... including actions to provide information, to deal with clusters of rare diseases in a population and to support relevant patient organisations ...
There are are least 3 presentations of disease clusters as enumerated above.
The most common is the common epidemic, such as a cluster of gastroenteritis after a shared church picnic; this represents an increase in a common disease which is recognized because it occurs in a short time and space fashion in a particular group of individuals. Clusters of rare diseases are noted because of the rarity of the disease; an example would be the 3 cases of angiosarcoma of the liver associated with workers from 2 plants using vinyl chloride. Finally, sometimes the cluster is recognized in an unusual population based on known epidemiology; an example of this would be testicular cancer in male workers older than 40 years of age in a particular industry since testicular cancer is a disease of younger and much older men.
