Dengue Epidemic in Southern Vietnam, 1998
Dengue Epidemic in Southern Vietnam, 1998
A widespread epidemic of dengue hemorrhagic fever (DHF) occurred in southern Vietnam in 1998, with 438.98 cases/100,000 population and 342 deaths. The number of DHF cases and deaths per 100,000 population increased 152.4% and 151.8% over a 1997 epidemic. Dengue viruses were isolated from 143 patient blood samples; DEN-3 virus was identified as the predominant serotype, although a resurgence of DEN-4 was noted.
Since 1963, the incidence of dengue hemorrhagic fever (DHF), a leading cause of hospitalization and death in children, has steadily increased in Vietnam. In 1998, a widespread DHF epidemic affected 19 provinces in southern Vietnam (Figure 1); 119,429 cases of DHF and 342 deaths were reported (Figure 2); and the rates per 100,000 population were 438.98 and 1.26, respectively, for a case-fatality rate of 0.29%, an increase of 152.4% and 151.8% over those of a 1997 epidemic (288.02 and 0.83). The epidemic curve was similar to those of previous years: cases increased substantially from June to November. Peak transmission occurred from July to September, closely associated with the rainy season, a breeding period for the mosquito vector. DHF cases were reported in the first quarter in Ben Tre (1,387.2/2.4/100,000), Binh Phuoc (635.1/0), and Kien Giang Provinces (568.4/2.9).
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Figure 1. Nineteen provinces in southern Vietnam with mortality rates per 100,000 population, 1998.
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Figure 2. Reported cases of dengue hemorrhagic fever in southern Vietnam, 1963-1998.
We describe epidemiologic, virologic, and serologic studies carried out during the epidemic.
A widespread epidemic of dengue hemorrhagic fever (DHF) occurred in southern Vietnam in 1998, with 438.98 cases/100,000 population and 342 deaths. The number of DHF cases and deaths per 100,000 population increased 152.4% and 151.8% over a 1997 epidemic. Dengue viruses were isolated from 143 patient blood samples; DEN-3 virus was identified as the predominant serotype, although a resurgence of DEN-4 was noted.
Since 1963, the incidence of dengue hemorrhagic fever (DHF), a leading cause of hospitalization and death in children, has steadily increased in Vietnam. In 1998, a widespread DHF epidemic affected 19 provinces in southern Vietnam (Figure 1); 119,429 cases of DHF and 342 deaths were reported (Figure 2); and the rates per 100,000 population were 438.98 and 1.26, respectively, for a case-fatality rate of 0.29%, an increase of 152.4% and 151.8% over those of a 1997 epidemic (288.02 and 0.83). The epidemic curve was similar to those of previous years: cases increased substantially from June to November. Peak transmission occurred from July to September, closely associated with the rainy season, a breeding period for the mosquito vector. DHF cases were reported in the first quarter in Ben Tre (1,387.2/2.4/100,000), Binh Phuoc (635.1/0), and Kien Giang Provinces (568.4/2.9).
(Enlarge Image)
Figure 1. Nineteen provinces in southern Vietnam with mortality rates per 100,000 population, 1998.
(Enlarge Image)
Figure 2. Reported cases of dengue hemorrhagic fever in southern Vietnam, 1963-1998.
We describe epidemiologic, virologic, and serologic studies carried out during the epidemic.
