Dengue is a subtropical mosquito-borne disease that exhibits up to four serotypes. It is widespread in tropical regions of southeast Asia, Africa, and the Americas, infecting an estimated 50 to 100 million people every year (World Health Organization Website 2006) . Primary infections are sometimes asymptomatic, while secondary infections are more severe, with about 5% of secondary infections leading to dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS), the potentially fatal forms of the disease (World Health Organization Website 2006) .