Chapter 10
Epidemiology
By Boundless
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Epidemiology is the study of the patterns, causes, and effects of health and disease conditions in defined populations.
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Epidemiological studies include disease etiology, disease surveillance and screening, biomonitoring, and clinical trials.
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Epidemiology is the study of the patterns, causes, and effects of health and disease conditions in set populations.
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Koch's postulates are four criteria designed in the 1880's to establish a causal relationship between a causative microbe and a disease.
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Even in Koch's time, it was recognized that infectious agents could be responsible for disease without fulfilling all of the postulates.
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An occurrence of disease greater than would be expected at a particular time and place is called an outbreak.
The severity and duration of diseases vary greatly and are important for epidemiological studies.
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Host-pathogen interactions are the interactions taking place between a pathogen (e.g. virus, bacteria) and their host (e.g. humans, plants).
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Modern nucleic acid-based microbial detection methods make it possible to identify microbes that are associated with a disease.
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The spread and severity of infectious disease is influenced by many predisposing factors.
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After an pathogen invades a host, it undergoes a series of phases that eventually lead to multiplication of the pathogen.
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Once discovered, natural reservoirs elucidate the complete life cycle of infectious diseases, providing effective prevention and control.
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Defining the means of transmission of a pathogen is important in understanding its biology and in addressing the disease it causes.
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Pathogens have evolved to adapt to their environment and their host in order to survive.
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Working with microorganisms, especially pathogens, requires special equipment and safety practices.
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The index case is identified in epidemiology studies by tracking down the infected patients to try to determine how the disease originated.
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Nosocomial infections can cause severe pneumonia and infections of the urinary tract, bloodstream, and other parts of the body.
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Numerous risk factors in the hospital setting can predispose a patient to infection.
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The most important and frequent mode of transmission of nosocomial infections is by direct contact.
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Hospitals have sanitation protocols regarding uniforms, equipment sterilization, washing, and other preventive measures.
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Descriptive epidemiology focuses on describing disease distribution by characteristics relating to time, place, and people.
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Epidemiology draws statistical inferences, mostly about causes of disease in populations based on available samples of it.
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Experimental epidemiology uses an experimental model to confirm a causal relationship suggested by observational studies.
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Promotion of hand washing, breastfeeding, delivery of vaccinations, and distribution of condoms are examples of public health measures.
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Global health is the health of populations in a global context and transcends the perspectives and concerns of individual nations.
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An emerging infectious disease is a disease with a rate of incidence that has increased in the past 20 years, and could increase in the near future.
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Biological warfare (BW) is the use of biological toxins or infectious agents with the intent to kill or incapacitate.
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Technology aids in the identification of new infectious agents, but it also contributes to the emergence of new diseases.
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An epidemic occurs when new cases of a disease, in a given human population, and during a given period, substantially exceed expectations.
- Overview of Viruses
- Structure of Viruses
- Classifying Viruses
- Culturing Viruses
- Viral Replication