[Laryngeal squamous cell carcinoma in a 12-year-old boy]. / Plattenepithelkarzinom des Larynx bei einem 12-jährigen Jungen.

This is a case report on a middle grade differentiated keratinized squamous cell carcinoma of the larynx in a 12-year-old boy. Squamous cell carcinoma of the larynx is very rare in children and adolescents and in older literature studies less than 70 cases have been reported in children. Histologically the same variants are present as in adults. The way to the final diagnosis of laryngeal carcinoma often takes longer in children because dysphonia or dyspnoe are often caused by other pediatric diseases, risk factors such as those found in adults cannot be elucidated and many symptoms can be due to incomplete development of the laryngeal skeleton. Generally speaking, prior radiation therapy of the neck region and papillomatosis have been described as risk factors. In rare cases translocations or mutations can play a causative role.

Integration of human papilloma virus type 26 in laryngeal cancer of a child.

Squamous cell carcinoma (SCC) in larynx is rare with children and adolescents. Usually larynx cancer is common with male smokers in the 7th decade. Among patients with no history of tobacco and/or alcohol consumption several factors have can play a role in the outbreak of laryngeal cancer: such as individual predisposition, radiation, gastroesophageal reflux, viral infection, dietary factors and environmental influences. In literature only few cases of laryngeal cancer with children are reported. Recent studies show that the most frequent laryngeal malignancy is the embryonal rhabdomyosarcoma. Besides the recurrent respiratory papillomatosis (RRP) based on an infection with human papilloma virus (HPV) types 6 and 11 (low risk) and types 16 and 18 (high risk) is known for a possible malignant transformation towards a SCC. HPV type 26 is only reported as low risk type HPV associated with cervical cancer. Final diagnosis often takes a long time. Initial symptoms such as hoarseness, cough or shortness of breath are often referred to more typical pediatric diseases or laryngeal development.

Aymptomatic CMV viremia is associated with increased levels of serum amyloid A in patients with advanced HIV-infection.

OBJECTIVE: We evaluated assays for the measurement of acute phase protein levels in plasma for their usefulness to identify sensitively an inflammatory response to active cytomegalovirus CMV infection in HIV-infected patients. METHODS: Plasma samples were collected from 28 CMV-seropositive patients with advanced HIV-infection (CD4-cell count <200/microl) before commencement of antiretroviral therapy. Sensitivity, specificity, and area under receiver operating characteristic curve for the selected acute phase protein assays (haptoglobin, fibronectin, high-sensitivity C-reactive protein (hs-CRP), human interleukin-6, serum amyloid A (SAA), and human lipopolysacharide binding protein) were compared with results of a CMV-specific PCR assay. RESULTS: CMV viremia was detectable in 8/28 patients. Levels of SAA correlated well with those of hs-CRP (r' = 0.439, P = 0.019 (Spearman rank correlation)). Levels of SAA >3 mg/L discriminated with 100% sensitivity and 40% specificity between HIV-infected patients with and without active CMV infection. Sensitivity of fibronectin was 100% and specificity 15% at a threshold-value corresponding with the lower limit of normal values as defined by the manufacturer of the assay (>29 mg/dL). Levels of the other acute phase proteins evaluated did not correlate with detection of CMV-DNA in plasma. CONCLUSION: Increased levels of SAA indicate sensitively an inflammatory response to active CMV infection. Use of a CMV-specific virological assay is required to confirm the specificity of a high SAA-level but may be limited to samples with high SAA-levels. Hence, screening for increased levels of SAA in patients with advanced HIV-infection may allow early identification of active CMV infection.

Biotypes of group A streptococci from patients with pharyngitis and soft tissue infections.

This study determined the biotypes of group A streptococci (GAS) isolated from 66 pharyngeal and 62 skin and soft-tissue infections. Among all GAS isolates tested, the most common biotypes were 1 and 3, irrespective of the isolation source and the severity of clinical symptoms. However, compared with the pharyngeal group, a more heterogeneous distribution of biotypes was observed among the cutaneous group of isolates, including seven isolates that were non-typeable but had an identical biotype pattern, suggesting that they may represent a new biotype.

Prevalence, incidence, and clinical relevance of the reverse transcriptase V207I mutation outside the YMDD motif of the hepatitis B virus polymerase during lamivudine therapy.

The reverse transcriptase V207I mutation within the hepatitis B virus (HBV) polymerase is associated with resistance to lamivudine in vitro. The prevalence of this mutation in treatment-naive patients was 1% (1/96). A follow-up of the patient carrying this mutation prior to treatment revealed no loss of sensitivity of HBV to lamivudine in vivo.

Fatal influenza A infection with Staphylococcus aureus superinfection in a 49-year-old woman presenting as sudden death.

A fatal case of influenza A infection with Staphylococcus aureus superinfection in a previously healthy 49-year-old woman presenting as sudden, unexpected death is reported. Autopsy revealed severe necrotizing tracheobronchitis and hemorrhagic pneumonia. Microscopic examination of the trachea and bronchi showed mucosal necrosis and a dense lympho-monocytic infiltration of all layers. The lungs showed focal hemorrhagic pneumonia. No pathological changes were detectable in the myocardium. Influenza A virus was detected in bronchi and lung samples obtained during autopsy by the polymerase chain reaction (PCR) and bacterial superinfection with Staphylococcus aureus was shown by culturing from tracheal, bronchial and pulmonary swabs obtained during autopsy. PCR assays for the detection of Panton-Valentine leukocidin performed from all samples were negative. This case demonstrates the need for an interdisciplinary approach towards an organism-specific diagnosis of potentially infection-related deaths undergoing a medico-legal autopsy. With improved diagnostic possibilities such as PCR and DNA sequencing, forensic pathologists can, in close association with the field of microbiology, make a significant contribution to the detection of highly infectious agents which must be notified to the authorities. This will increase particularly the knowledge about the influence of these agents on sudden, unexpected deaths in outpatients.

Prevalence of SENV-H viraemia among healthy subjects and individuals at risk for parenterally transmitted diseases in Germany.

The prevalence of a newly described DNA virus (SENV-H) was examined in a population of 599 individuals by polymerase chain reaction (PCR). All individuals were assigned to a nonrisk or a risk group depending on the presence of historical or serological factors indicating an increased risk for parenterally transmitted diseases. In a group of 226 healthy blood donors, 38 (16.8%) were found to be SENV-H viraemic. The highest prevalence of SENV-H viraemia was observed among patients infected by HIV (28 of 63; 44.4%). Contrarily, of 78 individuals on maintenance haemodialysis, only 10 (12.8%) were found positive in the SENV-H PCR. Our results demonstrate that SENV-H viraemia is widespread in the general population. Therefore, it seems to be questionable if parenteral transmission is the main route for spreading SENV-H. The hepatitis-inducing capacity of SENV-H is unclear. However, taking our clinical and epidemiological data into account it seems unlikely that this virus is responsible for hepatitis.

[Hepatitis C. Virology, transmission modes, clinical aspects, prevention and therapy]. / Hepatitis C Virologie, Ubertragungswege, Klinik, Prävention und Therapie.

Of the various forms of chronic viral hepatitis, in Germany 60-70% are caused by the hepatitis C virus (HCV). The virus arrives inconspicuously, i.e. an acute infection only leads to an increase in transaminases in 40% of cases and to an increase in bilirubin in only 20%. However, approximately 90% of infections take a chronic course and in 20% this leads to cirrhosis after only 20 years. The infection rate of medical personnel is not significantly higher than in the general population. The transmission of HCV from patients to medical personnel, e.g. by needle stick injuries, is very rare and the risk of infection is less than 1%. Even less frequently transmission of HCV in the reverse direction from medical personnel to patients occurs. An active or passive prophylactic immunization is not possible and protective immunization is not yet foreseeable. Recently, progress has been made with chemotherapeutical treatment of HCV. The present state-of-the-art is pegylated interferon-a in combination with ribavirin. The success rate in HCV genotypes 2 and 3 is clearly higher with 70-80% than in genotypes 1 and 4 with approximately 40%. Both drugs have significant side-effects but better forms of medication are not yet available.

Correlation of hepatitis B virus load with loss of e antigen and emerging drug-resistant variants during lamivudine therapy.

It remains unclear whether sequential assessment of hepatitis B virus (HBV) load during lamivudine therapy can predict the loss of hepatitis B e antigen or emergence of drug-resistant variants. Therefore, a longitudinal study was carried out in 28 consecutive patients with chronic hepatitis B who started lamivudine therapy for a median of 12 months (range, 6-31). HBV DNA copy numbers were determined at 3-month intervals. From month 6 onward, HBV viral load below the detection limit of the PCR was predictive of the loss of envelope antigen (P = 0.043). Continuously detectable HBV DNA during the first 12 months of treatment indicated emergence of drug-resistant variants (P = 0.034). These data suggest that the goal of lamivudine therapy should be complete suppression of serum HBV DNA.

Comparison of three HCV genotyping assays: a serological method as a reliable and inexpensive alternative to PCR based assays.

BACKGROUND: Determination of hepatitis C virus (HCV) genotypes and subtypes is of rising clinical importance. In times where also an increasing need for cost effectiveness can be observed, the demand for fast and easy performable assays grows. OBJECTIVES: To evaluate and compare different genotyping methods regarding their reliability, practicability, and expense in the daily routine. METHODS: Sera of 39 patients infected with different HCV subtypes were examined by a serological genotyping assay (NS-4 IBA), by the widely used INNO-LiPA HCV II, and by a nucleotide sequencing method. RESULTS: The tests performed equally well in terms of HCV subtyping and no different results were obtained. However, the serotyping assay provided the results in less than half the time needed by the other two assays. Significant differences were also observed regarding the 'hands on' times and the costs. The technical equipment which was necessary to perform the assays is significantly reduced using the serological assay. CONCLUSION: Our study demonstrates that the serological test offers the opportunity to determine HCV genotypes and subtypes reliably, fast, easy, and cost effective.

Strategies for reliable diagnosis of hepatitis C infection: the need for a serological confirmatory assay.

The aim of the study was to examine whether the diagnosis of Hepatitis C (HCV) infection can be obtained reliably without using an immunoblot-based confirmation assay. 1,708 EIA-reactive serum samples were examined retrospectively for (i) optical density value in the screening assay, (ii) reactivity in an immunoblot assay, and (iii) result by RT PCR. In 1,394 (81.0%) samples positive results were obtained by both the HCV EIA and the confirmation assay. OD-values > or = 2.2 were observed in 1026 of these samples, but covered the range from 0.4 to 2.1 in the other 368 samples. The combination of HCV EIA reactivity and indeterminate immunoblot assay was observed in 134 (7.8%) serum samples. HCV RNA was detected in 58 cases by PCR. The OD-values of these 58 samples ranged from 0.4 to >2.2. Especially reactivity against the core recombinant protein was indicative of PCR positivity. The reactivity by the HCV EIA could not be confirmed by immunoblot assay or PCR in 180 (10.5%) sera. These false reactive sera showed OD values by EIA from 0.3 to 2.1. It is concluded that no threshold values can be defined which would allow differentiation between positive, indeterminate, and false reactive result by HCV EIA without producing an unacceptably high number of false negative diagnoses. Not using immunoblot-based confirmation would result in many additional PCR examinations. Therefore, confirmation of reactive HCV EIA results by a serological confirmatory assay must remain an essential part of the diagnostic procedure.

20-fold increase in risk of lamivudine resistance in hepatitis B virus subtype adw.

We investigated subtype-dependent development of lamivudine resistance in hepatitis B virus (HBV) longitudinally in 26 consecutive patients (13 adw and 13 ayw carriers) during antiviral treatment of chronic hepatitis B. Lamivudine resistance developed in seven adw carriers and one ayw carrier. Risk of lamivudine resistance was significantly higher for adw carriers than for ayw carriers (p=0.03). We believe that the adw subtype of HBV is associated with a high risk of lamivudine resistance, which might be linked to simultaneous changes of the HBsAg that occurs with the emergence of resistance.

Relevance of reactivity in commercially available hepatitis C virus antibody assays.

Sera from 2,148 patients were tested with a third-generation microparticle enzyme immunoassay (MEIA), a confirmatory assay, and a reverse transcription-PCR. Overall, 85.6% of reactivities were confirmed, 13.2% were shown to be unspecifically reactive, and 1.2% were indeterminate. The rate of confirmed MEIA reactivities clearly depended on the strength of the reactivity.

Application of HIV-1 genotypic-resistance testing prevents the evolution of further resistance mutations in heavily pretreated patients.

BACKGROUND: Resistance-associated mutations in HIV-1 evolve even under highly active antiretroviral therapy. OBJECTIVE: To evaluate the clinical efficacy of genotypic-resistance testing (GRT), to estimate the potential of a given antiretroviral therapy for prevention of further resistance mutations. STUDY DESIGN: Ten patients were treated prospectively with drugs, according to the results of a GRT. Five patients were allocated to group I in which antiretroviral therapy could be switched to an effective regimen (consisting of at least three sensitive drugs, from at least two different classes of antiretroviral substances). Five patients (group II) had no option for effective therapy, and continued to be treated non-effectively (at least one applicated substance class only intermediately sensitive, or resistant). GRT and quantitative viral cultures were performed longitudinally for 8 months. Also, plasma HIV-1 RNA, total CD4+ cells, and rates of productively infected CD4+ cells were determined. RESULTS: All the patients in group I showed a significant decrease of HIV-RNA of >1 log/ml (mean, -1.35 log/ml, P=0.025). The mean increase of CD4+ cells was 46 (not significant). The rate of productively infected CD4+ cells decreased significantly (mean, -16 productively infected CD4+ cells per 10(6) total CD4+ cells, P=0.04). In this group no further resistance mutations were detected after 8 months. In group II, none of the patients showed a significant decrease of HIV-1 RNA (mean, +0.05 log/ml), total CD4+ cells decreased (mean, -35, not significant), the rate of productively infected CD4+ cells increased significantly (mean, +124 productively infected CD4+ cells per 10(6) total CD4+ cells, P=0.04), and 4 of 5 patients had additional mutations in the RT gene conferring multi-drug resistance within 8 months (P=0.048). CONCLUSIONS: GRT is predictive of the efficacy of a therapeutic regimen, in particular regarding evolution of further resistance mutations.

Biofilm formation by Staphylococcus epidermidis depends on functional RsbU, an activator of the sigB operon: differential activation mechanisms due to ethanol and salt stress.

Staphylococcus epidermidis is a common pathogen in medical device-associated infections. Its major pathogenetic factor is the ability to form adherent biofilms. The polysaccharide intercellular adhesin (PIA), which is synthesized by the products of the icaADBC gene cluster, is essential for biofilm accumulation. In the present study, we characterized the gene locus inactivated by Tn917 insertions of two isogenic, icaADBC-independent, biofilm-negative mutants, M15 and M19, of the biofilm-producing bacterium S. epidermidis 1457. The insertion site was the same in both of the mutants and was located in the first gene, rsbU, of an operon highly homologous to the sigB operons of Staphylococcus aureus and Bacillus subtilis. Supplementation of Trypticase soy broth with NaCl (TSB(NaCl)) or ethanol (TSB(EtOH)), both of which are known activators of sigB, led to increased biofilm formation and PIA synthesis by S. epidermidis 1457. Insertion of Tn917 into rsbU, a positive regulator of alternative sigma factor sigma(B), led to a biofilm-negative phenotype and almost undetectable PIA production. Interestingly, in TSB(EtOH), the mutants were enabled to form a biofilm again with phenotypes similar to those of the wild type. In TSB(NaCl), the mutants still displayed a biofilm-negative phenotype. No difference in primary attachment between the mutants and the wild type was observed. Similar phenotypic changes were observed after transfer of the Tn917 insertion of mutant M15 to the independent and biofilm-producing strain S. epidermidis 8400. In 11 clinical S. epidermidis strains, a restriction fragment length polymorphism of the sigB operon was detected which was independent of the presence of the icaADBC locus and a biofilm-positive phenotype. Obviously, different mechanisms are operative in the regulation of PIA expression in stationary phase and under stress induced by salt or ethanol.

Prevalence of a novel DNA virus (TTV) among patients on maintenance hemodialysis.

BACKGROUND/AIMS: A recently detected DNA virus (TTV) has been assumed to be responsible for posttransfusion hepatitis in humans. Until now it is unclear whether patients on maintenance hemodialysis are at increased risk of acquiring TTV. METHODS: Serum samples derived from 143 chronically hemodialyzed patients were examined for TTV viremia by nested PCR. All serum specimens were also investigated for viremia and for the presence of antibodies of hepatitis C virus (HCV) and GB virus C/hepatitis G virus (GBV-C/HGV) by PCR and serological assays, respectively. RESULTS: The prevalence of TTV was determined to be 18.8% (n = 27), for HCV a prevalence of 15.4% (n = 22) and for GBV-C/HGV of 8.4% (n = 12) could be demonstrated. Parallel infection by TTV and HCV was detected in only 1.4% (n = 2) of the patients. In no serum sample could TTV and GBV-C/HGV be detected in parallel. None of the solely TTV-viremic individuals had clinical or biochemical signs of liver disease. CONCLUSION: From our data we conclude that TTV viremia is widespread among hemodialysis patients and can be detected in 18.8%. Since no viremic patient had clinical or biochemical signs of liver disease, the hepatitis-inducing capacity of TTV remains unclear.

Quantitative detection of hepatitis C virus RNA by light cycler PCR and comparison with two different PCR assays.

The new Light Cycler technology was adapted to the detection of hepatitis C virus (HCV) RNA in clinical samples. Sera from 81 patients were tested by Light Cycler PCR, AMPLICOR HCV Monitor assay, and in-house PCR. Our data demonstrate that Light Cycler is a fast and reliable method for the detection and quantitation of HCV RNA.

Nosocomial outbreak of vancomycin-resistant Enterococcus faecium at a German university pediatric hospital.

Nosocomial Infections caused by vancomycin-resistant enterococci (VRE) are an emerging threat to critically ill patients. At the University Hospital Eppendorf, VRE were isolated from 38 patients between August 1993 and April 1997, of whom 32 were hospitalized at the Department of Pediatrics. Pulsed-field gel electrophoresis revealed that 26 Enterococcus faecium isolates from patients of the Department of Pediatrics were identical or closely related, and that isolates from three additional patients of the same department were possibly related. All of these isolates were of vanA genotype. They were resistant to glycopeptides, ampicillin, ciprofloxacin, clindamycin, and erythromycin. Most isolates displayed high-level resistance to gentamicin, but all remained susceptible to quinupristin/dalfopristin. Implementation of stringent hand disinfection and environmental disinfection policies, as well as measures for patient isolation contained this first outbreak of VRE at a German Children's hospital, which emphasizes the importance of hygienic measures for the control of nosocomial spread of these organisms.

Identification of three essential regulatory gene loci governing expression of Staphylococcus epidermidis polysaccharide intercellular adhesin and biofilm formation.

The formation of adherent multilayered biofilms embedded into a glycocalyx represents an essential factor in the pathogenesis of Staphylococcus epidermidis biomaterial-related infections. Using biofilm-producing S. epidermidis 1457 and transposon Tn917 carried on plasmid pTV1ts, we isolated nine isogenic biofilm-negative transposon mutants. Transduction by S. epidermidis phage 71 was used to prove the genetic linkage of transposon insertions and altered phenotypes. Mapping of the different transposon insertions by Southern hybridization and pulsed-field gel electrophoresis indicated that these were inserted in four unlinked genetic loci. According to their phenotypes, including quantitative differences in biofilm production in different growth media, in the amount of the polysaccharide intercellular adhesin (PIA) produced, in the hemagglutination titers, and in the altered colony morphology, the mutants could be separated into four phenotypic classes corresponding with the genetic classes. Synthesis of PIA was not detectable with class I and II mutants, whereas the amount of PIA produced reflected the residual degree of biofilm production of class III and IV mutants in different growth media. Chromosomal DNA flanking the transposon insertions of five class I mutants was cloned and sequenced, and the insertions were mapped to different locations of icaADBC, representing the synthetic genes for PIA. Expression of icaADBC from a xylose-dependent promoter in the different isogenic mutant classes reconstituted biofilm production in all mutants. In a Northern blot analysis no icaADBC-specific transcripts were observed in RNA isolated from mutants of classes II, III, and IV. Apparently, in addition to icaADBC, three other gene loci have a direct or indirect regulatory influence on expression of the synthetic genes for PIA on the level of transcription.