First case of imported chikungunya infection in Croatia, 2016

Boris Luksic,1,2 Nenad Pandak,2,3 Edita Drazic-Maras,1 Svjetlana Karabuva,1 Mislav Radic,2,4 Andrea Babic-Erceg,5 Ljubo Barbic,6 Vladimir Stevanovic,6 Tatjana Vilibic-Cavlek5,7,8 1Clinical Department of Infectious Diseases, University Hospital Centre Split, Split, Croatia; 2School of Medicine, University of Split, Split, Croatia; 3Department of Infectious Diseases, General Hospital “Dr Josip Bencevic”, Slavonski Brod, Croatia; 4Department of Rheumatology and Clinical Immunology, University Hospital Centre Split, Split, Croatia; 5Croatian National Institute of Public Health, Zagreb, Croatia; 6Department of Microbiology and Infectious Diseases with Clinic, Faculty of Veterinary Medicine, University of Zagreb, Zagreb, Croatia; 7Reference Centre for Diagnosis and Surveillance of Viral Zoonoses of the Ministry of Health of the Republic of Croatia, Zagreb, Croatia; 8School of Medicine, University of Zagreb, Zagreb, Croatia Abstract: In recent years, several European countries reported cases of imported chikungunya infection. We present the first imported clinically manifested chikungunya fever in Croatia. A 27-year-old woman returned to Croatia on 21 March 2016, after she stayed in Costa Rica for two months where she had noticed a mosquito bite on her left forearm. Five days after the mosquito bite she developed severe arthralgias, fever and erythematous papular rash. In next few days symptoms gradually subsided. After ten days she felt better, but arthralgias re-appeared accompanied with morning stiffness. Two weeks after the onset of the disease she visited the infectious diseases outpatient department. The physical examination revealed rash on the trunk, extremities, palms and soles. Laboratory findings showed slightly elevated liver transaminases. Serological tests performed on day 20 after disease onset showed a high titer of chikungunya virus (CHIKV) IgM and IgG antibodies which indicated CHIKV infection. CHIKV-RNA was not detected. Serology to dengue and Zika virus was negative. The patient was treated with nonsteroid anti-inflammatory drugs and paracetamol. Her symptoms ameliorated, however, three months later she still complaint of arthralgias. The presented case highlights the need for inclusion of CHIKV in the differential diagnosis of arthralgia in all travelers returning from countries with documented CHIKV transmission. Keywords: chikungunya, imported, Croati