[Pertussis outbreak in a poorly immunized community].
BACKGROUND
The aim of this study was to describe the clinical, serological and epidemiological findings of a pertussis outbreak in an insufficiently vaccinated gipsy community.


METHODS
Ten cases (catarrhal illness with cough of 2 weeks duration) were identified through an active search. In four of them, two paired serum samples were obtained and total IgG against Bordetella pertussis and IgG and IgA against pertussis toxin (PT) and filamentous hemagglutinin (FHA) were determined. The diagnostic criteria was seroconversion. A comparative analysis between cases and healthy children younger than 15 years (gipsy community) was carried out and we estimated, by means of a logistical regression analysis, the odds ratio (OR) of several factors.


RESULTS
The highest attack rate (50%) was found in the 5 to 9 year-old group; 30% cases had not been vaccinated while 50% had been incorrectly vaccinated. No significant differences for age, gender or the vaccine status were detected. Three cases showed seroconversion for total IgG and two for IgG-PT and IgA-PT. Other possible pathogens were ruled out by serology.


CONCLUSIONS
Despite the high vaccine coverage against pertussis in paediatric age in Spain, some susceptible population groups remain, mainly due to an incorrect vaccination. Our serological results firmly support the suspicion of B. pertussis as the etiologic agent of the outbreak.
Segura del Pozo
Javier
J
Servicio de Salud Pública del Area III. Consejería de Sanidad. Comunidad de Madrid. Alcalá de Henares. Madrid. Spain. javier.segura@madrid.org
Sanz Moreno
Juan Carlos
JC
Gascón Sancho
María Jesús
MJ
Ramos Lledó
Esther
E
de Ory Manchón
Fernando
F
Fernández Díaz
Marisa
M
D000907:Antibodies, Bacterial / Q000097:blood; D001886:Bordetella pertussis / Q000276:immunology / Q000302:isolation & purification*; D002648:Child; D002675:Child, Preschool; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007223:Infant; D008297:Male; D012307:Risk Factors; D006178:Romani People; D012698:Serologic Tests; D013030:Spain / Q000453:epidemiology; D014611:Vaccination; D014917:Whooping Cough / Q000453:epidemiology* / Q000276:immunology
D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G