Endemic, Epidemic, Pandemic What do they mean?

 

Author: Ann O Leary
The swine flu vaccination program began a couple of weeks ago and is now in full swing. Some of the terminology used in discussing this infection can be quite confusing so here are some terms you may come across.
An infection is said to be Endemic in a population when there is a constant amount of infection present. For example in the UK there will be a number of chicken pox cases reported each year. The chicken pox is passed around from person to person but as long as the number infected remains more or less the same each year, then we can say that chicken pox is endemic in the population.
On the other hand if we take malaria as an example, we will find a number of cases detected each year in travelers returning from abroad. The number may even be the same from year to year. There is one significant difference however, and that is, that the infection cannot be passed on from person to person. In the case of malaria we need the presence of an external factor for the disease to run through the population. This factor is the malaria carrying mosquito and since this insect does not exist in the UK, the disease cannot become endemic.
The definition rests on the fact that the numbers infected each year remains substantially the same and that the disease is capable of passing from person to person.
An Epidemic occurs when new cases of infection exceed substantially what is normally expected in a population. The epidemic could be restricted to a specific hub such as a school or a city or it could affect an entire country. For an epidemic we need high levels of infection that eventually level out and fall back.
For a Pandemic to occur we need a completely new disease to emerge which can be transmitted globally. The present swine flu pandemic is such a disease.
When we hear of an epidemic or pandemic we assume the worst. It is important to remember that the terms refer to numbers and transmission of infection. The terms do not refer to the seriousness of the disease. For example it is possible to have a pandemic of a very mild infection. So when we hear of epidemics or pandemics we need to look at the disease in question as well as the risk of infection .
Another term to look at is Vaccination itself. Normally our bodies produce antibodies in response to an infection. Pharmaceutical companies create vaccines by taking organisms and treating them so that they cannot cause an infection. When the vaccine is administered our bodies automatically respond as if an infection has occurred and we are prompted to produce antibodies. By taking a vaccine we give ourselves advance protection against specific diseases.
Article Source: http://www.articlesbase.com/health-articles/endemic-epidemic-pandemic-what-do-they-mean-1628450.html
About the Author
Ann O Leary is a biomedical scientist and a commentator on health care issues through her blog "Thoughts on a Healthy Lifestyle". http://www.ann-o-leary.com