What are the stages in the natural history of disease?
Events that occur in the natural history of a communicable disease are grouped into four stages: exposure, infection, infectious disease, and outcome (see Figure 1.6).
Why is it important to know the natural history of disease?
One of the reasons that natural history studies are so important is that they help a rare disease, such as Dravet syndrome, to be better understood. It studies the hallmarks of the disease and how they progress over time, while unfolding patterns that might otherwise go unnoticed.
What is natural history in medicine?
In medicine, a natural history study is a study that follows a group of people over time who have, or are at risk of developing, a specific medical condition or disease.
What are diseases examples?
Examples are SARS, influenza, the common cold, tuberculosis (TB), Hepatitis A and B. Diseases spread from animals to humans, such as avian influenza, are known as zoonotic diseases.
What is the meaning of the natural history of disease?
Natural history of disease refers to the progression of a disease process in an individual over time, in the absence of treatment.
What are the five stages of disease?
The five periods of disease (sometimes referred to as stages or phases) include the incubation, prodromal, illness, decline, and convalescence periods (Figure 2).
Who studies natural history?
A person who studies natural history is called a naturalist or natural historian. Natural history encompasses scientific research but is not limited to it. It involves the systematic study of any category of natural objects or organisms.
What was the first natural theory of disease?
He noted the presence of “little worms” or “animalcules” in the blood and concluded that the disease was caused by microorganisms. He was the first to attribute infectious disease to a microscopic pathogen, inventing the germ theory of disease, which he outlined in his Scrutinium Physico-Medicum (Rome 1658).
What are the 5 types of diseases?
There are four main types of disease: infectious diseases, deficiency diseases, hereditary diseases (including both genetic diseases and non-genetic hereditary diseases), and physiological diseases. Diseases can also be classified in other ways, such as communicable versus non-communicable diseases.
What are the six stages of infection?
The six links include: the infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and susceptible host. The way to stop germs from spreading is by interrupting this chain at any link.
Which is an example of a natural history of disease?
Natural history of disease refers to the progression of a disease process in an individual over time, in the absence of treatment. For example, untreated infection with HIV causes a spectrum of clinical problems beginning at the time of seroconversion (primary HIV) and terminating with AIDS and usually death.
How did Leavel and Clark explain the natural history of disease?
The Theory of “Web of Causation” • The “epidemiological triad theory” was very effectively used by Leavel and Clark in explaining the natural history of disease and levels of prevention for obviating such departures from the state of health.
Which is the cause of every human disease?
• Every human disease is caused by a microbe or germ, which is specific for that disease and one must be able to isolate the microbe from the diseased human being. ROBERT KOCH LOUIS PASTEUR 13. Epidemiological Triad 14. Epidemiological Triad 15.
Which is a factor that initiates the disease process?
For cancer, the exposure may be a factor that initiates the process, such as asbestos fibers or components in tobacco smoke (for lung cancer), or one that promotes the process, such as estrogen (for endometrial cancer). After the disease process has been triggered, pathological changes then occur without the individual being aware of them.