Contents lists available at ScienceDirect Ticks and Tick-borne Diseases journal homepage: www.elsevier.com/locate/ttbdis Short communication Tick-borne encephalitis outbreak following raw goat milk consumption in a new micro-location, Croatia, June 2019 Maja Ilic a,b, *, Ljubo Barbic c , Maja Bogdanic b , Irena Tabain b , Vladimir Savic d , Mirjana Lana Kosanovic Licina e , Bernard Kaic b , Andreja Jungic d , Marko Vucelja f , Vlado Angelov g , Marinka Kovacevic h , Dobrica Roncevic h , Samira Knezevic i , Vladimir Stevanovic c , Irena Slavuljica i,j , Danijela Lakoseljac h , Ninoslava Vickovic k , Marina Bubonja-Sonje i,j , Lisa Hansen a,l , Tatjana Vilibic-Cavlek b,m a European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control (ECDC), Gustav III:s Boulevard 40, 169 73 Solna, Sweden b Croatian Institute of Public Health, Rockefellerova 7, 10000 Zagreb, Croatia c Faculty of Veterinary Medicine, University of Zagreb, Heinzelova 55, 10000 Zagreb, Croatia d Croatian Veterinary Institute, Savska Cesta 143, 10000 Zagreb, Croatia e Andrija Stampar Teaching Institute of Public Health, Mirogojska Cesta 16, 10000 Zagreb, Croatia f Faculty of Forestry, University of Zagreb, Svetosimunska Cesta 25, 10000 Zagreb, Croatia g Veterinary Ambulance, Grabanj Ul. 8, 51300 Delnice, Croatia h Primorje-Gorski Kotar County Teaching Institute of Public Health, Kresimirova 52a, 51000 Rijeka, Croatia i Clinical Hospital Center Rijeka, Kresimirova 42, 51000 Rijeka, Croatia j Faculty of Medicine, University of Rijeka, Brace Branchetta 20/1, 51000 Rijeka, Croatia k University Hospital of Infectious Diseases Dr. Fran Mihaljevic, Mirogojska Cesta 8, 10000 Zagreb, Croatia l National Institute for Public Health and Environment (RIVM), Antonie Van Leeuwenhoeklaan 9, 3721 MA Bilthoven, the Netherlands m School of Medicine, University of Zagreb, Salata 3, 10000 Zagreb, Croatia ARTICLE INFO Keywords: Tick-borne encephalitis Croatia Goat milk One health ABSTRACT In June 2019, the Croatian Institute of Public Health was informed of a cluster of patients with laboratory confirmed tick-borne encephalitis (TBE) from the Gorski Kotar region. Five of the six patients with TBE reported consuming raw (unpasteurized) goat milk in the two week period before symptom onset, and one reported a recent tick bite. To assess risk factors for infection, we selected six control individuals from among healthy family and community members, and conducted a case-control analysis. None of the cases or controls were vaccinated against TBE. Individuals with TBE (cases) had 25 (95 % CI 0.8-1410.2, p = 0.021) times higher odds of raw goat milk consumption compared to healthy controls. Milk samples from 12 goats from the implicated farm were tested for the TBE virus (TBEV) using RT-PCR. TBEV RNA was not detected in the milk, but serological testing of goats and other farm animals yielded evidence of exposure to the virus: Six goats from the flock had TBEV neutralizing antibodies. Our findings suggest that the vehicle for the outbreak was raw goat milk from a single farm. Following public health advice to cease consumption of raw dairy products, no further cases have been reported. 1. Introduction Tick-borne encephalitis (TBE) is an emerging arboviral disease that affects several mammals. In humans, exposure to tick-borne en- cephalitis virus (TBEV) can lead to potentially fatal infection of the central nervous system (CNS), and may cause long-term neurological sequelae (Haglund et al., 1996). While TBEV is typically transmitted by the bite of infected ticks, humans can also become infected through consumption of unpasteurised dairy products from infected livestock including goats, sheep and cows (Bogovic and Strle, 2015; Böhm et al., 2017; Caini et al., 2012). Approximately two-thirds of people infected with TBEV have no symptoms of illness. Among those with clinical symptoms, TBE takes a monophasic or biphasic course: the first phase is characterized by non-specific symptoms like fever, fatigue, headache, https://doi.org/10.1016/j.ttbdis.2020.101513 Received 4 January 2020; Received in revised form 29 June 2020; Accepted 11 July 2020 ⁎ Corresponding author at: Croatian Institute of Public Health, Rockefellerova 7, 10000 Zagreb, Croatia. E-mail address: ms.majailic@gmail.com (M. Ilic). Ticks and Tick-borne Diseases 11 (2020) 101513 Available online 16 July 2020 1877-959X/ © 2020 Elsevier GmbH. All rights reserved. T