Mycobacterium setense Infection in Humans

tions, 3) low levels of platelets (<100 × 109/L) and 4) increased capillary permeability (5). Our patient fulfi lled all 4 criteria. Few cases of reported DHF fulfi ll criterion 3 due to the short duration of severe thrombocytopenia in mild clinical forms (8). Increased vascular permeability was shown in our patient by the peritoneal and bilateral pleural effusions. The probability of diagnosing dengue fever in Europe increases with travel to dengue-endemic areas, in view of the increase of DHF numbers (2006–2007) and several outbreaks around the world, even during the nondengue season (9). Frequent travelers are more at risk for DHF. In a recent European publication, 17% of patients with imported dengue fever exhibited a secondary immune response, thus having a higher risk of developing DHF in the future (6). Serologic tests confi rm dengue infection only if a 4-fold increase in titers in consecutive serum samples occurs, as in our case. In dengue-endemic areas, despite the higher disease incidence, many cases still fail to meet WHO criteria (9). A comprehensive revision of dengue and DHF series (8) shows differences in applying WHO criteria for diagnosis, and sometimes the correlation was poor between criteria-fulfi lling cases and severity of disease. Some reports (6,8) suggest that WHO criteria should be reviewed and perhaps new parameters should be established to defi ne severe dengue disease. Although our patient was not infected in Europe, lessons from the recently described chikungunya outbreak in Italy indicate the possibility of new arbovirus outbreaks in previously non–disease-endemic areas due to the increasingly established presence of vectors like Ae. albopictus (10). Dengue virus infection should therefore be considered in the differential diagnosis of fever in returning travelers. DHF diagnosis, although unusual, could become more frequent in the future. Acknowledgments We thank Manuel Corachan for his critical reading of the manuscript and Carolyn Daher for assistance with manuscript preparation.