Dengue and Dengue Haemorrhagic Fever in the Americas
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DJ Gubler, Sc. D.

Historical Background

Dengue was first described clinically in the Americas in 1780, when a large epidemic occurred in Philadelphia, Pennsylvania, USA(1). Little information is available on the occurrence of dengue-like illnesses in the region between 1780 and the late 1820s. From 1826 - 1828, major epidemics of dengue-like illness occurred in the southern United States and in Caribbean Basin countries. It was during these epidemics that the name dengue came into general use to describe the disease(2). Epidemics have subsequently occurred in the region at irregular intervals (Table 1). In recent years, however, the intervals have become progressively shorter, with major epidemics occurring every one to five years.

Table 1. History of epidemic dengue-like illness in the Americas*

* Adapted from Ehrenkran et al(2), 1971.

00000000The virus serotypes involved in early epidemics are not known. Serologic studies in Panama suggested that dengue 2 (DEN-2) was responsible for the 1941 - 1942 outbreak(3), but that dengue 3 (DEN-3) was also present(4). DEN-2 was the first virus to be isolated in the American region (in Trinidad, 1953)(5). DEN-3 was responsible for major epidemics in the early 1960s and early 1970s(2). In 1977, dengue 1 (DEN-1) was introduced into the Americas for the first time, although retrospective serologic evidence suggests that it may have been present many years earlier(3,6). Finally, Dengue 4 (DEN-4) was introduced into the Americas in 1981(7) and since that time, three serotypes, DEN-1, -2 and -4, have been transmitted simultaneously in many of the countries of the region where Aedes aegypti occurs. DEN-3 transmission has not been documented in the Americas since 1977. But the serotype has been introduced into the region by travellers from Asia on numerous occasions in the 1980s(8).