 Like these youngsters, most of us go through our daily lives without fear, even though there are dangers all around us. We're often exposed to organisms that can cause disease, but few of them make us ill. We have organisms of disease in our bodies, but they usually cause us no harm. We are relatively safe from disease. It has not always been this way. In ages past, killer epidemics were a recurring nightmare, wiping out whole families and decimating great cities. The early settlers of America may have hoped they could escape the terrors of epidemic, but it followed them here. Cholera, yellow fever, smallpox and others, any one of them capable of decimating the population. When an epidemic ravaged out of control, no one was safe. The rich succumbed, along with the poor, the prominent, along with the unknown. Doctors were all but powerless, their hands and potions unable to check the tide of epidemic. Even in normal times, the people could never be free from fear. They knew that an epidemic in one colony might quickly sweep through others. Infectious disease was the scourge of mankind. Infectious disease, what do we mean by the term? Well, to begin with, it's a condition caused by a living organism, virus, bacteria and the like. Infectious means that it's what your grandmother might have called catching. It can be passed from one person to another, or sometimes from an animal to man. Disease means that there are visible signs of interaction between the organism and the patient. Fever, for example, is the most common sign. Now the important question is, how does an infectious disease spread? It all starts with a pathogenic organism. Then there has to be some kind of reservoir, a place where the organism can live. This is usually a human, though it may also be an animal. In order to spread, the organism has to find some exit out of the body and some means of transmission to another person. Next, the organism finds its way into another host's body, through the mouth or nose, through a mucous membrane, or through an opening in the skin. Finally, to complete the chain of transmitting the disease, the host must be susceptible. If the host is immune, disease will not occur. These six elements must all occur for the spread of an infectious disease. An infectious organism, a reservoir, means of escape, transmission and entry, and a susceptible host. In any group of people exposed to an organism of infectious disease, some may contract the illness, others not. Why? Many factors come into play. Let's imagine that an organism has entered some of these people and considered the possibilities. This girl has a high resistance to the disease and does not become ill. Another person who does not eat a balanced diet or whose resistance is low may be very susceptible. This girl had only a slight exposure. Her body easily resisted the few organisms that entered. Persons who have had the same disease before may still have antibodies in their system. In many diseases, this is enough to provide strong resistance. Yet general health is no guarantee. A strong, athletic man can succumb to a disease that may pass over the people around him. Another person may develop such a mild case that no symptoms appear and the disease passes unnoticed. And still another may remain well, yet become a reservoir in which the organism lives. That person is a carrier, unknowingly transmitting the disease to others. Age is a factor too. Some diseases are not often acquired by children, while others, like Khubinkov, attack mostly the young. The same with older people. As long as they are strong and in good health, they are less susceptible to some diseases than the rest of the population. But more susceptible to others. Hospital workers can build up an immunity to many diseases, receiving inoculations and immunizations as required. Their resistance is very high. In order for you to understand the precautions necessary with an infectious disease patient, it's vital that you be aware of how the organisms escape and how they are transmitted from one person to the next. For example, consider this patient with a disease that affects the urinary or intestinal tract. The organism escapes in the urine or feces. If she's ambulatory, there is little risk. But if a bedpan is used, it becomes contaminated. And only careful handling prevents the germs from being transmitted to you and on to other patients. A patient with a draining wound or lesion presents a different kind of problem. Everything the drainage gets on becomes contaminated. Dressings, linen, the patient's gown and so forth. Those things in turn can transmit the germs to your hands and clothes and around the hospital. Unless you take the proper precautions. These consist of hand washing before and after patient contact. Using two sets of gloves, changing them and washing your hands between removal of the old dressing and application of the new dressing. But the most common avenue of escape for microorganisms is the respiratory tract. When the germ infects the mouth, nose, sinuses, throat or lungs, breathing provides an escape. And a call for sneeze can send germs halfway across the room. The air itself becomes a means of transmission. Germs can float suspended in the air for a considerable time. Anyone entering could inhale them. And they settle on everything around. Which means they can also be transmitted by contact. There are so many variables from one disease to the next that you can't make any assumptions. Take infectious hepatitis, for example. It's a disease that attacks the liver. Organisms occur in the feces and urine. But they also apparently escape from the mouth. And the bloodstream carries the germs too. Hybridermic needles as well as blood samples drawn from the patient will be contaminated. In other words, there are no simple rules. It's never enough to be told the patient has an infectious disease. You've got to know the precautions necessary for the particular disease. With a respiratory disease, just about anything brought into the room can become contaminated. Even housekeeping becomes a problem. Germs that have settled to the floor can be picked up by a buffer and carried to other rooms. For this reason, the use of a buffer is not recommended. No matter how careful you usually are, it's easy to slip up unless you're alert to the problem every moment. The problems of keeping infectious disease from spreading are in one way much less intense than they used to be due to the success of prevention. Smallpox vaccine, for example, has been so widely administered that we've come close to wiping out the disease all over the world. There was no way to prevent poliomyelitis until a few years ago, and thousands of children became crippled every year. Today, because of the Saban vaccine, it's rare to find a case in this country. Yellow fever and malaria have been greatly reduced due to the elimination of breeding sites and killing of the mosquitoes that carry them. But a major problem still remaining in less advanced parts of the world has to do with sanitation. When human waste goes into the river that also supplies the water for drinking, organisms of dysentery and other diseases spread easily. Sanitation can also become a problem in the aftermath of a national disaster. A major task for medical personnel sent in to help is to take preventive measures before an epidemic can start. In the hospital when an infectious case is identified, it's the doctor's job to control the disease. And everybody's job to keep it from spreading. Medics and nurses play a vital part in this. You are constantly on the move between patients and you cannot afford to get careless. You must know the procedures for these specific disease, know how the organism escapes and how it's transmitted, know how long it can survive outside a reservoir and how it can be destroyed. All microorganisms we are normally concerned about will be destroyed by exposure to the steam sterilization process. There are too many variables for you to remember them all. Don't rely on memory. Find out. Infectious disease sometimes spreads through a hospital when it does. It's often because people have grown careless and taken shortcuts with the procedures. Don't you let that happen. Always be on guard. Today's children will grow up in a world increasingly free of infectious disease. Someday we may completely be free of it, but that's not likely in your lifetime or in theirs. Meanwhile, your jobs demand care to break the chain of transmission and keep infectious disease from spreading within the hospital.