Tropical DiseasesDL ppt Tropical Diseases dengue fever by mikeholy

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									Global Warming Effects on
        Tropical Diseases
   Warming effects on infectious
• Vector borne diseases such as malaria,
  yellow and dengue fever and encephalitis
  are not necessarily related to temperature
• Most vectors prefer a small range of warm
Lab testing of West Nile Virus Transmission with mosquitoes and birds.

     Reisen, WK. (2006). Effects of temperature on the transmission of West Nile virus by
     Culex tarsalis (Diptera : Culicidae). Journal of Medical Entomology, 43(2), 309-317.
•   Six villages in the West
    Usambara Mountains in
    northeast Tanzania,

      Left Axis=Biting Rates
      Right Axis =Rainfall and

Bodker, R. 2003. Relationship between altitude and intensity of malaria transmission in the Usambara Mountains,
Tanzania. Journal of Medical Entomology 40 (5): 706-717.
   Warming Effects on Infectious
• Humidity increase varies in different
  locations on Earth due to global warming
• Disease increase varies on location for
  global warming
• Temperate zones such as United States
  might see increase in diseases (Texas
  outbreaks of Malaria for example)
   Disruption of an ecosystem
• Vector predators, such as bats or birds
  that consume insects may migrate to new
  locations to avoid hotter climates
• Vector populations could grow due to the
  missing predators and infectious diseases
  could further increase
  Spreading of Infectious Diseases
• If global warming continues, birds or other animal reservoirs might
  have to migrate to new habitats, exposing new diseases in new
• West Nile virus infects more than 30 North American mosquito
  species, which together transmit infection to at least 150 bird
  species, many of which migrate to new and distant locations,
  spreading the virus to rural and urban ecosystems throughout North
  and Central America
         Emerging Diseases
• HIV, SARS, H5N1 (Bird Flu), and other
  new diseases appearing in the last 30
  years are definitely influenced by global
  warming but there are other greater
  factors including the ease of air travel and
  population growth for humans
Morens, DM. (2004). The challenge of emerging and re-emerging infectious diseases. Nature, 430(6996), 242-249.

Red represents newly emerging diseases; blue, re-emerging/resurging diseases; black, a 'deliberately emerging' disease.

Many diseases emerged and re-emerged because of global warming?
Possibly, but there are certainly other factors.
• Global warming contributes in introducing
  and spreading more diseases globally, but
  in the short term, it definitely would not
  cause any an epidemic situations by itself

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