West Nile Virus France

Title: Case of West Nile virus infection in person residing in Nice, Alpes Maritime Department, France: First case detected since 2015

To: Travel Medicine, DoH, DFAT, IBTS, HPRA

cc: HPSC operational support, GZV team

From: HPSC – Early Warning and Response System alert

Urgency*: For information only

Date: October 25th 2017

Time: 8.20am

Reference No: 20171024FR0001

Update No: New

Cascade to: Not required

On 20 October 2017, the French National Reference Centre for Arboviruses (NRC, IRBA Marseille) confirmed a West Nile virus (WNV) infection in a person in their early seventies residing in Nice, Alpes-Maritimes department. Serum collected during the acute phase of a dengue-like illness that occurred on 4 September 2017 tested weakly positive for anti-dengue IgM in a private clinical laboratory. Upon negative dengue serology, PCR and AgNS1 test results at the NRC, a late serum was sampled on 28 September. The NRC identified an anti-flavivirus IgM and IgG seroconversion that was later characterized as a WNV infection by neutralization test.

With the exception of a short day-trip in San Remo, Liguria region, Italy late August, the patient resided in Nice throughout the theoretical incubation period. Given the absence of recent WNV activity declared in humans or animals and the short time spent in Liguria during day-time only, the most probable place of infection retained for this patient was Nice.

For the record, the last human case of WNV disease was detected in 2015 in Nîmes, Gard department, amidst an outbreak of equine WNV disease. Since 2015 no increased avian mortality and no equine case of WNV infection have been detected in France through wildlife and veterinary surveillance.

Upon confirmation of this case of WNV infection, seasonal human and animal surveillance of WNV conducted yearly from June through October has been extended up to 15 November 2017. Safety measures were applied to blood and organ donation including NAT screening for WNV of blood and organ donors from Alpes-Maritimes and deferral of donors who spent at least one night in Nice. In absence of further evidence of WNV activity this measures will be lifted in December 2017.

Actions requested: For information only

Additional documents:

For and on behalf of Dr Kevin Kelleher
A/Director, HSE Health Protection Surveillance Centre
Early Warning and Response System (EWRS) contact point for Ireland
25-27 Middle Gardiner Street
Dublin 1

*Immediate: Cascade within 6 hours; Urgent: Cascade within 24 hours; Non-urgent: Cascade within 2 working days; For information: There is no need to cascade the information and only those who receive the message directly need to be aware of its content.