Are we missing respiratory viral infections in infants and children? Comparison of a hospital-based quality management system with standard of care

OBJECTIVES

Hospital-based surveillance of influenza and acute respiratory infections relies on International Classification of Diseases (ICD) codes and hospital laboratory reports (Standard-of-Care). It is unclear how many cases are missed with either method, i.e. remain undiagnosed/coded as influenza and other respiratory virus infections. Various influenza-like illness (ILI) definitions co-exist with little guidance on how to use them. We compared the diagnostic accuracy of standard surveillance methods with a prospective quality management (QM) programme at a Berlin children's hospital with the Robert Koch Institute.

METHODS

Independent from routine care, all patients fulfilling pre-defined ILI-criteria (QM-ILI) participated in the QM programme. A separate QM team conducted standardized clinical assessments and collected nasopharyngeal specimens for blinded real-time quantitative PCR for influenza A/B viruses, respiratory syncytial virus, adenovirus, rhinovirus and human metapneumovirus.

RESULTS

Among 6073 individuals with ILI qualifying for the QM programme, only 8.7% (528/6073) would have undergone virus diagnostics during Standard-of-Care. Surveillance based on ICD codes would have missed 61% (359/587) of influenza diagnoses. Of baseline ICD codes, 53.2% (2811/5282) were non-specific, most commonly J06 ('acute upper respiratory infection'). Comparison of stakeholder case definitions revealed that QM-ILI and the WHO ILI case definition showed the highest overall sensitivities (84%-97% and 45%-68%, respectively) and the CDC ILI definition had the highest sensitivity for influenza infections (36%, 95% CI 31.4-40.8 for influenza A and 48%, 95% CI 40.5-54.7 for influenza B).

CONCLUSIONS

Disease-burden estimates and surveillance should account for the underreporting of cases in routine care. Future studies should explore the effect of ILI screening and surveillance in various age groups and settings. Diagnostic algorithms should be based on the WHO ILI case definition combined with targeted testing.

[Diagnostically Approach to Pediatric Carpal Fractures: a Retrospective Analysis]

INTRODUCTION

Carpal fractures in children are rare, but can be missed, as their clinical symptoms are unspecific and discrete. Even X-ray diagnosis is difficult. Timely diagnosis and consistent therapy are especially important for scaphoid fractures, as they can help to avoid complications such as non-union or avascular necrosis. A diagnostic approach to paediatric carpal fractures will be discussed on the basis of the following group of patients.

METHODS

Retrospective analysis of children under 14 years treated in our institution between 09/2010 and 02/2012 for clinically suspected carpal fracture. In the primary evaluation, all children underwent standard X-rays of the hand and/or wrist. All patients were treated by cast immobilisation until complete clinical recovery. All patients with clinical signs of carpal fracture were treated by cast immobilization, even with normal X-rays. The clinical follow-up examination was after 10 to 14 days. In patients with persistent complaints, MRI was performed. We retrospectively evaluated the records of all patients: the fractured carpal bone, and X-ray and MRI-diagnosis were stated. We calculated the mean difference between first presentation and MRI and the mean period for total recovery, in patients with fracture or non-fracture.

RESULTS

61 children (27 boys and 34 girls, mean age 11.5 y) were included in our study. The mean delay between accident and time of first presentation to our paediatric ED was 0.6 days. In primary X-rays, a carpal fracture was demonstrated in only in 2 (3.3 %) patients, but was suspected in only 6 (9.8 %) of patients. In 53 (87.9 %) patients, there was no radiographic evidence of carpal fracture. 14 patients underwent additional scaphoid views, but scaphoid fracture was confirmed in only 1 (7 %) of these patients. In 3 (21.4 %) patients, a scaphoid fracture was suspected and in 10 patients a carpal fracture could be excluded. After a mean time of 11.8 days, all patients underwent a clinical follow-up examination. 32 (54 %) patients had persistent symptoms and MRI was done after a mean time of 17 days. Carpal fracture was then excluded in 12/32 (37 %) patients and was diagnosed in another 20/32 (63 %) children. There were 14 scaphoid fractures, including 3× bone bruise lesions, 4 capitate fractures, 3 triquetral fractures, including 1× bone bruise lesion and 1 bone bruise lesion of the trapezoid. In patients with proven carpal fracture, it took a mean time of 56 days for complete recovery, in comparison with 15 days in patients with excluded carpal fracture. Surgical therapy was unnecessary in any of the patients, and there were no complications.

CONCLUSION

In children with clinical and radiographic carpal fracture, diagnosis is difficult and often unsuccessful at first. Even in discrete clinical complaints, generous cast immobilization is essential and clinical follow up is recommended not later then 14 days. In patients with persistent clinical symptoms, MRI is the imaging method of choice, as it is capable of detecting carpal fractures and even bone bruise lesions with high sensitivity, thereby avoiding unnecessary diagnostic or therapeutic stress for the patients.

Age-related prevalence of cross-reactive antibodies against influenza A(H3N2) variant virus, Germany, 2003 to 2010

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Age-related prevalence of cross-reactive antibodies against influenza A(H3N2) variant virus, Germany, 2003 to 2010

To estimate susceptibility to the swine-origin influenza A(H3N2) variant virus (A(H3N2)v) in the German population, we investigated cross-reactive antibodies against this virus and factors associated with seroprotective titre using sera from representative health examination surveys of children and adolescents (n = 815, 2003–06) and adults (n = 600, 2008–10). Antibodies were assessed by haemagglutination inhibition assay (HI); in our study an HI titre ≥ 40 was defined as seroprotective. We investigated associated factors by multivariable logistic regression. Overall, 41% (95% confidence interval (CI): 37–45) of children and adolescents and 39% (95% CI: 34–44) of adults had seroprotective titres. The proportion of people with seroprotective titre was lowest among children younger than 10 years (15%; 95% CI: 7–30) and highest among adults aged 18 to 29 years (59%; 95% CI: 49–67). Prior influenza vaccination was associated with higher odds of having seroprotective titre (odds ratio (OR) for children and adolescents: 3.4; 95% CI: 1.8–6.5; OR for adults: 2.4; 95% CI: 1.7–3.4). Young children showed the highest and young adults the lowest susceptibility to the A(H3N2)v virus. Our results suggest that initial exposure to circulating seasonal influenza viruses may predict long-term cross-reactivity that may be enhanced by seasonal influenza vaccination.

[Detection of local influenza outbreaks and role of virological diagnostics]

For many years, the Working Group on Influenza (AGI) has been the most important influenza surveillance system in Germany. An average sample of the population is covered by both syndromic and virological surveillance, which provides timely data regarding the onset and course of the influenza wave as well as its burden of disease. However, smaller influenza outbreaks cannot be detected by the AGI sentinel system. This is achieved by the information reported by the mandatory notification system (Protection Against Infection Act, IfSG), which serves as the second pillar of the national influenza surveillance. Approaches to recognize such outbreaks are based either on reported influenza virus detection and subsequent investigations by local health authorities or by notification of an accumulation of respiratory diseases or nosocomial infections and subsequent laboratory investigations. In this context, virological diagnostics plays an essential role. This has been true particularly for the early phase of the 2009 pandemic, but generally timely diagnostics is essential for the identification of outbreaks. Regarding potential future outbreaks, it is also important to keep an eye on animal influenza viruses that have repeatedly infected humans. This mainly concerns avian influenza viruses of the subtypes H5, H7, and H9 as well as porcine influenza viruses for which a specific PCR has been established at the National Influenza Reference Centre. An increased incidence of respiratory infections, both during and outside the season, should always encourage virological laboratory diagnostics to be performed as a prerequisite of further extensive investigations and an optimal outbreak management.

Low Dose Oral Combination Chemoprophylaxis with Oseltamivir and Amantadine for Influenza a Virus Infections in Mice

In the present study, the effect of combining anti-influenza drugs active at different steps of the influenza virus replication cycle, oseltamivir as a neuraminidase (NA) inhibitor and amantadine targeting M2 protein, was investigated in vivo by oral administration in a mouse model of aerosol influenza virus infection and in vitro in MDCK cells. In mice, doses of oseltamivir and amantadine providing 50-60% survival against A/Hongkong/1/68 (H3N2) or A/PR/8/34 (H1N1) were capable of conferring complete protection when used simultaneously, suggesting that increased inhibition of influenza virus replication by combining oseltamivir and amantadine in vitro translates into protection from lethal infection of mice. The combination of amantadine with oseltamivir required 15-fold less oseltamivir than monotherapy to confer complete protection against lethal aerosol influenza virus infection. Remarkably, amantadine-based combination chemoprophylaxis was even effective against amantadine-resistant A/PR/8/34 influenza virus. Thus, combination chemotherapy may be more efficacious than monotherapy against newly emerging Influenza A subtypes.

Contact investigation of a case of human novel coronavirus infection treated in a German hospital, October-November 2012

On 24 October 2012, a patient with acute respiratory distress syndrome of unknown origin and symptom onset on 5 October was transferred from Qatar to a specialist lung clinic in Germany. Late diagnosis on 20 November of an infection with the novel Coronavirus (NCoV) resulted in potential exposure of a considerable number of healthcare workers. Using a questionnaire we asked 123 identified contacts (120 hospital and three out-of-hospital contacts) about exposure to the patient. Eighty-five contacts provided blood for a serological test using a two-stage approach with an initial immunofluorescence assay as screening test, followed by recombinant immunofluorescence assays and a NCoV-specific serum neutralisation test. Of 123 identified contacts nine had performed aerosol-generating procedures within the third or fourth week of illness, using personal protective equipment rarely or never, and two of these developed acute respiratory illness. Serology was negative for all nine. Further 76 hospital contacts also tested negative, including two sera initially reactive in the screening test. The contact investigation ruled out transmission to contacts after illness day 20. Our two-stage approach for serological testing may be used as a template for similar situations.

Contact investigation of a case of human novel coronavirus infection treated in a German hospital, October-November 2012

On 24 October 2012, a patient with acute respiratory distress syndrome of unknown origin and symptom onset on 5 October was transferred from Qatar to a specialist lung clinic in Germany. Late diagnosis on 20 November of an infection with the novel Coronavirus (NCoV) resulted in potential exposure of a considerable number of healthcare workers. Using a questionnaire we asked 123 identified contacts (120 hospital and three out-of-hospital contacts) about exposure to the patient. Eighty-five contacts provided blood for a serological test using a two-stage approach with an initial immunofluorescence assay as screening test, followed by recombinant immunofluorescence assays and a NCoV-specific serum neutralisation test. Of 123 identified contacts nine had performed aerosol-generating procedures within the third or fourth week of illness, using personal protective equipment rarely or never, and two of these developed acute respiratory illness. Serology was negative for all nine. Further 76 hospital contacts also tested negative, including two sera initially reactive in the screening test. The contact investigation ruled out transmission to contacts after illness day 20. Our two-stage approach for serological testing may be used as a template for similar situations.

Assays for laboratory confirmation of novel human coronavirus (hCoV-EMC) infections

We present a rigorously validated and highly sensitive confirmatory real-time RT-PCR assay (1A assay) that can be used in combination with the previously reported upE assay. Two additional RT-PCR assays for sequencing are described, targeting the RdRp gene (RdRpSeq assay) and N gene (NSeq assay), where an insertion/deletion polymorphism might exist among different hCoV-EMC strains. Finally, a simplified and biologically safe protocol for detection of antibody response by immunofluorescence microscopy was developed using convalescent patient serum.

A Novel Homozygous WDR72 Mutation in Two Siblings with Amelogenesis Imperfecta and Mild Short Stature

Amelogenesis imperfecta (AI) is a clinically and genetically heterogeneous group of inherited defects of enamel formation. In isolated AI (no additional segregating features), mutations in at least 7 genes are known so far, causing dominant, recessive or X-linked AI and allowing the identification of the molecular etiology in 40-50% of affected families. We report on 2 siblings (an 11-year-old female and a 7-year-old male) born to consanguineous Turkish parents, with AI and mild, proportionate short stature. Both parents have normal teeth, but mother, maternal grandmother and great-grandfather are/were also of short stature. A spine X-ray performed in the girl excluded brachyolmia. Affymetrix GenomeWide SNP6.0 Array analysis identified no pathogenic copy number changes, but showed sharing of large homozygous regions, including chromosome band 15q21.3 containing the WDR72 gene. WDR72 sequence analysis in both siblings revealed homozygosity for a novel stop mutation in exon 10 (c.997A>T, p.Lys333X) explaining the AI phenotype. Mutations in WDR72 are a very rare cause of autosomal-recessive hypomaturation type of isolated AI. The mutation described in our patients specifies the diagnosis AI IIA3 and represents only the sixth WDR72 mutation reported so far. The WDR72 protein is critical for dental enamel formation, but its exact function is still unknown.

[Ultrasound as a viable alternative to standard X-rays for the diagnosis of distal forearm fractures in children]

AIM

Distal forearm fractures are very common in childhood. Radiography of the wrist is the standard diagnostic procedure. But because of higher sensitivity of growing bones to ionising radiation the diagnostic use of X-rays should be minimised as much as possible. Recent studies have shown that distal forearm fractures in children can be safely and reliably diagnosed using only ultrasound. The aim of our study was to evaluate and confirm the safety and applicability of the ultrasound diagnostic procedure in comparison to X-ray diagnosis under routine conditions of our paediatric emergency department.

PATIENTS AND METHODS

We investigated 115 patients aged 2-14 years. After clinical assessment patients with suspected forearm fractures first underwent ultrasound examination of the metaphyseal forearm followed by standard two view radiographs of the wrist. Ultrasound and radiographic findings were then compared and sensitivity and specificity for ultrasound were calculated. In 9 patients with suspected displacements, sonographic and radiographic axis measurement were done and also compared.

RESULTS

Radiologically we found 62 patients with 78 distal forearm fractures. By ultrasound we also diagnosed 52 fractures. All patients with no fractures were correctly diagnosed as well. Referring to X-rays we calculated for ultrasound a sensitivity of 94.9 %, a specificity of 98 %, a negative predictive value of 97.4 % and a positive predictive value of 96.1 %. The mean difference of the deformities of the radius in the sagittal section measured sonographically and radiologically were 1.7° (SD 1.6°).

CONCLUSION

We confirm ultrasound is an applicable, rapid and safe alternative to X-rays in diagnosing metaphyseal forearm fractures in children. Even sonographic axis measurement seems to be a viable method. Thereby ultrasound potentially reduces the X-ray burden in children and additionally accelerates the diagnostic procedure.

Vaccination against pandemic H1N1 (2009) in patients after allogeneic hematopoietic stem cell transplantation: a retrospective analysis

Purpose

Limited data are available on immunologic responses to primary pandemic H1N1 (2009) vaccination in recipients of allogeneic hematopoietic stem cell transplantation (HSCT) recipients. In 2009 serologic responses to either pandemic H1N1 (2009) vaccine (n = 36) or pandemic H1N1 (2009) infection (n = 2) were studied in 38 HSCT recipients.

Methods

Responses were measured with a standard hemagglutination-inhibition assay. Fourteen patients had active chronic graft-versus-host disease (cGvHD) at the time of vaccination/infection and seven patients had cGvHD in remission; 11 patients had no immunosuppressive therapy, and 27 patients were on immunosuppressive therapy. Nineteen patients (53%) responded to pandemic H1N1 (2009) vaccination. Two patients had pandemic H1N1 (2009) infection without prior vaccination, and one patient had severe pandemic H1N1 (2009) infection with acute respiratory distress syndrome despite prior single vaccination.

Results

Non-responders to pandemic H1N1 (2009) vaccination more often had cGvHD (65 vs. 53%) and received second- or third-line therapy (53 vs. 11%), while responders mostly had first-line therapy for cGvHD. While vaccine responders had no or single agent immunosuppressive therapy, non-responders frequently received moderate or intense immunosuppressive therapy. All vaccine recipients previously treated with rituximab were non-responders.

Conclusions

In summary, the overall response to pandemic H1N1 (2009) vaccination in HSCT recipients was modest. Patients receiving combined immunosuppressive therapy for steroid-refractory cGvHD barely responded to pandemic H1N1 (2009) vaccination.

Comparison of the novel ResPlex III assay and existing techniques for the detection and subtyping of influenza virus during the influenza season 2006-2007

Influenza virus is a major cause of disease worldwide. The accurate detection and further subtyping of influenza A viruses are important for epidemiologic surveillance, and subsequent comprehensive characterization of circulating influenza viruses is essential for the selection of an optimal vaccine composition. ResPlex III is a new multiplex reverse transcriptase polymerase chain reaction (RT-PCR)-based method for detecting, typing, and subtyping influenza virus in clinical specimens. The ResPlex III assay was compared with other methods with respect to sensitivity and accuracy, using 450 clinical specimens obtained from subjects throughout Germany during the 2006–2007 influenza season. Samples were analyzed for the presence of influenza virus in Madin-Darby canine kidney (MDCK) cells by rapid cell culture using peroxidase staining and conventional cell culture confirmed by hemagglutination inhibition assay, a rapid diagnostic assay (Directigen Flu A+B test; BD Diagnostic Systems, Heidelberg, Germany), in-house real-time RT-PCR (RRT-PCR), and ResPlex III (Qiagen, Hilden, Germany). ResPlex III had the highest sensitivity for detecting influenza virus in clinical specimens, followed by in-house RRT-PCR (96% compared with ResPlex III). Conventional cell culture in MDCK cells, rapid culture, and quick test assays were substantially less sensitive (55%, 72%, and 39%, respectively). Virus subtyping results were identical using ResPlex III and the standard virological subtyping method, hemagglutination inhibition. ResPlex III is a quick, accurate, and sensitive assay for detecting and typing influenza A and B viruses and subtyping influenza A viruses in clinical specimens, and might be considered for a supplemental role in worldwide seasonal and pandemic influenza surveillance.

Comparison of hemagglutination inhibition assay, an ELISA-based micro-neutralization assay and colorimetric microneutralization assay to detect antibody responses to vaccination against influenza A H1N1 2009 virus

The hemagglutination inhibition (HI) assay has been the main method used to investigate immune responses to vaccination against influenza H1N1 (2009) virus. However microneutralization tests (MNT) have been shown to be more sensitive and more specific. In this study, the three methods of choice: (i) the HI assay, (ii) an ELISA-based conventional MNT and (iii) a colorimetric MNT in terms of their ability to detect antibody responses in serum pairs collected from 43 healthy individuals before and 21 days after vaccination were compared. The colorimetric MNT was established yielding intra- and inter-run imprecisions of 7.5% and 12.4%, respectively. Testing of antisera to seasonal influenza viruses demonstrated the assay to be specific for antibodies to influenza H1N1 (2009) virus. A good correlation between the three methods was found, being highest for the ELISA-MNT and the colorimetric MNT (r=0.714 for geometric mean titers (GMT) and r=0.695 for titer increases). Similar rates of fourfold titer increases were detected: 95.3% in the ELISA-MNT vs. 93.0% in colorimetric MNT and 95.3% in HI assay. The ELISA-based MNT demonstrated the highest titer range leading to the highest postvaccination GMT and the highest titer increase (>50-fold). The lowest GMTs were measured with the HI assay, while the colorimetric MNT detected the highest GMT in prevaccination sera. Taken together, similar seroconversion rates were obtained with the three assays. The ELISA-MNT appeared to be the best method to compare absolute pre- and postvaccination GMTs. The colorimetric MNT, being less labour-intensive than the ELISA-MNT, seems to be a suitable tool in vaccination studies.

Neuroimaging in a Three-Year-Old Girl - MRI without Anesthesia: Easier than One Thinks. A Case Report

Magnetic resonance imaging (MRI) is the imaging modality of choice in the diagnosis of structural brain abnormalities in children. Routine scans are usually not reliable in pediatric neuroimaging without sedation before the age of seven. Before this age sedation or general anesthesia with procedural risks and additional costs might be needed. We report on MRI in a 3.1-year-old patient referred after a first seizure performed with a combination of role model and self-experience. MRI with high imaging quality was performed without the need for anesthesia in our daily routine. The imaging procedure was performed without previous preparation needed and within target date.Our reported technique of a combination of role model and self-experience, avoiding anesthesia in a 3.1-year-old girl is suitable for children and it is applicable in the daily routine.

How deadly is seasonal influenza-associated pneumonia? The German Competence Network for Community-Acquired Pneumonia

The emergence of new influenza virus subtypes has rekindled the interest in the clinical course and outcome of patients with influenza-associated pneumonia. Based on prospective data from 5,032 patients with community-acquired pneumonia (CAP) included in the German Competence Network for Community-Acquired Pneumonia (CAPNETZ), we studied the incidence, clinical characteristics and outcome of patients with influenza-associated CAP and compared these findings with patients without influenza. Diagnosis relied on a positive PCR for influenza in throat washings. 160 patients with influenza-associated CAP were identified (3.2% of total population, 12% of those with defined aetiology). 34 (21%) patients with seasonal influenza had a concomitant pathogen (mostly Streptococcus pneumoniae). Patients with influenza-associated CAP were significantly older, had been vaccinated less often and had preceding antibacterial treatment less often. 30-day mortality was low (4.4%) and not different to that of patients with pneumonia caused by bacterial (6.2%) or viral (other than influenza) pathogens (4%). Patients with influenza plus a bacterial pathogen (mixed influenza-associated pneumonia) had a higher mortality than those with pure influenza-associated pneumonia (9% versus 3.2%). Mortality was higher in patients with mixed compared with pure influenza-associated pneumonia. However, we could not observe any excess mortality in patients with influenza-associated pneumonia.

[Six-month clinical results with the light adjustable lens]

PURPOSE

The aim of this study was to evaluate the six-month clinical results of the light adjustable lens (LAL).

MATERIAL AND METHODS

In 20 eyes of 12 patients with cataract a cataract surgery with implantation of a light adjustable lens has been performed. 2 ¹/₂ weeks after surgery all intraocular lens adjustments were carried out. Preoperatively, immediately before the adjustment procedures and 1 month, 3 and 6 months after the adjustment procedure a complete ophthalmic examination was performed.

RESULTS

All cataract surgeries have been carried out without any complications. 2 ¹/₂ weeks after surgery the mean spherical equivalent was + 0.39 D (standard deviation [SD] ± 0.79 D). 6 months after the adjustment procedure the spherical equivalent was -0.07 D (SD ± 0.25 D). 6 months after the adjustment procedure all patients were within ± 0.5 D of intended refraction. Two weeks after surgery the mean cylinder was -0.82 D (SD ± 0.67 D) and was reduced after the adjustments to -0.14 D (SD ± 0.30 D).

DISCUSSION

The light adjustable lens is a new IOL with the ability to correct up to two dioptres of sphere and cylinder after implantation. Our clinical results are promising. Especially the astigmatic correction is very promising, but further clinical investigations with larger patient numbers and longer follow-up are necessary.

Household transmissibility and other characteristics of seasonal oseltamivir-resistant influenza A(H1N1) viruses, Germany, 2007-8

During the influenza season 2007-8, the proportion of seasonal influenza A(H1N1) viruses resistant to the neuraminidase inhibitor oseltamivir increased worldwide. We conducted an investigation to compare patients infected with oseltamivir-resistant (ose-R) and oseltamivir- susceptible (ose-S) influenza A(H1N1) viruses regarding risk factors for resistance and the capability to transmit in the household setting. Within a cohort of 396 laboratory confirmed influenza patients from sentinel physicians we conducted a nested case-control study among patients infected with A(H1N1). Thirty patients in the cohort were infected with influenza B, none with influenza A(H3N2) and 366 with A(H1N1). Of the 366 A(H1N1) viruses 52 (14%) were ose-R. Demographic characteristics, oseltamivir exposure, travel history and outcome were not significantly different between ose-S and ose-R patients. Among 133 households in the nested case-control study, secondary household attack rates in households with ose-R cases and households with ose-S cases were similar (23 versus 26%; p-value=0.54). Ose-R household status and occurrence of secondary cases were associated with an odds ratio of 0.85 (95% confidence interval 0.38-1.88). We conclude that seasonal ose-R influenza A(H1N1) viruses have transmitted well in the household setting.

Household transmissibility and other characteristics of seasonal oseltamivir-resistant influenza A(H1N1) viruses, Germany, 2007-8

During the influenza season 2007-8, the proportion of seasonal influenza A(H1N1) viruses resistant to the neuraminidase inhibitor oseltamivir increased worldwide. We conducted an investigation to compare patients infected with oseltamivir-resistant (ose-R) and oseltamivir- susceptible (ose-S) influenza A(H1N1) viruses regarding risk factors for resistance and the capability to transmit in the household setting. Within a cohort of 396 laboratory confirmed influenza patients from sentinel physicians we conducted a nested case-control study among patients infected with A(H1N1). Thirty patients in the cohort were infected with influenza B, none with influenza A(H3N2) and 366 with A(H1N1). Of the 366 A(H1N1) viruses 52 (14%) were ose-R. Demographic characteristics, oseltamivir exposure, travel history and outcome were not significantly different between ose-S and ose-R patients. Among 133 households in the nested case-control study, secondary household attack rates in households with ose-R cases and households with ose-S cases were similar (23 versus 26%; p-value=0.54). Ose-R household status and occurrence of secondary cases were associated with an odds ratio of 0.85 (95% confidence interval 0.38-1.88). We conclude that seasonal ose-R influenza A(H1N1) viruses have transmitted well in the household setting.

Oseltamivir-resistant influenza A(H1N1) viruses detected in Europe during season 2007-8 had epidemiologic and clinical characteristics similar to co-circulating susceptible A(H1N1) viruses

During the 2007-08 influenza season, high levels of oseltamivir resistance were detected among influenza A(H1N1) viruses ina number of European countries. We used surveillance data to describe influenza A(H1N1) cases for whom antiviral resistance testing was performed. We pooled data from national studies to identify possible risk factors for infection with a resistant virus and to ascertain whether such infections led to influenza illness of different severity. Information on demographic and clinical variables was obtained from patients or their physicians. Odds ratios for infection with an oseltamivir resistant virus and relative risks for developing certain clinical outcomes were computed and adjusted through multivariable analysis. Overall, 727 (24.3%) of 2,992 tested influenza A(H1N1) viruses from 22 of 30 European countries were oseltamivir-resistant. Levels of resistance ranged from 1% in Italy to 67% in Norway. Five countries provided detailed case-based data on 373 oseltamivir resistant and 796 susceptible cases. By multivariable analysis, none of the analysed factors was significantly associated with an increased risk of infection with anoseltamivir-resistant virus. Similarly, infection with an oseltamivir-resistant virus was not significantly associated with a different risk of pneumonia, hospitalisation or any clinical complication. The large-scale emergence of oseltamivir-resistant viruses in Europe calls for a review of guidelines for influenza treatment.

Oseltamivir-resistant influenza A(H1N1) viruses detected in Europe during season 2007-8 had epidemiologic and clinical characteristics similar to co-circulating susceptible A(H1N1) viruses

During the 2007-08 influenza season, high levels of oseltamivir resistance were detected among influenza A(H1N1) viruses in a number of European countries. We used surveillance data to describe influenza A(H1N1) cases for whom antiviral resistance testing was performed. We pooled data from national studies to identify possible risk factors for infection with a resistant virus and to ascertain whether such infections led to influenza illness of different severity. Information on demographic and clinical variables was obtained from patients or their physicians. Odds ratios for infection with an oseltamivir resistant virus and relative risks for developing certain clinical outcomes were computed and adjusted through multivariable analysis. Overall, 727 (24.3%) of 2,992 tested influenza A(H1N1) viruses from 22 of 30 European countries were oseltamivir-resistant. Levels of resistance ranged from 1% in Italy to 67% in Norway. Five countries provided detailed case-based data on 373 oseltamivir resistant and 796 susceptible cases. By multivariable analysis, none of the analysed factors was significantly associated with an increased risk of infection with an oseltamivir-resistant virus. Similarly, infection with an oseltamivir-resistant virus was not significantly associated with a different risk of pneumonia, hospitalisation or any clinical complication. The large-scale emergence of oseltamivir-resistant viruses in Europe calls for a review of guidelines for influenza treatment.

[Investigation of a family cluster of influenza A/H1N1 infections in Germany, 2009]

INTRODUCTION

On May 3, 2009, a first case of influenza A/H1N1 infection occurred in the federal state of Saxony-Anhalt, Germany. In order to stop the possible spread of the virus and to study the epidemiological and clinical characteristics of the infection, an investigation was launched by the local health authorities and the RKI.

METHODS

Standardised questionnaires were used to assess demographic and clinical data. Specimens were collected from case patients and close contacts and were analysed for influenza A/H1N1 using real-time PCR.

RESULTS

The index patient showed fever and coughing 3.5 days after returning from a holiday in Mexico. The local health authorities were informed on May 3, and measures were rapidly implemented. These measures included a trace-back of possible contact persons, isolation of the case and close contacts, prophylactic treatment with Oseltamivir. Virological investigations showed that the case shedded viral genome up until the last day of antiviral therapy. Viral genome was also detected in the spouse and the son of the patient. Both showed no symptoms under a prophylactic treatment with antiviral medication. No viral genome was detected in three other family members, and in six other contact persons outside of the family.

DISCUSSION

The spread of the virus was contained due to the fast response of the local health authorities. Two secondary cases occurred in the family. These cases remained asymptomatic, possibly due to antiviral prophylaxis. Epidemiological and virological results suggest that the influenza A/H1N1 virus has a longer incubation period and that viral shedding may probably be prolonged when compared with seasonal influenza.