TY - JOUR
T1 - Temporal trends in invasive pneumococcal disease and pneumococcal serotypes over 7 decades
AU - Harboe, Zitta B
AU - Benfield, Thomas
AU - Valentiner-Branth, Palle
AU - Hjuler, Thomas
AU - Lambertsen, Lotte
AU - Kaltoft, Margit
AU - Krogfelt, Karen
AU - Slotved, Hans Christian
AU - Christensen, Jens Jørgen
AU - Konradsen, Helle B
N1 - Keywords: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; Cohort Studies; Denmark; Female; History, 20th Century; History, 21st Century; Humans; Incidence; Infant; Infant, Newborn; Male; Middle Aged; Pneumococcal Infections; Retrospective Studies; Serotyping; Streptococcus pneumoniae; Young Adult
PY - 2010/2/1
Y1 - 2010/2/1
N2 - Background. Pneumococcal infections have historically played a major role in terms of morbidity and mortality. We explored historical trends of invasive pneumococcal disease (IPD) and pneumococcal serotypes in a population exposed to limited antibiotic selective pressure and conjugate pneumococcal vaccination (PCV). Methods. Retrospective cohort study based on nationwide laboratory surveillance data on IPD collected uninterruptedly in Denmark during 1938-2007. Changes in the reported incidence and trends of pneumococcal serotypes were explored using nonlinear regression analysis. Results. There were 25,502 IPD cases included in our study. The median incidence of IPD increased from 2.8 cases per 100,000 population (interquartile range [IQR], 1.5-2.6) during the first 4 decades to 15.7 cases per 100,000 population (IQR, 7-20.4) during the 1980s and 1990s, mainly attributed to an increase in the number of bacteremia cases. The incidence of meningitis remained relatively stable, with a median of 1.3 cases per 100,000 population (IQR, 0.9-1.6). The proportions of serotypes/groups 4 and 9 increased; the proportion of serotype 18C decreased; the proportions of serotypes 6, 7F, 14, and 23F remained stable; and serotype 2 nearly disappeared. Before the 1960s, serotypes 1, 2, 3, and 5 presented peaks every 2-3 years, becoming less frequent during the 1970s with peaks every 7-10 years. Between 20% and 90% of IPD in children <5 years were caused by PCV serotypes during the last 4 decades. Cases of IPD caused by serotype 19A increased before introduction of PCV. Between 1993 and 2007, the level of resistance to macrolides and β-lactams was ≤6%. Conclusions. The epidemiology of IPD and single serotypes has constantly changed over the past 7 decades. PCV serotypes appeared to dominate the pneumococcal population.
AB - Background. Pneumococcal infections have historically played a major role in terms of morbidity and mortality. We explored historical trends of invasive pneumococcal disease (IPD) and pneumococcal serotypes in a population exposed to limited antibiotic selective pressure and conjugate pneumococcal vaccination (PCV). Methods. Retrospective cohort study based on nationwide laboratory surveillance data on IPD collected uninterruptedly in Denmark during 1938-2007. Changes in the reported incidence and trends of pneumococcal serotypes were explored using nonlinear regression analysis. Results. There were 25,502 IPD cases included in our study. The median incidence of IPD increased from 2.8 cases per 100,000 population (interquartile range [IQR], 1.5-2.6) during the first 4 decades to 15.7 cases per 100,000 population (IQR, 7-20.4) during the 1980s and 1990s, mainly attributed to an increase in the number of bacteremia cases. The incidence of meningitis remained relatively stable, with a median of 1.3 cases per 100,000 population (IQR, 0.9-1.6). The proportions of serotypes/groups 4 and 9 increased; the proportion of serotype 18C decreased; the proportions of serotypes 6, 7F, 14, and 23F remained stable; and serotype 2 nearly disappeared. Before the 1960s, serotypes 1, 2, 3, and 5 presented peaks every 2-3 years, becoming less frequent during the 1970s with peaks every 7-10 years. Between 20% and 90% of IPD in children <5 years were caused by PCV serotypes during the last 4 decades. Cases of IPD caused by serotype 19A increased before introduction of PCV. Between 1993 and 2007, the level of resistance to macrolides and β-lactams was ≤6%. Conclusions. The epidemiology of IPD and single serotypes has constantly changed over the past 7 decades. PCV serotypes appeared to dominate the pneumococcal population.
U2 - 10.1086/649872
DO - 10.1086/649872
M3 - Journal article
C2 - 20047478
SN - 1058-4838
VL - 50
SP - 329
EP - 337
JO - Clinical Infectious Diseases
JF - Clinical Infectious Diseases
IS - 3
ER -
