Serogroup-Specific Epidemiology of Streptococcus pneumoniae: Associations with Age, Sex, and Geography in 7,000 Episodes of Invasive Disease

Abstract

A study sample of 7,010 episodes of invasive Streptococcus pneumoniae disease was obtained by combining 13 existing datasets. Disease episodes due to each of 12 pneumococcal serogroups (1, 3-9, 14, 18, 19, and 23) were then compared with episodes in a constant internal control group to describe serogroup-specific variations in disease frequency by age, sex, and geographic origin. The results are presented as odds ratios (with 95% confidence intervals) derived by logistic regression, with adjustment for the major confounders, including dataset of origin. Variation in the male:female ratios between serogroups is small, suggesting that capsular characteristics are an unlikely explanation for the male preference of S. pneumoniae. Serogroups associated with higher nasopharyngeal prevalence (e.g., 19 and 24) are relatively more common in Europe and North American, while the invasive serotypes 1 and 5 are much more common in South America. The custom of reporting serogroup frequencies in two age groups, children and adults, conceals much of the variation in the age distributions across the whole span of life. The reduction of risk associated with serogroups 6, 14, 18, 19, and 23 beyond childhood follows different gradients, being most abrupt in serogroups 14 and most gradual in serogroup 18. The relative risk of disease with serotype 1 declines steadily throughout life, while with serotypes 3 and 8 it increases over middle age. Serogroups 7 and 23 are found unusually frequently in the third decade of life. Because of the wide differences in the epidemiology of individual serogroups of S. pneumoniae, it is questionable whether pneumococcal infection should continue to be classified as a single disease entity.

Invasive bacterial infections of children in a rural province in the central Philippines.

“…This observation is in agreement with earlier ones: even though serotype 1 rarely colonizes the nasopharynx, it was among the most common serotypes isolated from invasive infections in several studies in developing countries. 11,29 Serotypes/groups 1, 6, and 23 comprised more than 80% of our blood isolates, and serogroups/types 6, 19, and 23 were most common among nasal isolates. In agreement with these findings, serotypes/groups 1, 6, 19, and 23 have been found to be the most common among isolates from invasive pneumococcal infections in children in a tertiary care hospital in Metro Manila, The Philippines.…”

“…Reports of these diseases in rural populations in developing countries have been published for The Gambia 6,7 and Papua New Guinea. 8 From the point of view of ongoing development of pneumococcal conjugate vaccines, the significant variations reported between the distribution of most common pneumococcal serogroups/types in developing countries [9][10][11][12] and the shortage of serogroup/type information from Asia 13 are of great importance.…”

Sensibilidad antibiótica y recomendaciones de tratamiento para Streptococcus pneumoniae

“…Este mayor porcentaje de resistencia en los aislamientos de edad pediátrica puede explicarse porque es en esta edad cuando el consumo de antibióticos es mayor y se encuentra bien establecida la asociación entre consumo de antibióticos y aparición de resistencias 17 . El porcentaje de colonización por Streptococcus pneumoniae es mayor en niños que en adultos [1][2][3] , además los niños se colonizan con mayor frecuencia con serotipos más resistentes a los antibióti-cos, por lo tanto son más frecuentes las infecciones causadas por estos serotipos [18][19][20] . Los aislamientos más resistentes fueron los procedentes de exudados óticos, y los más sensibles los de hemocultivo, con resultados similares a los de otras series 13 .…”

La vacuna neumocócica conjugada heptavalente (Prevenar™): Diferencias en su efectividad en distintas poblaciones

“…La edad, la tasa de hospitalización y la resistencia antibiótica a menudo se asocian entre sí, así como con determinados serotipos, lo que hace difícil distinguir la contribución de cada variable 31 . Por ejemplo, los niños pequeños presentan con mayor frecuencia meningitis neumocóci-cas que los mayores, tienden a ser más frecuentemente hospitalizados, aún con formas clínicas similares, y es más probable encontrar en ellos cepas resistentes a antibióticos [32][33][34] .…”