others to acquire an infection.
• SUSCEPTIBLE HOST

  Impairment of the body’s natural defenses and a

  number of other factors can affect susceptibility to

  infection.
• IMMUNIZATION

  Is the process of introducing vaccine into the body

  to produce antibodies that will protect our body

  against a specific infectious agent.
• I. IMMUNIZATION

  Most vaccine are given more than once since the

  first dose gives only half projection the body

  needs. A second shot or “booster” is needed to

  give the body full projection against the disease
• DPT (Diptheria, pertussis and tetanus) vaccine

  An early start with DPT reduces the chance of severe

  pertussis
• Diptheria-

  by Corynebacterium diptheriae
• Pertussis-

  Bordetella pertussis
• Tetanus-

  Clostridium tetani
• OPV (Oral Polio Vaccine)

  the extent of protection against polio is increased

  the earlier the OPV is given
• Poliomyelitis

  Polio virus
• Measles-

  by Measles virus
• Mumps-

  by Mumps virus
• German measles-

  caused by Rubella virus
• Meningitis-

  Haemophilus influenza
• Hepatitis B vaccine

  an early start of hep. B reduces the chance of

  acquiring hepatic CA.
• BCG (Bacillus of Calmette and Guerin)

  Given at the earliest possible protects against the

  possibility of infection from other family

  members.
• Tuberculosis- caused by Mycobacterium

  tuberculosis
• CDT (Cholera, Dysentery, Typhoid)

  Cholera- Caused by Vibrio cholera