An Imported Dengue Fever Case in Turkey and Review of the Literature

Dengue fever is an acute viral disease that can affect all age groups in tropical and subtropical countries. The predominant vectors are the mosquitoes namely Aedes aegypti and A.albopictus. Although there have been no case reports in Turkey due to DF, there is seroepidemiological evidence indicating the presence of Dengue virus (DENV) in Turkey. In this case report we presented an imported dengue fever case. The patient was 40 years old, previously healthy male, Switzerland citizen. He had immigrated from Dubai to India two weeks ago and after one week from immigration he attended to a hospital in India because of high fever. The NS1 antigen test (Bio-Rad Laboratories, USA) was found positive and the patient was followed-up with diagnosis of dengue fever in India. During his visit to Turkey, he attended to the hospital for a routine control and his analysis revealed thrombocytopenia (PLT: 48.000/mu l), leukopenia (white blood cell: 2800/mu L) and elevated liver enzymes (AST: 76 U/L, ALT: 83 U/L). Fever was not detected in follow-up. The patient had petechial rash on his lower extremities, white blood cell and PLT count increased to 4100/mu l and 93.000/mu l, respectively. Liver function tests revealed a decrease in AST (63 U/L) and ALT (78 U/L) on the third day. The PLT count increased to 150.000/ml. Since the patient had no fever and had normal physical and laboratory findings, he was discharged from the hospital. For the confirmation of dengue fever diagnosis the serum sample was sent to National Public Health Center, Virology Reference and Research Laboratory where IgM and IgG antibodies against DENV types 1-4 were investigated by indirect. immunofluorescence method (Euroimmun, Germany). The serum sample yielded positive result at the dilutions of 1/1000 for IgM and 1/10.000 for IgG. The last dilution of type 3 DENV IgM and IgG were determined high density of fluorescein, thus the serotype was identified as "DENV type 3". Travel-related diseases become important with increasing travel opportunities, globalization and transportation, recently. As a result, this imported case with foreign nationality was the first dengue fever case confirmed by clinical and laboratory tests in Turkey.