Can the booster interval for the tick-borne encephalitis (TBE) vaccine 'FSME-IMMUN' be prolonged? - A systematic review

Tick-borne encephalitis (TBE) vaccines are effective and well tolerated. However, their acceptance and use by the public in endemic areas are suboptimal. To some extent this is due to the complicated dosing schedule requiring frequent boosters at variable intervals that even change with age. Simplification of the dosing schedule has failed so far as it is debated if the persistence of TBE virus (TBEV) antibodies is the only relevant factor for protection or if immune memory plays a decisive role as well. The objective here is to present the available evidence to determine the need for boosters and their interval after a primary series of three doses of FSME-IMMUN. A systematic literature review was conducted with a focus on serology, particularly seropersistence, immune memory, effectiveness, and vaccine breakthroughs (VB) of FSME-IMMUN. While after a 3-dose primary series seropositivity persisted for more than 10 years in >90% of younger subjects, it dropped to 37.5% in those 60 years or older. In contrast, field effectiveness of FSME-IMMUN remains high in irregularly vaccinated subjects and thus does not correlate well with the percentage of subjects achieving an arbitrarily defined threshold of persisting antibodies. FSME-IMMUN booster doses led to increases in antibody responses within 7 days. VB are rare and remain poorly understood. VB did not increase, and vaccine effectiveness did not significantly decrease with time since completion of the primary vaccination series or with the time since administration of the last vaccine dose. For all these reasons, data identified from this systematic review suggest that seropersistence alone does not explain the high effectiveness of FSME-IMMUN irrespective of the time since the last vaccine dose was administered. Induction of immunological memory characterized by a rapid and sustained secondary immune response is proving to be an alternative mechanism of action for protection against TBE. In this context Switzerland and Finland have adopted a longer booster interval (i.e., 10 years) following the three-dose primary immunization schedule without any evidence of harm at a population level. Longer booster intervals will likely drive up vaccine uptake. There is a lack of data to base an interval recommendation beyond 10 years.

Seropersistence and booster response following vaccination with FSME-IMMUN in children, adolescents, and young adults

BACKGROUND

Tick-borne encephalitis (TBE) is a viral disease that can have a severe clinical course and considerable long-term morbidity. As no curative treatment exists, vaccination is the primary means of prevention. Long-term antibody seropersistence 2-5 years after the 3-dose primary immunization and 3-10 years after first booster was evaluated, as well as booster responses in children, adolescents and young adults.

METHODS

Subjects who participated in these phase 4 prospective, open-label follow-up studies received all vaccinations with FSME-IMMUN. After 3-dose primary immunization, subjects were followed for 2-5 years. Overall, 205 out of 358 subjects (57%) received the first booster and 179 of these subjects (87%) enrolled in a further 10-year follow-up. Antibody seropersistence was assessed annually. Subjects with a TBE antibody titer below a pre-specified cut-off at the yearly blood draw received a booster. Seropositivity rates and geometric mean fold rises (GMFRs) were assessed.

RESULTS

In children who received their 3-dose primary immunization between 1 and 15 years of age, the seropositivity rate 5 years after the 3rd dose was 84.9% by NT and 72.0% by ELISA. One month post-first booster, all subjects were seropositive by NT and 98.5% by ELISA. Response to first booster by GMFR ranged from 3.7 to 11.4. At 5 years post-first booster, seropositivity was 99.4% by NT and 97.5% by ELISA, and at 10 years, was 90.3% by NT and 87.7% by ELISA. Although seropositivity rates differed between age groups, all subjects (100%) who received a second booster responded with a robust increase of TBEV antibodies.

DISCUSSION

Long-lasting seropersistence of TBEV antibodies after the 3-dose primary immunization and first booster was demonstrated as well as a competent immune memory response in those who received a first or second booster at any time during the 15-year follow-up. Therefore, an extension of FSME-IMMUN booster interval up to 10 years after the 3-dose primary immunization seems warranted. ClinicalTrials.gov Identifier: NCT00894686.

Etomidate activates epileptic high frequency oscillations

OBJECTIVE

The short acting anesthetic etomidate has been shown to provoke epileptic spikes and rarely seizures. Influence of etomidate on the occurrence of epileptic HFO (high frequency oscillations) however is unknown. An HFO inducing effect of etomidate would allow further validation of the substance as a provocation measure in presurgical evaluation as well as provide insights into the common mechanisms of HFO, spike and seizure generation.

METHODS

We retrospectively analyzed EEG data from four patients who underwent etomidate activation during invasive video-EEG monitoring with subdural strip electrodes. Spikes were manually selected in raw data, HFO in band pass filtered data (80-250Hz). Rate and spatial distribution of HFO and spikes in three segments were compared: immediately after etomidate administration, as well as during slow wave sleep and while awake.

RESULTS

Rates of HFO and spikes increased significantly after etomidate administration: Overall average rates of spikes were 9.7/min during sleep, 10/min while awake and 61.4/min after etomidate. Average HFO rates were 9.5/min during sleep, 8.3/min while awake and 24.4/min after etomidate (p<0.001, non-parametric ANOVA). Spatial distributions of HFO and spikes after administration of etomidate were consistent with the seizure onset zone (SOZ) and area of resection when available (SOZ: two patients; resection: one patient; no information: one patient). Except for spurious events, no additional HFO and spike foci were seen with activation.

CONCLUSIONS

Etomidate administration activates spikes and HFO. Spatial distributions do not extend beyond electrodes showing spikes and HFO without Etomidate and seem consistent with the epileptic network.

SIGNIFICANCE

Etomidate activation is a safe procedure to provoke not only epileptic spikes but also HFO, which were shown to have a high specificity for the SOZ.

Pediatric disease burden and vaccination recommendations: understanding local differences

BACKGROUND

Diphtheria (D), tetanus (T), pertussis (P), hepatitis B (HepB), invasive Haemophilus influenzae type b (Hib) disease, and measles cause substantial global morbidity and mortality.

METHODS

This unique review highlights geographic differences in disease burden across certain countries in the African, Americas, Mediterranean, South-East Asian, and Western Pacific World Health Organization (WHO) regions, and relates this to vaccination coverage and local vaccine recommendations using the authors' countries as illustrations.

RESULTS

Substantial differences were observed in the incidence of these diseases and in vaccination coverage between the countries studied. Disease incidence often reflected inadequate surveillance, but also variable or poor vaccination coverage. Vaccination coverage against HepB was particularly low in the African and South-East Asian WHO regions; vaccination coverage against invasive Hib disease was low in these regions and in the Eastern Mediterranean and Western Pacific WHO regions. Vaccination schedules within some countries in these regions do not include, or have only recently included, vaccinations against HepB and Hib disease. The use of DTwP-HepB-Hib (diphtheria, tetanus, whole-cell pertussis, HepB, Hib) combination vaccines has now been adopted by some countries to help increase vaccination coverage.

CONCLUSIONS

Vaccination coverage and vaccination schedules vary markedly between the countries studied, often according to the resources available. DTwP-HepB-Hib combination vaccines represent a cost-effective option, with the potential to substantially reduce the burden associated with these diseases by increasing coverage and compliance.

Anesthesia in patients with neuromuscular disorders

Neuromuscular disorders (NMDs) are a heterogeneous group of neurological and muscular diseases. Patients present with typical features such as wasting and weakness of skeletal muscles. However, despite these common clinical signs, underlying etiologies are nearly as multifaceted as the number of the diseases. For the anesthesiologist, it is very important to know the origin of a particular disease to select an appropriate anesthetic technique. Patients with NMDs are markedly sensitive to several anesthetics. Many reported anesthesia-related complications were caused by the administration of drugs like depolarizing and non-depolarizing muscle relaxants, volatile anesthetics, or respiratory and cardiovascular depressant agents.

Vaccination greatly reduces disease, disability, death and inequity worldwide

In low-income countries, infectious diseases still account for a large proportion of deaths, highlighting health inequities largely caused by economic differences. Vaccination can cut health-care costs and reduce these inequities. Disease control, elimination or eradication can save billions of US dollars for communities and countries. Vaccines have lowered the incidence of hepatocellular carcinoma and will control cervical cancer. Travellers can be protected against "exotic" diseases by appropriate vaccination. Vaccines are considered indispensable against bioterrorism. They can combat resistance to antibiotics in some pathogens. Noncommunicable diseases, such as ischaemic heart disease, could also be reduced by influenza vaccination. Immunization programmes have improved the primary care infrastructure in developing countries, lowered mortality in childhood and empowered women to better plan their families, with consequent health, social and economic benefits. Vaccination helps economic growth everywhere, because of lower morbidity and mortality. The annual return on investment in vaccination has been calculated to be between 12% and 18%. Vaccination leads to increased life expectancy. Long healthy lives are now recognized as a prerequisite for wealth, and wealth promotes health. Vaccines are thus efficient tools to reduce disparities in wealth and inequities in health.

Vaccination greatly reduces disease, disability, death and inequity worldwide

In low-income countries, infectious diseases still account for a large proportion of deaths, highlighting health inequities largely caused by economic differences. Vaccination can cut health-care costs and reduce these inequities. Disease control, elimination or eradication can save billions of US dollars for communities and countries. Vaccines have lowered the incidence of hepatocellular carcinoma and will control cervical cancer. Travellers can be protected against "exotic" diseases by appropriate vaccination. Vaccines are considered indispensable against bioterrorism. They can combat resistance to antibiotics in some pathogens. Noncommunicable diseases, such as ischaemic heart disease, could also be reduced by influenza vaccination. Immunization programmes have improved the primary care infrastructure in developing countries, lowered mortality in childhood and empowered women to better plan their families, with consequent health, social and economic benefits. Vaccination helps economic growth everywhere, because of lower morbidity and mortality. The annual return on investment in vaccination has been calculated to be between 12% and 18%. Vaccination leads to increased life expectancy. Long healthy lives are now recognized as a prerequisite for wealth, and wealth promotes health. Vaccines are thus efficient tools to reduce disparities in wealth and inequities in health.

Varicella vaccination in Europe: are we ready for a universal childhood programme?

Safe and effective vaccines against varicella zoster virus (VZV), the aetiological agent of varicella and shingles, have been available in Europe for the last 5-10 years. The USA has had a universal childhood vaccination policy since 1995 and this has resulted in a dramatic decrease in the incidence, morbidity and mortality related to varicella. The economic and medical burden of VZV has led to discussions regarding both the desirability and feasibility of a similar routine immunisation policy for all European children. This article examines the epidemiology of varicella in Europe and how the data emerging from the USA can be used to achieve adequate prevention of the disease. It looks into the current evidence of the health economic evaluation of universal varicella vaccination and explores the concerns surrounding such a policy, including the postulated impact on the incidence of zoster. In conclusion, the Society of Independent European Vaccination Experts (SIEVE) recommends that the immunisation of susceptible adolescents needs to be urgently implemented, in addition to the current recommendations targeting high-risk patients, their close contacts with a negative history of varicella and seronegative health-care workers. A universal policy, optimally incorporating a two-dose schedule, will be needed to finally reduce the burden of disease of varicella from a societal point of view. The SIEVE recommends the implementation of such a policy as soon as financially and practically possible.

How to optimise the coverage rate of infant and adult immunisations in Europe

BACKGROUND

Although vaccination has been proved to be a safe, efficacious, and cost-effective intervention, immunisation rates remain suboptimal in many European countries, resulting in poor control of many vaccine-preventable diseases.

DISCUSSION

The Summit of Independent European Vaccination Experts focused on the perception of vaccines and vaccination by the general public and healthcare professionals and discussed ways to improve vaccine uptake in Europe. Despite the substantial impact and importance of the media, healthcare professionals were identified as the main advocates for vaccination and the most important source of information about vaccines for the general public. Healthcare professionals should receive more support for their own education on vaccinology, have rapid access to up-to-date information on vaccines, and have easy access to consultation with experts regarding vaccination-related problems. Vaccine information systems should be set up to facilitate promotion of vaccination.

SUMMARY

Every opportunity to administer vaccines should be used, and active reminder systems should be set up. A European vaccine awareness week should be established.

Immunogenicity, reactogenicity, and immune memory after primary vaccination with a novel Haemophilus influenzae-Neisseria meningitidis serogroup C conjugate vaccine

We evaluated two formulations of a new combined Haemophilus influenzae type b (Hib)-meningococcal serogroup C (MenC)-tetanus toxoid (TT) conjugated vaccine and two formulations of a new MenC-TT vaccine (trials 711202/001 and 711202/008; clinical trial register numbers NCT00135486 and NCT00135564 [www.ClinicalTrials.gov]). A total of 520 healthy infants were randomized to receive primary vaccination (at 2, 3, and 4 months) with either MenC-TT plus diphtheria-tetanus-acellular pertussis (DTPa)-hepatitis B virus (HBV)-inactivated poliovirus (IPV)/Hib, Hib-MenC-TT plus DTPa-HBV-IPV, or MenC-CRM(197) plus DTPa-HBV-IPV/Hib (control). At 12 to 15 months, subjects received a polysaccharide challenge with meningococcal polysaccharide C plus a DTPa-HBV-IPV/Hib booster. Immune responses were assessed 1 month after dose 2, 1 month after dose 3, and prior to and 1 month after the booster. After primary vaccination, there was no difference between groups in seroprotection rates as measured by titers of serum bactericidal antibody (SBA) to MenC (> or = 1:8) or concentrations of anti-polyribosyl ribitol phosphate (PRP) antibody (> or = 0.15 microg/ml). Prior to the booster, there was no difference between groups in SBA seroprotection rates, whereas anti-PRP seroprotection rates were significantly higher after priming with Hib-MenC-TT. Booster doses induced large increases in SBA and anti-PRP antibodies in primed groups, indicating successful priming with induction of immune memory. Reactogenicity and safety were similar in all groups during the primary and booster phases. A novel combined Hib-MenC-TT conjugate vaccine induced MenC and Hib responses comparable to those induced by licensed monovalent vaccines. A Hib-MenC-TT conjugate vaccine provides vaccination against two major pathogens in a single injection and is a suitable candidate for use in primary or booster vaccination schedules.

Assessment of nine candidate DTP-vaccines with reduced amount of antigen and/or without adjuvant as a fourth (booster-) dose in the second year of life

BACKGROUND

The incidence of local reactions to diphtheria-, tetanus and acellular pertussis (DTaP-) vaccines in infants and toddlers increases with each subsequent dose, and entire thigh swellings (ETS) have been reported. Lowering the amount of antigen or of adjuvant may decrease the reactogenicity of DTaP while maintaining a protective immune response.

OBJECTIVES

Following priming with three doses of a DTaP vaccine during infancy, the safety, reactogenicity and immunogenicity of nine different candidate DTaP-vaccines with reduced amounts of antigen and/or adjuvant given as fourth (booster) dose were evaluated.

METHODS

Study participants were healthy infants aged 15-27 months at the time of booster vaccination. Each participant had received three doses of a DTaP vaccine (Infanrixtrade mark, GlaxoSmithKline, Rixensart, Belgium; "reference DTaP") at age 3, 4, and 5 months as part of a previous clinical trial. More than 20,000 children were eligible for participation in the current study protocol at the time. In a first phase at a University hospital-based vaccination study center, nine sequential cohorts of 63-119 study subjects received one of nine different candidate vaccines. Patients and study personal were blinded with regard to which vaccine was currently in use. Reactogenicity was solicited from parents using diary cards. Blood was drawn prior to and 4 weeks after vaccination and immediately centrifuged. The serum was stored at -20 degrees C until serology was performed by ELISA tests. As soon as the first candidate vaccine with adequate reactogenicity and immunogenicity profile was identified in the first study phase, a second study phase was initiated in parallel, to evaluate the safety and reactogenicity of the respective candidate vaccine in private practices in large cohorts (1613-2095 study subjects per group).

RESULTS

In the first study phase, DTaP with no aluminum induced the highest frequency of ETS and fever. All other candidate vaccines caused lower rates of local and general reactions than the reference DTaP. As a general rule, vaccines with less antigen induced fewer reactions, although there was no strict dose-response effect and the difference, e.g. between a one-tenth and a one-fifth DTaP dose (DTaP 1/5; DTaP 1/10) was not clinically relevant. Separate injections of Td and aP caused fewer general reactions than the respective TdaP combination and local reactions were higher at the aP than at the Td injection site. Again, as a general rule, reduced amounts of antigen induced lower antibody concentrations, although all vaccines induced "protective" anti-tetanus and anti-diphtheria antibody responses. A total of 92-100% of children showed seroresponses to pertussis antigens even when vaccinated with reduced amounts of the respective pertussis antigen. Elimination of aluminum from DTaP vaccine induced higher anti-tetanus-antibody concentrations and so did a reduction of the amount of diphtheria antigen. Additional examples for antigen interaction were increased antibody concentrations, observed with injection of Td and aP into different limbs. In the second study phase, all three vaccines evaluated (one with a reduced amount of diphtheria antigen, TdaP; one with reduced amounts of all antigens, tdap; and one with a fifth dose of the reference vaccine (DTaP 1/5)) were safe and had an acceptable reactogenicity profile in a total of 4871 study subjects.

CONCLUSIONS

Local reactions due to DTaP booster doses in the second year of life can be reduced by reducing the amount of antigen in the respective vaccine while an adequate immunogenicity is maintained. Aluminum-free vaccines induced ETS and fever most commonly. Any changes in vaccine composition should lead to a full evaluation of the new product.

Human toll-like receptor 4 mutations are associated with susceptibility to invasive meningococcal disease in infancy

Toll-like receptor 4 (TLR4) is required for efficient recognition of bacterial infections. We investigated an association between 2 TLR4 mutations (Asp(299)Gly and Thr(399)Ile) and meningococcal disease in 197 patients and 214 healthy controls by allele-specific real time polymerase chain reaction and direct sequencing. Although the allele frequency was not higher in the overall patient population, a significantly higher frequency in the 40 patients younger than 12 months of age (P = 0.007) was observed. We conclude that TLR4 mutations represent a risk factor for meningococcal disease in this age group.

Onset and duration of mivacurium-induced neuromuscular block in patients with Duchenne muscular dystrophy †

BACKGROUND

To determine the response to mivacurium, we prospectively studied onset time and complete spontaneous recovery from mivacurium-induced neuromuscular block in patients with Duchenne muscular dystrophy (DMD).

METHODS

Twelve boys with DMD, age 5-14 yr, seven of them wheelchair-bound, ASA II-III, and 12 age- and sex-matched controls (ASA I) were enrolled in the study. Anaesthesia was induced with fentanyl 2-3 microg kg(-1) and propofol 3-4 mg kg(-1) titrated to effect, and maintained by continuous i.v. infusion of propofol 8-12 mg kg(-1) and remifentanil as required. The lungs were ventilated with oxygen in air. Neuromuscular transmission was assessed by acceleromyography using train-of-four (TOF) stimulation every 15 s. After baseline readings, a single dose of mivacurium 0.2 mg kg(-1) was given. The following variables were recorded: (i) lag time; (ii) onset time; (iii) peak effect; (iv) recovery of first twitch from the TOF response to 10, 25 and 90% (T(10), T(25), T(90)) relative to baseline; (v) recovery index (time between 25 and 75% recovery of first twitch); and (vi) recovery time (time between 25% recovery of first twitch and recovery of TOF ratio to 90%). For comparison between the groups the Mann-Whitney U-test was applied.

RESULTS

There were no differences between the groups in lag time, onset time and peak effect. However, all recorded recovery indices were significantly (P<0.05) prolonged in the DMD group. The median (range) for time points T(10), T(25) and T(90) in the DMD and control group was 12.0 (8-16) vs 8.4 (5-15) min, 14.1 (9-20) vs 10.5 (7-17) min and 26.9 (15-40) vs 15.9 (12-23) min, respectively. The recovery index and recovery time were similarly prolonged in the DMD group.

CONCLUSIONS

These results support the assumption that mivacurium-induced neuromuscular block is prolonged in patients with DMD.

The Descriptive Epidemiology of Severe Lower Respiratory Tract Infections in Children in Kiel, Germany

BACKGROUND

Lower respiratory tract infections (LRI) inflict a high burden of disease in children worldwide. Longitudinal, descriptive epidemiological data on different forms of LRI are urgently needed to differentiate this burden, compare population-based incidence rates between countries and to recognize trends.

PATIENTS AND METHODS

From July 1996 to June 2000, all children hospitalized with LRI, i. e. laryngo-tracheo-bronchitis (LTB), bronchitis, wheezing bronchitis-bronchiolitis (WBB), bronchopneumonia and pneumonia, in the municipal area of Kiel, Schleswig-Holstein, Germany, were analyzed by cross-sectional studies. Naso-pharyngeal aspirates (NPA) were analyzed by an in-house 9-valent multiplex-RT-PCR.

RESULTS

In the 4-year observational period, 1 072 children aged 0 to 16 years (median 23 months) were hospitalized with LRI: 12 % (median 28 months) with LTB, 11 % (median 17 months) with bronchitis, 28 % (median 13 months) with WBB, 26 % (median 26 months) with bronchopneumonia and 22 % (median 47 months) with pneumonia. The prevalence of chronic underlying conditions (20 %) and low gestational age (13 %) varied in the different forms of LRI. The cumulative incidence rate of LRI rose steadily over the 4 years. The highest fraction was contributed by WBB, while pneumonia declined. The highest incidence rate ratio was attributable to respiratory syncytial virus (RSV, 0.46) and to children under 2 years of age.

CONCLUSIONS

LRI, especially obstructive forms of LRI, are increasing in Germany as described earlier for the USA, UK and Sweden. The major burden is carried by children under 2 years. RSV is the single pathogen with the highest impact.

Population-Based Incidence of Severe Pneumonia in Children in Kiel, Germany

BACKGROUND

Elaborated data on the descriptive epidemiology of community-acquired pneumonia (CAP) are a prerequisite to estimate the impact of new vaccines.

PATIENTS AND METHODS

From July 1996 to June 2000, all children (0-16 years) admitted to one of the two pediatric hospitals in Kiel and being resident in the municipal area of Kiel were investigated by cross-sectional studies and prospective testing using a 9-valent in-house m-RT-PCR method.

RESULTS

In the 4-year period, 514 children were included (mean age 46, median 40 months): 279 were diagnosed with bronchopneumonia (BPN, median age 26 months), 235 with pneumonia (PN) (47 months); within the latter 69 cases had lobar PN (55 months), 41 atypical PN (51 months) and 28 parapneumonic effusions (74 months). An underlying chronic condition was present in 22.8 % and 10.1 % were born prematurely. The population-based incidence rates (per 100,000 per year) were on average 300 for children 0-16 years, 163 for BPN, 136 for PN, 53 for lobar PN, 24 for atypical PN and 16 for parapneumonic effusions. The rate was stable or slightly declined over the observation period. 61 % of infants and 45 % of children under 5 years of age have to be hospitalized having contracted CAP. The highest fraction of 34 and 25 %, respectively, was attributable to RSV. Viruses were not diagnosed significantly more often in BPN than in PN, if stratified by age.

CONCLUSION

The incidence and the admission rate of severe CAP is lower than in the USA. The high rate of empyema warrants enhanced surveillance as an indicator for antibiotic resistance or changing impact of pneumococcal serotypes. Misclassification, also with ICD codes, is a major issue. Well analyzed epidemiological recruitment areas are a valid tool to generate precise data in Germany.

RSV-prevention in children guided by a web-based early warning system

BACKGROUND

Passive immunization with palivizumab is expensive and requires considerable logistic effort. So far 5 monthly injections from November to March are recommended. The RSV season onset and its duration, however, shows considerable variation. In many countries on the northern hemisphere a dual rhythm is described.

METHOD

A web-based early warning system within the research network PID-ARI.net is in place since 2002. The surveillance data are published online weekly via www.pid-ari.net. This enables physicians to carry out interventions, like passive immunization for RSV, synchronously with the epidemiology of a given pathogen instead of a rigid schedule. The surveillance of PID-ARI.net is based on a 19 valent multiplex RT-PCR on naso-pharyngeal aspirates. The samples are provided by hospitals and offices in Freiburg, Mainz and Schleswig-Holstein (north, middle, south of Germany). Children with lower airway infections are prospectively enrolled.

RESULTS

In the time period from July 1999 to June 2003 with 20 months of recommended palivizumab application, 5 months (25 %) would have been not on target. In two seasons the start of the vaccine campaign would have been too early (waste of two months). In one season the application would have started one month too late and in two seasons the vaccine campaign would have been stopped two months too early leaving the vaccinees on risk for acquiring RSV.

CONCLUSIONS

The web-based early warning system of PID-ARI.net is the first, pathogen-specific, comprehensive and fast surveillance-system for airway pathogens in Europe. It facilitates the epidemic-synchronous use of the passive immunization with palivizumab and by this increases its efficiency and should safe costs.

A global perspective on vaccine safety and public health: the Global Advisory Committee on Vaccine Safety

Established in 1999, the Global Advisory Committee on Vaccine Safety advises the World Health Organization (WHO) on vaccine-related safety issues and enables WHO to respond promptly, efficiently, and with scientific rigor to issues of vaccine safety with potential global importance. The committee also assesses the implications of vaccine safety for practice worldwide and for WHO policies. We describe the principles on which the committee was established, its modus operandi, and the scope of the work undertaken, both present and future. We highlight its recent recommendations on major issues, including the purported link between the measles-mumps-rubella vaccine and autism and the safety of the mumps, influenza, yellow fever, BCG, and smallpox vaccines as well as that of thiomersal-containing vaccines.

Tolerability of the Biken acellular pertussis vaccine in adults with or without previous vaccination against pertussis in childhood

PURPOSE

The objective of this study was to assess the local and systemic tolerability of two batches of the Biken acellular pertussis (Pa) vaccine following administration of a single vaccine dose to adults with or without a history of prior pertussis immunization. The results from this study were compared to data from published literature.

PATIENTS AND METHODS

In a controlled, open-labeled double-blind trial, 518 healthy male and female adults with or without primary pertussis immunization were enrolled at three centers. All study participants had received one single dose (0.5 ml) of the Biken two-component (23.4 mg PT; 23.4 mg FHA) Pa vaccine deeply intramuscularly. Local and systemic adverse events were solicited for 4 days using diary cards. On two occasions, between day 4-7 and between day 12-16 postvaccination, vaccinees were reexamined. At the end of the observation period (day 28) vaccinees had to send a preprinted letter to the study center indicating their state of health.

RESULTS

One serious adverse event (acute appendicitis) occurred and was considered not to be related to the study vaccine. At the injection site, redness > 20 mm was observed in one subject (0.2%), and swelling > 20 mm was seen in ten subjects (1.98%). Edematous swelling occurred in three subjects (0.59%). In 27 subjects (5.34%) a "late-onset muscle mass swelling" could be palpated, usually occurring on day 6-12 postvaccination. 429 subjects (84.78%) experienced none or only slight tenderness on pressure during the. rst 4 days postvaccination, moderate tenderness on pressure was reported by 60 subjects (11.86%) and severe tenderness by 16 vaccinees (3.16%). Systemic side effects were rare: no fever > 38.5 degrees C was observed, and only seven subjects (1.39%) took antipyretics. Five patients (0.99%) experienced exhaustion or nausea. The vast majority of the participants (97.43%) would opt for the vaccination again.

CONCLUSION

The study vaccine was safe and induced only infrequently and mostly mild, local or general symptoms that all resolved spontaneously. It was well tolerated and accepted in adults.

Rocuronium for muscle relaxation in two children with Friedreich's ataxia

Friedreich's ataxia is a rare hereditary neurodegenerative disease caused by a defect in the gene that encodes a mitochondrial protein called frataxin. We report the use of rocuronium 0.6 mg kg(-1) in two adolescent girls with Friedreich's ataxia undergoing propofol-sufentanil-oxygen-air anaesthesia for spinal surgery. Neuromuscular transmission was monitored using acceleromyography, and onset and recovery times were recorded. The clinical duration of rocuronium was comparable to that of children without neuromuscular disease (25% recovery T(1)=44 and 24 min for patients 1 and 2 respectively).

The safety, reactogenicity and immunogenicity of a 7-valent pneumococcal conjugate vaccine (7VPnC) concurrently administered with a combination DTaP-IPV-Hib vaccine

To evaluate immune responses, safety and reactogenicity of the concomitant use of DTaP-IPV-Hib and the newly available 7-valent pneumococcal conjugate (7VPnC) vaccines when given as the primary immunization series in early infancy. A total of 231 healthy infants were enrolled at 11 German study centers and randomized to receive either 7VPnC plus DTaP-IPV-Hib vaccines concomitantly into opposite limbs at age 2, 3, 4 and 11-15 months (7VPnC group) or DTaP-IPV-Hib vaccine at the same ages plus a 7VPnC "catch-up vaccination" at ages 6, 7, 8 and 11-15 months (Control group). Blood samples were drawn before and 4 weeks after the first three vaccine doses and 4 weeks after the fourth dose. Local and general side effects (i.e. safety) were solicited by diary cards. Immune responses were determined by ELISA except for antibodies to polioviruses (neutralization assay). Post-dose 3, a significant antibody response against all seven pneumococcal vaccine-serotypes was observed in the 7VPnC group only. Post-dose 4 geometric mean concentrations (GMCs) were similar in both groups. GMCs for other vaccine antigens were comparable between groups except for diphtheria (higher in the 7VPnC group) and pertactin (lower in the 7VPnC group), although after three vaccine doses there was a 28-fold rise in GMCs from baseline. Both vaccines were generally well-tolerated although there were minor differences in the frequency of local reactions and somewhat more fever or drowsiness in the 7VPnC group. The use of DTaP-IPV-Hib and the 7VPnC vaccine was safe, well-tolerated and immunogenic when given concomitantly at age 2, 3 and 4 months or when given separately with 7VPnC as a catch-up vaccination at age 6, 7, 8 months and as a concomitant booster immunization at age 11-15 months.

An outbreak of rubella aboard a ship of the German Navy

BACKGROUND

During May and June 1996, an outbreak of rubella occurred offshore aboard a ship of the German Navy. The outbreak spread among 330 crew members over a period of 9 weeks, ending 2 days after the ship's return. This is the first detailed epidemiological investigation of a rubella outbreak on a ship, describing temporal progression, clinical manifestations, immunization status and seroprevalence of the population exposed.

PATIENTS AND METHODS

Outbreak investigation using a questionnaire, health records and rubella serology (hemagglutination inhibition (HI) test and EIA).

RESULTS

Of the 330 crew members 298 (90%) participated in the investigation. The outbreak was continuous without a peak and ended abruptly after the ship's return. It resulted in 20 cases, 11 of which were clinically symptomatic. A total of 35 (12%) crew members were susceptible to rubella prior to the outbreak, resulting in an attack rate of 57%. The highest risk for infection was linked to accommodation aboard the ratings deck (chi(2)-test, p = 0.004) with most favorable conditions of transmission. Only 9% of the participating crew were able to provide complete proof of their immunization status. The positive predictive value of a past history of rubella for the presence of antibodies against rubella was 59%.

CONCLUSION

The transmission of rubella that we describe aboard a ship was facilitated by the unusually close proximity of the crew and their insufficient immunity. Documentation of immunization was inadequate in this population.

The incidence of influenza-associated hospitalizations in children in Germany

Since new vaccines and anti-viral drugs for influenza have become available, collation of actual and country-specific epidemiological data is essential. Since respiratory syncytial virus (RSV) is a well known paediatric airway pathogen and some epidemiological data exist already, a comparison between influenza and RSV seems warranted. From July 1996 to June 2001 the naso-pharyngeal aspirates (NPA) of children from birth to 16 years of age, admitted to one of the two paediatric hospitals in Kiel, Germany, were investigated by a nine-valent multiplex reverse transcriptase PCR assay. NPA were investigated in 60.8 % of 3,469 children admitted with an acute respiratory tract infection. Community-acquired or nosocomial infections (in parentheses) due to influenza A were diagnosed in 122 (10) children, due to influenza B in 14 (2) and due to RSV in 325 (24) cases. Patients with influenza A (median 752 days) and influenza B (median 966 days) were older than patients with RSV (median 168 days). The spectrum of disease presentation was broader in influenza than in RSV. In each winter, admissions with influenza were less common than those with RSV. Influenza B only occurred in 2 of the 5 years. The cumulative, population-based incidences per 100,000 children 0-16 (0-5, >5-16) years of age were 53 (123, 22) for influenza A, 16 (30, 9) for influenza B and 165 (453, 4) for RSV. Cardiac conditions and asthma were the major risk factors for admission to hospital with influenza A (RR 9.8, 4.1) and RSV (8.5, 2.1) infections. Underlying conditions were most common in influenza B. Low gestational age doubled the risk for admission to hospital with influenza A infection, but did not show a dose-effect relationship as in RSV. The burden of influenza-positive hospitalizations was about one third that of RSV. The incidence was similar to reports from the United States. Targeting children with underlying conditions, especially cardiac conditions and asthma in the German immunization programme is appropriate, as long as no policy for vaccination of the general paediatric population exists.

Ratio of patient's height to thyromental distance improves prediction of difficult laryngoscopy

Several tests have been proposed to predict difficult laryngoscopy or intubation. The thyromental distance (TMD) is often used for these purposes but this measurement, used alone, is unreliable. This study tested the hypothesis that the ratio of the patient's height to TMD (ratio of height to TMD = RHTMD) would improve the accuracy of predicting difficult laryngoscopy compared with TMD alone. Two hundred and seventy patients were evaluated preoperatively using the TMD and RHTMD. The two tests were compared analyzing the area under the receiver operating characteristic curves (AUC). Difficult laryngoscopy occurred in 16 patients (5.9%). The AUC of RHTMD was significantly greater (P < 0.007) when compared to TMD, indicating a more accurate prediction by the RHTMD. A ratio of 25 for the RHTMD was found to be the optimal cut-off value to predict difficult laryngoscopy. When the sensitivity of both tests was 0.81, the RHTMD had a significantly greater specificity (0.91) than the TMD (0.73). Based on our results, we recommend that the RHTMD should be used instead of the TMD.

Burden of disease in hospitalized RSV-positive children in Germany

BACKGROUND

In spite of a large amount of data from other countries, those on the burden of disease attributed to respiratory syncytial virus (RSV) in Germany are lacking and are urgently needed.

METHOD

In a population-based cross-sectional study from July 1996 to June 1999 150 children from birth to 16 years of age hospitalized in Kiel and tested positive for RSV by polymerase chain reaction were investigated. Stepwise linear and logistic regression models were applied to predict a bacterial co-infection as well as the duration of hospitalization.

RESULTS

Pneumonia (54 %) and wheezing bronchitis (including bronchiolitis, 27 %) were the predominating diagnoses; 25 % had an underlying condition. Four patients needed nasal continuous airway pressure and one intermittent mandatory ventilation; none died. According to the surrogate markers CRP and immature neutrophil fraction, 20 % to 30 % were suspected to have a bacterial co-infection on admission; antibiotics were prescribed in 65 % of the patients. The average duration of hospitalization was 9 days and was best predicted by young age, the presence of an underlying condition, intercostal retractions and high CRP on admission.

CONCLUSIONS

Bacterial co-infection is the major confounder in burden of disease analyses in RSV. The decision not to administer antibiotics to children hospitalized with RSV can be risky, particularly when there is considerable diagnostic uncertainty. Within the realm of current clinical practice, complications and deaths related to RSV are rare in Germany.

Seasonality of respiratory syncytial virus-positive hospitalizations in children in Kiel, Germany, over a 7-year period

BACKGROUND

Elaborate, long-term data on the rhythm, seasonality and severity of the yearly respiratory syncytial virus (RSV) epidemics in Germany are lacking.

PATIENTS AND METHODS

A longitudinal investigation was undertaken of children from birth to 16 years of age admitted with an RSV infection in the two pediatric hospitals in Kiel between July 1994 and June 2001. To compare the severity of the individual seasons, the incidences and the proportion of RSV-positive hospitalized children aged 0 to 2 years from the denominator area of Kiel were compared.

RESULTS

During the 7-year period, the nasopharyngeal aspirates of 2,367 children were investigated; RSV was detected in 384 (16.2%). The seasons from 1994/95 to 1996/97 started late (December to January) and ended between March and May. Since 1997/98 it seems that a late season is followed by an early season (start in September to October) in a 2-year pattern.

CONCLUSION

No fixed rhythm of the RSV season can be identified as yet. Ascertainment bias is unlikely to explain the differences in rhythm. The incidence of RSV-positive hospitalizations seems to be increasing.

Detection of delayed vaccinations: a new approach to visualize vaccine uptake

For the prevention of pertussis and invasive Haemophilus influenzae type b (Hib) infections, each with a peak for mortality and serious complications in the first year of life, early vaccination is important and needs adequate monitoring. In a 1999 national coverage survey the timing of uptake of these vaccines in German children was therefore assessed conventionally at defined age thresholds and with a new adaptation of the Kaplan-Meier (KM) method estimating immunization uptake over time by 1 minus the survival function s(t). Only 6% and 9% of children were vaccinated against pertussis and Hib in accordance with the national recommended primary vaccination schedule. Coverage levels for the primary vaccination course of 50% and 90% were attained for pertussis after 6.6 and 16.3 months respectively and for Hib after 7.0 and 24.3 months. These estimates were only possible with the KM method which proved useful to monitor vaccination programmes and will allow the comparison of vaccination uptake in different populations.

New LightCycler PCR for rapid and sensitive quantification of parvovirus B19 DNA guides therapeutic decision-making in relapsing infections

Detection of parvovirus B19 DNA offers diagnostic advantages over serology, particularly in persistent infections of immunocompromised patients. A rapid, novel method of B19 DNA detection and quantification is introduced. This method, a quantitative PCR assay, is based on real-time glass capillary thermocycling (LightCycler [LC]) and fluorescence resonance energy transfer (FRET). The PCR assay allowed quantification over a dynamic range of over 7 logs and could quantify as little as 250 B19 genome equivalents (geq) per ml as calculated for plasmid DNA (i.e., theoretically >or=5 geq per assay). Interrater agreement analysis demonstrated equivalence of LC-FRET PCR and conventional nested PCR in the diagnosis of an active B19 infection (kappa coefficient = 0.83). The benefit of the new method was demonstrated in an immunocompromised child with a relapsing infection, who required an attenuation of the immunosuppressive therapy in addition to repeated doses of immunoglobulin to eliminate the virus.

Severe complications of varicella in previously healthy children in Germany: a 1-year survey

OBJECTIVE

Varicella is a common infectious disease, usually benign and self-limited, and complications are believed to be rare. The purpose of this study was to describe the epidemiology of severe varicella complications in immunologically healthy children in Germany.

METHODS

Information on any admission of children with a severe complication associated with chickenpox was solicited throughout 1997 from all 485 pediatric hospitals in Germany using an established surveillance system. The case definition included nonimmunocompromised individuals who were up to 16 years of age and hospitalized with neurologic complications, bacterial superinfections, or hematologic complications.

RESULTS

The response rate to the surveillance questionnaire during the observation period was high: 93.4%. Of the 153 reported cases, 119 met the case definition. There was a seasonal distribution of reported complications with a peak in March. The majority of complications occurred in preschool-age children with a maximum age of 4 years. No gender predominance was found with a distribution of 56 female and 63 male patients. Multiple entries for complications were allowed. The most frequent complications were neurologic, which were reported in 73 children (61.3%); cerebellitis was the leading diagnosis (n = 48), followed by encephalitis (n = 22), meningitis (n = 2), and central facial palsy (n = 1). A total of 46 (38.6%) infectious complications were identified. Superinfections of the skin were present in 31 (26.0%), pyogenic arthritis was present in 5 (4.2%), osteomyelitis was present in 4 (3.3%), necrotizing fasciitis was present in 3 (2.5%), orbital cellulitis was present in 2 (1.6%), and pneumonia was present in 1 (0.8%). Streptococcus pyogenes was the leading cause of bacterial infections (18 cases [15.1%]), with invasive disease in 6 patients (8.4%) and linked to 4 of 8 cases with defect healing. Infectious complications were reported in the majority in younger children up to 4 years of age, whereas neurologic complications occurred more frequently in an older age range. Five children experienced thrombocytopenia or severe anemia. There was no bleeding disorder, no fatality, and no case of Reye syndrome reported during the 1-year observation period. In total, 8 (6.7%) of 119 patients reported having long-term sequelae, 6 attributable to infectious complications and 2 to persistent deficits after neurologic complications.

CONCLUSION

This is the first prospective nationwide study of severe complications of varicella in immunologically healthy children. Related to 14 025 867 children up to the age of 16, a crude incidence of severe chickenpox complications of 0.85/100 000 could be calculated [corrected]. The actual hospitalization rate attributable to complicated chickenpox is probably much higher, because this calculation refers to a population theoretically at risk and not the truly susceptible individuals. The results of this study demonstrate considerable morbidity with a comparatively high rate of encephalitis, osteomyelitis, and pyogenic arthritis. Although infectious complications were present in only 38.6% of the reported cases, they contributed disproportionately to the cases with chronic sequelae. Looking at these cases in more detail, S pyogenes involvement was identified as the major risk factor for invasive disease with an unfavorable long-term outcome. varicella-zoster virus, chickenpox/epidemiology, chickenpox/complications, encephalitis, cellulitis, osteomyelitis, necrotizing fasciitis, group A beta-hemolytic streptococci, Europe.

Factors influencing vaccine uptake in Germany

While vaccines have virtually eliminated many infectious diseases in Germany, vaccination coverage in children, adolescents and adults is still unsatisfying. This situation is mainly due to inadequate remuneration of vaccination services, structural deficits in the health care system and a lack of motivation. Political support and leadership would most likely be able to change this situation.

Haemophilus influenzae type b disease: impact and effectiveness of diphtheria-tetanus toxoids-acellular pertussis (-inactivated poliovirus)/H. influenzae type b combination vaccines

BACKGROUND

Since 1996 in Germany primary infant immunization against Haemophilus influenzae has been most commonly given in the form of diphtheria-tetanus toxoids-acellular pertussis/H. influenzae type b (DTaP/Hib) or diphtheria-tetanus toxoids-acellular pertussis (-inactivated poliovirus)/H. influenzae type b (DTaP-IPV/Hib) combination vaccines. These combination vaccines elicit lower anti-Hib antibody concentrations than the equivalent Hib conjugate administered as a separate injection, but the clinical relevance of this phenomenon is unknown.

METHODS AND FINDINGS

To assess the impact of DTaP/Hib combination vaccines on the incidence of invasive Hib disease in Germany, two independent surveillance systems, one hospital- and one laboratory-based, were used during 1998 and 1999 for detection of cases. Vaccination histories of all cases detected were obtained by telephone contact with parents or health care providers. During the 2-year study period invasive H. influenzae disease in the <5-year age group continued to fall, with a mean annual incidence of 1.01/100 000 children. National vaccination coverage rates revealed that only 70% of children given DTaP/Hib or DTaP-IPV/Hib received the recommended three doses in their first year of life, but the overall effectiveness of these vaccines was high at 97.5% (95% confidence interval, 96.3 to 98.4) for those who had received at least one dose. In subjects who received the full 3-dose schedule, effectiveness was 98.8% (95% confidence interval, 98.2 to 99.3).

CONCLUSION

Although it is well-documented that DTaP/Hib vaccines elicit lower anti-Hib titers than separate vaccines, such combinations are effective in reducing the incidence of invasive H. influenzae type b disease.

Incidence of respiratory syncytial virus-positive hospitalizations in Germany

Epidemiological data, especially population-based data, on respiratory syncytial virus (RSV)-related hospitalizations in Germany have been lacking to date. Since Palivizumab (Synagis, Abbott, USA) is already available and new vaccines for active immunization are under development, these data are urgently needed. From July 1996 to June 1999, nasopharyngeal aspirates of children hospitalized in Kiel with an acute respiratory tract infection were tested by multiplex reverse transcriptase polymerase chain reaction. Of 1,241 patients, 150 (12.1%) were RSV positive. RSV was the predominant pathogen detected through the end of the second year. In 37 (25%) children an underlying condition was present. For the city of Kiel and close surroundings, the cumulative incidence of RSV-positive hospitalizations in infants was 1,214/10(5) (725/10(5) in children less than 2 years). For those children less than 2 years old born with a gestational age of less than 32 weeks or 32-37 weeks, the cumulative incidence was 2,025/10(5) and 1,202/10(5), respectively (dose-effect response). For the group less than 32 weeks of age, bronchopulmonary dysplasia (BPD) as an underlying condition carried a relative risk of 17.8. The RSV season began between the end of September and January and ended between March and July. The population-based incidence of RSV-positive hospitalizations in Kiel is close to that reported from the UK and Scandinavia. Throughout Germany, approximately 10.000 RSV-related hospitalizations in infants can be expected annually. Prematurity is an effect modifier and BPD a strong risk factor for RSV-positive hospitalization in population-based studies. There is considerable variation in the start and end of the yearly epidemic.

Epidemiology of pneumococcal disease in children in Germany

Recently published and as yet unpublished data allow a reasonable estimate of the annual burden of pneumococcal disease in Germany. At least 277,000 episodes of otitis media and at least 2,000 episodes of sinusitis occur in children under the age of 5 y. Pneumococcal meningitis was found in 200 children under the age of 16 y; the estimate for all age groups ranges from 450 to 1100 cases. Of approximately 150,000 cases of ambulatory pneumococcal pneumonia, at least 63,000-105,000 patients are hospitalized each year.

CONCLUSION

Further studies of pneumococcal epidemiology in Germany are needed, and continued surveillance will be necessary for a better understanding of the overall burden of pneumococcal disease in children as well as adults.

Immunogenicity and reactogenicity of the Biken acellular pertussis vaccine in young adults

To assess the reactogenicity and immunogenicity of the Biken acellular pertussis vaccine (Pa) following administration of a single vaccine dose to young adults with or without a history of prior pertussis immunization, 104 healthy, male and female adults without primary pertussis immunization were enrolled in Mainz (former West Germany; "not previously pertussis vaccinated", N-PPV-group); in parallel, 103 adults with a history of having received >/=four doses of a combined diphtheria-, tetanus-toxoid, whole-cell pertussis vaccine (DTwP) were enrolled in Magdeburg (former East Germany; "previously pertussis-vaccinated", PPV-group). Large areas of redness (>20 mm) were seen in 2.9%/1.0% of subjects in the N-PPV/PPV group, and a large swelling was seen in 6.8%/1.0%, respectively. As compared to baseline concentrations, antibody titers to PT and FHA were 77-(PT)/64-(FHA) (N-PPV group) and 94-(PT)/126-(FHA) fold (PPV group) higher. The study vaccine was safe and induced infrequent and mostly mild, local and general symptoms that all resolved spontaneously; it was highly immunogenic in adults, whether or not they had been previously vaccinated with DTwP.

Primary vaccination of infants with diphtheria-tetanus-acellular pertussis-hepatitis B virus- inactivated polio virus and Haemophilus influenzae type b vaccines given as either separate or mixed injections

OBJECTIVE

The aim of this open, multicenter, randomized trial was to evaluate the immunogenicity and reactogenicity of a candidate combined diphtheria-tetanus-acellular pertussis-hepatitis B virus-inactivated polio virus (DTaP-HBV-IPV) vaccine when given as either a mixed or as separate concomitant injections with Haemophilus influenzae type b (Hib) vaccine.

STUDY DESIGN

A total of 359 subjects were randomized to receive either DTaP-HBV-IPV/Hib (mixed administration - 180 subjects) or DTaP-HBV-IPV + Hib (separate administration in opposite limbs - 179 subjects) at 2, 3, and 4 months of age.

RESULTS

After vaccination, seroprotective antibody concentrations against diphtheria, tetanus, hepatitis B, and polio viruses and a high (> or = 97%) pertussis vaccine response were seen in almost all study participants. All subjects except one in the mixed administration group had postvaccination Hib anti-PRP antibody concentrations > or = 0.15 microg/mL. Of subjects in the mixed and separate group, 77.2% (geometric mean antibody concentration, 2. 62 microg/mL) and 88.6% (geometric mean antibody concentration, 4.45 microg/mL) had Hib anti-PRP concentrations > or = 1 microg/mL, respectively. The addition of the Hib component to the 5-component vaccine did not increase the incidence of local or general reactions.

CONCLUSION

Both administrations of the candidate vaccine were found to be safe, immunogenic, and well tolerated. Although anti-PRP geometric mean antibody concentrations and the percent of subjects achieving the 1 microg/mL seroprotective level were lower after the mixed administration, they were in the range seen with monovalent Hib vaccines or with other DTaP-based/Hib combinations licensed in some European countries. Therefore both administrations have the potential to simplify childhood immunization.

Proportion of invasive pneumococcal infections in German children preventable by pneumococcal conjugate vaccines

The incidence and serotype distribution of Streptococcus pneumoniae as a cause of invasive diseases are unknown with regard to most European countries. From January 1997 through December 1998, population-based nationwide prospective surveillance was undertaken for invasive pneumococcal disease (IPD) in children in Germany, based on monthly independent reports from all pediatric hospitals and from clinical microbiology laboratories. On the basis of 896 reported IPD cases (including 404 with meningitis), the incidences per 10(5) children in different age groups were as follows: children aged <1 year, 18.9 (9.7 for meningitis); children aged <2 years, 16. 0 (7.2 for meningitis); for children aged <5 years, 8.9 (3.9 for meningitis); and for children aged <16 years, 3.2 (1.4 for meningitis). The proportions of cases involving strains (304 serotyped) included in conjugate vaccines were as follows: for the 7-valent vaccine, 52%; for the 9-valent, 62%; and for the 11-valent, 71%. None of the isolates were resistant to penicillin or cefotaxime. Although the rate for meningitis is similar, other manifestations of IPD are less commonly diagnosed in Germany than in other countries. The serotype distribution only partially matched that used in the recent development of pneumococcal conjugate vaccines.

Epidemiological investigation of nine respiratory pathogens in hospitalized children in Germany using multiplex reverse-transcriptase polymerase chain reaction

The aim of this study was to generate urgently needed data on respiratory pathogens in German children using an economical and efficient tool. Nasopharyngeal aspirates of hospitalized children 0-16 years of age with an acute respiratory tract infection were tested by a nine-valent multiplex reverse-transcriptase polymerase chain reaction. Of 1281 children, 449 (35%) had an acute respiratory tract infection caused by at least one of the organisms studied; there were 29 cases of dual infection. At least 34-42% of severe acute respiratory tract infections in children under 5 years of age were caused by viruses. In children over 5 years of age, this proportion was 23% (P<0.001). Infection during the first 2 years of life was most frequently due to respiratory syncytial virus (n = 162 cases). Parainfluenza virus type 3 (n = 22) and type 1 (n = 14) were detected almost exclusively in children under 5 years of age. Influenza A (n = 90) and adenoviruses (n = 98) were prevalent in all age groups. The frequency of influenza B virus isolation (n = 17) rose significantly after the age of 5 years. Mycoplasma pneumoniae infection (n = 24 cases, 5.2%) was most frequent in 5- to 16-year-old patients. Only one case of Chlamydia pneumoniae infection was found. Since the distribution of pathogens within the different types of lower respiratory tract infections is very similar, it seems that host factors determine which form of lower respiratory tract infection develops in an individual patient. The multiplex reverse-transcriptase polymerase chain reaction may, in the future, become an important tool for epidemiological studies as well as for individual diagnosis.