ACTIVE LABORATORY-BASED SURVEILLANCE AND CONTROL OF DENGUE HAEMORRHAGIC FEVER AT COMMUNE LEVEL, 1997

Summary

In response to the increase of the number of cases and deaths due to Dengue Haemorrhagic Fever (DHF) in southern Vietnam, an active laboratory-based surveillance and control for dengue/DHF was implemented with the aim to monitor the disease activity and to evaluate its results regarding DHF surveillance and control. This approach is outlined, as follows: To monitor the dengue viruses transmitted in the areas, Mac ELISA tests were used to detect dengue virus circulation by testing the blood of patients with nonspecific febrile illness. The patient’s sera were collected by health workers of Commune Health Centers, then taken to the Center for Preventive Medicine of Dong Nai province and processed to detect dengue-specific IgM antibody to provide early detection of the dengue transmission. A rapid-response emergency vector control was proceeded when specific dengue antibodies were detected to kill infected mosquitoes, with the aim to limit the virus spreading into subsequent parts of the village. The goal of this study is to prevent major dengue epidemics by reducing dengue transmission. The rationale is that if we can decrease incidence, we will automatically reduce the likelihood of DHF/DSS occurring in the region. After a one-year experience, we found that the use of insecticide aerosol can reduce the DHF morbidity to a lower level and the use of ULV spraying has no effect for the DHF control in an endemic area.