Salud Pública de México (Jan 2002)
Carriage of antibiotic-resistant pneumococci in a cohort of a daycare center Portadores nasofaríngeos de neumococo antibiótico-resistente en niños asistentes a guardería
Abstract
Objective. To define epidemiologic relationships to determine the prevalence and potential risk factors for nasopharyngeal colonization by antibiotic-resistant pneumococci, their serotypes and their antibiotic susceptibility patterns in children attending a daycare center (DCC). Material and Methods. A prospective cohort study was conducted among children (n=53) attending the DCC at Hospital Infantil de México Federico Gómez, which is staffed by 20 employees. Patients were enrolled in the study during a two-year period from September 1997 to September 1999. All the participants were followed prospectively, swabbing them every four months. The strains recovered were typed and screened for susceptibility to several antibiotics. The daycare records were reviewed also. Odds ratios and fisher's exact test: or chi square test of significance were computed from contingency tables as appropriate. Exact 95% confidence intervals were computed for odds ratios. Data analysis was performed using Epi statistics program version 6.04 a. Results. Pneumococci were recovered from 45/53 of the infants at one or more visits. A total of 178 isolates were carried. The carriage rate was 47%. Only 7 adults acquired pneumococci during the study. Types 6,14,19 and 23 were prevalent and represented 77% of the total. Antibiotic-resistant strains were higher to penicillin and erythromycin. Conclusions. Children were frequent carriers of pneumococci, the rate of carriage was high in infancy and tended to decrease with age. The types commonly carried by children were the same as those causing invasive disease. There is a high proportion of carriers with antibiotic-resistant S. pneumoniae strains. Children who have had frequent antimicrobial courses are at particular risk.Objetivo. Analizar longitudinalmente la dinámica de colonización por Streptococcus pneumoniae, determinar la prevalencia, los factores de riesgo potencial para la colonización nasofaríngea con cepas de neumococo resistentes, determinar los serotipos y el perfil de sensibilidad a varios fármacos antimicrobianos. Material y métodos. Estudio prospectivo de una cohorte de niños de guardería, hecho de septiembre de 1997 a septiembre de 1999 entre 53 niños asistentes a la guardería del Hospital Infantil de México Federico Gómez, atendida por 20 empleados. Todos los participantes fueron seguidos en forma prospectiva, tomándose exudado nasofaríngeo cada cuatro meses. Los S. pneumoniae aislados se tipificaron y sometieron a pruebas de sensibilidad a diversos fármacos. Las razones de momios y la prueba exacta de Fisher o ji cuadrada se efectuaron a través de tablas de contingencia; se utilizaron intervalos de confianza a 95% para las razones de momios. Para el análisis se empleó el programa estadístico EPI INFO, versión 6.04 a. Resultados. S. pneumoniae se recuperó de 45/53 niños en una o más de las tomas. Se aisló un total de 178 cepas. El promedio de portador fue de 47%. Sólo siete adultos adquirieron un neumococo durante el estudio. Los tipos 6, 14, 19 y 23 representaron 77% del total. Se encontró elevada resistencia a la penicilina y eritromicina. Conclusiones. El estado de portador nasofaríngeo de S. pneumoniae, es un proceso dinámico. La colonización ocurre durante los primeros meses de vida y comprende solamente unos cuantos serotipos de neumococo. El estado portador disminuye conforme avanza la edad. Se encontró alta proporción de portadores con cepas resistentes de neumococo. Los niños que recibieron varios cursos de antimicrobianos, fueron los que mostraron mayor riesgo de presentar estado portador.
