Increase in notified acute respiratory infection clusters in nursing homes: Surveillance 2011 – 2012 in Paca, France Teija Korhonen EPIET fellow, Cire Sud, Marseilles, France ESCAIDE 24 th October 2012

About 750 nursing homes in Provence-Alpes-Côte d’Azur (Paca) Elderly people vulnerable Close living conditions Background

Recommendations by the High Council of Public Health in 2005 Surveillance system in Paca since 2005 in order to –promote prevention efforts and influenza vaccinations –facilitate early cluster detection and guide control efforts –conduct epidemiological investigations when severe outbreaks Circular by the Ministry of Health in 2006 Surveillance history

Describe notified acute respiratory infection (ARI) clusters in nursing homes in Paca in 2011 – 2012 Compare characteristics to the four previous influenza seasons –explore trends Objectives of this presentation

Person with a cough AND at least one symptom from both lists: dyspnea, chest pain, whistles, recent auscultatory findings fever, sweating, headache, joint pain, sore throat, nasal discharge Case definition of ARI

If three or more cases of ARI within eight days –residents and personnel Nursing home personnel reports to the Regional Health Office Information transferred to the national ARI surveillance database –weekly national and regional reports ARI cluster surveillance

Number of notified ARI clusters in nursing homes by week of illness onset of the first case in Paca October 2011 – April 2012

84 clusters: 1745 residents and 325 personnel ill 28% average AR for residents 9% average AR for personnel 10% (137) of ill residents hospitalised 5% (86) of ill residents died At least one confirmed case of influenza in 60% of clusters Influenza A(H3N2) identified in seven outbreaks Results – surveillance

Dominant type A(H3N2) –1648 typed: 82% A(H3N2) 31% of A(H3N2) differed from the vaccine strain * Bull Epidémiol Hebd. 2012;38: Results – virus types in France 2011 – 2012 *

Number of notified ARI clusters in nursing homes by influenza season in Paca since

Results – comparison with previous seasons Influenza virus types in France since 2007 SeasonPredominant strains% A(H1N1) – influenza B60 – A(H3N2) A(H1N1)pdm A(H1N1)pdm09 – influenza B50 – A(H3N2)80

Significant p-values (< 0.05) Results – comparison with previous seasons Mean of Number of clusters8434 Case-fatality (%)52.8 Clusters with at least one confirmed influenza case (%) 6012

Largest amount of notified ARI clusters since the implementation of the surveillance system Circulation of A(H3N2) –first time predominant virus since season 2008 – 2009 –one third variant from the vaccine strain Increased cluster-ascertainment –better familiarisation with the system –potential underreporting Discussion

Explore reasons for non-participation to increase reporting Investigate possible differences in ARI outbreak management between participating and non-participating nursing homes Evaluate ARI surveillance at the regional and national level Recommendations

Personnel of the participated nursing homes Caroline Six, Francis Charlet, Philippe Malfait and other colleagues in the InVS and the Regional Health Office in Paca Kostas Danis and Ioannis Karagiannis Acknowledgements