Improving global surveillance
Epidemiological and laboratory-based surveillance is required to monitor and guide dengue/DHF prevention and control programmes regardless of whether these are based on mosquito control or possible vaccination if an effective and safe vaccine becomes available. However, though there are standard case definitions for dengue and dengue haemorrhagic fever (DHF), the reporting of dengue/DHF is not standardized. Epidemiological and laboratory data are often collected by different institutions and reported in different formats, and are therefore difficult to collate. This results in delayed collection and analysis at the regional/global levels, vital for epidemic prediction and preparedness.
To address these problems, WHO has created DengueNet as a central data management system to collect and analyse standardized epidemiological and virological data in a timely manner, and to present epidemiological trends, as soon as new data are entered and to provide both historical and real-time data. DengueNet currently houses data from 1995-2001.
The DengueNet system responds to the WHO resolution on dengue fever/DHF prevention and control adopted at the 55th World Health Assembly in May 2002, asking Member States to strengthen surveillance and emphasizing the critical importance of strengthening laboratory diagnosis in affected countries.
Building on the existing network of dengue laboratories in the Americas, WHO is now launching a pilot test of DengueNet focusing on data quality and active participation of national programmes. Forty epidemiologists and virologists participated in the first meeting on DengueNet implementation in the Americas region. The group considered the need for global epidemiological and laboratory surveillance of dengue and DHF; the national laboratory capacities in the Americas region; and the epidemiological data and reporting requirements for DengueNet. See the report on DengueNet in the Weekly Epidemiological Record. Implementation of DengueNet is planned for South-East Asia and the Western Pacific regions in 2003.
When fully in place, DengueNet will provide public health authorities and the general public with immediate real time data on dengue/DHF cases and deaths and circulating dengue virus serotypes.