In the same way that increased global travel by people makes it easier for pathogens to spread quickly around the world, the increased transit of goods also creates new opportunities for the transmission of disease.

The tropical disease dengue, which causes severe pain in the bones, high fever, chills, vomiting, diarrhea, and severe exhaustion, infects up to 100 million people each year. Dengue mostly affects people in urban areas of the tropics. However, the disease has become widely spread by several especially hardy breeds of mosquitoes that brought the illness to many new populations. According to the World Health Organization, “The incidence of dengue has grown dramatically around the world in recent decades. Some 2.5 billion people – two fifths of the world’s population – are now at risk from dengue. WHO currently estimates there may be 50 million dengue infections worldwide every year.”⁸

Source: NRDC Issue Paper, July 2009
The Asian tiger mosquito has found a new home in the Western Hemisphere, bringing dengue with it. These mosquitos can now be found in Latin America to as far north as Chicago. The insects thrive in small pools of water such as flowerpots, gutters, birdbaths and plastic covers, and are believed to have been originally transported around the world by shipments of used tires.

The worldwide trend toward urbanization is also believed to have propelled the spread of dengue. Epidemiologists have tracked the disturbing growth of this epidemic in the Western Hemisphere:

• Small outbreaks of dengue have been reported in several American cities, including Houston, over the past decade
• A large outbreak struck Puerto Rico in 1994, sickening 20,000 people.
• A more severe illness associated with multiple exposures to dengue, known as dengue hemorrhagic fever, spread rapidly in Latin America over the last two decades. The World Health Organization (WHO) reports that in 2007 alone, there were over 26.000 reported cases of dengue hemorrhagic fever in the Americas.

8 Source:  http://www.who.int/mediacentre/ factsheets/fs117/en/

* Picture: http://www.who.int/mediacentre/factsheets/fs117/en/

Next: Food-borne Illness