Management of the febrile child without a focus of infection in the era of universal pneumococcal immunization

Should strategies of management of invasive disease in the febrile child without focus of infection (occult bacteremia) be reconsidered in communities with universal immunization of infants with the conjugate vaccines for Haemophilus influenzae type b and Streptococcus pneumoniae (PCV7)? The incidence of occult bacteremia is likely to decrease with the virtual elimination of H. influenzae type b and vaccine serotype pneumococcal invasive diseases. The number of children with fever coming to physicians' offices, however, is unlikely to change. The challenge of distinguishing the febrile child with invasive bacterial disease who requires aggressive therapy from the febrile child who has a viral infection and requires only symptomatic therapy will persist. The bacteriology of invasive disease in infants and young children in 2002 will include pneumococcal serotypes not in PCV7; serotypes in PCV7 that occur in the unimmunized, partially immunized or fully immunized child (vaccine failures); Neisseria meningitidis; Salmonella spp., group A Streptococcus, Staphylococcus aureus and gram-negative enteric bacilli. Management plans published in the 1990s suggested an aggressive diagnostic approach to the febrile child 3 to 36 months old who was toxic or had a temperature of >39 degrees C. Diagnostic tests included white blood cell counts, cultures of blood and urine and chest radiograph and lumbar puncture as indicated by clinical signs and administration of parenteral ceftriaxone. Although PCV7 was extraordinarily effective in prevention of serotype-specific invasive pneumococcal disease in clinical trials, pediatricians need to know whether the results based on 38,000 enrollees will be maintained as millions of children are immunized. In addition questions about change in serotype of pneumococci causing invasive disease (serotype switching), herd immunity and durability of protection after immunization need to be answered. Until more experience is available to answer these questions, the febrile child without focus of infection should be managed without consideration of immunization with PCV7. Evaluation of the organism (serotype) and the host (acute and convalescent sera) should be undertaken for each case of invasive pneumococcal disease in this era of universal pneumococcal immunization.     

Pneumococcal bacteremia among infants with fever without known source before and after introduction of pneumococcal conjugate vaccine in the Basque Country of Spain

BACKGROUND: The introduction of vaccination with the heptavalent pneumococcal conjugate vaccine (PCV7) has produced an important decrease in the incidence of Streptococcus pneumoniae occult bacteremia (OB). In Spain, PCV7 became available in the last months of 2001, but, to date, it has not been included in the official vaccination schedule of the public health system. OBJECTIVE: To describe the impact of pneumococcal vaccination with PCV7 on the incidence of OB caused by S. pneumoniae in infants aged 3-36 months presenting to our pediatric emergency department. PATIENTS AND METHODS: This is a retrospective case series of all blood cultures obtained from January 1, 2000 to December 31, 2005 in our pediatric emergency department from infants with fever without known source. We evaluated rates of blood cultures positive with S. pneumoniae before (January 1, 2000-December 31, 2001) and after (January 1, 2004-December 31, 2005) PCV7 introduction, excluding 2 transitional years (January 1, 2002-December 31, 2003). RESULTS: Implementation of vaccination with PVC7 in our area resulted in a 57.5% reduction of OB caused by S. pneumoniae (1.62-0.69%) (P < 0.05). There were 30 cases of bacteremia caused by S. pneumoniae, 19 before and 11 after PCV7 introduction. Between the 2 periods of time studied the number of cases of infants aged 3-36 months with fever without known source, increased from 8052 to 9799 (21.6%) and the total blood cultures drawn significantly increased from 1171 to 1575 (34.5%) (P < 0.01). Despite more frequent blood culturing in febrile patients, the rate of OB caused by PCV7-serotypes decreased significantly by 79% (1.19-0.25%) (P < 0.01) and the proportion of OB caused by nonvaccine serotypes increased minimally from 0.42 to 0.44%. In the post-PVC7 period, 4 infants presented with S. pneumoniae OB caused by PCV7 serotypes; 2 had not received PCV7, and 2 (6 and 7 months old) had received one dose. CONCLUSION: After PCV7 introduction in our area, rates of S. pneumoniae OB caused by vaccine serotypes decreased significantly despite only moderate use of the vaccine in our population.     

Bacteremia in feverish children presenting to the emergency department: a retrospective study and literature review

Aim: To evaluate the incidence of bacteremia, and the isolated pathogens, in well‐appearing children with fever without source (FWS) presenting to the pediatric emergency department (PED), after pneumococcal conjucate vaccine ‐ 7 valent (PCV‐7) widespread introduction in the Veneto region of north‐eastern Italy, and to review the main literature contributions on the subject. Methods: Blood cultures performed at the PED of Padova from 1 June 2006 to 31 January 2009 in febrile children aged 1–36 months were retrospectively retrieved. Medical records of previously healthy well‐appearing children with FWS were identified and reviewed. Results: The study finally included 392 patients. Bacteremia rate was 0.34% (95% CI 0–1) in the age group 3–36 months and 2% (95% CI 0–4.7) in infants 1–3 months. No Streptococcus pneumoniae was isolated. The literature review identified 10 relevant studies carried out in the USA and Spain showing an overall bacteremia rate <1% for feverish children aged 3–36 months, with values <0.5% in settings with high PCV‐7 coverage. Conclusion: Overall bacteremia rate is currently <0.5% in well‐appearing children aged 3–36 months with FWS attending the PED in areas with PCV‐7 widespread vaccination and is sufficiently low to preclude laboratory testing in favour of close follow‐up. Further research is needed to evaluate a more conservative approach in infants 2–3 months of age.     

Prevalence of Pneumococcal Bacteremia in Children with Sickle Cell Disease

We performed a retrospective chart review of children with sickle cell disease hospitalized for fever at our local institution. We reviewed 456 hospitalizations in 133 patients between January 2006 and June 2012. The prevalence of true bacteremia was 4%. The mean C-reactive protein values and temperatures were nonsignificantly higher in patients with positive blood cultures. The mean time to detection was 22.5 hours in bacteremia compared to 32.6 hours in blood cultures that grew contaminants (p = .034). Only two (0.4%) cases of pneumococcal bacteremia were reported and both occurred before May 2010, which marks the introduction of 13-valent pneumococcal vaccine (PCV13). Both patients with pneumococcal bacteremia had discontinued penicillin prophylaxis after the age of 5 years. The first patient was immunized but contracted a nonvaccine serotype (23B). The second patient was partially vaccinated and acquired a vaccine-preventable serotype (23F). Both serotypes were sensitive to ceftriaxone and vancomycin; one was resistant to penicillin. This is the first study reporting the prevalence of pneumococcal bacteremia since the introduction of PCV13.     

Pneumokokkenkonjugatimpfstoffe �C Expertenkonsens

In addition to a 10-valent pneumococcal conjugate vaccination (PCV10), a 13-valent vaccination (PCV13) has been available in Germany since December 2009. Changing from PCV7 to PCV13 is possible and problem-free at any point in a vaccine series; from PCV7 to PCV 10, however, only at booster vaccine. The question arises as to whether an additional vaccine with PCV13 is advisable for those children having completed PCV7 and PCV10 vaccine series. Children at increased risk of pneumococcal infection according to the guidelines set out by the Standing Vaccination Committee (STIKO) at the Robert Koch Institute who have been vaccinated with PCV7 but not with PPV23 should in principle be vaccinated with PCV13. The risk group could possibly also include healthy children cared for in public facilities from an early age. Children already pre-vaccinated with PPV23 (according to PCV7 or PCV10 vaccine), as well as those only vaccinated with PPV23 should receive the PCV13 vaccine, whereby in the case of the latter a minimum interval of 8?weeks should be observed. In any event, paediatricians should evaluate the individual risk of each patient and make recommendations to their parents not only on the basis of STIKO recommendations, but also on the basis of what is most advisable.     

Program Szczepień Ochronnych w 2017 roku − powszechne szczepienia przeciwko pneumokokom u dzieci

In Poland, starting from 2017, mandatory vaccination against pneumococcus in children will be financed. There are two conjugate vaccines: PCV10 and PCV13 for children from 2 months of age. PCV10 vaccine was purchased for mandatory vaccination programme. In 2011?2015, PCV13 vaccine in children provided more than 20% broader serotypes coverage than the PCV10 vaccine (www.koroun.edu.pl). PCV13 is the only vaccine that demonstrated protection against invasive and non-invasive diseases caused by serotype 19A, which is the most common multi-drug resistant serotype in the population (approximately 80% of the isolates of 19A are MDR). Serotype 19A was the third most common serotype after 6B and 14, responsible for invasive pneumococcal disease (IPD) in children up to 2 years of age. The vaccine PCV10 does not include antigen of serotype 19A.In Kielce, over the last 10 years of the universal immunization programme, PCV7 / PCV13 in children showed reduction in carriage of penicillin-resistant serotypes of Streptococcus pneumoniae. Indirect effect as a decrease in pneumonia in non-vaccinated elderly population has been observed.Pediatric Group of Experts on the Immunization Programme by the Ministry of Health, based on the Polish data KOROUN, recommended vaccine PCV13 for the implementation as universal immunization for children. The arguments for the recommendation take into account the broadest serotype coverage, reducing the carriage of antibiotic-resistant serotypes and the impact of PCV13 vaccine to reduce pneumonia in non-vaccinated population.Vaccination in high-risk groups, including preterm newborns, remains unchanged. For this group, PCV13 is recommended.In the assessment of the effective prevention of pneumococcal disease, serotype coverage, real-world effectiveness of vaccines and health benefits for the entire population should be taken into account.     

Low risk of bacteremia in children with febrile seizures

OBJECTIVE: To evaluate the risk of bacteremia in children with febrile seizures treated as outpatients. METHODS: A retrospective cohort study was performed involving 379 children aged 2 to 24 months presenting to an urban tertiary care children's hospital emergency department with a febrile seizure between February 1, 1993, and May 31, 1996. RESULTS: The mean patient age was 15.9 months, and 217 (57%) were male. In 40 patients (10.6%), the use of oral antibiotics before initial emergency department evaluation was reported. Bacteremia occurred in 8 (2.1%) of 379 children studied. None of the children with bacteremia had received previous antibiotics. The causative organisms were Streptococcus pneumoniae in 7 cases and group A Streptococcus in 1 case. There were 5 contaminated cultures (1.3%). Although 2 of the 8 children with bacteremia ultimately required admission, there were no serious adverse outcomes. Six of 7 episodes of S pneumoniae bacteremia were caused by serotypes included in the pneumococcal conjugate vaccine, which was not available at the time of this study. CONCLUSIONS: Children 2 to 24 months of age with febrile seizures are at similar risk for occult bacteremia as those with fever alone. Widespread use of the pneumococcal conjugate vaccine may further decrease the incidence of bacteremia in this population.     

Current issues regarding the use of pneumococcal conjugate and polysaccharide vaccines in Australian children

OBJECTIVE: To present the results of child pneumococcal vaccination studies in the setting of current Australian disease epidemiology and immunization policy, and issues that clinicians should consider in discussions with families. METHODS: This paper includes a narrative review of randomized, controlled, double blind studies and systematic reviews which evaluated the efficacy of child pneumococcal vaccination. RESULTS: 7PCV is expected to prevent > 80% of childhood invasive pneumococcal disease (IPD, includes meningitis, septicaemia/bacteraemia) and the associated mortality. 7PCV may prevent 6% of all pneumonia, 18% of radiographically-defined pneumonia, 6% of all otitis media (OM) and 20%-40% of tympanostomy tube procedures. It may also reduce IPD due to antibiotic-resistant pneumococci, and prevent IPD in unvaccinated individuals. The impact of replacement disease caused by non-vaccine serotypes is not yet known. Pneumococcal polysaccharide vaccines given to 2-year-old children may prevent approximately 19% of all and 26% of recurrent OM. CONCLUSION: The Australian Standard Vaccination Schedule recommends universal infant immunization with seven-valent pneumococcal conjugate vaccine (7PCV). Universal infant 7PCV will prevent pneumococcal diseases and deaths. The potential for its impact to be reduced in the long-term by serotype replacement must be closely monitored. Information concerning disease epidemiology, vaccine efficacy and safety, disease risk perception and national costs may prove useful in discussions with families.     

Immunization registry-based recall for a new vaccine.

BACKGROUND: Immunization recall for specific vaccines may be necessary to "catch up" children with newly available vaccines or recall children after vaccine shortages. The extent to which immunization registry-based recall can increase immunization rates for a new vaccine has not been prospectively studied. OBJECTIVE: To assess the efficacy of letter/telephone recall for immunization with pneumococcal conjugate vaccine (PCV7) in an economically disadvantaged urban population. DESIGN/METHODS: Randomized controlled trial at an inner-city teaching hospital. Using an immunization registry, we randomly assigned children aged 6 weeks to 22 months unimmunized for PCV7 to an intervention group (n = 610) or a control group (n = 624). The intervention consisted of letter and telephone recall for PCV7 vaccination. Two months after intervention, receipt of 1 or more doses of PCV7 was assessed. Intention-to-treat analysis was used. RESULTS: We were unable to successfully contact 42.3% of the intervention subjects by mail and telephone. In the intervention group, 23.0% (140 children) received PCV7 within 2 months compared with 20.2% (126 children) in the control group (P = NS). No intervention effect was evident when children were stratified by age. A large proportion of the study population had Medicaid insurance (51.2%) or were uninsured (28.5%), but response to PCV7 recall did not vary by insurance status. CONCLUSIONS: Letter and telephone recall for PCV7 vaccine did not significantly increase the rate of PCV7 immunization in an inner-city teaching hospital serving a disadvantaged population. The effectiveness of recall appears to have been limited by the inability to reach many subjects by mail and telephone.     

Fever without apparent source on clinical examination

PURPOSE: This review discusses recent literature that has focused on the epidemiology, clinical and laboratory evaluation and treatment of episodes of acute illnesses associated with fever and also of prolonged episodes of fever in children. RECENT FINDINGS: Articles addressed the epidemiology of invasive pneumococcal disease in children in other countries that have not yet initiated vaccination with the conjugated pneumococcal vaccine. From the United States there was a report of the decreased occurrence of invasive pneumococcal disease in patients being provided primary care who had been vaccinated with conjugated pneumococcal vaccine. Another report outlined the experience at children's hospitals with invasive pneumococcal disease in the years pre- and post-introduction of pneumococcal vaccine. One of the studies found that there was a slight increase in pneumococcal disease caused by non-vaccine serotypes. Another group of articles focused on serious bacterial infections in infants with fever who are positive for respiratory syncytial virus (RSV). All studies found a significant occurrence of urinary tract infections in these patients. One report found that bacteremia may occur in such patients if less than 28 days of age. Finally articles from Turkey, Thailand, and Italy give excellent discussions about the range of diagnoses and key clinical findings that may be seen in children with prolonged fever. SUMMARY: In the review period, there was a particular emphasis on invasive disease caused by S. pneumoniae and the impact of vaccination with conjugated pneumococcal vaccine, on the occurrence of serious bacterial infection in febrile infants with RSV infections, and on the broad spectrum of diagnoses in children with prolonged fever in varying geographic locales.     

Incidence of occult bacteremia among highly febrile young children in the era of the pneumococcal conjugate vaccine: a study from a Children's Hospital Emergency Department and Urgent Care Center

BACKGROUND: The optimal diagnostic approach to and management of well-appearing, highly febrile young children has been a matter of debate owing to the possibility of clinically inapparent, or occult, bacteremia (OB). The most common causative organism of OB is Streptococcus pneumoniae. Universal immunization with a heptavalent pneumococcal conjugate vaccine (PCV7) has recently been implemented, but there are limited data on the impact of this vaccine on the incidence of OB. OBJECTIVE: To evaluate the incidence of OB in the era of routine use of PCV7. METHODS: We conducted a retrospective cohort study of highly febrile (temperature, 39 degrees C) children between the ages of 2 months and 36 months who had blood cultures performed in the emergency department or urgent care center between December 11, 2001, and March 5, 2003, and were discharged to home at the time of the initial visit. RESULTS: Of 329 blood cultures obtained from children who met inclusion criteria and did not meet exclusion criteria, 3 (0.91%; 95% confidence interval, 0%-1.9%) yielded a pathogenic bacterium; all were S pneumoniae. Neither an elevated total white blood cell count, an elevated absolute neutrophil count, nor an increased percentage of bands was highly predictive of OB. Blood cultures positive for organisms were more commonly due to contaminants (4; 95% confidence interval, 0%-2.4%) than pathogens. CONCLUSIONS: In the PCV7 era, OB is uncommon in highly febrile children 2 to 36 months of age. With continued use of PCV7, the routine practice of obtaining blood cultures and complete blood cell counts may no longer be indicated in previously healthy, well-appearing, highly febrile children 2 to 36 months of age, particularly those who have received at least 1 dose of PCV7.     

Pneumokokkenkonjugatimpfstoffe

Many studies worldwide have demonstrated that PCV7, the first available conjugate vaccine against pneumococci, is very effective in preventing invasive pneumococcal diseases such as septicaemia and meningitis as well as in preventing pneumonia and acute otitis media. The incidence of infections due to Streptococcus pneumoniae, nasopharyngeal carriage of this pathogen, and direct consequences of pneumococcal infection (such as hospitalisation and antibiotic use) have been shown to be reduced in PCV7-vaccinated infants. Recent publications also revealed the efficacy of PCV7 in Germany, its effectiveness following the general vaccination campaign in 2006, and its cost-effectiveness. A new pneumococcal conjugate vaccine based on the established technology of PCV7, designated PCV13 due to an additional six serotypes, will provide an extended serotype coverage of 90%. While this vaccine is already licensed in Chile, Mexico and Mauritius PCV13 will probably be available in Germany at the end of 2009. Based on various studies with excellent results – particularly regarding the safety, tolerability, and immunogenicity of PCV13 – a smooth transition from PCV7 to PCV13 will be possible.     

Cost-effectiveness of pneumococcal conjugate vaccine: evidence from the first 5 years of use in the United States incorporating herd effects

BACKGROUND: Pneumococcal conjugate vaccine (PCV) has been in routine use in the United States for 5 years. Prior U.S. cost-effectiveness analyses have not taken into account the effect of the vaccine on nonvaccinated persons. METHODS: We revised a previously published model to simulate the effects of PCV on children vaccinated between 2000 and 2004, and to incorporate the effect of the vaccine in reducing invasive pneumococcal disease (IPD) in nonvaccinated persons during those years. Data from the Active Bacterial Core Surveillance of the Centers for Disease Control and Prevention (2000-2004) were used to estimate changes in the burden of IPD in nonvaccinated adults since the introduction of PCV (compared with the baseline years 1997-1999). Results combined the simulated effects of the vaccine on the vaccinated and nonvaccinated populations. RESULTS: Before incorporating herd effects in the model, the PCV was estimated to have averted 38,000 cases of IPD during its first 5 years of use at a cost of dollar 112,000 per life-year saved. After incorporating the reductions in IPD for nonvaccinated individuals, the vaccine averted 109,000 cases of IPD at a cost of dollar 7500 per life-year saved. When the herd effect was assumed to be half that of the base case, the cost per life-year saved was dollar 18,000. CONCLUSIONS: IPD herd effects in the nonvaccinated population substantially reduce the cost, and substantially improve the cost-effectiveness, of PCV. The cost-effectiveness of PCV in actual use has been more favorable than predicted by estimates created before the vaccine was licensed.     

Invasive pneumococcal infections in children with asplenia

BACKGROUND: Asplenia is associated with an increased risk of infections caused by Streptococcus pneumoniae. Overwhelming infection can be fulminate and lead to a fatal outcome. OBJECTIVE: To review the epidemiology and clinical course of invasive S. pneumoniae infections in children with asplenia before the release of the conjugate pneumococcal vaccine. METHODS: Children with S. pneumoniae infections from eight children's hospitals in the US were identified prospectively from September, 1993, to August, 1999. Further demographic, medical and microbiologic information was gathered retrospectively from the charts of patients with asplenia. RESULTS: Twenty-two asplenic patients with 26 episodes of invasive S. pneumoniae were identified. This represents 1% of the 2,581 episodes of invasive S. pneumoniae infections identified in our study. Twelve had congenital asplenia (CA), and 10 had undergone surgical splenectomy. Nine of the patients with CA had associated complex congenital heart disease. The median age at first infection was 12.5 months for CA patients as compared with 69 months in children with surgical splenectomy (P < 0.001). Seventy-five percent of those eligible had received the polysaccharide pneumococcal vaccine. The most common serotypes isolated were 6B (8), 23F (7), 18C (2) and 19A (2). Antimicrobial prophylaxis had been prescribed for 82% of the study cohort. Clinical presentations of the 26 episodes included fever (22), shock (7), petechiae or purpura (7), disseminated intravascular coagulation (5) and respiratory distress (5). Clinical illness included bacteremia alone (12), meningitis alone (8), bacteremia with otitis media-sinusitis (3), bacteremia with pneumonia (2) and meningitis with osteomyelitis (1). Five of the 6 patients who died had meningitis. Three of the survivors (19%) had significant morbidity, and all of them had meningitis. Two patients had 2 episodes each, and 1 patient had 3 episodes. All but 1 of the multiple episodes was with a different serotype. Forty-six percent of isolates were nonsusceptible to penicillin, and 19% were nonsusceptible to ceftriaxone. There was no association between antimicrobial resistance and mortality. CONCLUSIONS: Invasive pneumococcal disease in patients with asplenia has a high mortality, especially in those with meningitis. Even though the new conjugate vaccine might increase protection, 19% of patients had disease caused by serotypes not included in the current heptavalent vaccine. Clinicians should continue to be aggressive in evaluating asplenic patients with unexplained fevers.     

Surveillance for invasive pneumococcal disease during 2000-2005 in a population of children who received 7-valent pneumococcal conjugate vaccine

OBJECTIVES: To assess the incidence of invasive pneumococcal disease (IPD) in all children younger than 5 years of age in the Northern California Kaiser Permanente (NCKP) health care system during a 5-year surveillance period (2000-2005) after the introduction in April 2000 of routine use of 7-valent pneumococcal conjugate vaccine (PCV7). METHODS: This was a laboratory-based surveillance study of all children younger than 5 years of age in the NCKP health care system from April 2000 to March 2005. The comparison group was all children younger than 5 years of age in the NCKP health care system from April 1996 to March 2000. Data obtained from clinical databases included microbiologic identification and susceptibility testing; serotyping of isolates; immunization records; and IPD diagnoses for inpatients and outpatients. IPD was defined as a positive culture of Streptococcus pneumoniae from a normally sterile body site. RESULTS: For all serotypes, the mean annual incidence of IPD during the postlicensure surveillance period was 15.3 cases/100,000 person-years (10(5) p-y) compared with 62.5 cases/10(5) p-y in the prelicensure years of 1996-2000. The average incidence of IPD caused by vaccine serotypes was reduced from 50.1 cases/10(5) p-y during the prelicensure years to 4.9 cases/10(5) p-y during the postlicensure period. The average incidences of IPD caused by cross-reactive and by nonvaccine serotypes were 5.8 and 5.3 cases/10(5) p-y, respectively, during the prelicensure years and 2.5 and 6.2 cases/10(5) p-y, respectively, during the postlicensure period. Of the 131 IPD cases observed during the postlicensure surveillance period, bacteremia (50.4%) and pneumonia (31.3%) were the most common diagnoses. During the 5-year postlicensure surveillance period, only 3 subjects who were identified to be fully vaccinated for age with PCV7 (3 doses by 7 months of age or 4 doses by 18 months of age) developed vaccine-serotype IPD. CONCLUSION: The incidence of IPD has significantly decreased in a large population of children after the introduction of PCV7. Vaccine-type IPD was rare in patients who received full 4-dose immunization with PCV7. There is no clear evidence of a significant increase in nonvaccine-serotype IPD. Introduction of a 4-dose infant schedule of PCV7 into this population has resulted in a marked and sustained reduction of IPD in children.     

The future of pneumococcal conjugate vaccines for prevention of pneumococcal diseases in infants and children

Seven-valent pneumococcal conjugate vaccine (PCV7) was licensed in February 2000. In June 2000, the Advisory Committee on Immunization Practices and the American Academy of Pediatrics recommended the universal administration of pneumococcal conjugate vaccine for all children 23 months of age and younger and for children 24 to 59 months of age who are at high risk for serious pneumococcal disease. Since then, >23 million doses have been administered in the United States. Postlicensure surveillance of invasive pneumococcal disease (IPD) in the United States from the Active Bacterial Core Surveillance program at the Centers for Disease Control and Prevention and the Northern California Kaiser Permanente Vaccine Study Center has reported a decline in IPD and in pneumococcal disease incidence as a result of vaccine serotypes, respectively. During this period, issues critical to the long-term success of PCV7 have become more relevant: Will PCV7 be as effective in groups of children who are at high risk for IPD as in healthy children? Will nonvaccine types replace vaccine serotypes in the nasopharynx and in disease? Why are the results of the clinical trials different for IPD and for acute otitis media? How many doses of PCV7 and what concentrations of antibody are necessary for protection? Will universal administration of PCV7 to children younger than 2 years reduce antimicrobial drug resistance and alter prescribing patterns of physicians for febrile infants? Have there been unanticipated adverse events or benefits observed? The purpose of this report is to review the current data available to address these questions and to identify gaps that will require additional knowledge to determine the ultimate value of pneumococcal conjugate vaccines in reducing the burden of pneumococcal disease in infants and children.     

儿童下呼吸道感染常见细菌病原分布及耐药现状

下呼吸道感染(LRTI)尤其肺炎,是主要的儿童杀手。在发展中国家儿童LRTI病原菌以细菌为主。肺炎链球菌是最重要的社区获得性LRTI细菌病原。随着7价肺炎链球菌结合疫苗的应用,非疫苗血清型菌株所致的侵袭性肺炎链球菌疾病增多,且对抗生素的耐药性增强。社区获得性耐甲氧西林金黄色葡萄球菌(CA-MRSA)和医院获得性耐甲氧西林金黄色葡萄球菌(HA-MRSA)有着不同的遗传背景,其耐药性也有明显差异。革兰阴性杆菌仍是医院获得性LRTI的重要病原菌。社区获得性LRTI与医院获得性LRTI常见细菌病原有区别,亦有重叠。了解儿童LRTI常见细菌病原的分布及耐药现状,对指导临床合理诊治至关重要。     

Fever without source in children 0 to 36 months of age

Although fever in the young child (0-36 months) is a common clinical problem, the evaluation and treatment of febrile children remain controversial. Furthermore, universal vaccination with the heptavalent pneumococcal conjugate vaccine (PCV7) has changed the epidemiology of invasive bacterial disease in young children. This article addresses the approach to febrile neonates (0-28 days old), young infants (1-3 months old), and older infants and toddlers (3-36 months old) in the PCV7 era.     

The Impact of the Heptavalent Pneumococcal Conjugate Vaccine on Risk Factors for Streptococcus pneumoniae Carriage in Children

BACKGROUND:: The aim of the study was to investigate whether the 7-valent pneumococcal conjugate vaccine (PCV7) alters common risk factors of nasopharyngeal carriage by Streptococcus pneumoniae in children. METHODS:: From July 2005 through December 2010, we performed a cross-sectional study investigating risk factors associated with pneumococcal carriage in children. Parents of participating children completed questionnaires including whether or not the children received PCV7 vaccination. RESULTS:: Among 9705 children, 20.2% of them received at least 1 dose of the PCV7 vaccine. Multivariate logistic regression models identified older age, having 1 sibling in a family, history of acute otitis media and household exposure to smoking as independent risk factors for pneumococcal carriage in the unvaccinated group, but not associated with pneumococcal carriage in the vaccinated group. The number of siblings ≥2 in a family, history of upper respiratory tract infection and child-care attendance were strong factors associated with pneumococcal carriage in children, regardless of vaccination. In vaccinated group, breast-feeding was associated with increased nonvaccine type pneumococcal carriage, mainly in children with upper respiratory tract infection. CONCLUSIONS:: PCV7 decreased the association between pneumococcal carriage and older age, 1 sibling in a family, history of acute otitis media and household exposure to smoking, but increased the association between pneumococcal carriage and breast-feeding.     

Increase in invasive nonvaccine pneumococcal serotypes at two hospitals in Barcelona: was replacement disease to blame?

Aim: To describe an increase in the incidence of invasive pneumococcal disease (IPD) caused by serotypes not contained in the heptavalent pneumococcal conjugate vaccine (PCV7) in children in two hospitals in Barcelona with different vaccine uptake. Methods: Cumulative incidences of IPD, vaccine and nonvaccine serotypes (NVSTs), and main clinical presentations before (1998–2001) and after vaccine introduction (2005–2008) were compared. Results: The incidence of IPD in children aged <2 years at Hospital Germans Trias i Pujol covering a population in which PCV7 was not widely used showed a nonsignificant increase from 29.9 to 58.8 per 100 000 child‐years between both periods. Following vaccine introduction, there was a 2.5‐fold increase in IPD caused by NVSTs in children aged <5 years. Analysis of trends in the almost fully vaccinated population of Hospital de Barcelona revealed a nonsignificant reduction in IPD incidence in children aged <2 years from 63.1 to 26.0 per 100 000 child‐years. NVSTs in children aged <5 years showed a nonsignificant 1.7‐fold increase in the vaccine period at this centre. Conclusions: The paradoxical increase in invasive infections caused by NVSTs in these populations with different vaccine use suggests that these changes were not driven only by PCV7.