Epidemiology Of Invasive Pneumococcal Infections Research Articles

Epidemiology of invasive pneumococcal infections: manifestations, incidence and case fatality rate correlated to age, gender and risk factors.

BackgroundIncidence, manifestations and case-fatality rate (CFR) of invasive pneumococcal disease (IPD) vary with age and comorbidities. New vaccines, changing age distribution, prolonged survival among immunocompromised patients and improved sepsis management have created a need for an update of basic facts to inform vaccine recommendations.MethodsAge, gender and comorbidities were related to manifestations and death for 2977 consecutive patients with IPD in a Swedish region with 1.5 million inhabitants during 13 years before introduction of pneumococcal conjugate vaccines (PCV) in the infant vaccination program. These data were related to population statistics and prevalence of several comorbidities, and compared with two previous studies giving a total follow-up of 45 years in the same area.ResultsThe annual incidence was 15/100,000 for any IPD and 1.1/100,000 for meningitis; highest among elderly followed by children < 2 years. It was 2238/100,000 among myeloma patients, followed by chronic lymphatic leukemia, hemodialysis and lung cancer, but not elevated among asthma patients. CFR was 10 % among all patients, varying from 3 % below 18 years to 22 % ≥ 80 years. During 45 years, the IPD incidence increased threefold and CFR dropped from 20 to 10 %. Meningitis incidence remained stable (1.1/100,000/year) but CFR dropped from 33 to 13 %. IPD-specific mortality decreased among children <2 years from 3.1 to 0.46/100,000/year but tripled among those ≥65 years.ConclusionsIPD incidence and CFR vary widely between age and risk groups and over time even without general infant vaccination. Knowledge about specific epidemiological characteristics is important for informing and evaluating vaccination policies.

Epidemiology of invasive pneumococcal infections in children aged 0-6 years in Denmark: a 19-year nationwide surveillance study

Epidemiology of invasive pneumococcal infections in children aged 0-6 years in Denmark: a 19-year nationwide surveillance study

Epidemiology of invasive pneumococcal infections in children aged 0-6 years in Denmark: a 19-year nationwide surveillance study.

The impact of the new pneumococcal conjugate vaccines on invasive disease burden in Danish children was evaluated by analysing the results from the last 19 years of a nationwide surveillance of invasive pneumococcal infections. During 1981-1999, the Streptococcus Unit at Statens Serum Institut, Copenhagen, received 1123 invasive pneumococcal isolates from children aged 0-6 years. Nearly 72% (71.8%) of the pneumococcal isolates were from children aged <2 y. The median ages of children with pneumococcal meningitis and bacteraemia were 10.2 mo and 15.9 mo, respectively. The incidence of pneumococcal meningitis remained stable during the study period. The mean annual incidence rates of pneumococcal meningitis among children aged <1, <2, and <7 years were 17.4, 12.4, and 4.3 per 100,000, respectively, during 1981-1999 (overlapping age groups are used throughout this article to facilitate the comparison of incidence data from different countries or among different studies). The annual incidence of pneumococcal bacteraemia increased from 1981 to 1996, after which a slight fall was noted. During the last six years of the study period, the mean annual incidence rates of bacteraemia were 30.1, 32.5, and 14.0 per 100,000 children aged < 1, < 2, and < 7 years. In the 1990s, pneumococcal isolates with reduced sensitivity to penicillin (0-5% each year) and erythromycin (7.4% in 1999) emerged as a cause of invasive infections in children aged 0-6 years in Denmark. During 1981-1999, 10 serotypes (1, 4, 6A, 6B, 7F, 9V, 14, 18C, 19F, 23F) caused 82% of invasive infections in Danish children. Importantly, no significant temporal changes in overall serotype distribution or differences in serotype distributions between girls and boys could be documented during the study period. According to the Kaiser Permanente trial, the 7-, 9-, and 11-valent pneumococcal conjugate vaccines will probably cover around 60%, 70%, and 80%, respectively, of all invasive pneumococcal infections in Danish children aged 0-6y, corresponding to 12-14 episodes of meningitis and 40-60 episodes of bacteraemia per year.

Epidemiology of invasive pneumococcal infections in infants and young children in Metropolitan Santiago, Chile, a newly industrializing country.

To study the epidemiology of invasive pneumococcal infections in infants and young children in Santiago, Chile, as a representative pediatric population in a newly industrializing country where pneumococcal conjugate vaccines may be used in the future. A 5-year retrospective laboratory-based review (1989 to 1993) was followed by a 3-year prospective laboratory and hospital surveillance study in two of the six health administrative areas of Santiago to detect all hospitalized cases of invasive pneumococcal disease (defined as Streptococcus pneumoniae isolated from blood, cerebrospinal fluid or another normally sterile site) among infants and children (0 to 23 months of age in the retrospective and 0 to 59 months of age in the prospective study). During the 5-year retrospective survey the incidence of invasive pneumococcal disease was 90.6 cases per 10(5) infants 0 to 11 months old and 18.5 cases per 10(5) toddlers 12 to 23 months old. Similar rates (60.2 per 10(5) infants and 18.1 per 10(5) toddlers) were recorded during the 3 years of prospective surveillance. Among the 110 cases in children 0 to 59 months of age detected during the 3-year prospective surveillance, 2 clinical forms, pneumonia and meningitis, accounted for 87.2% of all cases; 13 of the 49 pneumonia patients (26%) had empyema as a complication. Notably 40 of the 110 cases (36.4%) occurred before 6 months of age (63.4% of the 63 infant cases). Serotypes 1, 14, 5 and 6B were the most prevalent. Overall 76 and 69%, respectively, of S. pneumoniae isolates were antigenic types that would be covered by the 11- or 9-valent conjugate vaccines under development. Invasive pneumococcal infections in Santiago, Chile, exhibit an epidemiologic pattern intermediate between that of developing and industrialized countries. The high burden of disease in early infancy dictates that an accelerated immunization schedule (beginning in the perinatal period) or maternal immunization with pneumococcal vaccines should be explored.

Epidemiology of Invasive Pneumococcal Infections in Children in Finland

To study the epidemiologic characteristics of invasive infections in children caused by Streptococcus pneumoniae to provide background data for vaccination programs. A nationwide laboratory-based prospective surveillance of all invasive pneumococcal infections in children during 1985 through 1989. A network of all microbiologic laboratories and pediatric wards in Finland. Children aged 0 to 15 years who were admitted to a hospital with S pneumoniae isolated from blood, cerebrospinal fluid, or deep aspirate sample. Four hundred fifty-two invasive pneumococcal infections were diagnosed in 1985 through 1989. The annual incidence rate was 8.9 per 100,000 children less than 16 years of age (24.2 per 100,000 among children less than 5 years of age and 45.3 per 100,000 among those less than 2 years of age). The most common clinical entities were bacteremia without focus (310 cases), pneumonia (66 cases), and meningitis (51 cases), with other focal infections seen in 25 cases. The pneumococcal groups/types 14, 6, 19, 7, 18, and 23 comprised 78% of all invasive infections. Streptococcus pneumoniae is a common cause of invasive infections in children in Finland. A pneumococcal conjugate vaccine containing the six most common groups/types could prevent up to 70% of invasive pneumococcal infections of children in Finland if fully protective in infancy.

Epidemiology of invasive pneumococcal infections in children in Finland

Epidemiology of invasive pneumococcal infections in children in Finland