SARS-CoV-2 Antibody Kinetics in Unvaccinated Hospitalized Children With COVID-19

BACKGROUND

Antibody levels decline a few months post-acute COVID-19, but humoral memory persists in adults. Age and disease severity may affect antibody responses. This study aims to evaluate the presence and durability of antibody responses in children with COVID-19.

METHODS

A prospective, single-center study, involving unvaccinated children 0-16 years of age who were hospitalized with COVID-19 between October 2020 and December 2021, was conducted. Serological testing for anti-Spike severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG and neutralizing antibodies was performed at diagnosis and at 1-, 3-, 6- and 12-months post-infection.

RESULTS

A total of 65 immunocompetent children were enrolled [mean age (±SD): 6.7 (±6.4) years; males: 56.9%]. At 3 months, 40/44 (91%) children were seropositive; seropositivity persisted in 22/26 (85%) children at 6 months and in 10/12 (83%) children at 12 months. There was no evidence that age was modifying the prediction of variance of SARS-CoV-2 IgG levels. In contrast, SARS-CoV-2 IgG levels varied with time and disease severity. The association with time was non-linear, so that with increasing time there was a significant reduction in SARS-CoV-2 IgG levels [coef, 0.044 (95% confidence interval {CI}: 0.061-0.028), P < 0.001]. For each increment of time, the higher disease severity group was associated with 0.9 lower SARS-CoV-2 IgG levels. Everyone varied from the average effect of time with an SD of 0.01, suggesting that individuals may have different trajectories across time.

CONCLUSION

Disease severity, but not age, influences antibody titers among children hospitalized with COVID-19. SARS-CoV-2 infection induces durable seroconversion in these children with detectable IgG levels at 1 year after infection.

SARS-CoV-2 seroprevalence among children in Greece during Omicron variant period

The Omicron variant is associated with increased transmissibility, but evidence about the impact of Omicron in seropositivity of children is limited. This study aims to evaluate SARS-CoV-2 seroprevalence in children during the different variants' subperiods. A prospective multicenter seroprevalence study was conducted in 7 University public hospitals in Greece from November 2021 to August 2022 (3 subperiods: November 2021-February 2022, March 2022-May 2022, June 2022-August 2022). Children from different age groups, admitted to the hospital or examined in outpatient clinics for reasons other than COVID-19 were enrolled. Neutralizing antibodies (Nabs), anti-Spike (anti-S) and anti-nucleocapsid (anti-N) SARS-CoV-2 IgG in serum were evaluated. A total of 2127 children (males:57,2%; median age:4,8years) were enrolled. Anti-N IgG seropositivity increased from 17,8% in the first sub-period to 40,7% in the second sub-period and then decreased in the third sub-period (36,7%). Anti-S IgG seropositivity appeared to have an increasing trend over the study period, starting from 34,8% and reaching 80,7%. Children aged 1-4 years old have significantly higher anti-N IgG titers compared to children aged 0-1 years old (p < 0,001). Infants have significantly lower anti-S IgG titers compared to all other age groups (p < 0,001). Immunocompromised children and infants have the lowest seropositivity for NAbs.Conclusions During the Omicron period, seropositivity significantly increased, as a result of higher transmissibility. Neonates and infants have lower antibody titers compared to other age groups, while young children aged 1-4 years old present higher antibody titers, suggesting that this age group may mount a higher antibody response. Continuous surveillance seroprevalence studies are needed in children, in order to identify the true extent of SARS-CoV-2 and guide the planning of adequate public health measures.

Multisystem inflammatory syndrome in children (MIS-C): A nationwide collaborative study in the Greek population

Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe hyperinflammatory condition that may occur following SARS-CoV-2 infection. This retrospective, descriptive study of children hospitalized with multisystem inflammatory syndrome in children (MIS-C) in 12 tertiary care centers from 3/11/2020 to 12/31/2021. Demographics, clinical and laboratory characteristics, treatment and outcomes are described. Among 145 patients (95 males, median age 8.2 years) included, 123 met the WHO criteria for MIS-C, while 112 (77%) had serological evidence of SARS-CoV-2 infection. Fever was present in 99%, gastrointestinal symptoms in 77%, mucocutaneous involvement in 68% and respiratory symptoms in 28%. Fifty-five patients (38%) developed myocarditis, 29 (20%) pericarditis and 19 (13%) coronary aneurysms. Among the above cases 11/55 (20%), 1/29 (3.4%) and 5/19 (26.3%), respectively, cardiac complications had not fully resolved at discharge. Underlying comorbidities were reported in 18%. Median CRP value was 155 mg/l, ferritin 535 ng/ml, PCT 1.6 ng/ml and WBC 14.2 × 109/mm3. Most patients had elevated troponin (41.3%) and/or NT-pro-BNP (49.6%). Intravenous immunoglobulin plus corticosteroids were used in 117/145 (80.6%), monotherapy with IVIG alone in 13/145 (8.9%) and with corticosteroids alone in 2/145 (1.3%). Anti-IL1 treatment was added in 15 patients (10.3%). Thirty-three patients (23%) were admitted to the PICU, 14% developed shock and 1 required ECMO. Mortality rate was 0.68%. The incidence of MIS-C was estimated at 0.69/1000 SARS-CoV-2 infections. Patients who presented with shock had higher levels of NT-pro-BNP compared to those who did not (p < 0.001). Acute kidney injury and/or myocarditis were associated with higher risk of developing shock.

CONCLUSION

MIS-C is a novel, infrequent but serious disease entity. Cardiac manifestations included myocarditis and pericarditis, which resolved in most patients before discharge. Timely initiation of immunomodulatory therapy was shown to be effective. NT-pro-BNP levels may provide a better prediction and monitoring of the disease course. Further research is required to elucidate the pathogenesis, risk factors and optimal management, and long-term outcomes of this clinical entity.

WHAT IS KNOWN

• MIS-C is an infrequent but serious disease entity. • Patients with MIS-C present with multi-organ dysfunction, primarily involving the gastrointestinal and cardiovascular systems.

WHAT IS NEW

• NT-pro-BNP levels may provide a better prediction and monitoring of the disease course. • Acute kidney injury and/or myocarditis were associated with higher risk of developing shock.

Raising AWaRe-ness of Antimicrobial Stewardship Challenges in Pediatric Emergency Care: Results from the PERFORM Study Assessing Consistency and Appropriateness of Antibiotic Prescribing Across Europe

BACKGROUND

Optimization of antimicrobial stewardship is key to tackling antimicrobial resistance, which is exacerbated by overprescription of antibiotics in pediatric emergency departments (EDs). We described patterns of empiric antibiotic use in European EDs and characterized appropriateness and consistency of prescribing.

METHODS

Between August 2016 and December 2019, febrile children attending EDs in 9 European countries with suspected infection were recruited into the PERFORM (Personalised Risk Assessment in Febrile Illness to Optimise Real-Life Management) study. Empiric systemic antibiotic use was determined in view of assigned final "bacterial" or "viral" phenotype. Antibiotics were classified according to the World Health Organization (WHO) AWaRe classification.

RESULTS

Of 2130 febrile episodes (excluding children with nonbacterial/nonviral phenotypes), 1549 (72.7%) were assigned a bacterial and 581 (27.3%) a viral phenotype. A total of 1318 of 1549 episodes (85.1%) with a bacterial and 269 of 581 (46.3%) with a viral phenotype received empiric systemic antibiotics (in the first 2 days of admission). Of those, the majority (87.8% in the bacterial and 87.0% in the viral group) received parenteral antibiotics. The top 3 antibiotics prescribed were third-generation cephalosporins, penicillins, and penicillin/β-lactamase inhibitor combinations. Of those treated with empiric systemic antibiotics in the viral group, 216 of 269 (80.3%) received ≥1 antibiotic in the "Watch" category.

CONCLUSIONS

Differentiating bacterial from viral etiology in febrile illness on initial ED presentation remains challenging, resulting in a substantial overprescription of antibiotics. A significant proportion of patients with a viral phenotype received systemic antibiotics, predominantly classified as WHO Watch. Rapid and accurate point-of-care tests in the ED differentiating between bacterial and viral etiology could significantly improve antimicrobial stewardship.

External validation of a multivariable prediction model for identification of pneumonia and other serious bacterial infections in febrile immunocompromised children

OBJECTIVE

To externally validate and update the Feverkids tool clinical prediction model for differentiating bacterial pneumonia and other serious bacterial infections (SBIs) from non-SBI causes of fever in immunocompromised children.

DESIGN

International, multicentre, prospective observational study embedded in PErsonalised Risk assessment in Febrile illness to Optimise Real-life Management across the European Union (PERFORM).

SETTING

Fifteen teaching hospitals in nine European countries.

PARTICIPANTS

Febrile immunocompromised children aged 0-18 years.

METHODS

The Feverkids clinical prediction model predicted the probability of bacterial pneumonia, other SBI or no SBI. Model discrimination, calibration and diagnostic performance at different risk thresholds were assessed. The model was then re-fitted and updated.

RESULTS

Of 558 episodes, 21 had bacterial pneumonia, 104 other SBI and 433 no SBI. Discrimination was 0.83 (95% CI 0.71 to 0.90) for bacterial pneumonia, with moderate calibration and 0.67 (0.61 to 0.72) for other SBIs, with poor calibration. After model re-fitting, discrimination improved to 0.88 (0.79 to 0.96) and 0.71 (0.65 to 0.76) and calibration improved. Predicted risk <1% ruled out bacterial pneumonia with sensitivity 0.95 (0.86 to 1.00) and negative likelihood ratio (LR) 0.09 (0.00 to 0.32). Predicted risk >10% ruled in bacterial pneumonia with specificity 0.91 (0.88 to 0.94) and positive LR 6.51 (3.71 to 10.3). Predicted risk <10% ruled out other SBIs with sensitivity 0.92 (0.87 to 0.97) and negative LR 0.32 (0.13 to 0.57). Predicted risk >30% ruled in other SBIs with specificity 0.89 (0.86 to 0.92) and positive LR 2.86 (1.91 to 4.25).

CONCLUSION

Discrimination and calibration were good for bacterial pneumonia but poorer for other SBIs. The rule-out thresholds have the potential to reduce unnecessary investigations and antibiotics in this high-risk group.

A multi-platform approach to identify a blood-based host protein signature for distinguishing between bacterial and viral infections in febrile children (PERFORM): a multi-cohort machine learning study

BACKGROUND

Differentiating between self-resolving viral infections and bacterial infections in children who are febrile is a common challenge, causing difficulties in identifying which individuals require antibiotics. Studying the host response to infection can provide useful insights and can lead to the identification of biomarkers of infection with diagnostic potential. This study aimed to identify host protein biomarkers for future development into an accurate, rapid point-of-care test that can distinguish between bacterial and viral infections, by recruiting children presenting to health-care settings with fever or a history of fever in the previous 72 h.

METHODS

In this multi-cohort machine learning study, patient data were taken from EUCLIDS, the Swiss Pediatric Sepsis study, the GENDRES study, and the PERFORM study, which were all based in Europe. We generated three high-dimensional proteomic datasets (SomaScan and two via liquid chromatography tandem mass spectrometry, referred to as MS-A and MS-B) using targeted and untargeted platforms (SomaScan and liquid chromatography mass spectrometry). Protein biomarkers were then shortlisted using differential abundance analysis, feature selection using forward selection-partial least squares (FS-PLS; 100 iterations), along with a literature search. Identified proteins were tested with Luminex and ELISA and iterative FS-PLS was done again (25 iterations) on the Luminex results alone, and the Luminex and ELISA results together. A sparse protein signature for distinguishing between bacterial and viral infections was identified from the selected proteins. The performance of this signature was finally tested using Luminex assays and by calculating disease risk scores.

FINDINGS

376 children provided serum or plasma samples for use in the discovery of protein biomarkers. 79 serum samples were collected for the generation of the SomaScan dataset, 147 plasma samples for the MS-A dataset, and 150 plasma samples for the MS-B dataset. Differential abundance analysis, and the first round of feature selection using FS-PLS identified 35 protein biomarker candidates, of which 13 had commercial ELISA or Luminex tests available. 16 proteins with ELISA or Luminex tests available were identified by literature review. Further evaluation via Luminex and ELISA and the second round of feature selection using FS-PLS revealed a six-protein signature: three of the included proteins are elevated in bacterial infections (SELE, NGAL, and IFN-γ), and three are elevated in viral infections (IL18, NCAM1, and LG3BP). Performance testing of the signature using Luminex assays revealed area under the receiver operating characteristic curve values between 89·4% and 93·6%.

INTERPRETATION

This study has led to the identification of a protein signature that could be ultimately developed into a blood-based point-of-care diagnostic test for rapidly diagnosing bacterial and viral infections in febrile children. Such a test has the potential to greatly improve care of children who are febrile, ensuring that the correct individuals receive antibiotics.

FUNDING

European Union's Horizon 2020 research and innovation programme, the European Union's Seventh Framework Programme (EUCLIDS), Imperial Biomedical Research Centre of the National Institute for Health Research, the Wellcome Trust and Medical Research Foundation, Instituto de Salud Carlos III, Consorcio Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Grupos de Refeencia Competitiva, Swiss State Secretariat for Education, Research and Innovation.

Immunogenicity 6 months post COVID-19 mRNA vaccination among adolescents with juvenile idiopathic arthritis on treatment with TNF inhibitors

OBJECTIVES

Mass vaccination is the most effective strategy for controlling the COVID-19 pandemic. This study aimed to evaluate the 6-month immunogenicity after BNT162b2-COVID-19 vaccination in adolescents with JIA on TNFi treatment.

METHODS

This single-centre study included adolescents with JIA treated with TNFi for at least 18 months. Patients received two doses of COVID-19 vaccine (Pfizer-BioNTech) from 15 April to 15 May 2021. Quantitative measurement of IgG antibodies to SARS-CoV-2-spike-protein-1 was performed at 1, 3 and 6 months post-vaccination.

RESULTS

Overall, 21 adolescents with JIA in clinical remission at the time of vaccinations were enrolled. None of them discontinued TNFi/MTX treatment at the time of vaccine administration or during the follow-up period. All patients developed a sustained humoral response against SARS-CoV-2 at 1 and 3 months after vaccination (P < 0.05). The antibody levels decreased significantly at 6 months post-vaccination (P < 0.01). The type of JIA did not reveal any differences in the humoral response at 3 (P = 0.894) or 6 months post-vaccination (P = 0.72). No difference was detected upon comparison of the immunogenicity between the different treatment arms (adalimumab vs etanercept) at 3 (P = 0.387) and 6 months (P = 0.526), or TNFi monotherapy vs combined therapy (TNFi plus methotrexate) at 3 (P = 0.623) and 6 months (P = 0.885).

CONCLUSIONS

Although mRNA vaccines develop satisfactory immunogenicity at 1 month and 3 months post-vaccination in adolescents with JIA on TNFi, SARS-CoV-2 antibody titres decrease significantly overtime, remaining at lower levels at 6 months. Further collaborative studies are required to determine long-term immunogenicity, real duration of immune protection and the need for a booster vaccine dose.

A national study of antibiotic use in Greek pediatric hematology oncology and bone marrow transplant units

OBJECTIVE

We surveyed antimicrobials used in Greek pediatric hematology-oncology (PHO) and bone marrow transplant (BMT) units before and after an intervention involving education regarding the 2017 clinical practice guidelines (CPG) for the management of febrile neutropenia in children with cancer and hematopoietic stem-cell transplant recipients.

DESIGN

Antibiotic prescribing practices were prospectively recorded between June 2016 and November 2017.

INTERVENTION

In December 2017, baseline data feedback was provided, and CPG education was provided. Prescribing practices were followed for one more year. For antibiotic stewardship, days of therapy, and length of therapy were calculated.

SETTING

Five of the 6 PHO units in Greece and the single pediatric BMT unit participated.

PARTICIPANTS

Admitted children in each unit who received the first 15 new antibiotic courses each month.

RESULTS

Administration of ≥4 antibiotics simultaneously and administration of antibiotics with overlapping activity for ≥2 days were significantly more common in PHO units in general hospitals compared to children's hospitals. Use of at least 1 antifungal was recorded in ∼47% of the patients before and after the intervention. De-escalation and/or discontinuation of antibiotics on day 6 of initial treatment increased significantly from 43% to 53.5% (P = .032). Although the number of patients requiring intensive care support for sepsis did not change, a significant drop was noted in all-cause mortality (P = .008).

CONCLUSIONS

We recorded the antibiotic prescribing practices in Greek PHO and BMT units, we achieved improved prescribing with a simple intervention, and we identified areas in need of improvement.

Potential benefit from the implementation of the Kaiser Permanente neonatal early-onset sepsis calculator on clinical management of neonates with presumed sepsis

To assess the potential benefit from the implementation of the Kaiser Permanente early-onset sepsis calculator (EOS-C), in terms of antibiotic use and requested laboratory tests, in a network of neonatal intensive care units (NICUs) in Greece, and to determine the incidence of early-onset sepsis (EOS) in Greek NICUs, a prospective surveillance study was conducted in 7 NICUs between April 2018 and June 2019. Data were collected for all newborns ≥ 34 weeks' gestation receiving empiric antibiotic therapy within the first 3 days of life. The number of live births and positive blood or cerebrospinal fluid cultures within the first 3 days of life were used for calculation of EOS incidence. Evaluation of possible impact of implementing the calculator was done by comparing the clinicians' recorded management to the calculator's suggested course of action. The unit-specific incidence of culture-proven EOS ranged between 0 and 2.99/1000 live births. The weighted incidence rate for all 7 units was 1.8/1000 live births. Management of EOS guided by the calculator could lead to a reduction of empiric antibiotic initiation up to 100% for the group of "well-appearing" neonates and 86% for "equivocal," lowering exposure to antibiotics by 4.2 and 3.8 days per neonate, respectively. Laboratory tests for blood cultures drawn could be reduced by up to 100% and 68%, respectively. Sensitivity of the EOS-C in identifying neonates with positive blood cultures was high.Conclusion: Management strategies based on the Kaiser Permanente neonatal sepsis calculator may significantly reduce antibiotic exposure, invasive diagnostic procedures, and hospitalizations in late preterm and term neonates. What is Known: • Neonates are frequently exposed to antibiotics for presumed EOS. • The Kaiser Permanente sepsis calculator can reduce antibiotic exposure in neonates.. What is New: • EOS calculator can be an effective antibiotic stewardship tool in a high prescribing country and can reduce invasive diagnostic procedures and mother-baby separation. • Incidence of EOS in Greece is higher compared to other European countries.

A National Survey Across Primary Care Pediatricians Regarding Immunization Views and Practices in Children With Rheumatic Diseases

METHODS

Cross-sectional survey conducted with an anonymous questionnaire of 34 items distributed to pediatricians via an online platform. Four hundred questionnaires were sent, and 256 were returned and analyzed using STATA 13. Data collection included demographics, questions on knowledge, perceptions, and opinions, as well as advice given to families.

RESULTS

The majority of doctors felt that vaccination in children with RDs is essential. Responders were using a variety of guidelines to reach a clinical decision. Fifty percent were hesitant to adhere to the national vaccination scheme without expert input. Reasons were as follows: not convinced from current literature that the vaccine is safe (32%), afraid to cause disease flare (43%), and unable to deal with parental concerns/refusal (54%). Twelve percent of responders felt that the RD may have been triggered by a vaccine. The majority (82%) of doctors were pro annual influenza vaccination. Seventy percent of doctors were keener to administer booster doses rather than primary ones.

CONCLUSIONS

Variation in opinion and clinical practice exists. Overall, although general pediatricians are informed regarding efficacy and adverse effects of immunizations in patients with RDs, there are steps to be made from principle to practice. Vaccinating these children is of vital importance, and primary care pediatricians should be updated regarding existing guidelines referring to this field.

The impact of COVID-19 during pregnancy on maternal and neonatal outcomes: a systematic review

Several months after the onset of the epidemic, COVID-19 remains a global health issue. Scientific data on pregnancy, perinatal outcomes and vertical transmission of SARS-CoV-2 are constantly emerging but are still limited and unclear. The purpose of this systematic review was to summarize current evidence on vertical transmission rates, maternal, perinatal and neonatal outcomes and mode of delivery in pregnancies affected by COVID-19. An extensive search was conducted in PubMed, Google Scholar, Embase, and Scopus databases up to June 20, 2020. A total of 133 articles (51 case reports, 31 case series, 40 cohort studies and 2 case-control studies) reporting data from 8,092 subjects (6,046 pregnant women and 2,046 neonates) were considered eligible for inclusion in the systematic review. A substantial proportion of pregnant women with COVID-19 underwent caesarean section (case reports 82.2%, case series 74.2% and cohort studies 66.0%). Regarding vertical transmission, most neonates were tested negative (case reports 92.7%, case series studies 84.2%, cohort studies 97.1% and case control studies 100%). Maternal mortality rates ranged from 1% in cohort studies to 5.7% in case reports; neonatal mortality ranged from 2% in case reports to 3.3% in case series. Vertical transmission of SARS-CoV-2 from mother to child is rare. Careful screening of pregnant women seems important and specific guidelines with evidence-based decision algorithms for the mode of delivery in the context of a pregnancy affected by COVID-19 should be established.

COVID-19 features in children and adolescents: a systematic review and pooled analysis

The purpose of the present study was to evaluate special features and probable correlations between symptoms, laboratory findings, treatment, and outcomes of COVID-19 in children and adolescents, through a systematic review and pooled analysis. Following database (Pubmed, Google Scholar, Scopus and Embase) search, forty articles were considered eligible identifying a total of 2,971 confirmed pediatric COVID-19 patients. Fever was reported in 55.1% of the cases, while 28.4% were asymptomatic. Radiological signs of pneumonia were observed in more than half of the cases and in 40.7% of asymptomatic patients. Fever showed the highest sensitivity (sensitivity: 60.3%, specificity: 48.8%), followed by cough (sensitivity: 47.4%, specificity: 76.7%), rhinorrhea (sensitivity: 21.1%, specificity: 88.4%) and diarrhea (sensitivity: 10.3%, specificity: 88.4%), in differentiating cases with positive radiological signs for pneumonia. Compared to school age children, preschoolers (adjusted OR=6.01, 95%CI: 1.73-20.91) were more prone to pneumonia findings. Various combinations of treatments were used across studies, without following any strict guidelines. Most children (>90%) had full recovery and rarely presented complications. Fever seems to be the most frequent symptom in pediatric COVID-19, but pediatricians should additionally evaluate cough, rhinorrhea, and diarrhea as indicators of SARS-CoV-2 infection. Asymptomatic cases were common, but not the majority, and a significant percentage had developed radiologic findings of pneumonia. Thorough reassessment of treatment and management guidelines should be helpful.

Child Car Safety: A Parental Survey at a Tertiary Care Emergency Treatment Center in Greece

OBJECTIVES

This study aimed to assess parental behavior in terms of child restraint systems (CRS) use under emergency conditions while driving to the hospital's outpatient settings as well as their routine child car safety (CCS) practices.

METHODS

A cross-sectional survey of parents/caregivers transporting children 13 years or younger was conducted at the Emergency Treatment Center of a pediatric tertiary care center in Athens, Greece. Participants completed a questionnaire inquiring about the possession of CRS, and type and use of appropriate CRS while driving to the Emergency Treatment Center and under routine conditions. In addition, presence and type of parental education with regard to CCS and the use of seat belts among drivers were assessed.

RESULTS

Of 444 participants, 51.4% children were carried restrained, although 48.6% were fastened in an improper seat for their age, in contrast with 23.7% who travel unrestrained on a daily basis. Forward-facing restraint seats were most popular, with 53.9% total use even in children younger than 2 years or older than 4 years, whereas booster seats (9.4%) and rear-facing restraint seats (18.2%) were inappropriately disfavored. Children younger than 4 years, male drivers, and drivers who had received information on CCS had higher odds of using CRS. The proportion of those had never been provided any CCS education was 38.5%.

CONCLUSIONS

Child restraint systems use was inappropriately low under routine conditions and declined even further under emergency circumstances. Most children younger than 2 years and older than 4 years traveled inappropriately restrained in a forward-facing restraint seat. Parents should be more intensively educated on child car safety seat and the proper CRS use.

Diagnosis and Management of a Young Girl With Tumor Necrosis Factor Receptor Associated Periodic Syndrome (TRAPS) Linked to a Novel Mutation

A nine-year-old girl with a two-month history of fever and generalized malaise, along with intermittent abdominal pain, immigrant myalgia, throat pain, anorexia, and long-standing failure to thrive, was admitted to our department for further investigation and treatment. Detailed medical history revealed recurrent inflammation attacks from a very young age and a heavily burdened family history. Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) was highly suspected. Genetic screening was performed and several members of the family were found to be carriers of C73Y mutation in exon 3, which is a novel tumor necrosis factor superfamily receptor 1A (TNFRSF1A) mutation. The girl was treated with an interleukin-1β inhibitor, canakinumab, which induced immediate and complete remission of disease that interestingly lasted for a long period even after medication discontinuation.

Development and validation of a Paediatric Early Warning Score for use in the emergency department: a multicentre study

BACKGROUND

Paediatric Early Warning Scores (PEWSs) are being used increasingly in hospital wards to identify children at risk of clinical deterioration, but few scores exist that were designed for use in emergency care settings. To improve the prioritisation of children in the emergency department (ED), we developed and validated an ED-PEWS.

METHODS

The TrIAGE project is a prospective European observational study based on electronic health record data collected between Jan 1, 2012, and Nov 1, 2015, from five diverse EDs in four European countries (Netherlands, the UK, Austria, and Portugal). This study included data from all consecutive ED visits of children under age 16 years. The main outcome measure was a three-category reference standard (high, intermediate, low urgency) that was developed as part of the TrIAGE project as a proxy for true patient urgency. The ED-PEWS was developed based on an ordinal logistic regression model, with cross-validation by setting. After completing the study, we fully externally validated the ED-PEWS in an independent cohort of febrile children from a different ED (Greece).

FINDINGS

Of 119 209 children, 2007 (1·7%) were of high urgency and 29 127 (24·4%) of intermediate urgency, according to our reference standard. We developed an ED-PEWS consisting of age and the predictors heart rate, respiratory rate, oxygen saturation, consciousness, capillary refill time, and work of breathing. The ED-PEWS showed a cross-validated c-statistic of 0·86 (95% prediction interval 0·82-0·90) for high-urgency patients and 0·67 (0·61-0·73) for high-urgency or intermediate-urgency patients. A cutoff of score of at least 15 was useful for identifying high-urgency patients with a specificity of 0·90 (95% CI 0·87-0·92) while a cutoff score of less than 6 was useful for identifying low-urgency patients with a sensitivity of 0·83 (0·81-0·85).

INTERPRETATION

The proposed ED-PEWS can assist in identifying high-urgency and low-urgency patients in the ED, and improves prioritisation compared with existing PEWSs.

FUNDING

Stichting de Drie Lichten, Stichting Sophia Kinderziekenhuis Fonds, and the European Union's Horizon 2020 research and innovation programme.

Immunogenicity and side-effects of the inactivated hepatitis A vaccine in periodic fever, aphthous stomatitis, pharyngitis, and adenitis patients

The aim of this study was to compare the immunogenicity and side-effects of hepatitis A virus (HAV) vaccination between periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) patients and healthy controls who have not been previously exposed to HAV. A prospective observational study was carried out of 28 PFAPA patients and 76 controls who received two doses of the vaccine. Immunogenicity was expressed as seroconversion and seroprotection rates; mean HAV-immunoglobulin G concentration was measured at 0, 1, 7 and 18 months. Side-effects were defined as incidence of adverse events and the effect of vaccination on PFAPA symptoms. All participants were seronegative and seroconverted at 1 month. One month after primary vaccination, 92.9% of PFAPA patients and 77.6% of the controls attained seroprotection, while the rates increased to 100% and 96.1%, respectively, 1 month after the second dose. Seroprotection rates remained adequate 1 year after completion of vaccination. In conclusion, two doses of the inactivated HAV vaccine are well-tolerated and effective in children with PFAPA.

Immunogenicity and safety of the inactivated hepatitis A vaccine in children with juvenile idiopathic arthritis on methotrexate treatment: a matched case-control study

OBJECTIVES

To describe the immunogenicity and side effects of immunisation against hepatitis A virus (HAV) in JIA patients on methotrexate treatment, who have not been previously exposed to HAV.

METHODS

Case-control study performed in JIA patients and healthy controls matched on age and gender. The subjects received two doses of inactivated anti-HAV vaccine (720 mIU/ml) intramuscularly at 0 and 6 months. Seroconversion, seroprotection rates and anti-HAV-IgG titres were measured at 1, 7 and 18 months. Children were monitored for adverse events.

RESULTS

83 JIA patients and 76 controls were enrolled in the study. At one month, seroprotection rates were lower in children with, as compared to those without JIA (48.2% vs. 65%; p=0.05). At 7 and 18 months, rates of seroprotection rose significantly and were similar in both groups. The titre of anti-HAV-IgG was lower in children with JIA than healthy children at all time points (p<0.001). Vaccines were well tolerated.

CONCLUSIONS

Two doses of inactivated HAV vaccine were well tolerated and immunogenic in most immunosuppressed children with JIA; however, a single dose of HAV vaccine was insufficient to induce seroprotection in half of the patients. Further studies are required to analyse the long-term immunity against HAV in this population and optimal HAV immunisation regimen.

Characteristics of Bordetella pertussis infection among infantsand children admitted to paediatric intensive care units in Greece: A multicentre, 11-year study

AIM

To describe children with pertussis who required intensive care.

METHODS

This is a retrospective analysis of pertussis admissions to all (six) national intensive care units in Greece from 2003 to 2013.

RESULTS

A total of 31 children were included, 28 of whom were younger than 12 months old. Cough was the most prominent symptom, being present in 27 of 31 (87%) patients, and on admission, only 7 (22.6%) satisfied the case definition. Mechanical ventilation was initiated in 13 (42%) patients. Six patients died because of respiratory failure (two) or multi-organ system failure (four). The patients who died had significantly higher white blood cell counts (WBC) (77 800-31 600, P = 0.031) and neutrophils (29 016-12 795, P = 0021) than those who survived and lower minimum values of serum sodium (125-133, P = 0002). They also had a longer duration of hospitalisation prior to their paediatric intensive care unit admission (6-1 days, P = 0022). Three patients were diagnosed with pulmonary hypertension, and only one of them survived. Age, gender and immunisation status did not differ between survivors and non-survivors. Two patients received exchange blood transfusion, and survival benefit was not apparent.

CONCLUSION

Young infants are at risk of severe pertussis, resulting in serious complications or death. Elevated WBC and low serum sodium are associated with higher mortality. Despite advances in life support and treatment of organ failure in childhood critical illness, pertussis still has substantial mortality.

Pandemic influenza A vs seasonal influenza A in hospitalized children in Athens

BACKGROUND

Data on pandemic H1N1 influenza (pH1N1) virus infection in hospitalised children are limited.

AIMS AND OBJECTIVES

To examine the epidemiological and clinical characteristics of children hospitalised with pH1N1 at a large tertiary-care centre in Athens and compare them with those of children hospitalised with seasonal influenza A in previous years.

METHODS

All children (n = 146) admitted with confirmed pH1N1 between October 2009 to February 2010 and January 2011 to May 2011 were included. Data on children ≧ 6 months of age (n = 109) were compared with those of 138 children admitted with seasonal influenza A who were examined during two previous influenza seasons (2002-2003 and 2004-2005).

RESULTS

The age distribution was similar between seasonal and pandemic H1N1. Bronchial asthma was significantly more common in the seasonal influenza group but the clinical presentation was similar in the two groups, except that fever was more common in patients with pH1N1. Children admitted with seasonal influenza were more likely to develop acute otitis media. There were no significant differences between the two groups for severe outcomes (admission to the ICU, mechanical ventilation or death). Only one child with seasonal influenza (0.6%) and three with pH1N1 influenza (2%) required admission to the ICU. Mean length of hospitalisation was longer in the seasonal influenza group.

CONCLUSION

Clinical manifestations were similar between pH1N1 and seasonal influenza, and the pandemic virus did not appear to cause more severe disease in hospitalised children.

Detection of acquired hemoglobinopathy in children with hematological malignancies at disease onset: results form a national referral centre

Abnormal hemoglobin synthesis is usually inherited but may also arise as a secondary manifestation of a hematological neoplasia. The objective of this study is to identify the presence of acquired hemoglobinopathy in children diagnosed with hematological malignancies and compare these against healthy controls. Prospective matched case-control study held from 2010 to 2012. For each patient with hematological malignancy two healthy controls matched on gender, age and race were recruited. Patients with other co-morbidities were excluded. All samples underwent supravital staining and high-performance liquid chromatography (HPLC) electrophoresis. Following identification of abnormal results, molecular genetic testing for all α- and β-thalassemia mutations prevalent in the Greek population was performed. Other causes of anemia were ruled out based on specific testing. A total of 44 (32 males) patients with a mean age of 7.1 years were enrolled in the study. Hematological disorders included acute lymphocytic leukemia (24), acute myeloid leukemia (8), non-Hodgkin lymphoma (8), Hodgkin disease (3), and Langerhans cell histiocytosis (1). Following exclusion of congenital hemoglobinopathies, atypical HPLC electrophoretic findings persisted in 18.1 % of the patient group, compared to 0 % in the control group (p < 0.001). The patient group showed marked microcytic anemia (p < 0.01) and detection of small inclusions (p = 0.034) on supravital staining. Comparison of the HPLC findings between the groups demonstrated significantly lower percentages of HbA (p = 0.02), normal HbA2 and higher percentage of fast moving Hb bands (p = 0.04) in the patient group. Interestingly, the majority of these patients belonged to the high-risk group. Acquired hemoglobinopathy is recognized in adult patients. This is a novel study describing evidence of abnormal erythropoiesis in children with hematological malignancies and in particular those classified as high-risk cancer patients according to international criteria.

Time trends in pediatric hospitalizations for varicella infection are associated with climatic changes: a 22-year retrospective study in a tertiary Greek referral center

BACKGROUND/AIMS

The transmission rate of air-borne infectious diseases may vary secondary to climate conditions. The study assessed time trends in the seasonality of hospitalized varicella cases in a temperate region in relation to climatic parameters prior to the implementation of universal varicella immunization.

METHODS

A retrospective descriptive study was conducted among all pediatric and adolescent varicella patients (n = 2366) hospitalized at the "Aghia Sophia" Children's Hospital during 1982-2003 in Athens, Greece. Date of infection was computed based on hospital admission date. Seasonal and monthly trends in the epidemiology of varicella infection were assessed with time series analysis (ARIMA modeling procedure). The correlation between the frequency of varicella patients and the meteorological parameters was examined by the application of Generalized Linear Models with Gamma distribution.

RESULTS

During 1982-2003, the occurrence of hospitalized varicella cases increased during summer (p = 0.025) and decreased during autumn (p = 0.021), and particularly in September (p = 0.003). The frequency of hospitalized varicella cases was inversely associated with air temperature (p<0.001). In contrast, the occurrence of hospitalized varicella cases was positively associated with wind speed (p = 0.009).

CONCLUSIONS

Pediatric hospitalizations for varicella infection rates have increased during summer and decreased during autumn in the examined temperate region. Time trends in hospitalized varicella cases are associated with climatic variables.

The effect of age on whole blood interferon-gamma release assay response among children investigated for latent tuberculosis infection

OBJECTIVE

To evaluate the effect of age upon QuantiFERON-TB Gold-In-Tube (QFT-IT) assay outcome among children examined for latent tuberculosis infection (LTBI).

STUDY DESIGN

A cross-sectional study was conducted among 761 children (mean age ± SD: 7.84 ± 4.68 years) evaluated for LTBI. Participants were examined with both tuberculin skin test and QFT-IT (Cellestis, Australia) and categorized into 4 age groups. Multivariate logistic and linear regressions were used to evaluate the association between selected demographic and patient characteristics upon the qualitative and quantitative QFT-IT outcomes. Agreement between the tuberculin skin test and QFT-IT within groups was evaluated with the κ statistic.

RESULTS

QFT-IT indeterminate results occurred more frequently among young children (8.1%; P < .0001) and children (2.7%; P = .025) than adolescents (0.7%). Among QFT-IT positive patients, infants had higher mean (± SD) interferon-gamma (IFNγ) concentration than adolescents. QFT-IT positive (vs negative) outcome was associated with origin from a high tuberculosis endemicity setting (AOR = 4.54; 95% CI, 3.22-6.25) and lack of previous Bacille Calmette Guerin immunization (AOR = 2.70; 95% CI, 1.89-3.85), but not patient age (AOR = 0.96; 95% CI, 0.92-0.99). However, among QFT-IT positive patients, the IFNγ concentration was inversely associated with patient age (P = .009) and positively with mitogen response (P = .0002). Agreement between tests was not significantly different between younger and older children in the different risk groups.

CONCLUSIONS

Qualitative QFT-IT assay results are not affected by patient age. However, indeterminate results occur more frequently among younger children. Among patients with LTBI the quantitative QFT-IT result (ie, IFNγ) is inversely associated with patient age.

Vaccination coverage among adolescents and risk factors associated with incomplete immunization

The compliance with vaccination recommendations in adolescence has not been well documented in Greece. The aims of the present study were to estimate the vaccination coverage in a sample of adolescents and to identify risk factors associated with incomplete immunization. Α total of 1,005 adolescents aged 11 to 19 years who were outpatient visitors at an Adolescent Health Unit were included in this study. Participation required parental presence and consent and presentation of the official Child Health Booklet, from which immunizations were transcribed. The highest coverage rates were observed for childhood immunizations: poliomyelitis and hepatitis B (both 96%), measles/mumps/rubella (MMR; 93.1%), and meningitidis C (MenC; 83.4%). By contrast, lower rates were shown for the booster dose of tetanus/diphtheria/pertussis (39.6%), for hepatitis A (HAV; 59.1%), for the varicella vaccine (13.8% among adolescents without disease history), and among girls for the human papillomavirus vaccine (11.9%). We found a significant association between age and series completion for MMR, MenC, and HAV, with lower uptake among older adolescents . Overall, 22.7% of study participants were fully vaccinated according to criteria employed. In particular, non-urban residents, non-nationals, and females had lower likelihood of being fully vaccinated. In conclusion, our findings suggest suboptimal vaccination coverage among our sample's adolescents, mandating that every effort should be made to increase uptake, particularly among the geographically dispersed and the culturally diverse and female adolescents.

Investigation of serum bactericidal activity in childhood and adolescence 3-6 years after vaccination with a single dose of serogroup C meningococcal conjugate vaccine

Serogroup C meningococcal conjugate vaccines were introduced in Greece in 2001, and although no cases of serogroup C meningococcal disease were recorded in 2004, a steady increase was observed since 2005. In this study, serum bactericidal activity was assessed in sera of 269 vaccinated children at a mean time of about 5 years after vaccination. Non-protective antibody titers were observed in most children vaccinated at age <6 years (85.9%), followed by those between 6 and 10 years (62.2%). This percentage was considerably lower in adolescents vaccinated at an age >10 years (37.8%) (p<0.01). Geometric mean concentrations of serum IgG antibodies against serogroup C showed a similar variation. The results indicate that serum bactericidal antibody titers significantly correlate with age of vaccination; most children do not have protective antibody titers few years after immunization in infancy and childhood whereas most adolescents maintain sustained protection.

The effectiveness of a 9-month regimen of isoniazid alone versus 3- and 4-month regimens of isoniazid plus rifampin for treatment of latent tuberculosis infection in children: results of an 11-year randomized study

BACKGROUND

A 9-month course of isoniazid monotherapy is currently recommended for the treatment of latent tuberculosis infection (LTBI) and has been shown to be effective in both children and adults. Reduced compliance with this regimen has forced physicians to explore shorter regimens. The aim of this study was to compare 3- and 4-month combination regimens of isoniazid plus rifampin with a 9-month regimen of isoniazid monotherapy for the treatment of LTBI in children.

METHODS

This prospective, randomized, controlled study was conducted over an 11-year period (1995-2005). In period 1 (1995-1998), 232 patients received isoniazid therapy for 9 months (group A), and 238 patients received isoniazid and rifampin for 4 months (group B). In period 2 (1999-2002), 236 patients were treated with isoniazid and rifampin for 4 months (group C), and 220 patients received the same regimen for 3 months (group D). All patients were observed for > or = 3 years.

RESULTS

Overall compliance with treatment was good, but patients who received isoniazid monotherapy were less compliant than were those who received short-course combination therapy (P=.011, for group A vs. group B; P=.510, for group C vs. group D). No patient in any group developed clinical disease during the follow-up period. New radiographic findings suggestive of possible active disease were more common in patients who received isoniazid monotherapy (24%) than in those treated with shorter regimens (11.8%, 13.6%, and 11% for groups B, C, and D, respectively; P=.001 for group A vs. group B; P=.418 for group C vs. group D). Serious drug-related adverse effects were not detected.

CONCLUSIONS

Short-course treatment with isoniazid and rifampin for 3-4 months is safe and seems to be superior to a 9-month course of isoniazid monotherapy.

X-linked susceptibility to mycobacteria is caused by mutations in NEMO impairing CD40-dependent IL-12 production

Germline mutations in five autosomal genes involved in interleukin (IL)-12–dependent, interferon (IFN)-γ–mediated immunity cause Mendelian susceptibility to mycobacterial diseases (MSMD). The molecular basis of X-linked recessive (XR)–MSMD remains unknown. We report here mutations in the leucine zipper (LZ) domain of the NF-κB essential modulator (NEMO) gene in three unrelated kindreds with XR-MSMD. The mutant proteins were produced in normal amounts in blood and fibroblastic cells. However, the patients' monocytes presented an intrinsic defect in T cell–dependent IL-12 production, resulting in defective IFN-γ secretion by T cells. IL-12 production was also impaired as the result of a specific defect in NEMO- and NF-κB/c-Rel–mediated CD40 signaling after the stimulation of monocytes and dendritic cells by CD40L-expressing T cells and fibroblasts, respectively. However, the CD40-dependent up-regulation of costimulatory molecules of dendritic cells and the proliferation and immunoglobulin class switch of B cells were normal. Moreover, the patients' blood and fibroblastic cells responded to other NF-κB activators, such as tumor necrosis factor-α, IL-1β, and lipopolysaccharide. These two mutations in the NEMO LZ domain provide the first genetic etiology of XR-MSMD. They also demonstrate the importance of the T cell– and CD40L-triggered, CD40-, and NEMO/NF-κB/c-Rel–mediated induction of IL-12 by monocyte-derived cells for protective immunity to mycobacteria in humans.

Disseminated nontuberculous mycobacterial infection in a child with interferon-gamma receptor 1 deficiency

We describe the case of a 2-year-old boy with disseminated infection by a rapidly growing, poorly pathogenic mycobacterial species that belonged to the Mycobacterium fortuitum-Mycobacterium peregrinum complex. He had a severe course characterized by a poor response to treatment and recurrent lymph node abscess formation. Sequencing of the interferon-gamma receptor 1 gene (IFNgammaR1) revealed that he was homozygous for a novel null mutation, 453delT. Patients presenting with disseminated infections by rapidly growing environmental mycobacteria must be investigated for complete IFNgammaR1 deficiency. The spectrum of IFNgammaR1 genotypes associated with this immunological disorder is expanding.

Invasive meningococcal disease in children in Greece: comparison of serogroup A disease with disease caused by other serogroups

Although invasive meningococcal disease caused by serogroup A is not prevalent in developed countries, a considerable number of cases were recently recorded in Greece. In this study, serogroup A meningococcal disease was compared prospectively with meningococcal disease caused by other serogroups, using similar settings of testing and management during a 5-year period between 1999 and 2003. The Neisseria meningitidis serogroup was determined in 262 cases. Serogroup B predominated, accounting for 158 (60%) of the cases. Serogroup A was second most frequent (19%), followed by serogroups W135 (11%), C (8%), and Y (2%). No cases due to serogroup C were recorded during the last year of the study. Patients with serogroup A disease were older and had a milder course compared to patients infected with serogroups B or C. Toxic appearance, purpura, thrombocytopenia, abnormal coagulation tests, and the need for admission to the intensive care unit, fluid resuscitation, inotropic drugs, and mechanical ventilation were less common. Although morbidity and mortality were lower in these patients, the differences were not significant. Serogroup B is predominant in our area, and the introduction of an effective vaccine against it is a priority. Serogroup A has emerged as the second most common serogroup, but the illness associated with it is milder.

Impact of influenza infection in healthy children examined as outpatients and their families

Decisions regarding the introduction of influenza immunization in healthy children require an accurate evaluation of influenza disease burden not only in the inpatient but also in the outpatient setting. We prospectively examined the impact of virologically confirmed influenza in 1462 outpatient children (> or = 6 months to < 14 years) and their families, during two consecutive influenza seasons. Influenza was documented in 573/1462 (39%) outpatients with febrile respiratory illness and accounted for 13.5% of all outpatient visits during the 14 weeks of each season. Acute otitis media (AOM) was the most common complication (18.5%) and about 40% of influenza positive patients received antibiotics. AOM and antibiotic use were more common in children younger than 5 years of age who accounted for 58% of all patients. For each child sick with influenza a mean of 1.34 workdays were lost by the parents. Family members of influenza positive children were more likely to develop a secondary respiratory illness and to require medical visits and antibiotic prescriptions. Influenza is associated with a heavy morbidity burden in the community that may be reduced considerably with the implementation of immunization in children younger than 5 years of age.

Invasive meningococcal disease presenting as Henoch-Sch�nlein purpura

Henoch-Schonlein purpura (HSP) is an acute systemic form of vasculitis that has been associated with a number of viral and bacterial infections. Described here are the cases of two children with invasive meningococcal disease who presented with clinical and laboratory findings typical of HSP. Meningococcal infection may have been the trigger for the manifestation of HSP in these patients.

Does respiratory syncytial virus subtype influences the severity of acute bronchiolitis in hospitalized infants?

Respiratory syncytial virus (RSV) subtypes A and B are present either simultaneously or alternate during yearly epidemics. It is still not clear whether clinical severity of acute bronchiolitis differs between the two subtypes. Reverse transcription polymerase chain reaction was used to subtype RSV in previously healthy infants hospitalized with RSV bronchiolitis during a winter epidemic. A severity index based on heart rate, respiratory rate, wheezing, difficulty in feeding and oxygen saturation was calculated upon admission. Infants infected with RSV subtype-A were found to have a significantly higher (more severe) clinical score than those infected with RSV-B. There was no statistically significant difference in duration of hospitalization or need of intensive care. Boys and infants younger than 3 months of age were also more severely affected than girls or older infants, respectively. These results support the notion that RSV-A-induced bronchiolitis is more severe than RSV-B-induced one, in agreement with the majority of previously published studies.

Etiology of community-acquired pneumonia in hospitalized school-age children: evidence for high prevalence of viral infections

BACKGROUND

Community-acquired pneumonia (CAP) in young children is most commonly associated with viral infections; however, the role of viruses in CAP of school-age children is still inconclusive.

METHODS

Seventy-five school-age children hospitalized with CAP were prospectively evaluated for the presence of viral and bacterial pathogens. Nasopharyngeal washes were examined by polymerase chain reaction for viruses and atypical bacteria. Antibody assays to detect bacterial pathogens in acute-phase and convalescent-phase serum samples were also performed.

RESULTS

A viral infection was identified in 65% of cases. Rhinovirus RNA was detected in 45% of patients; infection with another virus occurred in 31%. The most common bacterial pathogen was Mycoplasma pneumoniae, which was diagnosed in 35% of cases. Chlamydia pneumoniae DNA was not detected in any patient; results of serological tests were positive in only 2 patients (3%). Mixed infections were documented in 35% of patients, and the majority were a viral-bacterial combination.

CONCLUSIONS

The high prevalence of viral and mixed viral-bacterial infections supports the notion that the presence of a virus, acting either as a direct or an indirect pathogen, may be the rule rather than the exception in the development of CAP in school-age children requiring hospitalization.

Epidemiology of respiratory syncytial virus bronchiolitis in hospitalized infants in Greece

New therapies have been introduced for the prophylaxis and treatment of respiratory syncytial virus (RSV) infection in recent years. The aim of the study was to determine the epidemiological and clinical characteristics of infants hospitalized with bronchiolitis in our area. All patients under 1 year of age admitted with acute bronchiolitis during four consecutive RSV seasons from February 1, 1997 to June 30, 2000 were enrolled in the study. The records of patients admitted during the first season were reviewed retrospectively while the rest were followed prospectively. A total of 636 infants with bronchiolitis were admitted and RSV infection was documented in 61% of those tested. Admission to intensive care unit (ICU) was required for 6.2% of them and was more common in premature infants (26%) (p < 0.001). Case fatality rate was 0.7% (overall 0.3%). RSV bronchiolitis accounted for about 12% of all infant admissions during the 5 months of the yearly outbreak. Patients with documented RSV infection had a more severe illness with a higher ICU admission rate (6 vs. 1%, p = 0.008) and longer duration of hospitalization (mean 6.3 vs. 5.3 days, p < 0.001) compared to those who tested negative. Although none of the patients had a positive blood culture on admission a considerable number of them (210/636, 33%) were treated with antibiotics. RSV infection has a significant impact on infant morbidity in our settings which is more serious among those born prematurely. Documentation of RSV infection may be a marker of more severe illness in infants hospitalized with bronchiolitis. Antibiotic use has to be restricted since the occurrence of a serious bacteraemic illness on admission is a very rare event.

The evolving epidemiology of invasive meningococcal disease: a two-year prospective, population-based study in children in the area of Athens

In response to an increase in the incidence in invasive meningococcal disease (IMD) due to Neisseria meningitidis, a system of hospital- and laboratory-based surveillance was used in a prospective epidemiological and clinical assessment of IMD in children 0-13 years of age hospitalized in the Athens area between 1 January 1999 and 31 December 2000. The annual incidence of laboratory-confirmed disease was 10.2/100,000. Serogroup B strains were predominant. There was a sharp decrease in serogroup C from 19% of cases in 1999 to 3% in 2000 (P=0.013). Of note was the emergence of serogroup A responsible for 7% of the cases. The overall case fatality rate was 4.5%, but 2.8% for microbiologically confirmed cases. A remarkable decrease in disease severity assessed by admissions to intensive care units was noted during the second study year. Polymerase chain reaction-based methods for detection of meningococcal DNA were the sole positive laboratory test in 45% of the cases and the only test on which serogroup determination was based in 52% of groupable cases. The epidemiological and clinical profile of meningococcal disease appears to be rapidly evolving and close monitoring is required particularly for input into decisions regarding use of meningococcal vaccines.

Genetic relatedness of resistant and multiresistant Streptococcus pneumoniae strains, recovered in the Athens area, to international clones

The prevalence of resistance to antibiotics was examined among 318 Streptococcus pneumoniae strains isolated during 1998 and 1999 in a children's hospital in Athens. The rate of resistance to penicillin was 25.8% (intermediate 22%, resistant 3.8%); 42.5% of the strains were resistant to > or = 1 antibiotic and 20% were multidrug resistant. Resistance to penicillin was lowest in invasive strains (8.3%) and highest in ear isolates (31%). A review of the same microbiology laboratory's records revealed that there has been a gradual increase in penicillin resistance since 1988-1989, when it was 5%. Capsular types were determined for 77 strains resistant to > or = 1 antibiotic, and 69 (90%) of them belonged to the following five serotypes: 19F, 14, 9V, 23F, and 6B. Seventy-five strains were analyzed by pulsed-field gel electrophoresis (PFGE) and 59/75 (79%) shared five electrophoretic types. The largest cluster consisted of 19 serotype 19F strains, of which 18 were nonsusceptible to penicillin and most were multidrug resistant and shared a common and distinct electrophoretic pattern not resembling any known clone. A group of 17 strains that were nonsusceptible to penicillin belonged to serotypes 9V (10), 14 (6), and 19F (1) and shared a common PFGE type similar to the international clone Spain9V-3. Seven serotype 23F strains, of which five were multidrug resistant, belonged to the international clone Spain23F-1. Among the strains susceptible to penicillin but resistant to non-beta-lactam antibiotics, the largest cluster consisted of 13 isolates resistant to erythromycin that belonged to serotype 14 and shared an electrophoretic pattern characteristic of the clone England14-9. Finally, three serotype 6B strains were penicillin susceptible and multidrug resistant and had features similar to the Mediterranean 6B clone. The introduction and spread of several antibiotic-resistant international clones accounts at least in part for the increase in pneumococcal resistance observed in recent years in the Athens metropolitan area.

Epidemiology of invasive Haemophilus influenzae type b infections among children in Greece before the introduction of immunization

We prospectively examined the epidemiology of invasive Haemophilus influenzae type b (Hib) infections among children under 5 y of age in the Greater Athens area before the introduction of immunization. The annual incidence of systemic Hib infections was 12/100000. Meningitis was the most common clinical entity and accounted for 69% of the cases. In the prevaccine era, the incidence of systemic Hib disease, particularly that of meningitis, was much lower in Greece compared to rates reported from Northern and Central Europe.