Prevalence and molecular epidemiology of West Nile and Usutu virus infections in Croatia in the ‘One health’ context, 2018

Scientific paper - Original scientific paper

• Author: Tatjana Vilibić Čavlek
• Author: Vladimir Savić
• Author: Dario Sabadi
• Author: Ljiljana Perić
• Author: Ljubo Barbić
• Author: Ana Klobučar
• Author: Božana Miklaušić
• Author: Irena Tabain
• Author: Marija Santini
• Author: Marko Vucelja
• Author: Elizabeta Dvorski
• Author: Tamara Butigan
• Author: Gordana Kolaric‐Sviben
• Author: Tanja Potočnik‐Hunjadi
• Author: Mirta Balenović
• Author: Maja Bogdanić
• Author: Zdravko Andrić
• Author: Vladimir Stevanović
• Author: Krunoslav Capak
• Author: Marina Baličević
• Author: Eddy Listes
• Author: Giovanni Savini
• Author's institution: University of Zagreb; School of Medicine; (Department of Infectious Diseases)
• Author's institution: University of Zagreb; School of Medicine; (Department of Medical Microbiology and Parasitology)
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Clinical Medical Sciences; Medical Microbiology
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Clinical Medical Sciences; Infectology

Abstract (english)

In 2018, Croatia reported the largest outbreak of West Nile virus (WNV) infections as well as the re-occurrence of human Usutu virus (USUV) infections. For the first time, fatal WNV and USUV infections were detected in wild birds. We analysed epidemiological characteristics and molecular epidemiology of WNV and USUV infections detected during 2018 transmission season. From April to November, 178 patients with neuroinvasive disease and 68 patients with febrile disease were tested for WNV and USUV. Viral RNA was detected in cerebrospinal fluid (CSF) and urine samples using a real-time RT-PCR. Positive samples were tested by nested RT-PCR and nucleotide sequencing. IgM/IgG antibodies were detected in serum/CSF samples using ELISA with confirmation of cross-reactive samples by virus neutralization test (VNT). WNV neuroinvasive disease was confirmed in 54 and WNV fever in seven patients from 10 continental Croatian counties. Areas affected in 2018 were those in which cases occurred in previous seasons, while in three areas human cases were reported for the first time. Phylogenetic analysis of six strains from patients residing in different geographic areas showed circulation of WNV lineage 2. In three patients, neuroinvasive USUV infection was confirmed by RT-PCR or VNT. Sequence analysis of one detected strain revealed USUV Europe 2 lineage. During the same period, a total of 2,574 horse and 1,069 poultry serum samples were tested for WNV antibodies using ELISA. Acute asymptomatic WNV infection (IgM antibodies) was documented in 20/0.7% horses. WNV IgG antibodies were found in 307/11.9% horses and in 125/12.7% poultry. WNV RNA was detected in two goshawks and USUV RNA was detected in one blackbird from north-western Croatia. In the Zagreb area, 3,670 female mosquitoes were collected. One Culex pipiens pool collected in July tested positive for USUV RNA. Our results highlight the importance of continuous multidisciplinary 'One health' surveillance of these emerging arboviruses.

• Keywords (english): Adolescent; Adult; Aged; Aged, 80 and over; Animals; Chickens; Child; Croatia / epidemiology; Female; Flavivirus / isolation & purification; Flavivirus Infections / epidemiology; Flavivirus Infections / veterinary; Flavivirus Infections / virology; Horse Diseases / epidemiology; Horse Diseases / virology; Horses; Humans; Male; Middle Aged; Molecular Epidemiology; One Health; Poultry Diseases / epidemiology; Poultry Diseases / virology; Prevalence; Seroepidemiologic Studies; Turkeys; West Nile Fever / epidemiology; West Nile Fever / veterinary; West Nile Fever / virology; West Nile virus / isolation & purification; Young Adult
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review
• Publication version: Accepted version
• Journal title: Transboundary and Emerging Diseases
• Numbering: vol. 66, no. 5, pp. 1946-1957
• p-ISSN: 1865-1674
• e-ISSN: 1865-1682
• DOI: https://doi.org/10.1111/tbed.13225
• URN:NBN: urn:nbn:hr:105:966813
• Publication: 2019-09
• Document URL: https://onlinelibrary.wiley.com/doi/abs/10.1111/tbed.13225
• Type of resource: Text
• Access conditions: Open access
• Created on: 2021-02-11 09:32:45