Outbreak!: 50 Tales of Epidemics that Terrorized the World

by Beth Skwarecki

After she has digested the blood, she lays 100 to 200 eggs on a damp surface that’s likely to flood. In rainforests, that might be a hole in a tree. On a ship, or in a city, the mosquito can breed in rain barrels, tin cans, swamps, or anywhere the water is still. They will hatch in two days if they stay wet and the weather is warm; they can survive for two months if they dry out. If the mother mosquito bites someone who has yellow fever, she takes up the virus along with the blood. The virus replicates inside her gut, and migrates through her body to her salivary glands. She’ll inject that saliva into her next victim, because mosquitoes’ saliva contains chemicals that keep blood from clotting. In doing so, she will pass on the virus. The female Ae. aegypti needs a new blood meal for each batch of eggs, so over her lifetime she may have several opportunities to spread disease. The virus can also spread inside of her, colonizing her ovaries so that when she lays eggs, the young are already infected.