Weekly Epidemiological Report for the West Nile virus disease, Greece, October 2013

Transcription

1 Weekly Epidemiological Report for the West Nile virus disease, Greece, October 2013 This weekly epidemiological report aims to present briefly the reported cases of West Nile Virus (WNV) infection in Greece for the period 2013, and is updated weekly. 1 Data presented in this report are derived from the notifications of laboratory confirmed and probable cases of WNV infection sent to the Hellenic Centre for Disease Control and Prevention (HCDCP-KEELPNO) by the treating physicians and from the daily communication with specific laboratories: i) the Reference Laboratory for Arboviruses, Aristotelian University of Thessaloniki, ii) the Department of Microbiology, School of Medicine, University of Athens, iii) the Department of Microbiology, Infectious Disease Hospital of Thessaloniki, iv) the Hellenic Pasteur Institute and v) private microbiological laboratories performing diagnostic tests. The Department of Epidemiological Surveillance and Intervention of the HCDCP undertakes a verification procedure through communication with the treating physicians and the patients, as necessary. From the beginning of 2013 until 30/10/2013 (11:00am), 86 laboratory diagnosed cases of WNV infection have been reported to KEELPNO (including 8 deaths), of which 51 presented with neuro-invasive disease (WNND, encephalitis and/or meningitis and/or acute flaccid paralysis) and 35 cases with mild symptoms (febrile syndrome) (Table 1). One more death in a patient with WNND was attributed to other causes. Table 1. Number of reported cases with laboratory diagnosed WNV disease, Greece, period 2013, until (11:00am) Number of cases with central nervous system manifestations Number of cases without central nervous system manifestations Total number of cases Number of deaths [1] Cases diagnosed by (11:00am) [2] 1. The number of deaths is included in the total number of cases 2. One more death in a patient with WNND was attributed to other causes. Until 30/10/2013, 11:00am, 72 patients with WNV disease have been discharged from the hospital and two are still hospitalized, including one in an Intensive Care Unit (ICU) (Table 2).

2 Table 2. Current status of patients with laboratory diagnosed WNV infection until (11.00am) Current status of patients Number of cases Hospitalized in clinics 1 Hospitalized in ICU 1 Total number of patients that are being hospitalized 2 Total number of patients that have been discharged from the hospital Total number of patients that were not hospitalized Number of deaths attributed to WNV disease 8 Number of deaths attributed to other causes 1 Total number of cases 86 Figure 1 shows the reported WNND cases by week of symptom onset. The first diagnosed case of WNV infection for the transmission period 2013 reported onset of symptoms on 2 nd July 2013 (wk 27). Figure 1. Number of laboratory diagnosed WNND cases by week of symptom onset, Greece, 2013, until , 11.00am (n=51)* * The blue dotted line = WNND cases reported in 2010, the red dotted line = WNND cases reported in 2011 and the black dotted line = WNND cases reported in Each blue box represents one laboratory diagnosed case of WNND reported to KEELPNO in transmission period 2013.

3 Age of patients ranges between years, while the median age of WNND cases is 76 years (17-95 years). Table 3 and Figures 2 and 3 show the geographic distribution of the notified cases with laboratory diagnosed WNV disease at the level of suspected Municipalities of exposure. The patient s suspected place of exposure is a rough indicator of the area of WNV circulation. For one particular case, the suspected place of exposure is undetermined due to a complicated travel history during the incubation period. According to a serosurvey conducted in 2010 by the HCDCP and the National School of Public Health, at the epicentre of the WNV outbreak in Central Macedonia, WNND disease develops in 1:140 infected persons. Table 2. Reported cases with laboratory diagnosed WNV disease (with and without WNND) by suspected Municipality of exposure, Greece, transmission period 2013, until (11:00am) Regional Unit Suspected Municipality of exposure Number of cases with WNND Incidence of WNND per population * Number of cases without WNND 3 Spata- Artemida 1 2,96 1 Pallini 3 5,51 3 East Attica Rafina- Pikermi 1 4,93 0 Markopoulo Mesogeas 3 14,97 1 Peania 1 3,75 0 Vari- Voula- Vouliagmeni 1 2,07 0 Vrilissia 2 6,51 1 Chalandri 3 4,04 0 Penteli 1 2,86 0 North Section of Athens Heraklion 1 2,01 0 Agia Paraskevi 3 5,02 0 Filothei-Psichiko Papagou - Cholargou Maroussi 1 1,38 1 Central Section Galatsi 2 3,37 0

4 of Athens South Section of Athens Philadelphia-Chalkidona 1 2,81 0 Glifada Imathia Alexandria 1 2,41 2 Delta 1 2,18 1 Ambelokipoi - Menemeni Thessaloniki Oreokastro Chalkidona 1 2,97 0 Kordelio- Evosmos 1 0,98 0 Pella Pella 1 1,58 3 Xanthi 2 3,07 3 Xanthi Avdira 2 10,52 3 Topeiros 2 17,32 4 Kavala Nestos 5 22,39 4 Kavala Sintiki 1 4,51 0 Serres Visaltia 4 19,97 0 Heraklia 2 9,46 0 Serres 1 1,30 0 Ileia Andravida - Killini 1 4,63 0 Corfu Corfu 1 0,97 0 Undetermined place of exposure 1 0 Total Greece 51 0,47 35 * Calculations based on census data 2011 (Hellenic Statistical Authority).

5 Figure 2: Map showing the suspected place of exposure of reported cases with laboratory diagnosed WNV disease, Greece, 2013, until (11.00am) (n=85*).** 5 Source: HCDCP * For one particular case, the suspected place of exposure is undetermined **Each red dot represents one case with WNND and each blue triangle a case with mild symptoms (without WNND).

6 Figure 3: Map showing the suspected place of exposure of reported cases with laboratory diagnosed WNV disease, Region of Attiki, 2013, until (11.00am) (n=35).* 6 Source: HCDCP *Each red dot represents one case with WNND and each blue triangle a WNV case with mild symptoms (without WNND) CONCLUSIONS For the fourth consecutive transmission period, human West Nile virus infection cases are being recorded in Greece. It is expected that cases will continue appearing until the fall, both in the same areas where they were recorded in the past 3 years, as well as in new areas of WNV circulation. Until , human WNV cases were recorded from the regional units of Attiki, Thessaloniki, Imathia, Xanthi, Kavala, Serres, Corfu and Pella, where the circulation of WNV is known from previous years, as well as from the regional unit of Ileia, new area of the virus circulation. In Europe, during transmission period 2013 (up to ) cases of WNV disease have also been recorded in Israel, Russia, Serbia, F.Y.R.O.M., Italy, Romania, Hungary, Montenegro, Ukraine, Croatia, Bosnia & Herzegovina and Tunisia (source: ECDC). Epidemiological surveillance of disease, systematic and early implementation of mosquito control programs and personal protective measures against mosquito bites are the most appropriate measures for the control of the disease.

7 PUBLIC HEALTH MEASURES SUPPORTED BY THE HCDCP The following public health measures have been implemented by the Hellenic CDC and other involved stakeholders: 1. Enhanced surveillance for encephalitis and WNV disease in humans. i. Enhancing awareness of physicians about the surveillance of encephalitis and suspected cases: testing for West Nile virus infection in suspected cases (such as cases with encephalitis, aseptic meningitis, acute flaccid paralysis, fever of undetermined etiology) was recommended.. ii. iii. iv. Daily communication and information exchange with laboratories conducting diagnostic testing for West Nile virus. The Department of Epidemiological Surveillance and Intervention of HCDCP -within 24 hoursundertakes the investigation of every reported case of West Nile virus disease in order to determine the likely place of exposure, the risk factors and the severity of the disease. Daily update of stakeholders on the diagnosed cases (Ministry of Health, Ministry of Rural Development and Food, Regions, Directorate of Public Health and Social Welfare, National Centre for Blood Donations, National Transplant Organization, laboratories). 2. Awareness raising among health professionals by providing guidelines for the recognition and diagnosis of WNV disease and the recommended laboratory investigation of suspected cases (e.g. encephalitis cases). The Hellenic CDC website includes updated information for health professionals (case definition, instructions for samples, laboratory diagnosis, management) 3. Communication and health promotion activities for the public (schools, healthcare facilities) in various areas around the country. The Hellenic CDC website includes educational material for the public regarding the disease and the recommended protective measures against mosquito bites. 4. Coordination of a multisector Working Group (WG) on the definition of affected areas by vector borne diseases. This WG considers all available entomological and epidemiological data and decides on the characterization of affected areas, for the implementation of blood safety measures. The list is published on our website ( and updated regularly. 5. Communication to the National Centre for Blood Donations ( of the list of affected areas in order to issue the necessary blood safety measures to the blood donation units in all hospitals. 6. Entomological surveillance: In 2013, the HCDCP in collaboration with the Department of Parasitology, Entomology and Tropical Diseases of the National School of Public Health is implementing a targeted entomological surveillance program, in the Attica region. According to our findings, we recorded the circulation of West Nile virus in the area since the end of May Organized expansion of entomological surveillance nationwide has been planned in cooperation with local authorities and the subcontractors of the local mosquito control programs. 7. Collaboration and exchange of information with the Veterinary Public Health (VPH) services of the Ministry of Agriculture, especially regarding WNV infection in equidae. 8. HCDCP is collaborating with the University of Thessaly for the project: Control of West Nile Virus and Malaria- Strengthening of Surveillance in the Greek territory, funded by the NSRF ( ). The various work packages include the development of geographical information systems (GIS), the strengthening of epidemiological surveillance for both diseases, the mapping of mosquito habitats and mosquito sampling from high-risk areas, the strengthening of wild bird and horse monitoring for WNV transmission, informative campaigns addressing the public, especially high-risk groups, and health professionals who are involved directly with the control and treatment of both diseases. In the context of this program the following actions are being implemented: 7

8 a) The Veterinary School, Aristotelian University of Thessaloniki is undertaking a sero-epidemiological surveillance of household poultry (<6 mos old) in north Greece (circulation of WNV was recorded in Central Macedonia in June 2013). b) The Veterinary School, University of Thessaly undertakes surveillance of wild birds in various areas in Greece. c) E- learning platform for health professionals ( 8