[Q fever outbreak in an urban area following a school-farm visit].
OBJECTIVE
The aim of this study was to describe an outbreak of Q fever in a group of people (day care centre for mental-handicapped individuals) previously exposed to animals in a school-farm.


METHODS
A retrospective cohort study among the 25 mental-handicapped individuals and the 30 workers of the centre was performed. The information about symptoms and signs and antecedents of exposition was obtained by an epidemiological survey and a clinical-epidemiological case definition was established. Serum samples from 29 people (5 mental-handicapped individuals and 24 workers) were processed for serology (Indirect Immunofluorescence against Coxiella burnetii).


RESULTS
Twenty two cases of Q fever were detected. Ten were confirmed by serology (6 of them asymptomatic). More frequent symptoms were fever (100%), anorexia (81.3%), asthenia (68.8%) and non-productive cough (56.3%) among the 16 clinical cases. The risk of acute infection was 8.6 times higher in individuals of the centre that visited the school-farm (95% CI, 1.26-58.27).


CONCLUSIONS
The investigation of the epidemiological antecedents allowed to detect and confirm a Q fever outbreak, to identify the probable source of exposition and to orientate the clinical and serological diagnosis.
de los Ríos-Martín
Rosa
R
Servicio de Salud Pública del Area 4, Instituto de Salud Pública, Comunidad de Madrid, Madrid, España. rosa.delosrios@salud.madrid.org
Sanz-Moreno
Juan Carlos
JC
Martín-Martínez
Fernando
F
Tébar-Betegón
M Angeles
MA
Cortés-García
Marta
M
Escudero-Nieto
Raquel
R
D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood; D015331:Cohort Studies; D016001:Confidence Intervals; D016997:Coxiella burnetii / Q000302:isolation & purification*; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D008297:Male; D011778:Q Fever / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D012189:Retrospective Studies; D012306:Risk; D016036:Seroepidemiologic Studies; D012698:Serologic Tests; D013030:Spain / Q000453:epidemiology
D000907:Antibodies, Bacterial