Chapter 10
Insects, plants, livestock, domesticanimals and humans
Detrimental Aspects of Insects
Human Disease Transmission
1 out of 6 humans have suffered from aninsect-carried disease (Estimated)
Insects are vectors for the following (inhumans):
–Malaria, yellow fever, dengue fever,encephalitis, arborvirus,African sleepingsickness, bubonic pague, typhus, chagasdisease
Famous Insect caused diseases
Bubonic plague in Europe 1348 (25% ofEurope was knocked out)
End of Napoleon's dream in Russia(typhus)
Delay of Panama Canal (Malaria & yellowfever)
Casualties in U.S. Civil War (malaria,dengue fever, yellow fever)
Malaria **Sickle cell anemia**
1 person dies every 12 seconds
Transmitted by the female mosquitoes (males do notbite)
Discovered as a insect carried disease in late 1800s
Major health problem today (especially in the tropics)
The WHO (World Health Organization) attempted toeradicate in 1947. About 5-15 percent of the worldpopulation contracted the disease every year. U.S. isnow disease free
About 1000 travelers return to the U.S. each yr. WithMalaria
PLAGUE (black death)
Endemic disease of rodents
–Transmitted to humans by fleas. Once an insectingests infected blood, the alimentary canal becomesblocked and causes the flea to regurgitate infectedblood into new host (when flea tries to feed)
The pathogen (causing agent) localizes in thelymph gland (Bubonic plague). If the blood andlungs become infected(secondary) then in ispneumonic plague this can be transmitted toothers by sneezing and coughing.
Death results in 80% of human victims andoccurs in about 5 days
Major plague pandemics(localized to one area)
Plague of Justinian (A.D. 542)
Black Death of the Middle Ages (1346-1355)
European Plague (1870-1906)
Yellow Fever
Introduced to the world with slaveimportations from Africa
Spread through the tropical “New World”and as far north as New England.
Human infections result in death or lifelong immunity
Greater concern in the tropic regions
African sleeping sickness
Occurs south of the Sahara desert
Fatal if trypanosome protozoan affect thebrain and spinal cord
Transmitted by the tsetse flies
Onchocerciasis (river blindness)
Transmitted by black flies
20 million people are affected (most inAfrica)
Disease localizes in the skin & lymphglands, however if the worms enter theeye, it causes blindness
