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. 2019 Jul;24(28):1900038.
doi: 10.2807/1560-7917.ES.2019.24.28.1900038.

Extraordinary increase in West Nile virus cases and first confirmed human Usutu virus infection in Hungary, 2018

Anna Nagy  1   2 , Eszter Mezei  2   3 , Orsolya Nagy  1   4 , Tamás Bakonyi  5   6 , Nikolett Csonka  1 , Magdolna Kaposi  1 , Anita Koroknai  1 , Katalin Szomor  7 , Zita Rigó  7 , Zsuzsanna Molnár  3 , Ágnes Dánielisz  3 , Mária Takács  1   4
Affiliations

Extraordinary increase in West Nile virus cases and first confirmed human Usutu virus infection in Hungary, 2018

Anna Nagy et al. Euro Surveill. 2019 Jul.

Abstract

BackgroundDuring the 2018 WNV transmission season, similarly to other endemic areas in Europe, a large number of human West Nile virus (WNV) infections were reported in Hungary.AimsWe summarise the epidemiological and laboratory findings of the 2018 transmission season and expand experiences in flavivirus differential diagnostics.MethodsEvery patient with clinical suspicion of acute WNV infection was in parallel tested for WNV, tick-borne encephalitis virus and Usutu virus (USUV) by serological methods. Sera, whole blood and urine samples were also tested for the presence of viral nucleic acid.ResultsUntil the end of December 2018, 215 locally acquired and 10 imported human WNV infections were notified in Hungary. All reported cases were symptomatic; most of them exhibited neurological symptoms. In a large proportion of tested individuals, whole blood was the most appropriate sample type for viral nucleic acid detection, but because whole blood samples were not always available, testing of urine samples also extended diagnostic possibilities. In addition, the first human USUV infection was confirmed in 2018 in a patient with aseptic meningitis. Serological cross-reactions with WNV in different serological assays were experienced, but subsequent molecular biological testing and sequence analysis identified Europe lineage 2 USUV infection.ConclusionCareful interpretation and simultaneous application of different laboratory methods are necessary to avoid misdiagnosis of human USUV cases. Expansion of the laboratory-confirmed case definition criteria for detection of viral RNA in any clinical specimens to include urine samples could increase diagnostic sensitivity.

Keywords: Hungary; Usutu virus; West Nile virus; human infection; neuroinvasive disease.

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Conflict of interest statement

Conflict of interest: None declared.

Figures

Figure 1
Figure 1
Number of autochthonous and imported human cases of West Nile virus infection by week of symptom onset, Hungary, 2018 (n = 225), compared with 2013–2017 (n = 139)
Figure 2
Figure 2
Number of reported autochthonous and imported human cases of West Nile virus infection by year, Hungary, 2004–2018 (n = 438)
Figure 3
Figure 3
Geographical distribution of laboratory-diagnosed cases of West Nile fever and West Nile neuroinvasive disease by NUTS 3 region, Hungary, 2018 (n = 215)
Figure 4
Figure 4
Phylogenetic tree of Usutu virus sequences based on alignments of the NS5 partial region of the genome compared with patient sequence, Hungary, 2018
See this image and copyright information in PMC

References

    1. Ashraf U, Ye J, Ruan X, Wan S, Zhu B, Cao S. Usutu virus: an emerging flavivirus in Europe. Viruses. 2015;7(1):219-38. 10.3390/v7010219 - DOI - PMC - PubMed
    1. Papa A. Emerging arboviral human diseases in Southern Europe. J Med Virol. 2017;89(8):1315-22. 10.1002/jmv.24803 - DOI - PubMed
    1. Pealer LN, Marfin AA, Petersen LR, Lanciotti RS, Page PL, Stramer SL, et al. Transmission of West Nile virus through blood transfusion in the United States in 2002. N Engl J Med. 2003;349(13):1236-45. 10.1056/NEJMoa030969 - DOI - PubMed
    1. Iwamoto M, Jernigan DB, Guasch A, Trepka MJ, Blackmore CG, Hellinger WC, et al. Transmission of West Nile virus from an organ donor to four transplant recipients. N Engl J Med. 2003;348(22):2196-203. 10.1056/NEJMoa022987 - DOI - PubMed
    1. Aberle SW, Kolodziejek J, Jungbauer C, Stiasny K, Aberle JH, Zoufaly A, et al. Increase in human West Nile and Usutu virus infections, Austria, 2018. Euro Surveill. 2018;23(43):1800545. 10.2807/1560-7917.ES.2018.23.43.1800545 - DOI - PMC - PubMed

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