Indigenous peoples of the Americas Smallpox killed from one third to half of the native population of Hispaniola in 1518. By killing the Incan ruler Huayna Capac, smallpox caused the Inca Civil War of 1529–1532. Smallpox was only the first epidemic. Typhus (probably) in 1546, influenza and smallpox together in 1558, smallpox again in 1589, diphtheria in 1614, measles in 1618—all ravaged the remains of Inca culture. Smallpox killed millions of native inhabitants of Mexico. Unintentionally introduced at Veracruz with the arrival of Pánfilo de Narváez on April 23, 1520, smallpox ravaged Mexico in the 1520s, possibly killing over 150,000 in Tenochtitlán (the heartland of
Fish disease and parasites Fish can limit the impacts of pathogens and parasites with behavioural or biochemical means, and such fish have reproductive advantages. Interacting factors result in low grade infection becoming fatal diseases. In particular, things that causes stress, such as natural droughts or pollution or predators, can precipitate outbreak of disease. Disease can also be particularly problematic when pathogens and parasites carried by introduced species affect native species. An introduced species may find invading easier if potential predators and competitors have been decimated by disease. Pathogens which can cause fish diseases comprise: Parasites in fish are a common natural occurrence. Parasites can