Invasive pneumococcal disease in a third level pediatric hospital in Mexico City: epidemiology and mortality risk factors / Enfermedad neumocócica invasora en un hospital pediátrico de tercer nivel en la Ciudad de México: características epidemiológicas y factores de riesgo asociados con mortalidad

Objective. To assess the epidemiologic characteristics of invasive pneumococcal diseases (IPD) among a population in a pediatric hospital in Mexico City and analyze mortality-related risk factors, serotype distribution and antibiotic susceptibility related to S.pneumoniae. Material and Methods. We performed a retrospective review of IPD cases at a third level pediatric hospital between 1997-2004. Results. A total of 156 patients were included. The mortality rate was 27.5 percent and was associated with six pneumococcal serotypes: 14, 6B, 23F, 6A, 19F and 19A. There was no relationship between mortality and antimicrobial susceptibility pattern. A total of 28.2 percent of isolates were resistant to penicillin and 24.6 percent were resistant to cefotaxime. A statistically significant relationship was observed between mortality and previous underlying disease (CI 95 percent; 2.5-18.3; p< 0.05) using a multivariate logistic regression model. Conclusions. Our outcomes show that IPD mortality in our population is closely related to underlying disease and to six serotypes, five of which are included in the 7-valent pneumococcal conjugate vaccine.

Objetivo. Conocer la epidemiología de la enfermedad neumocócica invasora (ENI) en un hospital pediátrico y analizar los factores de riesgo relacionados con la mortalidad, la distribución de serotipos y el patrón de susceptibilidad de S. pneumoniae. Material y métodos. Revisión retrospectiva de los casos de ENI en un hospital pediátrico de tercer nivel, entre 1997 y 2004. Resultados. En 156 pacientes la mortalidad fue de 27.5 por ciento. Los serotipos de neumococo más frecuentemente relacionados con la mortalidad fueron: 14, 6B, 23F, 6A, 19F y 19A; no hubo relación de mortalidad con la resistencia a antibióticos. El 28.2 por ciento mostró resistencia a penicilina y 24.6 por ciento a cefotaxima. A través del modelo multivariado, se encontró una relación estadísticamente significativa entre la mortalidad y enfermedad previa (IC 95 por ciento; 2.5-18.3; p<0.05). Conclusiones. La mortalidad asociada a la ENI tuvo relación significativa con antecedente de una enfermedad previa y con seis serotipos, cinco incluidos en la vacuna neumocócica conjugada 7-valente.

Streptococcus pneumoniae isolates in healthy children attending day-care centers in 12 states in Mexico

OBJECTIVE: The aim of this study was to determine the prevalence of asymptomatic nasopharyngeal carriage of Streptococcus pneumoniae, which is a major factor in the transmission of this bacterium. MATERIAL AND METHODS: Nasopharyngeal cultures were performed on children attending 32 day-care centers in 12 states in Mexico. RESULTS: Streptococcus pneumoniae was isolated from the nasopharynx of 829 out of 2 777(29.9 percent) subjects aged two months to six years. All children lived in urban areas and 80 percent spent more than six hours daily in a day-care center. Streptococcus pneumoniae serotypes most frequently identified were: 19F (23 percent), 6B (15.6 percent), 23F (11.2 percent) and 6A (14.9 percent). Thirty-six percent of the isolates were susceptible to penicillin. CONCLUSIONS: Serotype distribution suggests the possible benefits that could be obtained from the heptavalent pneumococcal conjugate vaccine.

OBJETIVO: La intención de este estudio fue determinar la prevalencia de portadores nasofaríngeos asintomáticos de Streptococcus pneumoniae, el cual es el principal factor en la transmisión de esta bacteria. MATERIAL Y MÉTODOS: Los cultivos nasofaríngeos fueron realizados en niños que asisten a 32 estancias infantiles en 12 estados de México. RESULTADOS: Streptococcus pneumoniae fue aislado de la nasofaringe de 829 (29.9 por ciento) niños de los 2 777 incluidos en el estudio con un rango de edad de 2 meses a 6 años. Todos los niños vivían en áreas urbanas y 80 por ciento permanecían más de seis horas diarias en la estancia infantil. Los serotipos de Streptococcus pneumoniae más frecuentemente identificados fueron: 19F (23 por ciento), 6B (15.6 por ciento), 23F (11.2 por ciento) y 6 A (14.9 por ciento). Treinta y seis por ciento de los aislamientos fueron susceptibles a penicilina. CONCLUSIONES: La distribución de serotipos nos da una idea de los posibles beneficios que podrían obtenerse de la vacuna neumocóccica conjugada heptavalente.

Carriage of antibiotic-resistant pneumococci in a cohort of a daycare center

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 MÚxico 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.