Virological and Serological Surveillance of Dengue Epidemics in 19 Provinces in Southern Viet Nam during 2001

In 2001, 18 provincial centres for preventive medicine sent samples taken from DHF patients to the Arbovirus Laboratory at the Pasteur Institute, Ho Chi Minh City. The provinces with the highest rates of virus isolation were Tien Giang and Kien Giang. Dengue viruses were mostly isolated from patients diagnosed with viral syndrome and DHF grades I-II. Dengue-2 virus caused many cases of severe disease (grade III-IV), as compared with other serotypes. A total of 4,046 patient sera were tested by Mac-ELISA; the average positive rate was 56.13%. In areas with positive Mac-ELISA results, however, no control measures had yet been implemented to limit the increasing number of DHF outbreaks in the area.