Progress in the surveillance and control of Legionella infection in France, 1998-2008.
BACKGROUND
In France, the notification of Legionnaires' disease (LD) has been mandatory since 1987. Following a study showing an important under-reporting of the disease, the surveillance system was strengthened in 1997: the urinary antigen detection test was introduced as a new diagnostic tool and guidelines for prevention and control of the disease were implemented. After these measures, the incidence of LD increased gradually, reaching 2.5 per 100,000 in 2005, and then slightly decreased (2.0 per 100,000 in 2008).


METHODS
Data from the mandatory notification system and from the national reference centre for Legionella were analysed. Analysis covered the 1998-2008 period.


RESULTS
During the period 1998-2008 a total of 11147 cases of LD were reported in France through the mandatory system. The majority of cases were diagnosed by urinary antigen test. The median age of cases was 61 years, the male to female ratio was 2.9, and the case fatality rate was 13%. Exposure during travel was documented for 17% of cases. A hospital-acquired infection was suspected for 9% of cases, and this percentage decreased from 21% in 1998 to 7% in 2008. Over this period, 14 community outbreaks were identified involving 380 cases, and cooling towers were the most probable source of infection for 13. No outbreak was reported in 2008. Registration at the regional level of all cooling towers became mandatory at the end of 2004, and the 1997 prevention and control guidelines were updated in 2005. In recent years, several regulations have also been implemented in the hospital setting and care homes for the elderly.


CONCLUSIONS
All these measures have contributed to strengthen the French surveillance system and improve our ability to better prevent, detect, and control LD.
Institut de Veille Sanitaire, 12 rue du Val d'Osne, 94415 Saint Maurice Cedex, France.
Christine
C
Campese
Dounia
D
Bitar
Sophie
S
Jarraud
Catherine
C
Maine
Françoise
F
Forey
Jerome
J
Etienne
Jean Claude
JC
Desenclos
Christine
C
Saura
Didier
D
Che
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D018563:Disease Notification; D004196:Disease Outbreaks; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D016952:Legionella pneumophila / Q000302:isolation & purification; D007877:Legionnaires' Disease / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control; D008297:Male; D019221:Mandatory Reporting; D008875:Middle Aged; D011159:Population Surveillance; D012307:Risk Factors; D055815:Young Adult