1. Infectious Diseases
Objectives 4

2. Objective 4
Analyze
emerging and
re-emerging
infectious
diseases

3. Leading cause of death Globally, infectious diseases remain
the leading cause
of death, and they
are the 3rd leading
cause of death
in the US

4. Infectious Diseases
are the third leading
cause of death
in the United States

5. Emerging Infectious Diseases
1. Have not occurred in humans before,
2. Have occurred previously but affected only small numbers,
3. Or have occurred throughout human history, but only recently recognized as disease due to infectious agent

6. Emerging Infectious Diseases
Can be classified in 3 ways:
1. Have not occurred in humans before
An example is:
Global Threat in 2003
Severe Acute Respiratory Syndrome (SARS) is a mysterious respiratory illness that sickened more than 8,000 people worldwide and killed more than 750 between November 2002 and July 2003.

7. Emerging Infectious Diseases
Legionnaires Disease-
another example of a disease that has not occurred in humans before
Affects the respiratory system and is caused be the legionella bacteria.
This bacteria can multiply in water, especially cooling or plumbing systems, whirlpool spas, air conditioning systems and even the misters in grocery store produce departments. These are examples of new changes in technology.

8. Emerging Diseases Classification
2. Have occurred in humans previously but affected only small numbers
An example is:
Ebola
Ebola hemorrhagic fever (Ebola) is a very contagious illness that is often fatal in humans and nonhuman primates (monkeys, gorillas, and chimpanzees). It has appeared sporadically since it was first recognized in 1976.

9. Emerging Diseases Classification
3. Have occurred in humans throughout
human history, but only recently
recognized as a disease caused by an
infectious agent.
An example is:
Gastric Ulcer-prior to 1983
pylori bacterium was
considered “noninfectious”.
Symptoms are abdominal pain and indigestion

10. Give examples and the contributing factors for 3 emerging diseases
Lyme, 1982-conditions favoring tick vector and deer
AIDS, 1983-migration to cities, global travel, transfusions, organ transplants, IV drug use, multiple sex partners
cholera, 1992-evolution of new strain of bacteria

11. Re-emerging Infectious Diseases
Definition:
Once were major health problems globally
or in a particular country, then declined
dramatically, but are again causing health
problems for a significant proportion of the
population.
Re-emerging= occurred, declined and increased again

12. Re-emerging Infectious Diseases
Example:
Malaria is a mosquito
borne disease caused
by a parasite.

13. Malaria Left untreated, they may develop severe complications and die.
Each year million cases of malaria occur worldwide, and over one million people die, most of them young children in sub-Saharan Africa.

14. Why is malaria re-emerging?
Antibiotic
resistance
Fear of
vaccination

15. Re-emerging Infectious Diseases
Example: Tuberculosis

16. Why is tuberculosis re-emerging?
Antibiotic or drug resistance
Socioeconomic Issues that lead to an immunocompromised population

17. Give examples and the contributing factors for 3 re-emerging diseases
Pertussis-refusal to vaccinate based on fear of autism; decreased vaccine efficacy
Rubeola-failure to vaccinate or receive second dose
Yellow fever-insecticide resistance, urbanization, civil strife

18. Public health benefits
Public health can be improved with biomedical research.
The more we know the better we can understand, prevent or treat infectious diseases.
Research is key to knowledge.
Knowledge + choice = power
Power + behavior = increased human welfare

19. The End