Dengue in travellers is still underestimated

Dengue fever (DF), one of the main emerging virus diseases, also increases in German travellers, due to the increasing number of travellers to tropical regions.

We determined antibodies against DF virus in a group (n = 149) of long-distance travellers in order to evaluate the risk of acquiring DF. Serum samples were collected at the travel vaccination centre in Frankfurt/Main and DF seroprevalence in serum samples was determined using different antibody assays with particular attention to flavivirus cross-reactivity. So, antibodies against tick-borne encephalitis and previous flavivirus vaccination of the travellers were checked.

Depending on the test system, 8.7-19.5% of the screened travellers were found to be DF virus IgG antibody positive, significantly more than in previous investigations. Remarkably, younger adults and women are more often affected.

These data imply that the risk for travellers to acquire DF has been underestimated. Nevertheless, dengue haemorrhagic fever and dengue shock syndrome are still rare in travellers, but those with a history of dengue should be advised to protect themselves well from mosquitoes when travelling to endemic areas.