Viral shedding in children infected by pandemic A/H1N1/2009 influenza virus

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to investigate viral shedding in otherwise healthy children with pandemic A/H1N1/2009 influenza in order to define how long children with pandemic A/H1N1/2009 influenza shed the virus, and also plan adequate measures to control the spread of the disease within households.</p> <p>Findings</p> <p>In 74 otherwise healthy children with pandemic A/H1N1/2009 influenza, nasopharyngeal swabs were taken for virus detection upon hospital admission and every two days until negative. The nasopharyngeal swabs of all of the children were positive for pandemic A/H1N1/2009 influenza virus in the first three days after the onset of infection, and only 21.6% and 13.5% remained positive after respectively 11 and 15 days. No child was positive after more than 15 days. Viral load also decreased over time, and was not associated with patient age or the risk of pneumonia. Those who shed the virus for ≥ 9 days were not at any increased risk of suffering from more severe disease in comparison with those who shed the virus for a shorter time, but their households experienced a significantly higher number of influenza-like illness during the two weeks after the onset of the initial disease (72.3% <it>vs </it>41.4%; p < 0.05).</p> <p>Conclusions</p> <p>Regardless of their age, healthy children can shed pandemic A/H1N1/2009 influenza virus for up to two weeks after illness onset, and the households of the children who shed the virus for ≥ 9 days suffered a higher number of influenza-like illness in the two weeks following the onset of the first disease. This could suggest that when a completely unknown influenza virus is circulating, isolation period of infected children has to be longer than the 7 days recommended for the infections due to seasonal influenza viruses.</p

Antibody response of healthy children to pandemic A/H1N1/2009 influenza virus

<p>Abstract</p> <p>Background</p> <p>Little is known about the proportion of pediatric pandemic A/H1N1/2009 influenza cases who showed seroconversion, the magnitude of this seroconversion, or the factors that can affect the antibody level evoked by the pandemic A/H1N1/2009 influenza. Aims of this study were to analyse antibody responses and the factors associated with high antibody titres in a cohort of children with naturally acquired A/H1N1/2009 influenza infection confirmed by reverse-transcriptase polymerase chain reaction (RT-PCR).</p> <p>Results</p> <p>Demographic, clinical and virologic data were collected from 69 otherwise healthy children with pandemic A/H1N1/2009 influenza (27 females, mean age ± SD: 5.01 ± 4.55 years). Their antibody levels against pandemic A/H1N1/2009 and seasonal A/H1N1 influenza viruses were evaluated by measuring hemagglutination-inhibiting antibodies using standard assays. Sixty-four patients (92.8%) with pandemic A/H1N1/2009 influenza had A/H1N1/2009 antibody levels of ≥40, whereas only 28/69 (40.6%) were seroprotected against seasonal A/H1N1 influenza virus. Those who were seroprotected against seasonal A/H1N1 virus were significantly older, significantly more often hospitalised, had a diagnosis of pneumonia significantly more frequently, and were significantly more often treated with oseltamivir than those who were not seroprotected (<it>p </it>< 0.05). The children with the most severe disease (assessed on the basis of a need for hospitalisation and a diagnosis of pneumonia) had the highest antibody response against pandemic A/H1N1/2009 influenza virus.</p> <p>Conclusions</p> <p>Otherwise healthy children seem to show seroprotective antibody titres after natural infection with pandemic A/H1N1/2009 influenza virus. The strength of the immune response seems to be related to the severity of the disease, but not to previous seasonal A/H1N1 influenza immunity.</p

Collection by trained pediatricians or parents of mid-turbinate nasal flocked swabs for the detection of influenza viruses in childhood

This study evaluated the efficiency of pediatric mid-turbinate nasal flocked swabs used by parents in 203 children aged 6 months to 5 years with signs and symptoms of respiratory disease. Two nasal samples were collected from each child in a randomised sequence: one by a trained pediatrician and one by a parent. The real-time polymerase chain reaction influenza virus detection rates were similar in the samples collected using the two methods (Cohen's kappa = 0.86), as were the cycle threshold values. In comparison with the pediatrician-collected samples, the sensitivity and specificity of the parental collections were respectively 89.3% (95% confidence interval [CI]: 77.8-100%) and 97.7% (95% CI: 95.5-100%), and the positive and negative predictive values were respectively 86.2% (95% CI: 73.7-95.1%) and 98.2% (95% CI: 96.4-100%). The children were significantly more satisfied with the parental collections (median values ± standard deviation, 1.59 ± 0.55 vs 3.51 ± 0.36; p < 0.0001). These findings show that mid-turbinate nasal flocked swabs specifically designed for infants and children can be used by parents without reducing the influenza virus detection rate. Moreover, the direct involvement of parents significantly increases patient acceptance, thus simplifying collection and suggesting that this novel swab design should be considered for epidemiological surveys and vaccine efficacy studies

Clinical importance and impact on the households of oseltamivir-resistant seasonal A/H1N1 influenza virus in healthy children in Italy

A resistance of A/H1N1 influenza viruses to oseltamivir has recently emerged in a number of countries. However, the clinical and socioeconomic importance of this resistance has not been precisely defined. As children have the highest incidence of influenza infection and are at high risk of severe disease, the aim of this study was to evaluate the clinical importance and the impact on the households of oseltamivir-resistant seasonal A/H1N1 influenza virus in an otherwise healthy pediatric population. A total of 4,726 healthy children younger than 15 years with influenza-like illness were tested for influenza viruses by real-time polymerase chain reaction in the winters of 2007-2008 and 2008-2009 in Italy. The influenza A virus-positive samples underwent neuraminidase gene analysis using pyrosequencing to identify mutations H275Y and N294 S in A/H1N1, and E119V, R292K, and N294 S in A/H3N2. Among the A/H1N1 subtypes, the H275Y mutation was found in 2/126 samples taken in 2007-2008 (1.6%) and in all 17 samples (100%; p < 0.0001) taken in 2008-2009. No other mutation was identified in any of the A/H1N1 or A/H3N2 influenza viruses. No significant differences were found in terms of clinical importance or impact on the households between the children with oseltamivir-resistant seasonal A/H1N1 influenza virus and those with the wild-type. The spread of H275Y-mutated A/H1N1 seasonal influenza virus is a common phenomenon and the clinical importance and impact on the households of the mutated virus is similar to that of the wild-type in an otherwise healthy pediatric population

Comparison of nasopharyngeal nylon flocked swabs with universal transport medium and rayon- bud swabs with a sponge reservoir of viral transport medium in the diagnosis of paediatric influenza

This study compared a kit containing a nasopharyngeal nylon flocked swab and a tube with a liquid universal transport medium (UTM) with a kit containing a plastic-shafted rayon-budded swab with a sponge reservoir of viral transport medium for the molecular detection of influenza viruses in children. Respiratory samples were collected from 314 children aged ,5 years with influenza-like illness (186 males; mean age 2.32±2.27 years) using both swabs in a randomized sequence for each patient. The flocked swabs permitted the detection of 28 influenza A (8.9 %) and 45 influenza B (14.3 %) cases, and the rayon-bud swabs 26 influenza A (8.3 %) and 43 influenza B (13.7 %) cases, with detection rates of 23.2 and 22.0 %, respectively, and similar cycle threshold values. Paediatricians and laboratory staff were significantly more satisfied with both the simplicity (P ,0.0001) and rapidity (P ,0.0001) of the nasopharyngeal flocked swabs with UTM. These findings show that the flocked swabs with UTM and the rayon-bud swabs with a sponge transport medium are similarly efficient in preserving influenza virus nucleic acid, but that the kit containing a flocked swab with a UTM allows easier and more rapid collection and processing of specimens. INTRODUCTION Respiratory infections are the most common diseases of infants and children Antigen detection tests and PCR-based methods are both currently used to detect viruses in respiratory secretions There are various kits containing a nasopharyngeal swab and a tube with transport medium on the market, but only a few studies, mainly of adults, have compared their efficiency in collecting respiratory cells and preserving influenza virus nucleic acid Sample collection. Two samples were collected from each patient and transported by means of two kits: one containing a flexible nasopharyngeal nylon flocked swab and a mini-tube with 1 ml liquid universal transport medium (UTM; Copan Italia), and the other a rayon-budded swab with a tube containing a sponge pre-impregnated with transport medium (Virocult; Medical Wire &amp; Equipment). Using the swabs in a randomized sequence, two nasopharyngeal samples were collected from each child (one from each nostril) by trained paediatricians (L. C., L. G. and S. B.). The distance between the patient&apos;s nares and ear lobe was measured to estimate the length of insertion, after which the swabs were gently inserted towards the pharynx until resistance was felt and then rotated three times to obtain epithelial cells. They were then withdrawn and put into the tube containing the specific transport medium. All of the specimens were kept cool and delivered to the laboratory within 3 h of collection. Sample processing. In the laboratory, each swab was processed in triplicate by three researchers (C. G. M., C. D. and A. V.) as indicated by the manufacturers: 190 ml of the liquid transport medium for the flocked swabs was used directly, whereas the rayon-budded swabs were placed in a tube containing 1 ml liquid lysis buffer (the same amount as that contained in the mini-UTM), the tube was vortexed and incubated for 10 min at room temperature, and 190 ml of the solution was used for extraction. PCR. Viral RNA was extracted from all of the samples by means of a NucliSENS EasyMAG automated extraction system (bioMeriéux), using phocine distemper virus (PDV) as an extraction/PCR inhibition control as described previously (Bosis et al., 2005; Staff satisfaction. Trained paediatricians and members of the laboratory staff were asked to record their satisfaction with the simplicity and rapidity using the swabs after the enrolment of each patient or the completion of the analysis of each pair of swabs by completing a 5-point scale (from 5 &apos;very satisfied&apos; to 1 &apos;very dissatisfied&apos;). Statistical analysis. The data relating to the paired specimens collected from 314 children (186 males, 59.2 %), with a mean age of 2.32±2.27 years, were compared using SAS version 9.1 software (SAS Institute). Continuous variables were analysed using Wilcoxon&apos;s signed rank test or rank sum test as appropriate, and the categorical variables by means of contingency tables and a x 2 or Fisher&apos;s test. RESULTS AND DISCUSSION Satisfaction was based on a 5-point scale from 5 &apos;very satisfied&apos; to 1 &apos;very dissatisfied&apos;. .20 for influenza B virus. However, the paediatricians and laboratory staff were significantly more satisfied with both the simplicity (P ,0.0001) and the rapidity (P ,0.0001) of the nasopharyngeal flocked swabs with UTM. Our study showed that the flocked swabs with UTM and the rayon-budded swabs with transport medium preimpregnated sponge were similarly efficient in preserving influenza virus nucleic acid, but that the former were considered better in terms of the simplicity and rapidity of collection and laboratory testing. Systematic evaluation of the aetiology of paediatric respiratory infections is increasingly being considered an important means of preventing their spread and rationalizing therapy Our main finding was that the paediatricians preferred the flocked swabs because they were more flexible and made it easier and quicker to collect the samples. In addition, the laboratory staff found that the kit containing a flocked swab and liquid transport medium was advantageous insofar as it allowed RNA extraction and PCR to be performed directly on the liquid without the need to add further buffer, whereas the kit containing a transport medium pre-impregnated sponge required an additional step that made the procedure more complicated, timeconsuming and at risk of contamination. One limitation of this study is represented by the fact that the interpretation of the results on simplicity and rapidity of collection and laboratory testing may be devalued by repeated scoring and clustering by the same staff members. This means that further studies that involve several swab collectors and laboratory researchers are required to confirm our results. Moreover, our aim was to compare the efficiency of the two kits in detecting influenza virus nucleic acid, but further studies are required to evaluate the sensitivity of the two transport systems with serial dilutions of positive samples of influenza A and B viruses. Finally, a complete comparison of the sensitivity and specificity of the two kits should also include detection of other respiratory viruses that are commonly found in respiratory samples (e.g. respiratory syncytial virus, adenovirus, rhinovirus), and future research should address this aim. In conclusion, both the flocked swabs with UTM and the rayon-bud swabs with a sponge reservoir of viral transport medium allow adequate collection, transport and preservation of nasal secretions for influenza detection. However, the kit containing a flocked swab with a liquid transport medium facilitated rapid specimen collection and processing. These factors should be considered together with local costs when choosing a product to use in clinical practice. ACKNOWLEDGEMENT

Clinical and socioeconomic impact of different types and subtypes of seasonal influenza viruses in children during influenza seasons 2007/2008 and 2008/2009

<p>Abstract</p> <p>Background</p> <p>There are few and debated data regarding possible differences in the clinical presentations of influenza A/H1N1, A/H3N2 and B viruses in children. This study evaluates the clinical presentation and socio-economic impact of laboratory-confirmed influenza A/H1N1, A/H3N2 or B infection in children attending an Emergency Room because of influenza-like illness.</p> <p>Methods</p> <p>Among the 4,726 children involved, 662 had influenza A (143 A/H1N1 and 519 A/H3N2) and 239 influenza B infection detected by means of real-time polymerase chain reaction. Upon enrolment, systematic recordings were made of the patients' demographic characteristics and medical history using standardised written questionnaires. The medical history of the children was re-evaluated 5-7 days after enrolment and until the resolution of their illness by means of interviews and a clinical examination by trained investigators using standardised questionnaires. During this evaluation, information was also obtained regarding illnesses and related morbidity among households.</p> <p>Results</p> <p>Children infected with influenza A/H1N1 were significantly younger (mean age, 2.3 yrs) than children infected with influenza A/H3N2 (mean age, 4.7 yrs; p < 0.05)) or with influenza B (mean age, 5.2 yrs; p < 0.05). Adjusted for age and sex, children with influenza A/H3N2 in comparison with those infected by either A/H1N1 or with B influenza virus were more frequently affected by fever (p < 0.05) and lower respiratory tract involvement (p < 0.05), showed a worse clinical outcome (p < 0.05), required greater drug use (p < 0.05), and suffered a worse socio-economic impact (p < 0.05). Adjusted for age and sex, children with influenza B in comparison with those infected by A/H1N1 influenza virus had significantly higher hospitalization rates (p < 0.05), the households with a disease similar to that of the infected child (p < 0.05) and the need for additional household medical visits (p < 0.05).</p> <p>Conclusions</p> <p>Disease due to influenza A/H3N2 viral subtype is significantly more severe than that due to influenza A/H1N1 subtype and influenza B virus, which indicates that the characteristics of the different viral types and subtypes should be adequately considered by health authorities when planning preventive and therapeutic measures.</p

Helicobacter pylori Bacteremia: An Unusual Finding

We report a case of Helicobacter pylori transient bacteremia in a woman with ulcerated antral gastric cancer. The patient was hospitalized for laparoscopy and subtotal gastrectomy. After surgery she developed fever (39°C) and was empirically treated with levofloxacin. Blood cultures, collected and sent immediately to Laboratory, were positive for a spiral Gramnegative bacterium. This isolate was identified as H. pylori and the specific susceptibility test was performed. One day after the fever was decreased but antibiotic treatment with levofloxacin was continued and it was maintained until discharge. In summary, H. pylori transient bacteremia may occur as a rare complication after stomach surgery. Further studies are necessary to elucidate the potential role of H. pylori presence in blood