What type of epidemic is caused from common source?
Point source outbreaks (epidemics) involve a common source, such as contaminated food or an infected food handler, and all the exposures tend to occur in a relatively brief period.
What are the three main sources of an epidemic?
- Common-source. Point. Continuous. Intermittent.
What are the most common causes of epidemics?
There are five major factors that allow viruses to cause epidemics:
- Human population dynamics and behavior.
- Changes in insect or reservoir populations.
- Weather and climate changes.
- Changes to the viruses themselves.
- Meeting the challenges of new epidemics.
What is continuous common source epidemic?
This is a continuous common source epidemic in which exposure to the source is prolonged over an extended period of time and may occur over more than one incubation period. The down slope of the curve may be very sharp if the common source is removed or gradual if the outbreak is allowed to exhaust itself.
What are some examples of pandemics?
Other examples of pandemics in recent history
- The 2009 swine flu pandemic: The flu strain that caused this outbreak, H1N1, was first identified in the U.S. in April 2009.
- The HIV/AIDS pandemic: The first cases of HIV, the virus that causes AIDS, appeared in 1981.
Is measles a propagated epidemic?
Propagated (progressive source) epidemic. This outbreak of measles begins with a single index case that infects a number of other individuals. (The incubation period for measles averages 10 days with a range of 7-18 days.)
What are some examples of epidemics?
What is an Epidemic? The Centers for Disease Control and Prevention (CDC) describes an epidemic as an unexpected increase in the number of disease cases in a specific geographical area. Yellow fever, smallpox, measles, and polio are prime examples of epidemics that occurred throughout American history.
Is covid19 pandemic or epidemic?
COVID-19 is an infectious disease caused by a novel strain of coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-COV-2), resulting in a global pandemic.
What is propagated source epidemic?
A propagated epidemic occurs when the infection spreads from one person to another, e.g. through the air, via a vector, via contaminated food or water, or during unprotected sexual intercourse. A mixed epidemic can start with a common source and be followed by a propagated spread.
What are the causes of common source epidemics?
A. Common-Source Epidemics Common-source epidemics are frequently, but not always, due to exposure to an infectious agent. They can result from contamination of the environment (air, water, food, soil) by industrial chemicals or pollutant.
How does the epidemic curve of a common source outbreak work?
In a continuous common-source outbreak, the range of exposures and range of incubation periods tend to flatten and widen the peaks of the epidemic curve (Figure 1.22). The epidemic curve of an intermittent common-source outbreak often has a pattern reflecting the intermittent nature of the exposure.
How is an epidemic related to exposure to a disease?
The exposure to the disease agent is brief and essentially simultaneous, the resultant cases all develop within one incubation period of the disease. The epidemic tends to be explosive, there is a clustering of cases within a narrow interval of time, and More importantly, all the cases develop within one incubation period of the disease.
Can a propagated epidemic last longer than a common source?
A propagated outbreak is one that is spread from person to person. Be- cause of this, propagated epidemics may last longer than common source epidemics and may lead to multiple waves of infection if secondary and tertiary cases occur.