are diseases (sometimes they are called orphan diseases) are such illnesses that affect only the smallest part of the human population. To stimulate the research of these diseases and find the effective treatment a financial support from the government is often required.
Many of the orphan diseases are genetic ones and torture the person during the whole life even in the cases of a long latent period when the symptoms remain implicit for a long period of time. Many rare diseases tent to appear in an early childhood and nearly 30 % of children suffering from them don’t reach the age of 5 years old.
There is no single level of a particular disease dissemination to provide the reasons for considering it to be a rare or a common one. A disease may supposed to be a rare one in the one country or a detached community and widespread in another.
Today the non-contagious diseases are the main cause of reducing the life quality and a high death level. According to the statistics the amount of people suffering from such illnesses as diabetes or cancer has increased form 10 to 14 percent worldwide for the recent few years, and the death level connected with these illnesses has raised up to 1.5 percent. The International Association of Diabetics states that about 30 percent of the Earth population will develop diabetes by the year 2030.
Before the nineteenth century the situation was the same with the contagious illnesses. The epidemics of cholera and plaque often took place in Europe making the whole towns disappear. The reasons for the great amount of people deaths wasn’t known during those times as the stirrers of these diseases were discovered only in the late nineteenth century be Louis Pasteur and Robert Coch.