WEEKLY EPIDEMIOLOGICAL REPORT WEST NILE VIRUS INFECTION, GREECE - 14 November

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1 HELLENIC CENTRE FOR DISEASE CONTROL AND PREVENTION (KEELPNO) MINISTRY OF HEALTH AND SOCIAL SOLIDARITY WEEKLY EPIDEMIOLOGICAL REPORT WEST NILE VIRUS INFECTION, GREECE - 14 November This weekly epidemiological report aims to present briefly the reported cases of West Nile Virus (WNV) infection in Greece for the period Data presented in this report are derived from the notifications of laboratory confirmed cases sent to the Hellenic Centre for Disease Control and Prevention (KEELPNO) by their treating physicians. Laboratory data are also included from i) the Reference Laboratory for Arboviruses, Aristotelian University of Thessaloniki and ii) the Department of Microbiology, School of Medicine, University of Athens iii) the Department of Microbiology, Infectious Disease Hospital of Thessaloniki. The Department of Epidemiological Surveillance and Intervention of KEELPNO undertakes a verification procedure through communication with the treating physicians and the patients, if necessary. From the beginning of 2011 until 14/11/2011 (16:00), 101 laboratory confirmed cases of WN infection were reported, of which 76 presented with neuro-invasive disease (encephalitis and/or meningitis and/or acute flaccid paralysis) and 25 cases with mild symptoms (fever and/or rash). Eight deaths occurred in patients over 65 years of age with underline diseases (Table 1). One out of the 76 neuro-invasive cases is considered imported, as the patient was in Albania throughout the incubation period. Another neuro-invasive case was diagnosed in France. However, this patient was in Greece throughout the incubation period. The last reported case had onset of symptoms on 18 October No other cases have been reported to date. A new update will be posted on the website if new cases occur. However, surveillance of the disease will continue throughout the year. Table 1. Number of cases with laboratory confirmed WNV infection, Greece, period 2011 until (16:00) Number of cases with central nervous system manifestations [1] Number of cases without central nervous system manifestations Total number of cases Number of deaths [2] Cases diagnosed by (16:00) [1] Cases presenting with encephalitis and/or meningitis [2] The number of deaths is included in the total number of cases

2 The analysis that follows refers to the 75 cases of WN neuro-invasive disease (WNND) presenting with encephalitis and/or meningitis or acute flaccid paralysis and without reported travel history to another country during the incubation period. Figure 1 shows the reported WNND cases by date of symptom onset. The first case for 2011 reported onset of symptoms in week 28/2011 (11-17/7/2011). Figure 1. Number of laboratory confirmed WNND cases by week of symptom onset. Period 2011, until (16.00)* * The dotted line represents the number of WNND cases reported in Each box represents one case reported in period Patient age ranges between 2 89 years old (median age: 70 years).

3 Table 2 shows the geographic distribution (regional units) of the notified neuro-invasive cases. Of note is the fact that the patient s place of residence is a crude indicator of the area of virus circulation. Table 2. Place of residence of patients with WNND. Period 2011, until (16.00) Regional Unit of Residence Number of cases Incidence per population * Karditsa 8 6,89 Larisa 12 4,20 Viotia 5 3,99 Trikala 5 3,83 East Attica 15 3,71 Pella 5 3,45 Serres 5 2,65 Imathia 3 2,08 Chalkidiki 2 2,00 West Attica 2 1,32 Kozani 1 0,65 Thessaloniki 6 0,53 Evoia 1 0,48 Etolia and Akarnania 1 0,45 West Section of Attica 1 0,21 South Section of Attica 1 0,19 North Section of Attica 1 0,18 Central Section of Attica 1 0,09 Total Greece 75 0,67 * Calculated based on population data from the Hellenic Statistical Authority (estimates for 2008).

4 Figure 2: Map showing the place of residence of WNND cases, Greece. Period 2011, until (16.00) 1 Source: HCDCP 1 Each red dot represents one WNV neuro-invasive case.

5 Figure 3: Map showing the place of residence of WNND cases, Attica. Period 2011, until (16.00). Drosia Marathon Megara Artemis Source: HCDCP

6 CONCLUSIONS After the first outbreak of WNV infection in Greece in the summer of 2010 (mainly in Central Macedonia), it was expected that cases of WNV infection will also present this year, in the same region as well as in regions not affected during Sporadic cases of WNV infection have been reported until 14/11/2011 from Central and Western Macedonia, Etolia & Akarnania and Thessaly, regions affected in 2010, but also from Attica, Evoia and Viotia, which are new areas of WNV circulation. During 2011 a number of countries in the World Health Organization Region of Europe have reported WNV infection cases in humans (Romania, Russia, Albania, FYROM, Israel and Italy). Epidemiological surveillance, systematic and early mosquito control and personal protective measures against mosquito bites are the most appropriate measures for the control of the disease. PUBLIC HEALTH MEASURES BY HCDCP - Period 2011 The following public health measures have been implemented during period 2011: 1. Awareness raising among clinicians by providing guidelines for the recognition, management and diagnosis of encephalitis and WNV infection in particular. The Hellenic CDC site created a devoted page for WNV information (case definition, instructions for samples, laboratory diagnosis, management, educational material for the public) 2. Enhanced surveillance for encephalitis and WNV infections in humans. 3. A project on mosquito mapping was supported by the Hellenic CDC, in various areas in Greece, subcontracted to Ecodevelopment, SA. 4. Surveillance of mosquitoes was carried out by the Dept of Parasitology of the National School of Public Health. 5. Seroepidemiology study of household poultry in the area of Central Macedonia with the veterinary School, Aristotelian University of Thessaloniki. 6. Collaboration and exchange of information with the Veterinary Public Health (VPH) services of the Ministry of Agriculture, especially regarding WNV in equidae. 7. The Coordination Centre for Blood Safety coordinates the implementation of the guidance for blood and blood product safety according to EU directive. 8. Communication and health promotion activities in schools and healthcare facilities in various areas of the country (Macedonia, Thrace, Thessaly, East Attica). 9. Continuing collaboration and communication with the ECDC and the European Commission.