27. About 3,600 years ago, Egyptians noticed that symptoms of malaria (high fever, shaking chills, nausea, etc.) increased in prevalence during which natural phenomenon?
From Quiz History of Malaria
Answer:
Flooding of the Nile River
The Anopheles mosquito, sixty-some species of which can transmit malaria, breed in stagnant water. Within the mosquito, species of Plasmodium reproduce sexually and have genetically diverse offspring. When she bites a human (the only vertebrate host), the parasites are released into the blood stream and carried into the liver, where they reproduce asexually. They then re-enter the blood stream, invade red blood cells, multiply further, and burst out to infect more cells.