Health Professionals

Clinical Updates

19 October 2012

West Nile virus (human): Greece including Corfu

This updates case numbers and new areas of WNV transmission in Greece during 2012

As of 12 October there were 159 laboratory confirmed cases of WNV, including 16 deaths, from some prefectures of Greece; Attica (south suburbs of Athens), Aitoloakarnania, Evia, Pella, Ialkidiki, Imathia (where transmission had been recorded in previous years) and from the island of Samos and the areas of Ahaia, Arta, Corfu, Drama, Kavala, Lefkada and Xanthi which are areas where WNV transmission has never previously been reported [1].

Public health measures to control mosquito vectors are established in Greece together with enhanced surveillance and reporting procedures [1, 2]. 

West Nile virus

WNV is caused by a flavivirus; the primary hosts are birds and horses and the virus is transmitted by Culex spp. mosquitoes. WNV is established in several European and surrounding countries. A map of reported cases in the European Union and neighbouring countries in 2012 is available from the European Centre for Disease Prevention and Control.

The majority of WNV infections (around 80%) are asymptomatic. Less than 20% will experience a mild, self-limited illness with fever, headache, myalgias, and rash. Less than 1% of those infected will develop a more severe neurological syndrome of meningitis and/or encephalitis.

Advice for travellers

The risk of contracting WNV throughout Europe is generally considered to be low [3].  Those of advanced age and underlying medical conditions are at highest risk of developing severe neurological disease following WNV infection [4].

Individuals should take mosquito bite avoidance measures during the transmission season (generally June to October) when visiting risk areas. There are no vaccines that prevent WNV in humans.

Advice for health professionals

WNV in the European Union is a notifiable disease [5]. Physicians who see travellers with a characteristic febrile illness, who have returned from WNV endemic areas, including Greece, should be alert to the possibility of WNV infection. Relevant samples for testing together with a full clinical and travel history should be submitted to the Health Protection Agency Rare and Imported Pathogens Laboratory

References

1. Hellenic Centre for Disease Control and Prevention. Ministry of Health. Weekly Epidemiological Report 12 October, 2012. [Accessed 19 October, 2012]. Available at: http://www.keelpno.gr/Portals/0/Files/English%20files/WNV%

20reports%202012/Report-WNV_Weekly_2012_10_12.pdf

2. European Centre for Disease Prevention and Control. Rapid Risk Assessment. Epidemiological Situation of West Nile Virus in European Union. Update, 13 July, 2012. [Accessed 19 October, 2012]. Available at: http://www.ecdc.europa.eu/en/publications/Publications/1207-TER-Rapid-risk-assessment-West-Nile-virus.pdf

3. Health Protection Agency. West Nile Virus, general information. [Accessed 19 October, 2012] Available at: http://www.hpa.org.uk/Topics/InfectiousDiseases/Infections

AZ/WestNileVirus/GeneralInformation/wnile010WestNilevirus

GeneralInformationFAQs/#WNV_21

4. European Centre for Disease Prevention and Control. West Nile Fever: Factsheet for Health Professionals. [Accessed 19 October, 2012]. Available at: http://ecdc.europa.eu/en/healthtopics/west_nile_fever/basic_

facts/Pages/factsheet_health_professionals.aspx

5. European Centre for Disease Prevention and Control: EU Case Definition. [Accessed 19 October, 2012]. Available at: http://ecdc.europa.eu/en/healthtopics/west_nile_fever/basic

_facts/Pages/EU-case-definition.aspx

Links

European Centre for Disease Prevention and Control. West Nile Fever factsheet

Health Protection Agency: West Nile virus - Advice for Health Professionals

Health Protection Agency Rare and Imported Pathogens Laboratory

Health Protection Agency: West Nile Virus

NaTHNaC Health Information Sheet: West Nile virus

NaTHNaC Health Information Sheet: Insect bite avoidance