EPIDEMIOLOGICAL, VIROLOGICAL AND ENTOMOLOGICAL SURVEILLANCE TO PREDICT THE EPIDEMIC OF DENGUE FEVER/DENGUE HAEMORRHAGIC FEVER FROM 1998 TO 2001 IN SOUTHERN VIETNAM

 

Nguyen Thi Kim Tien, Luong Chan Quang, Do Quang Ha, Tran Khanh Tien

Pasteur Institute of Ho Chi Minh City

 

ABSTRACT

Dengue/dengue haemorrhagic fever is one of the highest morbidity diseases among declared infectious diseases in children of Southern Vietnam.

Dengue epidemic in 1998 is a very big one with morbidity of 455 cases/105 and mortality rate of 1.27/105; with dengue-3 as the predominant serotype. In 1999-2000, there was a lower morbidity (80.7 and 69.9 cases/105) and a lower mortality (0.23 and 0.18 deaths/105); the dengue-3 virus decreased and dengue-4 virus emerged. During the first 8 months of 2001, number of cases began increasing (67.8 cases/105), but were not higher than the average of the previous five years. However, there were epidemic in several provinces, such as An giang, Tien giang, Dong thap, Ba ria Vung tau. And there, number of cases increased higher than the average of the previous five years. Dengue-4 became the predominant serotype, especially in the epidemic provinces.

An excessive increase of the number of cases as compared with the average of the previous five years, and an increase circulation of new dengue virus serotype at the first quarter may be used as indicators to predict larger epidemics in the year.

There was no correlation of entomological indices with the epidemiological situation in this study.