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[Narrator:] The nurse has a number of responsibilities in the prevention and control
of communicable disease.
In order to fulfill them she must have a basic knowledge of the natural history of disease.
She must understand infection and contagion, and their relationship to man.
She must know the various types of disease- producing agents.
For instance, the animal and animal-like organisms such as the protozoa, the metazoa, and the arthropods.
The nurse must know that plant-like agents including bacteria, fungi, molds, and yeasts
can cause disease, as well as those without distinctive plant or animal characteristics
such as the viruses and rickettsiae.
While chemicals are not disease-producing agents,
they may cause injury to body tissues and increase susceptibility to infection.
Not only must the nurse know that agents can cause disease, she must also be familiar
with the methods by which disease is produced, whether by direct invasion of tissue,
as in streptococcal infections, or through the liberation of toxin, as in diphtheria.
She must recognize the various reservoirs of infection
and the vehicles and vectors of transmission.
For example, in a disease such as encephalitis, the nurse must know that the organism
is transmitted by a mosquito vector from its bird reservoir to a susceptible host,
either man or animal.
She must understand that a disease may be communicable during the incubation period,
the acute phase, or the convalescent stage.
In some diseases a carrier state may develop.
This state may be convalescent, as in polio; temporary, as in asymptomatic infections;
or permanent, as in typhoid fever.
She must also be familiar with the portals of entry and exit of an infective agent.
These include the skin and the mucus membranes of the respiratory,
digestive, and genitourinary tracts.
If the nurse is to know the natural history of diseases, she must be aware of the factors
affecting the disease process in the body.
One, characteristics of the organism; two, host resistance; and three, environment.
Significant characteristics of the organism include its virulence and resistance,
the number of organisms entering the body, and the rapidity with which it multiplies.
Host resistance depends upon external body defenses, which include complicated anatomical
structures such as the skin, the eyes, and the ears.
And the internal body defenses, the antibodies and other materials found
in the body fluids and tissues.
Other factors contributing to individual host resistance are age, sex, and racial heritage,
nutrition and general health, opportunity for exposure to a specific organism
through association, and the distance between the portals of entry of an organism
and the tissue for which it has specific affinity.
Environment, the third factor affecting the disease process, includes the various influences
in daily living.
These may range from climate and occupation to social and religious customs.
In understanding the natural history of disease, it is important that the nurse
also know the preventive and control factors affecting disease.
These include measures directed against the infective organisms,
procedures to prevent the organism from gaining access to other hosts,
steps taken to reduce environmental hazards,
and methods of improving host resistance.
Let's consider first the various measures directed against the infective organisms.
One is mechanical removal of the organisms by either handwashing, filtration, or other means.
Another is sanitization, the process of rendering an article aesthetically clean
and reducing the number of organisms.
Disinfection--the inactivation or destruction of certain organisms by chemicals, heat, cold,
or drying--is still another measure directed against the organism.
Disinfection, however, does not always kill or inactivate spores, viruses, or all vegetative forms.
The most satisfactory measure for destroying all organisms in or on an object is sterilization.
Exposure to steam under pressure in an autoclave is a common method.
Boiling, incineration, or heating, as in a dry oven, may also be used for this purpose,
but the time required to attain sterility is often damaging to some materials.
Even though these precautions are observed, some organisms do gain access to the body.
In such instances the administration of medically prescribed drugs including antibiotics
has proved to be an effective preventive measure.
A second preventive and control factor affecting disease is the employment of procedures
to prevent organisms from gaining access to others.
These procedures include isolation of the infected person
and the practice of aseptic or barrier techniques,
which can prevent the transfer of organisms.
The third factor of disease prevention and control is the reduction of environmental hazards.
The nurse contributes by supporting education, legislation, and corrective action.
Finally, the fourth factor involves improving host resistance.
While this is largely an individual responsibility, the nurse promotes it by active health supervision,
and by encouraging sufficient rest and relief from tension, optimum nutrition, personal cleanliness,
limited exposure, and immunization against diseases
for which there are available immunizing agents.
As a member of the health team, the nurse must apply her knowledge of the natural history of disease
when carrying out her activities in the prevention and control of communicable diseases.
Her activities include adequate surveillance for early detection of disease,
safe care of the sick to assure satisfactory recovery, enforcement of precautionary measures
to prevent the spread of disease, and initiation of prompt epidemiologic investigation
to find the source of infection and other persons who might be infected.
She may also be expected to immunize a family and its contacts,
give prophylactic and therapeutic treatment under medical direction,
and supervise the activities of disease carriers.
At every opportunity she continues the process of education of the individual, the family
and community groups.
She refers certain problems to other members of the health department, or to other agencies,
and reports her findings to the health officer and the attending physician.
In addition to general measures employed in the prevention and control of communicable diseases,
the nurse must employ specific procedures for each type of transmission.
Where mode of transmission is unknown or uncertain,
professional judgments must be relied upon to determine control.
Where the mode of transmission is known, as that of the respiratory diseases,
the nurse must try to minimize spread by contact, to reduce spread by fomites
and to encourage immunization when practical.
She must also try to reduce air contamination by proper ventilation,
by safe disposal of nose and throat secretions,
and by limiting activities which distribute organisms in the air.
Skin invasions and infections can be diminished by avoiding close contact with infected persons
or their personal articles,
by combating or avoiding pest insects,
by wearing protective clothing when exposed to insect-infested areas,
by avoiding careless handling of wild animals or their tissues,
and by consistently sterilizing syringes, needles, and other equipment.
Invasion of the genitourinary mucosa is best prevented by the practice of personal cleanliness
and the avoidance of promiscuous sexual contact.
In those diseases which spread from the gastrointestinal tract,
specific measures must be taken to break the chain of anal-oral transmission.
These include preventing contamination of water, food, and milk,
sterilizing materials possibly contaminated by sick persons,
locating and supervising carriers,
and promoting personal cleanliness.
These, then, are some of the responsibilities of the nurse.
With her knowledge of the many factors affecting the disease process,
she is better able to assume these responsibilities
and direct her activities toward the prevention and control of communicable disease.
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