Various forms of malaria have been already described in the works of Hippocrates, more than 2400 years ago, and from them it appears to have been one of the most frequent infectious diseases in ancient Greece, certainly the most frequent among those that could have serious consequences, including death.
While the role played by mosquitos was not known, one of the ancient theories about the cause of such infectious diseases (which was described by Varro) was not essentially different from modern theories. It supposed that the wind brings from the swamps a large number of small animals, which are so small that they cannot be seen, and which enter the human body causing the disease. Therefore the proximity of swamps should be avoided, to avoid the diseases.
While the role played by mosquitos was not known, one of the ancient theories about the cause of such infectious diseases (which was described by Varro) was not essentially different from modern theories. It supposed that the wind brings from the swamps a large number of small animals, which are so small that they cannot be seen, and which enter the human body causing the disease. Therefore the proximity of swamps should be avoided, to avoid the diseases.