(47) Widespread occurrence of an infectious disease in a community or an area is called _________ .
1 point
epidemic
disaster
disease
infection
Answers
Answer:
epidemic
Explanation:
widespread occurrence of an infectious disease in a community at a particular time. 'a flu epidemic' More example sentences
Answer:
Level of disease
The amount of a particular disease that is usually present in a community is referred to as the baseline or endemic level of the disease. This level is not necessarily the desired level, which may in fact be zero, but rather is the observed level. In the absence of intervention and assuming that the level is not high enough to deplete the pool of susceptible persons, the disease may continue to occur at this level indefinitely. Thus, the baseline level is often regarded as the expected level of the disease.
While some diseases are so rare in a given population that a single case warrants an epidemiologic investigation (e.g., rabies, plague, polio), other diseases occur more commonly so that only deviations from the norm warrant investigation. Sporadic refers to a disease that occurs infrequently and irregularly. Endemic refers to the constant presence and/or usual prevalence of a disease or infectious agent in a population within a geographic area. Hyperendemic refers to persistent, high levels of disease occurrence.
Occasionally, the amount of disease in a community rises above the expected level. Epidemic refers to an increase, often sudden, in the number of cases of a disease above what is normally expected in that population in that area. Outbreak carries the same definition of epidemic, but is often used for a more limited geographic area. Cluster refers to an aggregation of cases grouped in place and time that are suspected to be greater than the number expected, even though the expected number may not be known. Pandemic refers to an epidemic that has spread over several countries or continents, usually affecting a large number of people.
Epidemics occur when an agent and susceptible hosts are present in adequate numbers, and the agent can be effectively conveyed from a source to the susceptible hosts. More specifically, an epidemic may result from:
A recent increase in amount or virulence of the agent,
The recent introduction of the agent into a setting where it has not been before,
An enhanced mode of transmission so that more susceptible persons are exposed,
A change in the susceptibility of the host response to the agent, and/or
Factors that increase host exposure or involve introduction through new portals of entry.(47)
The previous description of epidemics presumes only infectious agents, but non-infectious diseases such as diabetes and obesity exist in epidemic proportion in the U.S.(51, 52)
Pencil graphic Exercise 1.10
For each of the following situations, identify whether it reflects:
Sporadic disease
Endemic disease
Hyperendemic disease
Pandemic disease
Epidemic disease
____ 22 cases of legionellosis occurred within 3 weeks among residents of a particular neighborhood (usually 0 or 1 per year)
____ Average annual incidence was 364 cases of pulmonary tuberculosis per 100,000 population in one area, compared with national average of 134 cases per 100,000 population
____ Over 20 million people worldwide died from influenza in 1918–1919
____ Single case of histoplasmosis was diagnosed in a community
____ About 60 cases of gonorrhea are usually reported in this region per week, slightly less than the national average
Check your answer.
Epidemic Patterns
Epidemics can be classified according to their manner of spread through a population:
Common-source
Point
Continuous
Intermittent
Propagated
Mixed
Other
A common-source outbreak is one in which a group of persons are all exposed to an infectious agent or a toxin from the same source.
If the group is exposed over a relatively brief period, so that everyone who becomes ill does so within one incubation period, then the common-source outbreak is further classified as a point-source outbreak. The epidemic of leukemia cases in Hiroshima following the atomic bomb blast and the epidemic of hepatitis A among patrons of the Pennsylvania restaurant who ate green onions each had a point source of exposure.(38, 44) If the number of cases during an epidemic were plotted over time, the resulting graph, called an epidemic curve, would typically have a steep upslope and a more gradual downslope (a so-called “log-normal distribution”).
Figure 1.21 Hepatitis A Cases by Date of Onset, November–December, 1978
A histogram shows increase and decrease in the number of Hepatitis A cases over time.
Image Description
Source: Centers for Disease Control and Prevention. Unpublished data; 1979.
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