The infectious diseases are considered as emerging when their occurrences have increased in the past few years and could increase in the coming time like SARS, H1N1, or HIV/Aids.
On the other hand, the re-emerging infectious disorders are those, which were once considered as the major health issues globally or in a specific nation, and then got diminished drastically, however, are again turning into the health issues for a substantial ratio of the population like tuberculosis and malaria.
