 |
Changes in global and local temperatures and rainfall could expand the geographical distribution of the
Aedes aegypti mosquito, affect its behavior, and increase the rate of development, thus increasing the risk of transmission of dengue. Additionally, extreme weather conditions, such as heat and heavy flooding, can produce the right environmental conditions for an outbreak. Major upsurges of dengue, in some nations such as Colombia in 1995, follow periods of heavy rains. It has been noted in the literature that in addition to climatic and environmental disruptions and changes, the movement of people, arthropod-vector, plants, and other particulars can increase exposure to dengue. The phrase “Viral Traffic” has been coined to describe the movement of viruses to new species or new individuals often through human acts -- in other words, viral traffic is enhanced by human traffic. Some emerging and re-emerging infections are caused by pathogens already present in the environment, but viral traffic and human traffic awaken them from their dormancy. Thus, prospects for reversing the recent trend of increased epidemic activity and geographic expansion of dengue are not promising. New dengue virus strains and serotypes will likely continue to be introduced into many areas where the population densities of
Aedes aegypti are at high levels.
However, the transmission dynamics of dengue virus are determined by the interaction of the environment, the agent, the host population, and the vector that exist together in a specific habitat. The magnitude and intensity of that interaction will define the dengue transmission in a community, region, or country.
|
