On the global level, there are several commonly occurring health issues, including:






At the end of this class, you will be able to:


1. Discuss how communicable diseases and infections are spread from one to another. 


2. Describe several communicable diseases and how to prevent them




There are many communicable, or infectious, diseases in our country and all around the world. They can be caused by a number of agents, or germs, like bacteria, a virus, fungus, and even worms. Some are minor and others can be very serious. Some cause only small symptoms; others can lead to death.



The chain of infection tells us how germs pass from one person, or thing, to a person that will get the infection.


This chain includes:


  1. the cause or the agent,
  2. the reservoir, or the place that the germs live,
  3. exit port,
  4. the way that a germ moves from one place to another,
  5. entry port, or the place that the germ enters the person, and
  6. the new host.





The Cause


Any pathogen, or germ, can lead to an infection. For example, it can start with a bacteria like TB or a strep throat, a virus like the “flu”, HIV/AIDS and the common cold, a fungus like thrush of the mouth, worms like round worms and tape worms and others.




This is the place where the germ lives, grows and multiplies. Germs can live and grow in animals, humans, and in things that are not alive like dirt, water, food, and on objects like door knobs, balls and medical supplies. Germs love to grow in damp and dark places.


Exit Port


Germs do not always stay in the place that they live. For example, germs that live in a person’s airway do not always stay there. They will leave the body with a cough or a sneeze. Germs that live in a person’s GI tract also leave and they can get passed onto another person.


E. coli is an example of a GI germ that is passed to other people and into our water and pools at times when a person does not wash their hands after they use the bathroom and when companies dump waste into our water. Pools may also have this germ because young children with diapers leave some of their feces in the water of the pool as they are splashing about.


Mode of Transmission


This is a how specific germs move from the exit to a new living place or host. Some germs are carried to other places via the air, direct contact, or touching something, or by being carried by another living thing like a flea,  tick, mouse or bat.


Entry Port


Germs find new places to go to after they have left their living place and they have been carried away. Some enter the person when the person takes in a breath of air (TB, colds). Others enter the body thru a break in the person’s skin. Others can enter the human body of a baby before it is born when the mother has it. HIV/AIDS is an example.


The New Host


Some people are more at risk than others for getting the germ inside their body. People with weak immune systems, like those with AIDS and those who have taken cancer drugs, are more apt to get an infection than those that are healthy and without diseases like AIDS/HIV.





There are several ways that germs can move from one place to another. You must know about these so that you can prevent the spread of infection as you do your job. These ways are discussed below.


Airborne occurs when the germs stays up in the air as a droplet or dust. The new host inhales the germ via air currents. 


Fecal- oral can be direct or indirect. Indirect fecal - oral occurs when the germ is spread via dirty and bad water or food. Direct fecal - oral transmission occurs when a germ on an object, like dirty hands, is passed to the mouth of another. For example, a cook may spread germs to others when they make meals for the customers after they do NOT wash their hands when they use the bathroom. You will see signs in every public bathroom telling the workers to wash their hands before going back to work. It is sad to say that if you stood in a public bathroom for a while that almost ½ the people will leave the bathroom without washing their hands.


Direct contact occurs with direct physical skin to skin contact. For example, “pink eye” spreads when the person rubs their eye and then touches the eye of another. The “pink eye” will then go to the other person. It can also be spread from the right eye to the left eye of the same person when they rub one eye and then the next.


Indirect contact happens when there is a non living object between the germ and the host. This object, called a fomite, can be a door handle, bed linens, forks, knives, and medical supplies, like a thermometer. For example, “pink eye” can be spread from a sister to a brother when they use the same face cloth, a non living item.


Sexual mode is direct contact via sexual contact. Some examples are AIDS/HIV and syphilis.


Direct inoculation is when a blood borne pathogen is directly put into a person’s blood. Some IV drug abusers who use dirty needles may get HIV. People that work in healthcare can get diseases like HIV and hepatitis when they are stuck with a used sharp item, like a used needle. Sharps in the workplace must be safely discarded and handled.   


Insect or animal bites is when a germ enters the person from an animal bite or an insect bite. For example, Lyme disease is carried by a tick and Rocky Mountain spotted fever is carried by a mosquito.




Carrier- the person who has the germ in their body and they are able to pass it to others but they do not know they have the infection. They do not have the signs of the communicable disease yet.


Incubation period is the period of time after a person is exposed to the germ until the signs begin to show up. During this period the germ grows and spreads in the body until the signs appear. This period can be very short or it can be for several years.


Immunity- the state when a person cannot get sick from a germ even if it goes into their body. For example, a person will not get measles after they get the shot and a person cannot get chicken pox again after they have had it once.




The stages of infection are:


  1. the incubation period when the germs live and multiple
  2. the prodromal stage when a fever or sore throat may occur but the real signs of the disease have not yet started
  3. the acute stage when the person becomes sick and has full signs
  4. the recovery stage when the person is done with the acute stage and they are getting better. This can be a couple of days up to several months.






These kinds of diseases are found not only in the United States but also around the world. We have a lot of “shots” that can prevent them in our country and we have a lot of  medicines in the US that can treat them.


The same is not true in all places around the world. Some places do not have shots to prevent them and they do not have the medicine that is needed to treat them. Also, new infections are coming up all the time. Some of these infections can not be treated with the medicines that we have. These “new germs” are not killed with the medicine. They resist it.


Childhood Diseases


Children are often very close to other children in places like school, day care and play places. This closeness makes them prone to get diseases from other children. You have probably gotten some of these yourself.


Children and adults can get what is called childhood diseases unless they get a shot to prevent it. Some of these diseases are chicken pox, measles, German measles, whooping cough and mumps. Many are spread with drops of saliva as the person coughs or sneezes. Others happen when a person touches or shares things, like a comb, with another person. Some examples of these are ring worm and lice on the head.


Some of these can cause the person serious harm, like polio. Others can seriously harm an unborn child when the mother gets it. On a good note, many of these diseases can be presented with a “shot” and most can only be gotten one time. For example, a person can get chicken pox one time, but a person can get ring worm more than one time.


Other Infectious Diseases


Some communicable diseases are often seen in homes, hospitals, and nursing homes. Some of the things that make a person prone to these include:


  • Age. Infants and older adults are at most risk. They are at greatest risk because their immune systems, which fight off infection, are not working at their peak level. They are not able to fight these infections off.
  • Other illness. People that have other diseases are not as able to fight off new infections as well as other people without these diseases can fight them off. They are not in a good state of health. For example, a person with diabetes may not be able to fight off infection to a small cut in their foot. A person without diabetes is well able to fight off the same infection when they get a small cut to their foot.
  • Poor nutrition. People who do not eat a good diet and who have poor nutrition are not able to fight off infections like those with good nutrition can.
  • HIV/AIDS and Cancer. People with HIV/AIDS and people who have gotten treatment for cancer have a poor immune system. These people will get infections more often and quicker than other people. They are just not able to fight them off.
  • Closeness. People who live close to each other in crowded places like nursing homes, assisted living places, prisons, over filled private houses, group homes and hospitals may get infections faster and more often than others who live in their own home alone. For example, the “flu” or a cold will spread very quickly in crowded places. They will spread even quicker when good infection control practices are not used.
  • A Break in the Skin. Infections can enter any break in the skin or opening in the body. The skin on the body is the first defense against infection. A person who has just had surgery to their knee, for example, is at risk for a surgical wound infection if it is not taken care of in the proper way.
  • An Entry Way to the Inside of the Body. Many ill people have tubes, catheters and lines. For example, people have G tubes for feedings when they can not eat with their mouth. They have urine catheters and they have IV lines for needed fluid and medicines. All of these items are a walkway for the germs to move from the outside of the body to the inside of the body. These tubes, lines and catheters must be taken care of in the proper manner to prevent an infection.




Simple handwashing is the single most effective thing that we can do to prevent the spread of germs and infection in hospitals, nursing homes, homes, schools and other healthcare places. Yes, handwashing is the MOST important thing that you can do to prevent the spread of infection from one person to another.

Healthcare workers’ hands carry most infections. It is our hands that carry germs from one person to another. We must wash our hands, keep our nails short and clean and avoid wearing a ring, other than a small and clean wedding band. Germs like to hide under moist and dark nails and rings. Rings and nails transport germs.

You use soap, water, lots of rubbing and a little time to wash your hands. Never hurry through the process. Do not ever skip a step. Do not forget to wash your hands. Remember, infections from your hands can kill your patients.

Infection control must be a part of EVERYTHING we do.

You MUST wash your hands:

  • as soon as you come to work
  • before you go into a patient or resident room
  • when you are leaving a patient or resident room
  • before and after each task you do
  • before and after you touch a person
  • before and after you put gloves on
  • before you leave a rest room
  • before taking a break
  • before and after you eat or handle food
  • after you cough or sneeze
  • after you blow your nose
  • after handling garbage or trash
  • when you are leaving work




Keeping Your Patients and Residents Healthy


Nursing assistants and other healthcare providers can work together to keep their patients and residents as healthy as possible.

We can help them to:

  • get a good diet,
  • get plenty of fluids,
  • get enough sleep and rest,
  • manage their stress,
  • get their flu, pneumonia or hepatitis B shots and
  • stay away from infections and other sick people, as much as possible.


Berman, Audrey, Shirlee Snyder, Barbara Kozier and Glenora Erb. (2010). Kozier & Erb's Fundamentals of Nursing: Concepts, Process, and Practice. 8th Edition. Pearson Prentice Hall.


Centers for Disease Control. (2002). “Infection Control”. [online] http://www.cdc.gov


Hockenberry, Marilyn J. and David Wilson. (2010).Wong's Essentials of Pediatric Nursing. 8th Edition. Elsevier Mosby.


Monahan, Frances Donovan and Wilma J. Phipps (2007). Phipps’ Medical-Surgical Nursing: Health and Illness Perspectives. 8th Edition. Elsevier Mosby.

Nettina, Sandra M. (2009). The Lippincott Manual of Nursing Practice. 7th Ed. Lippincott, Williams and Wilkins.

Copyright © 2010 Alene Burke