Skip directly to site content Skip directly to page options Skip directly to A-Z link Skip directly to A-Z link Skip directly to A-Z link
Volume 18, Number 10—October 2012
Letter

West Nile Virus Meningoencephalitis Imported into Germany

On This Page
Tables
Article Metrics
14
citations of this article
EID Journal Metrics on Scopus

Cite This Article

To the Editor: West Nile virus (WNV) is a single-stranded RNA virus in the family Flaviviridae that is transmitted to humans by mosquitoes. Approximately 80% of WNV infections in humans are asymptomatic, whereas ≈20% of infected persons experience fever, often accompanied by a rash. Less than 1% of infections are manifested as neuroinvasive disease, such as meningoencephalitis, polyradiculoneuritis, and polio-like flaccid paralysis (1). WNV is endemic in Africa, southern Asia, and northern Australia, and only sporadic cases or small epidemics are seen in Europe (2). In 1999, WNV emerged in North America. By 2010, ≈1.8 million persons had become infected, with 12,852 reported cases of meningoencephalitis and 1,308 deaths (2). In Europe, the last notable outbreak of WNV infection occurred in Greece in 2010; 197 persons were infected, and 33 died (3). The Czech Republic, Denmark, France, and the Netherlands reported laboratory-confirmed WNV infections in travelers returning from North America (1).

We report a case of WNV meningoencephalitis in a 28-year-old German woman, who sought treatment the emergency department of a hospital in Potsdam, Germany, on September 7, 2011. She had a 3-day history of fever of up to 40°C and mental confusion. Six days before admission, she had returned from a 2-week holiday trip to Ottawa, Ontario, Canada. She had spent most of her time in the city of Ottawa.

The patient’s medical history was unremarkable. She was in a reduced general condition because of a severe encephalitic syndrome characterized by somnolence, meningism, fever, and mental confusion. Laboratory investigations revealed leukocytosis with 15.000 leukocytes/µL (reference range 4,400–11,300 leukocytes/µL) and elevated C-reactive protein of 14.8 mg/L (reference <3 mg/L). Cerebrospinal fluid (CSF) analysis on the day of admission showed pleocytosis, 430 cells/µL (72% granulocytes, 27% lymphocytes. and 1% monocytes); elevated levels for total protein, 1,023 mg/L (reference range 150–450 mg/L); an albumin level of 637 mg/L (normal range 0–350 mg/L); and a moderately elevated level of the albumin quotient of 20 (reference range <6.5). The CSF/serum diagrams demonstrated a moderate disturbance of the blood–CSF barrier and a substantial intrathecal IgM synthesis of 27.6% (6.15 mg/L) but no intrathecal IgA or IgG synthesis. Results of magnetic resonance imaging of the brain were unremarkable. No parenchymal lesions were found.

Antimicrobial drug therapy was initiated with ceftriaxone and ampicillin. Acyclovir was administered empirically for herpes simplex encephalitis until this diagnosis was excluded. Molecular and serologic testing of serum and CSF samples revealed no acute infection with herpesviruses, enteroviruses, alphaviruses, orthobunyaviruses, and arenaviruses or with mycobacteria, Borrelia spp., Toxoplasma gondii, Chlamydia spp., Leptospira spp., and Mycoplasma pneumoniae. CSF and blood cultures were negative for fungi and bacteria, including mycobacteria. An encephalitic syndrome caused by N-methyl-D-aspartate antibodies was also excluded. On the basis of the patient’s travel history, the clinical symptoms, and the initial laboratory findings, WNV infection was suspected. Indirect immunofluorescence assays and virus neutralization tests (VNT) for WNV and other flaviviruses were performed as described (4). IgM and IgG against WNV were detected in serum and in CSF by indirect immunofluorescence assay with an 8-fold (IgM) and 32-fold (IgG) increase in serum titer from day 4 to day 26 (Table). WNV IgG and WNV IgM titers were higher than the titers of antibodies against the other flaviviruses tested (Table), indicating that the antibodies resulted from a WNV infection. The serologic diagnosis was further substantiated by detection of WNV neutralizing antibodies at day 11 (VNT titer 640). The VNT titer further increased to 2,560 on day 26 after onset of disease. Results of reverse transcription PCR were negative for WNV and members of genus Flavivirus in serum and CSF samples taken 4 days after disease onset. Attempts to isolate WNV from serum and CSF samples in cell culture failed as well. The patient recovered slowly and was discharged from the hospital in Potsdam on September 15, 2011. She was then referred to a neurologic rehabilitation center in Berlin and was discharged from there after 2 months with a characterization of restitutio ad integrum (i.e., full recovery, restoration to original condition).

We report a case of WNV infection imported into Germany that was unambiguously confirmed by laboratory testing. WNV meningoencephalitis was diagnosed on the basis of strict serologic criteria established by the Centers for Disease Control and Prevention (Atlanta, GA, USA) (5). In 2011, 69 clinical cases of WNV infection were reported from the province of Ontario, although no cases in the city of Ottawa were reported (Public Health Agency of Canada; www.eidgis.com/wnvmonitorca). This imported case adds to these cases and suggests that travelers are at risk, even if they visit only Ottawa. Physicians in Germany should be aware of the risk for WNV infection among travelers returning from Canada, especially during late summer.

Top

Jörg Schultze-Amberger1, Petra Emmerich1, Stephan Günther, and Jonas Schmidt-ChanasitComments to Author 
Author affiliations: Klinikum Ernst von Bergmann, Potsdam, Germany (J. Schultze-Amberger); and Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany (P. Emmerich, S. Günther, J. Schmidt-Chanasit)

Top

References

  1. Artsob  H, Gubler  DJ, Enria  DA, Morales  MA, Pupo  M, Bunning  ML, West Nile Virus in the New World: trends in the spread and proliferation of West Nile virus in the Western Hemisphere. Zoonoses Public Health. 2009;56:35769. DOIPubMedGoogle Scholar
  2. Kilpatrick  AM. Globalization, land use, and the invasion of West Nile virus. Science. 2011;334:3237. DOIPubMedGoogle Scholar
  3. Danis  K, Papa  A, Theocharopoulos  G, Dougas  G, Athanasiou  M, Detsis  M, Outbreak of West Nile virus infection in Greece, 2010. Emerg Infect Dis. 2011;17:186872. DOIPubMedGoogle Scholar
  4. Tappe  D, Schmidt-Chanasit  J, Ries  A, Ziegler  U, Müller  A, Stich  A. Ross River virus infection in a traveller returning from northern Australia. Med Microbiol Immunol (Berl). 2009;198:2713. DOIPubMedGoogle Scholar
  5. Centers for Disease Control and Prevention. Epidemic/epizootic West Nile virus in the United States: guidelines for surveillance, prevention, and control [cited 2012 Aug 4]. http://www.cdc.gov/ncidod/dvbid/westnile/resources/wnv-guidelines-aug-2003.pdf

Top

Table

Top

Cite This Article

DOI: 10.3201/eid1810.120204

1These authors contributed equally to this article.

Related Links

Top

Table of Contents – Volume 18, Number 10—October 2012

EID Search Options
presentation_01 Advanced Article Search – Search articles by author and/or keyword.
presentation_01 Articles by Country Search – Search articles by the topic country.
presentation_01 Article Type Search – Search articles by article type and issue.

Top

Comments

Please use the form below to submit correspondence to the authors or contact them at the following address:

Jonas Schmidt-Chanasit, Bernhard Nocht Institute for Tropical Medicine, Department of Virology, WHO Collaborating Centre for Arbovirus and Haemorrhagic Fever Reference and Research, Bernhard Nocht Strasse 74, D-20359 Hamburg, Germany

Send To

10000 character(s) remaining.

Top

Page created: September 19, 2012
Page updated: September 19, 2012
Page reviewed: September 19, 2012
The conclusions, findings, and opinions expressed by authors contributing to this journal do not necessarily reflect the official position of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions. Use of trade names is for identification only and does not imply endorsement by any of the groups named above.
file_external