Using routine diagnostic data as a method of surveillance of arboviral infection in travellers: a comparative analysis with a focus on dengue.

BACKGROUND In a large part of the developing world, limited infectious disease surveillance is performed. In laboratory information management systems data on diagnostic requests is available and may be amenable to trend analyses. We explored this potential, using DENV diagnostic requests as a model. METHOD Test results and anonymised information provided by clinicians were received for 8942 patients from diagnostic centres in the Netherlands from January 2000 to May 2011. The data were evaluated for completeness of a predefined minimal dataset and trends in DENV positive results by travel destination. Population travel data were obtained from a commercial registry, and dengue case notification data by country from WHO DengueNet. RESULTS Vaccination history was rarely reported (0.4%); travel destination was completed for 42% of requests; trends in diagnostic requests and IgM positive tests for this subset correlated to the WHO DENV notifications for the three main travel destinations, with some discrepancies. Additionally, this approach may provide information on disease outbreaks with other pathogens causing diseases clinically similar to DENV. PCR data proved to be insufficient for trend monitoring by country. CONCLUSION This approach is not straightforward, but shows potential for use as a source of additional information for surveillance of disease.