Global connections and disease

1. Global connections and disease Laura C. Harrington, PhD Department of Entomology

2. Goals for today • Understand the underlying factors and connections • that lead to global emergence of new infections • Recognize what types of pathogens are most likely • to emerge

3. Which of the following general classes of human pathogens are most likely to emerge rapidly with globalization? • Bacteria • Protozoa • Viruses • Fungi • Worms

4. Red represents newly emerging diseases; blue, re-emerging/resurging diseases; black, a 'deliberately emerging' disease. Morens et al. 2004. Nature 430, 242-249.

5. What factors lead to emerging/re-emerging pathogens?

6. Mutation of existing pathogens Ex: Y. pseudotuberculosis - inserting mutations in lab increases virulence

7. Influenza virus H5N1 Highly diverse infecting both humans and animals Can acquire genes readily from other animal viruses Host shifting

8. Re-assortment of viral pathogens Stevens et al.Nature Reviews Microbiology 4, 857-864 (November 2006) | doi:10.1038/nrmicro1530

9. Changing weather patterns and climate Range expansion of vectors and disease

10. Rice paddy irrigation Banana plantations Dams Clear cutting forests Logging Road building Changes in land use and agricultural practices

11. unplanned urbanization and poor sanitation

12. Waste

13. Poverty • Breakdown of • health care infrastructure

14. War and conflict

15. Increasing contact between humans and animals

16. rapid global travel over 760 million international arrivals annually

17. Drug abuse – HIV and other infections among intravenous drug users in USA Use of tampons - Toxic shock syndrome and Staphylococcus aureus infection Changes in human behavior/society

18. Use of new technology- air conditioning and water cooling- Legionnaires’ disease (Legionella pneomophila) Food processing technology – food borne illness Changes in technology

20. Chikungunya

21. Global spread of the Asian Tiger mosquito Pathogens transmitted by Ae. albopictus Chikungunya virus DEN 1-4 virus Dog heartworm virus Eastern Equine Encephalitis Jamestown Canyon virus Keystone virus LaCrosse virus Mayaro virus Orapouch virus Potosi virus Rift Valley Fever virus Ross River virus Sinbis virus Trivittatus virus West Nile virus Venezuelan Equine Encephalitis Dog heartworm

22. Dengue vector Aedes aegypti CNN: Thousands hit by Brazil outbreak of dengue (4/3/08) • 50-100 million dengue fever cases/year • 500,000 cases of DHF • 2/3 of world’s population at risk • among top global neglected diseases An 11-year-old boy is seen by a military doctor last weekend at a field hospital west of Rio de Janeiro, Brazil. No vaccine and no treatment for dengue

23. Increasing incidence of Dengue Infections Globally 1000 884 900 800 700 600 482 500 Cases per thousand 400 296 300 200 122 100 15 1 0 1955-59 1960-69 1970-79 1980-89 1990-99 2000-05 Years WHO: Dengue Net 2006

24. Review – factors giving rise to global emergence of human pathogens • Mutation, re-assortment and host shifting • Changing weather patterns and climate • Changes in land use • Unplanned urbanization and poor sanitation • Poverty, war and breakdown of public health infrastructure • Changes in human behavior and technology • Increasing contact between humans and animals