Types of disease

Types of disease - microorganism, often a normal resident,...

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Types of disease. Diseases can be defined in terms of their severity and duration. An acute disease  occurs rapidly and lasts a short time, while a chronic disease develops slowly and lasts a long time.  Influenza is an acute disease, while tuberculosis is a chronic disease. A subacute disease is a  disease that has vague symptoms and lasts a relatively long time. A latent disease remains inactive  in a host for a time and then becomes active.  Infections can be described as local infections if they are restricted to a small area of the body and  systemic infections if they spread throughout the body systems. The presence of multiplying  microorganisms in the blood is septicemia. Toxins present in the blood constitute toxemia.  Infectious diseases may also be described as primary diseases or secondary diseases. A primary  disease is the first illness that occurs, and a secondary disease is due to an opportunistic 
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Unformatted text preview: microorganism, often a normal resident, after the body's defenses have weakened. Modes of disease transmission. When a disease remains in a population, a source of pathogens called a reservoir of infection exists within the population. The reservoir can be human, animal, or nonliving, such as the soil. A human reservoir who has had the disease and recovered but continues to shed infectious organisms is called a carrier. Animal diseases spread to humans are called zoonoses. Among the principal routes of transmission of disease are contact, vectors, and vehicles. Contact can be direct or indirect. Direct transmission occurs from person to person by such things as touching, kissing, and sexual intercourse ( Figure 1 ). Indirect transmission occurs when a nonliving object is intermediary between two humans....
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This note was uploaded on 11/11/2011 for the course BIO 101 taught by Professor Pesthy during the Fall '07 term at Texas State.

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