Virological surveillance of dengue haemorrhagic fever epidemics in Southern provinces of Viet Nam from 1987 to 1998

ABSTRACT

In Southern Viet Nam, since 1987 up to now, the viroligical surveillance offered knowledge of the epidemic serotype of dengue virus by years and its activity cycle as dengue-1 is 6 years since 1990; dengue-3 was introduced since 1995 and still acting for 2 or 3 years in the future. Genomic structure of the DEN-2/Vietnam/87 is somewhat different in comparison with many topotypes in the world, but closely related to the DEN-2 topotype of Jamaica. A close relationship has demonstrated between the DEN-3/VietNam/97-98 with the DEN-3/Thailand/1987. Confirmed DHF cases are demonstrated through virological and serological surveillance in the first quarter of the year. Therefore, the active surveillance and the DHF control programme must be implemented within this time