Hansen's bacillus has a predilection for skin and nerves. It is installed on them to damage them, so that if, for example, comes to the optic nerve, can leave you blind. In the logic of numbers added together experts difficult sanitary and hygienic conditions by the countries most affected by this disease, for which there is no vaccine but treatment that is extended by six months or a year. In fact, in these countries only one hundred thirty of each affected receive treatment.