Impaired antibody memory to varicella zoster virus in HIV-infected children: low antibody levels and avidity*

OBJECTIVE

HIV-infected children have impaired antibody responses after exposure to certain antigens. Our aim was to determine whether HIV-infected children had lower varicella zoster virus (VZV) antibody levels compared with HIV-infected adults or healthy children and, if so, whether this was attributable to an impaired primary response, accelerated antibody loss, or failure to reactivate the memory VZV response.

METHODS

In a prospective, cross-sectional and retrospective longitudinal study, we compared antibody responses, measured by enzyme-linked immunosorbent assay (ELISA), elicited by VZV infection in 97 HIV-infected children and 78 HIV-infected adults treated with antiretroviral therapy, followed over 10 years, and 97 age-matched healthy children. We also tested antibody avidity in HIV-infected and healthy children.

RESULTS

Median anti-VZV immunoglobulin G (IgG) levels were lower in HIV-infected children than in adults (264 vs. 1535 IU/L; P<0.001) and levels became more frequently unprotective over time in the children [odds ratio (OR) 17.74; 95% confidence interval (CI) 4.36-72.25; P<0.001]. High HIV viral load was predictive of VZV antibody waning in HIV-infected children. Anti-VZV antibodies did not decline more rapidly in HIV-infected children than in adults. Antibody levels increased with age in healthy (P=0.004) but not in HIV-infected children. Thus, antibody levels were lower in HIV-infected than in healthy children (median 1151 IU/L; P<0.001). Antibody avidity was lower in HIV-infected than healthy children (P<0.001). A direct correlation between anti-VZV IgG level and avidity was present in HIV-infected children (P=0.001), but not in healthy children.

CONCLUSION

Failure to maintain anti-VZV IgG levels in HIV-infected children results from failure to reactivate memory responses. Further studies are required to investigate long-term protection and the potential benefits of immunization.

Molecular epidemiology of the nasal colonization by methicillin-susceptible Staphylococcus aureus in Swiss children

Nasal carriage of Staphylococcus aureus contributes to an increased risk of developing an infection with the same bacterial strain. Genetic regulatory elements and toxin-expressing genes are virulence factors associated with the pathogenic potential of S. aureus. We undertook an extensive molecular characterization of methicillin-susceptible S. aureus (MSSA) carried by children. MSSA were recovered from the nostrils of children. The presence of Panton-Valentine leukocidin (PVL), exfoliatins A and B (exfoA and exfoB), and the toxic-shock staphylococcal toxin (TSST-1) and agr group typing were determined by quantitative PCR. A multiple-locus variable-number of tandem repeat analysis (MLVA) assay was also performed for genotyping. Five hundred and seventy-two strains of MSSA were analysed. Overall, 30% were positive for toxin-expressing genes: 29% contained one toxin and 1.6% two toxins. The most commonly detected toxin gene was tst, which was present in 145 (25%) strains. The TSST-1 gene was significantly associated with the agr group 3 (OR 56.8, 95% CI 32.0-100.8). MLVA analysis revealed a large diversity of genetic content and no clonal relationship was demonstrated among the analysed MSSA strains. Multilocus sequence typing confirmed this observation of diversity and identified ST45 as a frequent colonizer. This broad diversity in MSSA carriage strains suggests a limited selection pressure in our geographical area.

H-ficolin serum concentration and susceptibility to fever and neutropenia in paediatric cancer patients

H-ficolin (Hakata antigen, ficolin-3) activates the lectin pathway of complement similar to mannose-binding lectin. However, its impact on susceptibility to infection is currently unknown. This study investigated whether the serum concentration of H-ficolin at diagnosis is associated with fever and neutropenia (FN) in paediatric cancer patients. H-ficolin was measured by time-resolved immunofluorometric assay in serum taken at cancer diagnosis from 94 children treated with chemotherapy. The association of FN episodes with H-ficolin serum concentration was analysed by multivariate Poisson regression. Median concentration of H-ficolin in serum was 26 mg/l (range 6-83). Seven (7%) children had low H-ficolin (< 14 mg/l). During a cumulative chemotherapy exposure time of 82 years, 177 FN episodes were recorded, 35 (20%) of them with bacteraemia. Children with low H-ficolin had a significantly increased risk to develop FN [relative risk (RR) 2.24; 95% confidence interval (CI) 1.38-3.65; P = 0.004], resulting in prolonged duration of hospitalization and of intravenous anti-microbial therapy. Bacteraemia occurred more frequently in children with low H-ficolin (RR 2.82; CI 1.02-7.76; P = 0.045). In conclusion, low concentration of H-ficolin was associated with an increased risk of FN, particularly FN with bacteraemia, in children treated with chemotherapy for cancer. Low H-ficolin thus represents a novel risk factor for chemotherapy-related infections.

Establishing glycaemic control with continuous subcutaneous insulin infusion in children and adolescents with type 1 diabetes: experience of the PedPump Study in 17 countries

AIMS/HYPOTHESIS

To assess the use of paediatric continuous subcutaneous infusion (CSII) under real-life conditions by analysing data recorded for up to 90 days and relating them to outcome.

METHODS

Pump programming data from patients aged 0-18 years treated with CSII in 30 centres from 16 European countries and Israel were recorded during routine clinical visits. HbA(1c) was measured centrally.

RESULTS

A total of 1,041 patients (age: 11.8 +/- 4.2 years; diabetes duration: 6.0 +/- 3.6 years; average CSII duration: 2.0 +/- 1.3 years; HbA(1c): 8.0 +/- 1.3% [means +/- SD]) participated. Glycaemic control was better in preschool (n = 142; 7.5 +/- 0.9%) and pre-adolescent (6-11 years, n = 321; 7.7 +/- 1.0%) children than in adolescent patients (12-18 years, n = 578; 8.3 +/- 1.4%). There was a significant negative correlation between HbA(1c) and daily bolus number, but not between HbA(1c) and total daily insulin dose. The use of <6.7 daily boluses was a significant predictor of an HbA(1c) level >7.5%. The incidence of severe hypoglycaemia and ketoacidosis was 6.63 and 6.26 events per 100 patient-years, respectively.

CONCLUSIONS/INTERPRETATION

This large paediatric survey of CSII shows that glycaemic targets can be frequently achieved, particularly in young children, and the incidence of acute complications is low. Adequate substitution of basal and prandial insulin is associated with a better HbA(1c).

Swiss recommendations for the management of varicella zoster virus infections

Infections with varicella zoster virus (VZV) are common viral infections associated with significant morbidity. Diagnosis and management are complex, particularly in immunocompromised patients and during pregnancy. The present recommendations have been established by a multidisciplinary panel of specialists and endorsed by numerous Swiss medical societies involved in the medical care of such patients (Appendix). The aim was to improve the care of affected patients and to reduce complications.

Serum levels of mannose-binding lectin and the risk of fever in neutropenia pediatric cancer patients

BACKGROUND

Fever in neutropenia (FN) is a frequent complication in pediatric oncology. Deficiency of mannose-binding lectin (MBL), an important component of innate immunity, is common due to genetic polymorphisms, but its impact on infections in oncologic patients is controversial. This study investigated whether MBL serum levels at cancer diagnosis are associated with the development of FN in pediatric cancer patients.

PROCEDURE

Serum MBL was measured using ELISA. Frequency, duration, and cause of FN were assessed retrospectively. Association with MBL level was analyzed using uni- and multivariate Poisson regression taking into account both intensity and duration of chemotherapy.

RESULTS

In 94 children, with a cumulative follow-up time of 81.7 years, 177 FN episodes were recorded. Patients with both very low MBL levels (<100 microg/L; risk ratio (RR), 1.93; 95% CI, 1.14-3.28; P = 0.014) and normal MBL levels (>or=1,000 microg/L; RR, P = 0.011) had significantly more frequent FN episodes than patients with low MBL levels (100-999 microg/L). Patients with very low MBL levels had significantly more episodes of FN with severe bacterial infection (bacteremia or pneumonia; RR, 4.49; 1.69 = 11.8; P = 0.003), while those with normal MBL levels had more FN episodes with no microbial etiology identified (RR, 1.85; 1.14 = 3.03; P = 0.014).

CONCLUSIONS

Very low MBL levels are associated with more frequent FN episodes, mainly due to severe bacterial infections. The surprising finding that children with normal MBL levels had more frequent FN episodes than those with low MBL levels needs testing in prospective studies.

[Lymphadenopathy and absences]

A 6-year-old boy presented with deterioration of general well-being during several weeks, headache and swelling of lymph nodes in the neck. In addition, the parents reported brief episodes resembling typical absence seizures. Serological tests and the examination of cerebrospinal fluid revealed neuroborreliosis. At the same time, electroencephalography showed characteristic patterns of absence epilepsy. The boy's condition improved rapidly during a 2-week course of intravenous ceftriaxone and after initiation of antiepileptic therapy. To our knowledge, absence epilepsy has not previously been reported in association with neuroborreliosis. We consider the two conditions to be coincidental.

Swiss recommendations for the management of varicella zoster virus infections

Infections with varicella zoster virus (VZV) are common viral infections associated with significant morbidity. Diagnosis and management are complex, particularly in immunocompromised patients and during pregnancy. The present recommendations have been established by a multidisciplinary panel of specialists and endorsed by numerous Swiss medical societies involved in the medical care of such patients (Appendix). The aim was to improve the care of affected patients and to reduce complications.

The prevalence of penicillin-non-susceptible Streptococcus pneumoniae among children aged < 5 years correlates with the biannual epidemic activity of respiratory syncytial virus

This study investigated whether the epidemiology of penicillin-non-susceptible pneumococci (PNSP) colonising small children correlated with the biannual epidemic activity of respiratory syncytial virus (RSV). Colonisation rates and the prevalence of PNSP among paediatric outpatients aged < 5 years was analysed between January 1998 and September 2003 using an established national surveillance network. Resistance trends were investigated using time-series analysis to assess the correlation with the biannual pattern of RSV infections and national sales of oral paediatric formulations of antibiotics and antibiotic prescriptions to children aged < 5 years for acute respiratory tract infections. PNSP rates exhibited a biannual cycle in phase with the biannual seasonal RSV epidemics (p < 0.05). Resistance rates were higher during the winter seasons of 1998-1999 (20.1%), 2000-2001 (16.0%) and 2002-2003 (19.1%), compared with the winter seasons of 1997-1998 (8.2%), 1999-2000 (11.6%) and 2001-2002 (9.5%). Antibiotic sales and prescriptions showed regular peaks during each winter, with no significant correlation with the biannual pattern of RSV activity and seasonal trends of PNSP. RSV is an important determinant of the spread of PNSP and must be considered in strategies aimed at antimicrobial resistance control.

Prävention der Frühsommer-Meningoenzephalitis (FSME)

Die aktive Immunisierung ist die einzige verfügbare Maßnahme, die zuverlässigen Schutz gegen die FSME vermittelt. Der Impfschutz dürfte bei über 95% liegen, FSME-Fälle bei korrekt Geimpften kommen aber vor. Neue Studien zeigen, dass die Dauer des Impfschutzes nach vollständiger Grundimmunisierung länger ist als bisher angenommen, und dass die meisten Personen ≥ 8 Jahre nach der letzten Dosis noch seropositiv sind. Die gültige Praxis von Auffrischimpfungen in Abständen von 3 Jahren ist deshalb Gegenstand aktueller Diskussionen. Bis zur Veröffentlichung neuer Empfehlungen kann, wenn vom Patienten gewünscht, als Alternative zur Auffrischimpfung eine FSME-IgG Titerbestimmung in Erwägung gezogen werden. Es wurde gezeigt, dass der Antikörpernachweis mit bestimmten kommerziellen ELISA Tests sehr gut mit dem Vorhandensein schützender Antikörper korreliert. Die FSME-Impfung ist in der Schweiz für alle Personen im Alter von über 6 Jahren empfohlen, die sich häufig in Zeckenbiotopen der bekannten FSME-Endemiegebiete aufhalten. Die Kosten der Impfung werden in dieser Indikation seit 2005 von den Krankenversicherern im Rahmen der obligatorischen Grundversicherung übernommen.

[Exanthema as a main symptom in the febrile child]

Distinguishing in febrile children between harmless rashes and those, which require specific action, is a common problem in pediatric primary care. Major exanthematous diseases necessitating emergency hospitalization include invasive meningococcal disease and rarely gram-negative septicaemia caused by other pathogens, staphylococcal and streptococcal toxic shock syndrome, endocarditis, fever and rash in travellers returning from tropical countries and drug hypersensitivity syndrome. Therapeutic intervention is also necessary in patients with scarlet fever, rheumatic fever, varicella in postpuberal and immunocompromised individuals, in Kawasaki's disease, in Still's disease and in other non-infectious, inflammatory diseases (e.g., familial mediterranean fever). Finally, various specific measures need to be taken in reportable diseases, erythema infectiosum (parvovirus B19), primary HIV infection and in Henoch-Schölein purpura.

Orbitale Komplikationen der pädiatrischen Rhinosinusitis: Konservative versus chirurgische Therapie und Analyse der Computertomografie

BACKGROUND

One of the most common complications of acute pediatric rhinosinusitis is orbital complication. For subperiosteal abscess, in particular, there are no generally accepted therapy recommendations.

PATIENTS

A retrospective study of 45 children with acute orbital rhinosinusitis complications, treated on an in-patient basis at the Department of ENT, Inselspital, University of Bern (1999-2004) is presented. The aim was to analyze conservative medical versus surgical treatment with regard to the individual stages of complications (according to the classification of Moloney, 1987) and, subsequently, to arrive at a therapy recommendation.

RESULTS

All children with preseptal cellulitis (stage I), 80 % of children with radiological a subperiosteal phlegmona (Stage IIA) and 67 % of the children with radiological a subperiosteal abscess (Stage IIB) could be treated conservatively. The child with the orbital cellulitis (Stage III) was treated surgically.

CONCLUSION

The preseptal cellulitis can be treated conservatively. We recommend an initial conservative therapy of 24 - 48 hours for subperiosteal phlegmona and subperiosteal abscess in the presence of normal vision. Surgical intervention should take place only if there is no improvement after this time interval. The orbital cellulitis should be treated primary surgically.

Frontotemporal dementia, semantic dementia, and Alzheimer's disease: the contribution of standard neuropsychological tests to differential diagnosis

CERAD-NAB (Consortium to Establish a Registry for Alzheimer's Disease-Neuropsychological Assessment Battery) data were compared between 51 patients with frontotemporal dementia, 13 with semantic dementia, and 69 with Alzheimer's disease. There were statistically significant differences between the 3 groups. Compared with patients with Alzheimer's disease, patients with frontotemporal dementia were more impaired on Animal Fluency but not on any other CERAD-NAB subtest. Patients with semantic dementia performed worse in Animal Fluency and Boston Naming Test compared with frontotemporal dementia and Alzheimer's disease. Multiple logistic regression analysis revealed that in the differentiation between frontotemporal dementia and Alzheimer's disease, the combination of Animal Fluency and Boston Naming Test correctly classified 90.5% of patients. In segregating semantic dementia and Alzheimer's disease, the combination of Boston Naming Test and Mini Mental State Examination resulted in a correct classification of 96.3%. These findings demonstrate that the Mini Mental State Examination and the language subtests of the CERAD-NAB are valuable clinical instruments for the differential diagnosis between early frontotemporal dementia, semantic dementia, and Alzheimer's disease.

Low incidence of respiratory syncytial virus hospitalisations in haemodynamically significant congenital heart disease

BACKGROUND

Haemodynamically significant congenital heart disease (CHD) is a risk factor for severe respiratory syncytial virus (RSV) disease in young children. Population based data on the incidence of RSV hospitalisations in CHD patients are needed to estimate the potential usefulness of RSV immunoprophylaxis using palivizumab.

AIMS

(1) To obtain population based RSV hospitalisation rates in children <24 months of age with CHD. (2) To compare these rates with non-CHD patients and with previous studies. (3) To determine the number of patients needed to treat (NNT) with palivizumab to prevent one RSV hospitalisation.

METHODS

Six year, longitudinal, population based study at an institution, which is the sole provider of primary to tertiary in-patient care for a precisely defined paediatric population.

RESULTS

RSV hospitalisation rates (per 100 child-years) in CHD patients aged <6, <12, 12-24, and <24 months of age were 2.5 (95% CI 0.8 to 5.6), 2.0 (0.8 to 3.8), 0.5 (0.1 to 1.8), and 1.3 (0.6 to 2.3), respectively, and the relative risk (RR) in comparison with non-CHD patients was 1.4 (0.6 to 3.1), 1.6 (0.8 to 3.2), 2.7 (0.7 to 9.7), and 1.8 (1.0 to 3.3), respectively. NNT was between 80 (35 to 245) and 259 (72 to 2140) for various age groups.

CONCLUSION

RSV hospitalisation rates in CHD patients were fourfold lower than reported from the USA. Based on these low rates and RR, unrestricted use of palivizumab does not appear to be justified in this study area.

Influenza-associated myositis in children

BACKGROUND

Influenza-associated myositis (IAM) is an infrequent and poorly known complication of influenza virus infection in children. The aim of this study was to describe five cases of IAM and to review the literature on IAM in children.

PATIENTS AND METHODS

We conducted a retrospective analysis of cases of IAM diagnosed at two university children's hospitals in Switzerland during two consecutive influenza seasons. Findings were compared with 39 individual case reports and five publications summarizing an additional 272 cases identified by a medical online library (MEDLINE) search.

RESULTS

Overall, 316 cases were analyzed. IAM typically occurred in school-aged children with a 2:1 male predominance. Influenza B and A viruses were identified in 76% and 24% of cases, respectively. The median interval between onset of influenza and onset of IAM was 3 days (range 0-18). The calf muscles were involved alone or together with other muscle groups in 69% and 31% of cases, respectively. Blood creatine phosphokinase (CPK) concentration was invariably elevated. Median duration to clinical recovery was 3 days (range 1-30). Rhabdomyolysis occurred in ten of 316 patients (3%), was more common in girls (80%), more often associated with influenza A (86%), and led to renal failure in eight patients (80%).

CONCLUSION

Clinical and laboratory findings of IAM are highly characteristic and allow a rapid diagnosis during the influenza season.