Dengue fever (DF) is an old disease that
became distributed worldwide in the
tropics during the 18th and 19th centuries
when the shipping industry and
commerce were expanding [1]. Both the
principal mosquito vector, Aedes aegypti,
and the viruses responsible for DF were
spread via sailing ships because the
mosquito used the stored water on the
ships as a breeding site and could
maintain the transmission cycle, even on
long voyages. When such a ship called at
a port, often both the mosquito and the
virus were introduced. Because of the
slow mode of transportation, epidemics
were infrequent, with intervals of 10 to
40 years. When a new dengue virus
(there are four serotypes: DEN-1, DEN-2,
DEN-3 and DEN-4) was introduced,
however, it frequently resulted in major
epidemics that affected numerous
countries in that region.