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Chapter 23: communicable diseases. Lesson 4: Emerging diseases and pandemics. I. Emerging infections. Some diseases are becoming more dangerous and widespread!
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Chapter 23: communicable diseases Lesson 4: Emerging diseases and pandemics
I. Emerging infections • Some diseases are becoming more dangerous and widespread! • Vaccines and modern technology have saved millions of lives, but communicable diseases continue to be the top causes of deaths worldwide. • Scientists now believe that some diseases once thought to be non-communicable may, in fact, be caused by infectious pathogens. (Alzheimer’s, diabetes)
Factors Contribute to the Spread of Emerging Infections Transport across borders Population movement Resistance to antibiotics Changes in food technology Agents of bioterrorism
AVIAN INFLUENZA Avian flu is passed to humans if there is direct contact with infected birds or contaminated surfaces. Because there is no vaccine and no cure, and because humans have little or no resistance to the virus, health authorities are watching this disease very carefully.
SALMONELLA AND E. coli Salmonella and E. coli are bacteria that sometimes live in animals’ intestinal tracts. If people come in contact with these bacteria by eating contaminated food produced by these animals, they may become ill.
II. How diseases affect the world • A. Diseases spread with amazing speed. B. Countries ARE connected through trade and travel- making it easy for infectious diseases to travel faster and farther than ever before.
C. Medical treatment and prevention requires constant research to find the causes and the cures for emerging diseases.
D. The increased development of antibiotics has saved countless lives. However, because they are so widely used, some pathogens have mutated into new forms that are resistant to antibiotics.
Pathogens become drug-resistant in a 3- step process Pathogens invade the body and cause illness Antibiotics attack the pathogens The pathogens that survive the antibiotics reproduce, creating a new generation of drug-resistant pathogens
Health agencies plan for the outbreak of a pandemic because a pandemic could be devastating. For example, the flu pandemic of 1918 resulted in about 675,000 deaths in the US and perhaps 50 million deaths worldwide. In the US, the federal government, under the leadership of the Department of Health and Human Services, coordinated planning throughout the country for the possibility of a pandemic occurring. Every state and many cities have plans of action in the case of a pandemic.