Part II the origin of infections

The infectious diseases of man are usually divided into two

' large groups. Some diseases aftect only man, others affect both

man and animals, with man most frequently infected from animals.

Every infectious disease has not only characteristic clinical manifestations but also its own specific way of invasion into the human body.

Such a disease as dysentery, which is one of the diseases of the intestinal infections, is spread through the intestines and stools.

The infections of the respiratory tract compose the second subgroup. During coughing or talking the pathogens are discharged from the infected organism with the mucus from the membranes^ of the respiratory tract into the air in the form of drops. The infection is spread when the air containing drops of mucus with the pathogens in it, is, breathed in. The diseases of this subgroup are diphtheria, smallpox, etc.

The diseases of the third subgroup are spread through the skin and the mucosa in which the pathogens multiply. In some cases it is the skin, in others it is the mucous membrane of the eye. Direct contact and various things belonging to the sick may be responsible for spreading the infective agent.

The diseases of the fourth subgroup are spread by living insects. The pathogens causing these infections circulate in the blood or lymph and are not discharged from the organism. The insects become infected as they ingest the blood of a diseased man. They become infectious for other people after the pathogens have multiplied in their organism.. All these diseases, of which encephalitis is an example, are called blood infections.

Infections in children

Once healthy children are past the first few months of life they are able to combat infections as well as adults. During the first few months the child may not have developed a sufficient number of antibodies to be able to combat successfully the many bacteria in his environment.

The process of developing antibodies takes place rapidly after six months of age, and healthy children may show an even greater resistance to the ordinary bacterial infections than adults.

Children tend to develop an immunity to the bacteria that flourish in their environment. However, such bacteria as staphylo-coccus, streptococcus, colon bacillus, and others can cause an

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infection if they gain access, to the child's body through a break in the skin or through one of his apertures.

There are some conditions which can affect a child's ability to combat an infection.

1. If a child is undernourished and lacks sufficient body proteins, vitamins and essential minerals, he will be poorly equipped to combat infections.

2. An anemic child will find it more difficult to mobilize his body resources to combat infections.

3. If there is a disease in one of the major organs, such as liver, kidneys, or bone marrow, a child will be less able to fight off the invasion of bacteria.

Any infection may cause temperatures as high as 105 °F to 106 °F in a, child. This is not a bad indication, as it demonstrates the child's ability to mobilize his defence mechanisms.

It is necessary to give a patient large quantities of fluids because most generalized infections are associated with temperature elevation and profuse sweating. Furthermore, large quantities of fluids tend to dilute the toxins produced by the bacteria.

Bed rest and prompt treatment of minor infections such as head colds or other upper respiratory infections will often prevent the onset of a more serious infection such as pneumonia.

It must be remembered that antibiotics are usually ineffective in ridding the body of a viral infection. However, they may be given to prevent a secondary invasion of bacteria that would complicate the original viral infection.

In certain instances the vaccines are effective in preventing the viral infection but not in curing it. For example, the measles virus can be prevented from taking hold within the body by vaccinating the child against it.

DISEASE

DISEASE is the unhealthy state of a body part, a physiological system, or the body as a whole. A disease may be a structural anomaly, such as a congenital heart defect, or a functional condition such as high blood pressure or trauma.

An important aspect of any disease is its etiology. Many diseases are known to be caused by infectious agents for example, childhood infectious diseases; the common cold and the flu and catarrhal jaundice are considered to be viral infections while inflamatory processes and abscesses being caused by bacteria. Another important aspect of a disease is the way of its manifes­tation — the symptoms and signs.

Diagnosis, the determination of the nature of a disease, is based on many factors including the signs, symptoms and often, laboratory arid clinical findings. To make a diagnosis a physician obtains information from a physical examination, from interviewing the patient or a family member, as well as from a medical history of the patient.

The physician having made a diagnosis states the possible prognosis of the disease, the course it is to take and an outcome of the disease.

The treatment considered most effective should be prescribed and may include medication, surgery, radiation therapy, etc.

Physicians know the course of the disease often to vary. It may have a sudden onset and a short duration in which case it is stated to be an abute disease. A disease may begin insidiously curable one or have a fatal outcome.