A confirmed case of DENV fever was defined as a patient with clinical symptoms (sudden fever onset >38.5° and duration ranging between 2 and 7 days, with the presence of two or more of the following symptoms: severe cephalalgia and retro-orbital pain, arthralgias, myalgias, learn more lumbago, maculopapular rash, and hemorrhagic

episodes) confirmed by laboratory tests (virus isolation; presence of viral RNA by RT-PCR; presence of IgM-specific antibodies in the serum; seroconversion or increase by at least four times of the antibody or presence of virus-specific antibodies, confirmed by neutralization, in single serum sample collected). A case-report form containing information about age, sex, countries visited, travel dates, and date of onset of symptoms was completed for each patient. We also estimated the number of imported infections to municipalities with international airports using data on arrivals in Italy from 2008 to October 2011 (Capstats.com, RDC Aviation Ltd, Nottingham, United Kingdom) and data derived from the surveillance system (January 2008–October 2011) in order to define the degree of underreporting. In our model to calculate the estimated number of imported CHIKV and find more DENV infections in Italy per 100,000 travelers we use as numerator the number of imported

cases derived from the surveillance system by visited area for each study year and as denominator the extrapolated number of travelers from the same areas as

those visited by notified imported cases each study year. All analyses were done using the STATA 11.2 software (Stata Corporation, College Station, TX, USA). Aldehyde dehydrogenase A total of 130 persons were notified from 10 Italian regions during the study period. The population of the reporting regions represents 72% of the Italian population (60 million). Of the 130 reported CHIKV and DENV cases: 57.7% were male, median age was 39 years (range 11–73 y), and most (79.2%) were Italian. A total of 21 (16.2%) were CHIKV, and 109 (83.8%) were DENV. Of the 21 CHIKV cases, 12 (57.1%) were Italian and 9 (42.9%) of other nationalities; 61.9% were females and 10 (47.6%), 6 (28.6%), and 5 (23.8%) were between 0 to 35, 36 to 50 and >50 years old of age, respectively. Overall, nine (42.8%) had visited the Indian Ocean Islands (Mauritius, Maldives, Bali, and Sri Lanka), nine (42.8%) had visited Asia, one (4.8%) had visited Africa, and for two (9.6%) the travel history was unknown. Of the 109 DENV confirmed cases, 93 (85.3%) were Italian and 16 (14.7%) of other nationalities; 61.5% were males and 44 (40.3%), 38 (34.9%), and 27 (24.8%) were between 0 to 35, 36 to 50, and >50 years old of age, respectively. Overall, 44 (40.4%) had visited Asia, 30 (27.5%) had visited Central-South America and Caribbean Islands, 11 (10.1%) had visited the Indian Ocean Islands (Mauritius, Maldives, Indonesia, and Sri Lanka), 10 (9.2%) had visited Africa, and for 14 (12.