Two-year periodicity of respiratory syncytial virus epidemics in Switzerland

BACKGROUND

The annual respiratory syncytial virus (RSV) epidemics vary in time and severity. The aims of this study were (1) to describe the time-related pattern of RSV epidemics in Switzerland and (2) to deduce the most effective time period for administration of prophylactic measures to high-risk patients.

PATIENTS AND METHODS

Descriptive study of (1) RSV hospitalizations between 1997 and 2001 at a pediatric hospital serving a population of 1 million and (2) of national RSV detection rates reported by diagnostic laboratories between 1988 and 1999.

RESULTS

497 RSV hospitalizations and 8,574 reported RSV detections occurring during four and 12 epidemics, respectively, were analyzed. There was fixed alternation of minor and major epidemics differing in the number of RSV infections (two to fourfold), evolution (median interval from onset to peak 13 weeks, range 4-13 weeks vs 8 weeks, range 7-10 weeks; p = 0.065) and median duration (26 weeks, range 24-29 weeks vs 19.5 weeks, range 18-21 weeks; p = 0.005). For minor epidemics it was estimated that a maximum of 85.6% (range, 79.4-86.6%) of annual RSV infections could be covered by a standard five-dose regimen of the monoclonal anti-RSV antibody palivizumab, if initiated in week 50. During major epidemics the most effective time of initiation would be week 43 (88.7%; range 81.9-94.6%).

CONCLUSION

RSV epidemiology in Switzerland is characterized by fixed biannual variation. In the absence of active RSV surveillance, such periodicity is useful for scheduling RSV prophylaxis and for hospital resources management.

[Update on childhood immunization in Switzerland]

The recommendations for routine childhood immunizations undergo continuous re-evaluation and are periodically amended. As a result of the near complete elimination of wild-type poliomyelitis, the oral poliomyelitis live vaccine (OPV) has been replaced by the inactivated vaccine (IPV) for the primary series in infancy. Recent seroepidemiologic data on the dynamics of decay of maternal measles antibodies in infants may lead to the recommendation of administering the first dose of the measles mumps rubella (MMR) vaccine at twelve months rather than at 15 to 23 months of age. The recently introduced hexavalent vaccines for the primary series in infancy provide immunization against hepatitis B without the need for additional injections. Finally, the introduction of pneumococcal conjugate vaccines, which are highly efficacious in infants and young children, will provide the opportunity for successful prevention of vaccine-type invasive pneumococcal infections.

[Antimicrobial resistance--consequences for ambulatory treatment of infections in children]

Increasing antimicrobial resistance among clinical isolates of Streptococcus pneumoniae calls for a revision of treatment strategies for pediatric infections, particularly for acute otitis media. Restrictive use of antimicrobials is the key strategy for slowing the spread of resistances. Before initiation of antimicrobial therapy, suspected bacterial infections should be confirmed clinically (e.g. by observation of the natural evolution) or microbiologically. For acute otitis media, oral amoxicillin remains the drug of choice because of superior middle ear pharmacokinetics and pharmacodynamics. Treatment failure caused by resistance of the infecting pneumococcus can be overcome be increasing the dose, and not by switching to another class of antibiotics (e.g., cephalosporin, macrolide, cotrimoxazole), which is less likely to achieve middle ear eradication a priori. Widespread macrolide resistance among isolates of S. pneumoniae precludes the use of this class of antimicrobials for empiric therapy of community-acquired pneumonia in children. Aminopenicillins are preferred because of their rapidly bactericidal activity against the most common organisms causing potentially progressive pneumonia in children.

Growth in human immunodeficiency virus type 1-infected children treated with protease inhibitors

To determine the long-term impact of antiretroviral treatment (ART) including a protease inhibitor (PI) on growth in children infected with the human immunodeficiency virus type I (HIV-1), a prospective multi-centre study was conducted in Switzerland on HIV-1-infected children treated with ritonavir (350 mg/m2 twice a day) or nelfinavir (20-30 mg/kg three times a day) in addition to two nucleoside reverse transcriptase inhibitors. Length or height of HlV-1-infected children from before (weeks -72, -48, -24, and 0) and after (weeks +24, +48, and +72) introducing a PI to the ART were compared. To allow for age- and gender-independent assessment, values were expressed in standard deviations from the mean. Complete data sets on body length were available for 44 children after 72 weeks of treatment with a PI. Preceding initiation of a PI, there was an overall decline in growth to -0.3 SD. Following start of a PI, an increase in growth was noted from weeks 0 to +24 (+0.33 SD, P=0.02) and from weeks +48 to +72 (+0.21 SD, P=0.03). The increase in growth was restricted to children with stunting before a PI was introduced (P=0.03), and was more marked in children younger than 3 years of age.

CONCLUSION

children infected with human immunodeficiency virus type 1 showed catch-up growth after addition of a protease inhibitor to their antiretroviral treatment, but this phenomenon was observed almost exclusively in children under 3 years of age.

Febrile seizures and parental anxiety: does information help?

AIM OF THE STUDY

To investigate the effect of febrile seizures on the behaviour and emotional situation of parents in order to improve our attitude towards these children and parents in future.

METHODS

We analysed 135 questionnaires on parents' behaviour and emotional situation during and after a febrile seizure in their children.

RESULTS

Febrile seizures were unknown to 44% of the parents. 121 parents (91%) reported severe anxiety on witnessing the first febrile seizure. In 69% the anxiety was so strong, that the parents believed their child would die. Severe anxiety was significantly associated with lack of knowledge about febrile seizures: 79% (no knowledge of febrile seizures) versus 59% (with knowledge). The level of anxiety appeared to be associated with low educational level, but not with ethnic background or income.

CONCLUSIONS

Our study shows that knowledge of febrile seizures among concerned parents in our region remains insufficient. The results are ambiguous. On the one hand we found an association between severe anxiety and lack of knowledge on febrile seizures, suggesting that information prior to the first febrile seizure might reduce the anxiety level and thus lead to appropriate reactions in case of recurrence. On the other hand although parents knew about febrile seizures, they still had very high anxiety levels and would react inappropriately in case of recurrence. Therefore if information is provided to parents, it must be specific, especially about which measures are to be taken or avoided respectively. A prospective study to observe positive and negative effects of preventive information is needed.

Febrile seizures and parental anxiety: does information help?

AIM OF THE STUDY

To investigate the effect of febrile seizures on the behaviour and emotional situation of parents in order to improve our attitude towards these children and parents in future.

METHODS

We analysed 135 questionnaires on parents' behaviour and emotional situation during and after a febrile seizure in their children.

RESULTS

Febrile seizures were unknown to 44% of the parents. 121 parents (91%) reported severe anxiety on witnessing the first febrile seizure. In 69% the anxiety was so strong, that the parents believed their child would die. Severe anxiety was significantly associated with lack of knowledge about febrile seizures: 79% (no knowledge of febrile seizures) versus 59% (with knowledge). The level of anxiety appeared to be associated with low educational level, but not with ethnic background or income.

CONCLUSIONS

Our study shows that knowledge of febrile seizures among concerned parents in our region remains insufficient. The results are ambiguous. On the one hand we found an association between severe anxiety and lack of knowledge on febrile seizures, suggesting that information prior to the first febrile seizure might reduce the anxiety level and thus lead to appropriate reactions in case of recurrence. On the other hand although parents knew about febrile seizures, they still had very high anxiety levels and would react inappropriately in case of recurrence. Therefore if information is provided to parents, it must be specific, especially about which measures are to be taken or avoided respectively. A prospective study to observe positive and negative effects of preventive information is needed.

Early detection of lung disease and its association with the nutritional status, genetic background and life events in patients with cystic fibrosis

Progression of lung disease is the most prominent cause of morbidity and death in patients with cystic fibrosis (CF), but the severity of lung disease and the rate of lung function decline are highly variable. An attempt was made to define accurate estimates of disease progression in these patients early diagnosed and prospectively evaluated until 10 years of age. The primary question to ask was whether functional abnormalities detected already in infancy are associated with functional derangements later on in life, and may be useful as parameters of prognostic value. Early diagnosis of CF can best be achieved by screening of mutation by new techniques (buccal cell brushing) in infants, even when the sweat test or accurate blood sampling is not available. Moreover, in infants lung function can be assessed by infant whole-body plethysmography enabling the study of the interrelationship with delayed weight gain and growth retardation, as well as the associations with the most common disease-causing mutations. Out of a cohort of 80 infants (39 males, 41 females) with CF a follow-up study was started with 50 CF infants diagnosed during infancy (mean age 4.6 +/- 4.0 months; range 0.1-12.7 months) and prospectively evaluated at 6-month intervals during the first 2 years of life. Moreover, in 32 CF children out of this cohort, follow-up was continued until 10 years of age. Differences were encountered with respect to the different events occurring during the first years of life, especially the onset of chronic colonization with Pseudomonas aeruginosa. The association between infant lung function and specific mutations (DeltaF508 homozygotes, frameshift DeltaF508/3905insT compound heterozygotes and nonsense DeltaF508/R553X compound heterozygotes) furthermore revealed that differences in lung function within the genetic groups are mainly related to the degree of pulmonary hyperinflation. Pulmonary hyperinflation was also associated with the degree of impaired nutritional status. An association between impaired gas exchange characteristics at 10 years of age and the degree of pulmonary hyperinflation during infancy finally demonstrates that by early mutation screening, lung function testing and assessment of the nutritional status predictors of disease progression later on in life can be defined. Therefore, preventive therapeutic measures should primarily be based on such prognostic factors.

Age-specific seroprevalence to varicella-zoster virus: study in Swiss children and analysis of European data

Up to date epidemiological data provide the rationale for potential varicella immunization strategies in Europe. The scope of this study was: (1) to generate new seroprevalence data by evaluating sera of 970 individuals aged 0-16 years for the presence of IgG against Varicella-zoster virus (VZV); and (2) to review existing seroprevalence data. Of 256 individuals >12 years of age, 96.1% (95% confidence interval [CI], 93.7-98.5) were seropositive. Swiss citizens > 12 years of age were less likely to be seronegative than foreign citizens (2.3 vs. 15.4%; odds ratio, 0.17; CI, 0.05-0.58). The age-specific seroprevalence curve demonstrated a peak at 7 years of age (84.9%; CI, 75.2-94.5) followed by lower rates at 8 and 9 years. A peak at 7-10 years of age was found in all previously reported seroprevalence curves (chi(2)-test for trend of pooled data, P = 0.09; Poisson analysis, P < 0.001). It is concluded that: (1) > 90% of individuals in Europe acquire immunity against VZV before adolescence; (2) there is no evidence for a recent upward shift of the age at primary varicella; and (3) there may be a north-to-south gradient of seroprevalence. The peak at 7-10 years may represent a transient loss of detectable antibody by some individuals.

Regional impact of prophylaxis with the monoclonal antibody palivizumab on hospitalisations for respiratory syncytial virus in infants

QUESTIONS

Palivizumab is approved in Switzerland for prevention of hospitalisation for RSV infection in children with one of the following risk factors: (1) history of prematurity < or = 35 weeks and age < or = 6 months or (2) chronic lung disease and age < or = 1 year. Regional data on the expected effectiveness of this monoclonal antibody are not available.

METHODS

(1) Retrospective, descriptive, single-site study on the characteristics of RSV hospitalisations during two consecutive seasons. (2) Extrapolation of data to generate population-based estimates on the impact of palivizumb if used according to the approved indications.

RESULTS

Of 242 RSV hospitalisations, 216 (89.3%) and 26 (10.7%) occurred in children without and with risk factors, respectively. Patients without and with risk factors had similar clinical courses with respect to ICU admission rate (11.6 vs. 11.5%) and rate of mechanical ventilation (3.2 vs. 3.8%). Of a total of 28 ICU admissions, 13 (46%) occurred among infants aged < or = 1 month without risk factors. Former premature infants were significantly older than patients with longer gestation (median age 7.5 vs. 3.7 months, p = 0.026). Applying the approved age criteria would have excluded 10 of 26 patients (38.5%) from eligibility for palivizumab. During the 1999/2000 RSV season, 36% of hospitalisations occurred after April 1, 2000. None of them may have been preventable had prophylaxis been started before November 1, 1999 and carried out for 5 months as recommended. In an annual birth cohort of 10,000, palivizumab as indicated would be expected to prevent between 5 and 7 RSV hospitalisations.

CONCLUSIONS

The impact of palivizumab on the prevention of RSV hospitalisations in the Canton of Bern, Switerland, is expected to be small, and the approved indications may not target infants at greatest risk for severe disease.

Regional impact of prophylaxis with the monoclonal antibody palivizumab on hospitalisations for respiratory syncytial virus in infants

QUESTIONS

Palivizumab is approved in Switzerland for prevention of hospitalisation for RSV infection in children with one of the following risk factors: (1) history of prematurity < or = 35 weeks and age < or = 6 months or (2) chronic lung disease and age < or = 1 year. Regional data on the expected effectiveness of this monoclonal antibody are not available.

METHODS

(1) Retrospective, descriptive, single-site study on the characteristics of RSV hospitalisations during two consecutive seasons. (2) Extrapolation of data to generate population-based estimates on the impact of palivizumb if used according to the approved indications.

RESULTS

Of 242 RSV hospitalisations, 216 (89.3%) and 26 (10.7%) occurred in children without and with risk factors, respectively. Patients without and with risk factors had similar clinical courses with respect to ICU admission rate (11.6 vs. 11.5%) and rate of mechanical ventilation (3.2 vs. 3.8%). Of a total of 28 ICU admissions, 13 (46%) occurred among infants aged < or = 1 month without risk factors. Former premature infants were significantly older than patients with longer gestation (median age 7.5 vs. 3.7 months, p = 0.026). Applying the approved age criteria would have excluded 10 of 26 patients (38.5%) from eligibility for palivizumab. During the 1999/2000 RSV season, 36% of hospitalisations occurred after April 1, 2000. None of them may have been preventable had prophylaxis been started before November 1, 1999 and carried out for 5 months as recommended. In an annual birth cohort of 10,000, palivizumab as indicated would be expected to prevent between 5 and 7 RSV hospitalisations.

CONCLUSIONS

The impact of palivizumab on the prevention of RSV hospitalisations in the Canton of Bern, Switerland, is expected to be small, and the approved indications may not target infants at greatest risk for severe disease.

Myopericarditis associated with central European tick-borne encephalitis

The case of an 11-year-old child with acute myopericarditis associated with central European tick-borne encephalitis is presented. Cardiac involvement was demonstrated by pericardial effusion, elevated serum concentration of troponin-I and cardiac arrhythmia. Co-infections with enteroviruses, Borrelia burgdorferi or the agent of human granulocytic ehrlichiosis were excluded. Recovery was uneventful.

CONCLUSION

Central European tick-borne encephalitis can be complicated by cardiac involvement.

Staphylococcus aureus septicaemia in a patient with cystic fibrosis

Although bacterial colonisation of bronchi may occur from early childhood onwards, infections extending beyond the lungs are uncommon in patients with cystic fibrosis. A 12-year-old boy with cystic fibrosis, receiving oral corticosteroids for 3 weeks because of allergic bronchopulmonary aspergillosis, experienced pneumonia and septicaemia caused by Staphylococcus aureus. He was treated with flucloxacillin, ticarcillin-clavulanate, aztreonam, cefazolin and rifampin according to resistance testing of S. aureus cultured from the blood. On day 25 the patient finally had recovered.

CONCLUSION

Systemic steroid therapy for allergic bronchopulmonary aspergillosis may favour life-threatening systemic bacterial infection which is rare in the immunocompetent patient with cystic fibrosis.

Long-term responses to treatment including ritonavir or nelfinavir in HIV-1-infected children. Pediatric AIDS Group of Switzerland

BACKGROUND

Knowledge concerning the long-term antiretroviral and immunological efficacy of protease inhibitors in children is limited.

PATIENTS AND METHODS

An open-label, prospective, multicenter clinical trial was conducted over a period of 72 weeks in Switzerland. 60 HIV-1 infected children (aged 0.3-16.9 years) naive to protease inhibitors were enrolled. Ritonavir or nelfinavir and at least one new nucleoside reverse transcriptase inhibitor were introduced into the current treatment regimen. HIV-1 RNA levels and CD4 cell counts were monitored after introducing the protease inhibitor, and the tolerability and safety of the drugs were assessed.

RESULTS

Dictated by chronological availability, 37 children received ritonavir and 23 nelfinavir. At baseline, children given ritonavir had higher mean plasma HIV-1 RNA levels (5.03 vs 4.63 log10 copies/ml; p = 0.001) and lower mean CD4 cell counts (277 vs 555 cells/microl; p = 0.009) than children given nelfinavir. Antiretroviral treatment (ART) naive children showed higher mean plasma HIV-1 RNA levels than non-naive (5.18 vs 4.64 log10 copies/ml; p = 0.02). The decline in plasma HIV-1 RNA levels 72 weeks after treatment with ritonavir and nelfinavir was -2.17 and -1.30 log10 copies/ml, respectively (p = 0.006) and in ART-naive vs non-naive patients -2.70 vs -1.39 log10 copies/ml (p < or = 0.01). 69% of ART-naive patients and 32% of non-naive patients achieved sustained plasma HIV-1 RNA levels < 400 copies/ml. Increases in CD4 cells were higher in ART-naive compared to non-naive patients (p < 0.04).

CONCLUSION

The antiretroviral and immunologic benefits of protease inhibitors are more profound in ART-naive than in non-naive children.

Diagnosis by polymerase chain reaction of pneumonia caused by Legionella pneumophila in an immunocompetent child

A 10-year-old, previously healthy child with pneumonia caused by Legionella pneumophila diagnosed by polymerase chain reaction (PCR) of serum is presented. Diagnostic methods were PCR of serum using two different primer sets, and the detection of specific antibody in paired sera using an indirect immunofluorescence assay. Legionella DNA was amplified from serum obtained before and on day 6, but not after completion of a 14-day course of oral clarithromycin. The etiologic role of L. pneumophila was confirmed by seroconversion. The report illustrates that L. pneumophila PCR of serum may contribute to the identification of this microorganism as a cause of severe pneumonia in immunocompetent children.

Acute community-acquired diarrhea requiring hospital admission in Swiss children

In order to ascertain the prevalence of agents that cause childhood diarrheal illness, stool specimens of 312 consecutive children with community-acquired diarrhea requiring admission were evaluated. Pathogens were detected in 166 (53%) of the 312 children (>/=2 pathogens in 28 children): Rotavirus (n=75), Salmonella spp. (n=37), Campylobacter spp. (n=24), Shigella spp. (n=5), Giardia spp. (n=4), Yersinia spp. (n=2), Aeromonas spp. (n=15), Cryptosporidium (n=15), enteropathogenic Escherichia coli (n=13), enterotoxigenic E. coli (n=7), and enterohemorrhagic E. coli (n=5). In conclusion, acute childhood diarrheal illness pathogens, such as Aeromonas, Cryptosporidium, and diarrheagenic E. coli, account for a large proportion of patients with a microbiologically positive stool specimen.

The UspA1 protein and a second type of UspA2 protein mediate adherence of Moraxella catarrhalis to human epithelial cells in vitro

The UspA1 and UspA2 proteins of Moraxella catarrhalis are structurally related, are exposed on the bacterial cell surface, and migrate as very high-molecular-weight complexes in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Previous analysis of uspA1 and uspA2 mutants of M. catarrhalis strain 035E indicated that UspA1 was involved in adherence of this organism to Chang conjunctival epithelial cells in vitro and that expression of UspA2 was essential for resistance of this strain to killing by normal human serum (C. Aebi, E. R. Lafontaine, L. D. Cope, J. L. Latimer, S. R. Lumbley, G. H. McCracken, Jr., and E. J. Hansen, Infect. Immun. 66:3113-3119, 1998). In the present study, isogenic uspA1, uspA2, and uspA1 uspA2 mutations were constructed in three additional M. catarrhalis strains: 012E, TTA37, and 046E. The uspA1 mutant of strain 012E had a decreased ability to attach to Chang cells. However, inactivation of the uspA1 gene in both strain TTA37 and strain 046E did not cause a significant decrease in attachment ability. Inactivation of the uspA2 gene of strain TTA37 did result in a loss of attachment ability. Nucleotide sequence analysis revealed that the predicted protein encoded by the uspA2 genes of both strains TTA37 and 046E had a N-terminal half that resembled the N-terminal half of UspA1 proteins, whereas the C-terminal half of this protein was nearly identical to those of previously characterized UspA2 proteins. The gene encoding this "hybrid" protein was designated uspA2H. PCR-based analysis revealed that approximately 20% of M. catarrhalis strains apparently possess a uspA2H gene instead of a uspA2 gene. The M. catarrhalis uspA1, uspA2, and uspA2H genes were cloned and expressed in Haemophilus influenzae cells, which were used to prove that both the UspA1 and UspA2H proteins can function as adhesins in vitro.

Autoantibodies directed against bactericidal/permeability-increasing protein in patients with cystic fibrosis: association with microbial respiratory tract colonization

BACKGROUND

Cystic fibrosis (CF) is associated with the appearance of serum autoantibodies directed against bactericidal/permeability-increasing protein (BPI).

OBJECTIVES

To determine the age-specific seroprevalence rates of anti-BPI-IgG and IgA in a population of patients with CF and to correlate anti-BPI antibody concentrations with microbial respiratory tract colonization and pulmonary function variables at the time of serum sampling and 6 years thereafter.

METHODS

Determination of BPI antibodies of the IgG and IgA isotypes using a commercial enzyme-linked immunosorbent assay in sera of a CF serum bank of 1992; correlation of anti-BPI antibody concentrations with age, clinical score, pulmonary function variables in 1992 and 1998, total serum immunoglobulin isotype concentrations and respiratory tract colonization with Pseudomonas aeruginosa and Aspergillus spp.

RESULTS

Seventy-one patients (age in 1992, 14.1 +/- 7.5 years) were studied. Reactivities for anti-BPI-IgG and IgA were found in 28 (39%) and 26 (37%) patients, respectively. The seroprevalence of anti-BPI-IgA, but not IgG, increased significantly with age. P. aeruginosa colonization was associated with elevated concentrations of anti-BPI-IgG (P = 0.003) and IgA (P = 0.037). There were significant negative correlations between pulmonary function variables (vital capacity, forced expiratory volume in 1 s) in 1992 and 1998, respectively, and concentrations of anti-BPI-IgG or IgA in a multiple regression analysis. Anti-BPI-IgG, but not IgA, remained significantly associated with P. aeruginosa colonization (P = 0.006) and with reduced vital capacity (P = 0.01) in 1998 after correction for total serum isotype concentration.

CONCLUSIONS

Anti-BPI-IgG are strongly associated with concurrent P. aeruginosa colonization and with long term restrictive pulmonary function abnormalities.

Outbreak among drug users caused by a clonal strain of group A streptococcus

We describe an outbreak among drug users of severe soft-tissue infections caused by a clonal strain of group A streptococcus of M-type 25. Cases (n = 19) in drug users were defined as infections (mainly needle abscesses) due to the outbreak strain. Comparison with controls showed that infected drug users bought drugs more often at a specific place. Drug purchase and use habits may have contributed to this outbreak.

[Infections in pregnancy]

Infections in pregnancy may complicate its course and harm the fetus or newborn after vertical transmission. Treatment of asymptomatic bacteriuria is mandatory in pregnant women given the high risk of secondary pyelonephritis. Intraamniotic infection usually arises by the ascending route and is associated with premature rupture of membranes. Vaginal infections promote preterm labour or premature rupture of membranes and may be transmitted to the child during labour. They must therefore be treated although they often cause little discomfort to the pregnant woman. Systemic infections due to viral, protozoal and bacterial pathogens may be transmitted transplacentally and cause embryopathies, fetopathies or neonatal infections. Depending on the responsible agent the negative impact on the course of pregnancy and on the fetus' or neonate's health can be prevented or reduced by prophylactic or therapeutic interventions.

Characterization of the Moraxella catarrhalis uspA1 and uspA2 genes and their encoded products

The uspA1 and uspA2 genes of M. catarrhalis O35E encode two different surface-exposed proteins which were previously shown to share a 140-amino-acid region with 93% identity (C. Aebi, I. Maciver, J. L. Latimer, L. D. Cope, M. K. Stevens, S. E. Thomas, G. H. McCracken, Jr., and E. J. Hansen, Infect. Immun. 65:4367-4377, 1997). The N-terminal amino acid sequences of the mature forms of both UspA1 and UspA2 from strain O35E were determined after enzymatic treatment to remove the N-terminal pyroglutamyl residue that had blocked Edman degradation. Mass spectrometric analysis indicated that the molecular mass of UspA1 from M. catarrhalis O35E was 83,500 +/- 116 Da. Nucleotide sequence analysis of the uspA1 and uspA2 genes from three other M. catarrhalis strains (TTA24, ATCC 25238, and V1171) revealed that the encoded protein products were very similar to those from strain O35E. Western blot analysis was used to confirm that each of these three strains of M. catarrhalis expressed both UspA1 and UspA2 proteins. Several different and repetitive amino acid motifs were present in both UspA1 and UspA2 from these four strains, and some of these were predicted to form coiled coils. Linear DNA templates were used in an in vitro transcription-translation system to determine the sizes of the monomeric forms of the UspA1 and UspA2 proteins from strains O35E and TTA24.

Complications of varicella in a defined central European population

AIMS

To describe complications of varicella requiring hospitalisation in a defined population (canton of Bern) and to compare the hospitalisation rates for varicella with published data.

METHODS

Retrospective analysis of hospital records of patients less than 16 years of age admitted with complications of varicella to the hospitals serving this population (University Children's Hospital of Bern and the Wildermeth Children's Hospital of Biel, Switzerland), and calculation of hospitalisation rates for varicella and its complications based on birth rates and varicella antibody prevalence rates.

RESULTS

From 1986 to 1996, 113 cases (median age, 5.6 years) were identified. Younger siblings were overrepresented (odds ratio (OR), 1.42; 95% confidence interval (CI), 1.09 to 1.84). Central nervous system (CNS) complications (26 patients; 23%) were found predominantly in previously healthy children (relative risk, 7.1; 95% CI, 1.01 to 49.86). Group A beta haemolytic streptococci were recovered from only one of 35 patients with bacterial complications. The hospitalisation rates for primary varicella (9.2/10(4) cases; 95% CI, 7.4 to 11/10(4), skin infections (2.0/10(4) cases; 95% CI, 1.2 to 2.9/10(4), and pneumonia (0.8/10(4) cases; 95% CI, 0.3 to 1.3/10(4)) were significantly lower than reported previously. The CNS complication rate (2.2/10(4) cases; 95% CI, 1.3 to 3.1/10(4) was among the highest rates reported.

CONCLUSIONS

The low hospitalisation rate in comparison with studies from elsewhere indicates that there is a large regional variability in complications associated with varicella. Such data should be taken into consideration when local varicella immunisation strategies are developed.