Published Date: 2010-08-10 19:00:07
Subject: PRO/AH/EDR> Encephalitis - Greece (04): (MC) WNV conf
Archive Number: 20100810.2742
ENCEPHALITIS - GREECE (04): (CENTRAL MACEDONIA) WEST NILE VIRUS CONFIRMED
A ProMED-mail post
ProMED-mail is a program of the
International Society for Infectious Diseases
Date: Tue 10 Aug 2010
From: Anna Papa [edited]
[Dr Papa's comments below are in response to the question concerning the
diagnostic tests used in establishing the laboratory diagnosis of West Nile
virus infection for the encephalitis cases occurring in Central Macedonia.
In the National Center for Arboviruses in the 1st Department of
Microbiology, in Aristotle University of Thessaloniki, Greece, we detected
up to now high IgG and IgM antibodies in serum samples, and IgM in CSF
samples (when available) in 20 cases with encephalitis or meningitis cases.
A quick recovery was seen in patients who presented additional exanthema,
which was reported to be a good prognostic marker (Huhn and Dworkin, Clin
Infect Dis 2006).
A commercial ELISA kit was used for serology. Identical results were taken
by "in-house" indirect immunofluorescence. Most patients are more than 70
years old, and 2 of them died (79 and 72 years old). Samples were IgM
negative for Toscana virus, tick-borne encephalitis virus, while in a few
patients a cross-reaction was seen with Dengue virus, however the titers in
Dengue virus were in the grey zone, or much lower than to WNV. No patient
reported a tick bite.
The weather this year was rainy, there is water even in the streams which
are usually dry this time of the year. This, together with high
temperatures provided a good environment for mosquitoes. An entomological
study is already started, and mosquitos from the exact regions where
patients are observed are already in our lab and their testing will start
tomorrow morning [11 Aug 2010]. In addition, horse and bird testing from
the regions is planned. The Hellenic Center for Infectious Diseases Control
has a webpage (<http://www.keelpno.gr/articles/topic/?id=3D981>) reporting
the cases and giving instructions for prevention of mosquito bites.
Assoc. Prof. Anna Papa
Head of the National Center for Arboviruses
1st Department of Microbiology
Aristotle University of Thessaloniki, Greece
[ProMED-mail thanks Dr Papa for the details concerning the laboratory tests
used and their plans for follow-up to the encephalitis outbreak in the
Central Macedonia area of Greece. We look forward to the results that their
field studies will generate. Flavivirus cross reactivity in the serological
tests appears not to have been a complicating factor in interpretation of
the results. Toscana virus, another etiological agent of human encephalitis
in Europe was excluded.
A map showing the location of Greek Central Macedonia can be accessed at
HealthMap/ProMED-mail interactive map of Greece can be accessed at
<http://healthmap.org/r/026S> - Mod.TY]