Influenza A (H3N2) infection followed by anti-signal recognition particle antibody-positive necrotizing myopathy: A case report.

A 60-year-old Japanese woman presented with subacute progressive muscle pain and weakness in her proximal extremities. She was diagnosed with influenza A (H3N2) infection a week before the onset of muscle pain. At the time of admission, she exhibited weakness in the proximal muscles of the upper and lower limbs, elevated serum liver enzymes and creatinine kinase, and myoglobinuria. She did not manifest renal failure and cardiac abnormalities, indicating myocarditis. Electromyography revealed myogenic changes, and magnetic resonance imaging of the upper limb showed abnormal signal intensities in the muscles, suggestive of myopathy. Muscle biopsy of the biceps revealed numerous necrotic regeneration fibers and mild inflammatory cell infiltration, suggesting immune-mediated necrotizing myopathy (IMNM). Necrotized muscle cells were positive for human influenza A (H3N2). Autoantibody analysis showed the presence of antibodies against the signal recognition particle (SRP), and the patient was diagnosed with anti-SRP-associated IMNM. She was resistant to intravenous methylprednisolone pulse therapy but recovered after administration of oral systemic corticosteroids and immunoglobulins. We speculate that the influenza A (H3N2) infection might have triggered her IMNM. Thus, IMNM should be considered as a differential diagnosis in patients with proximal muscle weakness that persists after viral infections.

Oseltamivir and S-Adenosyl-L-Methionine Combination as Effective Therapeutic Strategy for Suppression of Oxidative Damage in Lung Caused by Influenza Virus Infection in Mice.

BACKGROUND AND OBJECTIVES: The pathogenesis of influenza infection is associated with two general processes in the body: (a) lung damage based on virus replication; (b) overproduction of free radicals, antioxidant deficiency, and development of oxidative stress. To attack these aspects of flu pathogenesis, we explored the combined effect of the antiviral agent oseltamivir, and s-adenosyl-l-methionine (SAM) as a precursor of the endogenous antioxidant glutathione, in mice infected with influenza virus. METHODS: After inoculation of albino mice with 10 MLD50 of influenza virus A/Aichi/2/68 (H3N2), oseltamivir was applied twice a day, for five days post-infection in doses of 1.25 and 2.5 mg/kg. SAM was administered once a day for 10 days, starting 5 days before infection in doses of 50, 100 and 150 mg/kg. RESULTS: Monotherapy with SAM did not influence the markers of oxidative stress in the lung. Combination of SAM 50 mg/kg and oseltamivir 2.5 mg/kg affected best the virological parameters - viral titer, protection index, and mean survival time, as well as the biochemical markers of oxidative stress. INTERPRETATION AND CONCLUSIONS: Combining of SAM and oseltamivir in a dose of 1/4 of optimal therapeutic could be considered as a perspective therapy of influenza viral infection.

Influenza A virus shedding reduction observed at 12 weeks post-vaccination when newborn pigs are administered live-attenuated influenza virus vaccine.

BACKGROUND: Influenza A virus in swine (IAV-S) causes an acute respiratory disease of swine which results in great economic losses. A bivalent H1N1 and H3N2, NS1-truncated live-attenuated IAV-S vaccine (LAIV, Ingelvac Provenza™ ) has recently become available. OBJECTIVE: Reduction of shedding during an outbreak in the nursery or finisher is an important parameter from an epidemiological control strategy; therefore, a laboratory efficacy study was conducted to evaluate nasal virus shedding when vaccinated pigs were challenged with either heterologous H1N2 or H3N2 strains 12 weeks post-vaccination. METHODS: Between 1 and 5 days of age, pigs born to IAV-S seronegative dams were intranasally administered 1 mL of vaccine or saline. At 30 days post-vaccination, pigs were weaned and randomized into two different challenge groups consisting of vaccinated pigs and control pigs commingled within pens for the two challenge groups. At 85 days post-vaccination, pigs in the first group were challenged with A/Swine/North Carolina/001169/2006 H1N2 challenge strain, and the second group was challenged with A/Swine/Nebraska/97901-10/2008 H3N2. Nasal swabs were collected daily for five days and tested by virus isolation. RESULTS AND CONCLUSION: This study showed significant reduction in nasal virus shedding with regard to both frequency and duration. A 1 mL intranasal dose of Ingelvac Provenza™ given as early as 1 day of age showed protection for at least 12 weeks later as evidenced by the reduction of shedding live, viable virus after challenge with either a heterologous H1N2 strain or a heterologous H3N2 strain.

Application of an immunoglobulin Y-alkaline phosphatase bioconjugate as a diagnostic tool for influenza A virus.

The diagnosis of influenza A virus is essential since it can be confused with influenza A like illness and lead to inaccurate drug prescription. In this study, the M2e peptide, a strategic antigen that is conserved in all virus subtypes, was used as a diagnostic marker of influenza A. For the first time, M2e-specific IgY antibody was covalently conjugated to alkaline phosphatase (ALP) enzyme in the presence of glutaraldehyde. The antibody-enzyme bioconjugate was characterized by fluorescence and Fourier-transform infrared spectroscopy. Subsequently, the diagnostic value of this bioconjugate was evaluated by direct sandwich ELISA using nasopharyngeal swab samples positive/negative for H1N1 and H3N2, which were previously analyzed by rRT-PCR for influenza. In conclusion, the M2e-specific IgY-ALP bioconjugate demonstrated positive results for Influenza A in samples that were diagnosed as Influenza A via the RT-PCR method.

Nosocomial outbreak of influenza A H3N2 in an inpatient oncology unit related to health care workers presenting to work while ill.

OBJECTIVE: To describe an outbreak of influenza A in an oncology unit, highlighting infection control methods implemented, and examining reasons health care workers (HCWs) present to work with influenza-like illness (ILI). METHODS: Confirmed cases were defined by the presence of ILI and a positive nasopharyngeal polymerase chain reaction swab for influenza A H3. Probable cases were defined as exposed HCWs with ILI who were unavailable for polymerase chain reaction testing. Infection prevention measures included closing the ward for new admissions, oseltamivir prophylaxis for all exposed groups, and dismissal from work of HCWs with ILI until resolution of symptoms. An anonymous survey of the cases in our HCWs was conducted to better elucidate reasons behind presenteeism. RESULTS: Over the course of 8 days (November 16, 2017, to November 22, 2017), influenza was diagnosed in 7 of 10 inpatients on the oncology ward, 16 HCWs (14 confirmed, 2 probable), and 2 visitors. The suspected index case was an HCW. Of the surveyed HCWs, 64% presented to work despite feeling ill (ie, presenteeism). The most common reason was "sense of duty as a health care worker." CONCLUSIONS: This nosocomial outbreak of influenza highlights the challenges of protecting inpatients from viral respiratory tract infections. HCWs and patient visitors with ILI should avoid work or visiting until resolution of peak respiratory symptoms and adhere to strict respiratory etiquette.

Integrated analysis of microRNA-mRNA expression in A549 cells infected with influenza A viruses (IAVs) from different host species.

Although several miRNAs have been demonstrated to be involved in the influenza virus replication cycle, the identification of miRNAs and mRNAs that are expressed in A549 cells infected with influenza A viruses (IAVs) from different host species has remained poorly studied. To investigate the molecular mechanisms associated with the differential expression of miRNAs during influenza A virus infection, we performed global miRNA and mRNA expression profiling in A549 cells infected with human-origin seasonal influenza A virus H3N2 (Human_Br07), swine-origin influenza A virus H1N1 (SW_3861) or avian-origin influenza A virus H3N2 (AVI_9990). The miRNA and mRNA expression profiles were obtained by microarray and high-throughput sequencing analyses, respectively. The integrated analysis of differentially expressed miRNAs (DEMs) and differentially expressed genes (DEGs) was performed using bioinformatics tools, and the expression of miRNAs and mRNAs was validated by real-time quantitative polymerase chain reaction (RT-qPCR). We identified 20 miRNAs (6 upregulated and 14 downregulated) and 1286 mRNAs (935 upregulated and 351 downregulated) exhibiting the same differential expression trends in three infected groups of cells compared with an uninfected control. An integrated analysis of these expression profiles identified 79 miRNA-mRNA pairs associated with the influenza A reference pathway, and 107 miRNA-mRNA interactions were correlated with the defense of the virus. Additionally, the obtained results were supported by an RT-qPCR analysis of 8 differentially expressed miRNAs (hsa-miR-210-3p, hsa-miR-296-5p, hsa-miR-371a-5p, hsa-miR-762, hsa-miR-937-5p, hsa-miR-1915-3p, hsa-miR-3665, and hsa-miR-1290) and 13 differentially expressed mRNAs (IFNL1, CXCL10, RSAD2, MX1, OAS2, IFIT2, IFI44 L, MX2, XAF1, NDRG1, FGA, EGLN3, and TFRC). Our findings indicate that dysregulated miRNA expression plays a crucial role in infection caused by IAVs originating from different species and provide a foundation for further investigations of the molecular regulatory mechanisms of miRNAs involved in influenza A virus infection.

Neuroinvasion of influenza A/H3N2: a fatal case in an immunocompetent adult.

Acute necrotizing encephalopathy (ANE) is a severe neurologic complication caused by influenza virus that has been infrequently reported in adult population. The diagnosis is made on epidemiological, clinical, and neuroimaging suspicion, but is rarely confirmed by microbiological findings in samples from the central nervous system (CNS), thus making it difficult to define the mechanism of pathogenesis of influenza-associated encephalitis/encephalopathies (IAE). We report a microbiologically documented case of ANE caused by influenza A/H3N2, in a previously healthy adult patient infected during a flu epidemic in Asturias (Spain). Direct viral invasion of the CNS was demonstrated with the isolation of the virus in a brain biopsy.

Treatment with broadly neutralizing influenza antibodies reduces severity of secondary pneumococcal pneumonia in mice.

Secondary bacterial pneumonia is a frequent complication of influenza, associated with high morbidity and mortality. We hypothesized that treatment with neutralizing influenza A antibody AT10_002 protects against severe secondary pneumococcal infection in a mouse model of influenza A infection. Influenza A (H3N2) virus-infected male C57Bl6 mice were treated intravenously with either AT10_002 or a control 2 days postinfection. Seven days later, both groups were infected with Streptococcus pneumoniae and killed 18 hours later. Mice receiving AT10_002 showed less loss of bodyweight compared with controls (+1% vs -12%, P < .001), lower viral loads in bronchoalveolar lavage fluids (BALFs) (7 vs 194 RNA copies per µL; P < .001), and reduced bacterial outgrowth in lung homogenates (3.3 × 101 vs 2.5 × 105 colony-forming units per mg; P < .001). The treatment group showed lower pulmonary wet weights, lower cell counts, and lower protein levels in BALF compared with controls. Treatment with AT10_002 was associated with lower levels of tumor necrosis factor-α, interleukin (IL)-6, cytokine-induced neutrophil chemoattractant (KC), and interferon-γ in BALF and lower IL-6 and KC in lung homogenates. Treatment with anti-influenza antibody AT10_002 is associated with reduced weight loss, viral load, bacterial outgrowth, and lung injury in a murine model of secondary pneumococcal pneumonia following influenza infection.

Factors associated with influenza vaccination failure and severe disease in a French region in 2015.

Current influenza vaccination strategy is based on limited analyses of circulating strains and has some drawbacks, as illustrated during the 2014-2015 season with the circulation of A(H3N2) viruses belonging to divergent genetic subgroups. We reasoned that these strains, poorly neutralized in vitro, may have been associated with vaccination failure and more severe diseases. We conducted a study on a continuous series of 249 confirmed influenza infections. Incidence was three fold greater than in the previous three years. Most isolates were A(H3N2) viruses (78%) and clustered in subgroups 3C.2a (57%) and 3C.3b (43%). We identified 23 non-synonymous mutations that had already been identified during previous seasons at low frequencies, except mutation Q197H, present in 26% of 3C.3b isolates. We identified lung disorder, tobacco smoking and A(H1N1)pdm09 infection as risk factor of severe influenza disease. In contrast, young age (< 5 years), A(H3N2) infection and initial admission to an emergency department were associated with a better outcome of influenza infection.

Epidemiologic analysis of respiratory viral infections among Singapore military servicemen in 2016.

BACKGROUND: Respiratory illnesses have been identified as a significant factor leading to lost training time and morbidity among Singapore military recruits. A surveillance programme has been put in place to determine etiological agents responsible for febrile, as well as afebrile respiratory illnesses in a military camp. The goal of the study is to better understand the epidemiology of these diseases and identify potential countermeasures to protect military recruits against them. METHODS: From Jan 2016 - Jan 2017, a total of 2647 respiratory cases were enrolled into the surveillance programme. The cases were further stratified into Febrile Respiratory Illness (FRI, with body temperature > 37.5 °C) or Acute Respiratory Illness (ARI, with body temperature < 37.5 °C). Nasal washes were collected and tested by multiplex PCR to detect 26 different pathogens. RESULTS: One thousand ninety five cases (41% of total cases) met the criteria of FRI in which 932 cases (85% of FRI cases) were screened positive for at least one virus. The most common etiological agents for FRI mono-infection cases were Adenovirus E and Rhinovirus. Recruits infected with H3N2 influenza, Influenza B and Adenovirus E viruses were most likely presented as FRI cases. Notably, H3N2 influenza resulted in the greatest rise in body temperature. The remaining 1552 cases (59% of total cases) met the criteria of ARI in which 1198 cases (77% of ARI cases) were screened positive for at least one virus. The most common etiological agent for ARI mono-infection was Rhinovirus. The distribution pattern for dual infections was different for ARI and FRI cases. Maximum number of pathogens detected in a sample was five for both groups. CONCLUSION: Previous studies on respiratory diseases in military focused largely on FRI cases. With the expanded surveillance to ARI cases, this study allows unbiased evaluation of the impact of respiratory disease pathogens among recruits in a military environment. The results show that several pathogens have a much bigger role in causing respiratory diseases in this cohort.

Outbreak of influenza and rhinovirus co-circulation among unvaccinated recruits, U.S. Coast Guard Training Center Cape May, NJ, 24 July-21 August 2016.

Military and Coast Guard recruits are particularly susceptible to respiratory infections. Although seasonal influenza vaccinations are mandatory for recruits, the vaccine expires annually in June. On 29 July 2016, the U.S. Coast Guard Training Center Cape May, NJ, identified an increase in febrile respiratory illness (FRI) among recruits. During 24 July-21 August, a total of 115 recruits reported symptoms. A total of 74 recruits tested positive for respiratory infections: influenza A (H3) (n=34), rhinovirus (n=28), influenza/rhinovirus co-infection (n=11), and adenovirus/rhinovirus co-infection (n=1), while 41 recruits had no laboratory-confirmed specimen but were considered suspected cases. Only one recruit reported receiving the seasonal influenza vaccine within the previous 12 months. Influenza predominated during 24 July-6 August, whereas rhinovirus predominated during 7 August-20 August. Most (92.2%) cases were identified in four of 10 recruit companies; incidence rates were highest among recruits in weeks 2-4 of an 8-week training cycle. Key factors for outbreak control included rapid detection through routine FRI surveillance, quick decision-making and streamlined response by using a single chain of command, and employing both nonpharmaceutical and pharmaceutical interventions.

[Detection of influenza A, B and subtypes A (H1N1) pdm09, A (H3N2) viruses by multiple qrt-pcr in clinical samples]. / Detección de virus influenza A, B y subtipos a (H1N1) pdm09, A (H3N2) por múltiple rt-pcr en muestras clínicas.

OBJECTIVES.: To describe the clinical and epidemiological characteristics of patients diagnosed with epidermolysis bullosa (EB) at the Instituto Nacional de Salud (INSN) in Lima, Peru; a National Reference Center for this disease. MATERIAL AND METHODS: . Observational, descriptive and transversal study. We reviewed the clinical histories and laboratory tests of patients diagnosed with EB treated in INSN from 1993 to 2015. RESULTS.: 93 patients were registered. The average age was 7.9 ± 5.6 years; 53.8% (n = 50) were boys. Clinical forms corresponded to dystrophic EB with 41 (44.1%) cases, simple EB with 39 (41.9%) union EB cases with 8 (8.6%) and Kindler syndrome with 4 (4.3%) cases. The clinical form could not be identified in a case. A total of 48 cases (51.6%) came from Lima and Callao, and 45 cases (48.4%) from other provinces of the country. Extracutaneous manifestations involved gastrointestinal (44.1%), ocular (37.6%), odontogenic (87.1%), and nutritional (79.6%) involvement, as well as pseudosindactilia (16.1%). Chronic malnutrition (71.6%), acute malnutrition (17.6%) and anemia (62.4%) were found. Mortality corresponded to 6 cases (6.5%). CONCLUSIONS.: 93 cases of EB were reported in INSN, the predominant clinical presentation was the dystrophic form.

OBJETIVOS.: Estandarizar la técnica de reacción en cadena de la polimerasa en tiempo real (RT-PCR) múltiple para la detección de virus influenza A, B y tipificación de subtipos A (H1N1) pdm09, A (H3N2) en muestras clínicas. MATERIALES Y MÉTODOS.: Se analizaron 300 muestras de hisopado nasofaríngeo. Esta metodología fue estandarizada en dos pasos: la primera reacción detectó el gen de la matriz del virus de influenza A, gen de la nucleoproteína del virus influenza B y el gen GAPDH de las células huésped. La segunda reacción detectó el gen de la hemaglutinina de los subtipos A (H1N1) pandémico (pdm09) y A (H3N2). RESULTADOS.: Se identificaron 109 muestras positivas a influenza A y B, de las cuales 72 fueron positivas a influenza A (36 positivas a influenza A (H1N1) pdm09 y 36 positivos a influenza A (H3N2)) y 37 muestras positivas a influenza B. 191 fueron negativas a ambos virus mediante RT-PCR en tiempo real multiplex. Se encontró una sensibilidad y especificidad del 100% al analizar los resultados de ambas reacciones. El límite de detección viral fue del rango de 7 a 9 copias/µL por virus. Los resultados no mostraron ninguna reacción cruzada con otros virus tales como adenovirus, virus sincitial respiratorio, parainfluenza (1,2 y 3), metapneumovirus, subtipos A (H1N1) estacional, A (H5N2) y VIH. CONCLUSIONES.: La RT-PCR múltiple demostró ser una prueba muy sensible y específica para la detección de virus influenza A, B y subtipos A (H1N1, H3N2) y su uso puede ser conveniente en brotes estacionales.

Assessment of Molecular, Antigenic, and Pathological Features of Canine Influenza A(H3N2) Viruses That Emerged in the United States.

Background: A single subtype of canine influenza virus (CIV), A(H3N8), was circulating in the United States until a new subtype, A(H3N2), was detected in Illinois in spring 2015. Since then, this CIV has caused thousands of infections in dogs in multiple states. Methods: In this study, genetic and antigenic properties of the new CIV were evaluated. In addition, structural and glycan array binding features of the recombinant hemagglutinin were determined. Replication kinetics in human airway cells and pathogenesis and transmissibility in animal models were also assessed. Results: A(H3N2) CIVs maintained molecular and antigenic features related to low pathogenicity avian influenza A(H3N2) viruses and were distinct from A(H3N8) CIVs. The structural and glycan array binding profile confirmed these findings and revealed avian-like receptor-binding specificity. While replication kinetics in human airway epithelial cells was on par with that of seasonal influenza viruses, mild-to-moderate disease was observed in infected mice and ferrets, and the virus was inefficiently transmitted among cohoused ferrets. Conclusions: Further adaptation is needed for A(H3N2) CIVs to present a likely threat to humans. However, the potential for coinfection of dogs and possible reassortment of human and other animal influenza A viruses presents an ongoing risk to public health.

Structure-Guided Functional Annotation of the Influenza A Virus NS1 Protein Reveals Dynamic Evolution of the p85ß-Binding Site during Circulation in Humans.

Rational characterization of virulence and host-adaptive markers in the multifunctional influenza A virus NS1 protein is hindered by a lack of comprehensive knowledge about NS1-host protein protein interfaces. Here, we surveyed the impact of amino acid variation in NS1 at its structurally defined binding site for host p85ß, a regulator of phosphoinositide 3-kinase (PI3K) signaling. Structure-guided alanine scanning of all viral residues at this interface defined 10 positions contributing to the interaction, with residues 89, 95, 98, 133, 145, and 162 being the most important. A bioinformatic study of >24,000 publicly available NS1 sequences derived from viruses infecting different hosts highlighted several prevalent amino acid variants at the p85ß interface that either enhanced (I95) or weakened (N135, T145, L161, Y161, S164) p85ß binding. Interestingly, analysis of viruses circulating in humans since the 1918 pandemic revealed the temporal acquisition of functionally relevant variants at this interface. I95 (which enhanced p85ß binding) quickly became prevalent in the 1940s and experimentally conferred a fitness advantage to a recombinant 1930s-based H1N1 virus in human lung epithelial cells. Surprisingly, H1N1 and H3N2 viruses recently acquired T145 or N135, respectively, which diminished p85ß binding but apparently not the overall fitness in the human population. Evolutionary analyses revealed covariation of the NS1-p85ß binding phenotype in humans with functional changes at multiple residues in other viral proteins, suggesting an unexplored compensatory or synergistic interplay between phenotypes in vivo Overall, our data provide a resource to understand the consequences of the NS1-p85ß binding spectrum of different influenza viruses and highlight the dynamic evolution of this property in viruses circulating in humans.IMPORTANCE In humans, influenza A viruses are responsible for causing seasonal epidemics and occasional pandemics. These viruses also circulate and evolve in other animal species, creating a reservoir from which novel viruses with distinct properties can emerge. The viral nonstructural protein NS1 is an important host range determinant and virulence factor that exhibits strain-specific interactions with several host factors, although few have been characterized extensively. In the study described here, we comprehensively surveyed the impact of natural and unnatural NS1 variations on the binding of NS1 to host p85ß, a subunit of phosphoinositide 3-kinase that regulates intracellular metabolism and contributes to virus replication and virulence. We define the p85ß-binding site on NS1 and provide a predictive resource to assess this ability of NS1 in viruses from different hosts. Strikingly, we uncover a spectrum of p85ß binding by different NS1 proteins and reveal that viruses evolving in humans have undergone dynamic changes in this NS1 function over the last century.

Cambios en la presentación clínica de la influenza A H1N1pdm09 después de la pandemia / Changes in the clinical presentation of Influenza A H1N1pdm09 after the pandemic

Background: After the 2009 influenza pandemic the H1N1pdm09 strain circulate seasonally. In 2015, Puerto Montt Hospital in Chile faced a simultaneous outbreak of both seasonal H3N2 and H1N1pdm09 influenza A (IA). Aim: To evaluate the clinical differences between the two viral strains and recent changes in the behavior of H1N1pdm09 IA. Material and Methods: We set up a retrospective study including every adult hospitalized in Puerto Montt Hospital in 2015 due to IA, confirmed by reverse transcription polymerase chain reaction. We compared epidemiological data, clinical presentation, complications, and the outcome of patients with H1N1pdm09 versus those with seasonal influenza. In parallel, we compared 62 cases of thatH1N1 IA from 2015 with 100 cases who were hospitalized and analyzed in 2009. Results: Between July and October 2015, 119 adults with confirmed IA were hospitalized. From 2009 to 2015, the mean age of patients with IAH1N1pdm09 increased from 40.4 ± 17 to 58.8 ± 16 years (p < 0.01). Pneumonia as the cause of hospitalization decreased from 75 to 58% of patients, (p = 0.04). Likewise, the presence of comorbidities increased from 53 to 74%, (p < 0.01). Compared with seasonal H3N2, patients with IAH1N1pdm09 IA were more likely to require intensive care (p < 0.01) and mechanical ventilation (p < 0.01) and developed septic shock (p = 0.03). Their mortality was non-significantly higher (13 and 5% respectively). Conclusions: The clinical presentation of H1N1pdm09 IA has varied over time and now affects an older population, with a greater number of comorbidities. It also appears to be adopting the clinical behavior of a classic seasonal influenza virus.

Detección de virus influenza A, B y subtipos a (H1N1) pdm09, A (H3N2) por múltiple rt-pcr en muestras clínicas / Detection of influenza A, B and subtypes A (H1N1) pdm09, A (H3N2) viruses by multiple qrt-pcr in clinical samples

RESUMEN Objetivos. Estandarizar la técnica de reacción en cadena de la polimerasa en tiempo real (RT-PCR) múltiple para la detección de virus influenza A, B y tipificación de subtipos A (H1N1) pdm09, A (H3N2) en muestras clínicas. Materiales y métodos. Se analizaron 300 muestras de hisopado nasofaríngeo. Esta metodología fue estandarizada en dos pasos: la primera reacción detectó el gen de la matriz del virus de influenza A, gen de la nucleoproteína del virus influenza B y el gen GAPDH de las células huésped. La segunda reacción detectó el gen de la hemaglutinina de los subtipos A (H1N1) pandémico (pdm09) y A (H3N2). Resultados. Se identificaron 109 muestras positivas a influenza A y B, de las cuales 72 fueron positivas a influenza A (36 positivas a influenza A (H1N1) pdm09 y 36 positivos a influenza A (H3N2)) y 37 muestras positivas a influenza B. 191 fueron negativas a ambos virus mediante RT-PCR en tiempo real multiplex. Se encontró una sensibilidad y especificidad del 100% al analizar los resultados de ambas reacciones. El límite de detección viral fue del rango de 7 a 9 copias/µL por virus. Los resultados no mostraron ninguna reacción cruzada con otros virus tales como adenovirus, virus sincitial respiratorio, parainfluenza (1,2 y 3), metapneumovirus, subtipos A (H1N1) estacional, A (H5N2) y VIH. Conclusiones. La RT-PCR múltiple demostró ser una prueba muy sensible y específica para la detección de virus influenza A, B y subtipos A (H1N1, H3N2) y su uso puede ser conveniente en brotes estacionales.

ABSTRACT Objectives. To describe the clinical and epidemiological characteristics of patients diagnosed with epidermolysis bullosa (EB) at the Instituto Nacional de Salud (INSN) in Lima, Peru; a National Reference Center for this disease. Material and methods . Observational, descriptive and transversal study. We reviewed the clinical histories and laboratory tests of patients diagnosed with EB treated in INSN from 1993 to 2015. Results. 93 patients were registered. The average age was 7.9 ± 5.6 years; 53.8% (n = 50) were boys. Clinical forms corresponded to dystrophic EB with 41 (44.1%) cases, simple EB with 39 (41.9%) union EB cases with 8 (8.6%) and Kindler syndrome with 4 (4.3%) cases. The clinical form could not be identified in a case. A total of 48 cases (51.6%) came from Lima and Callao, and 45 cases (48.4%) from other provinces of the country. Extracutaneous manifestations involved gastrointestinal (44.1%), ocular (37.6%), odontogenic (87.1%), and nutritional (79.6%) involvement, as well as pseudosindactilia (16.1%). Chronic malnutrition (71.6%), acute malnutrition (17.6%) and anemia (62.4%) were found. Mortality corresponded to 6 cases (6.5%). Conclusions. 93 cases of EB were reported in INSN, the predominant clinical presentation was the dystrophic form.

Influenza vaccine effectiveness against influenza-associated hospitalization in 2015/16 season, Beijing, China.

BACKGROUND: Vaccination is recommended to prevent influenza virus infection and associated complications. This study aimed to estimate the influenza vaccine effectiveness (VE) against hospitalization in the 2015/16 season in Beijing. METHODS: Patients who were hospitalized in the 5 study hospitals between 1 Oct 2015 and 15 May 2016 were recruited. Influenza vaccination status was obtained for PCR-confirmed influenza patients and the selected controls who tested negative for the virus. Conditional logistic regression was used to estimate the influenza VE matching by calendar week, and adjusting for age, study sites, underlying medical conditions, smoking status, and hospital admissions over the past 12months. RESULTS: The overall VE was -37.9% (95% CI: -103.3, 6.5) against laboratory-confirmed influenza-associated hospitalization. The 2015-16 seasonal vaccine was had -61.9% (95% CI: -211.9, 15.9), -5.4% (95% CI: -108.1, 46.6) and -45.2% (95% CI: -152.6, 16.5) effectiveness to prevent infection from A(H1N1)pdm09, A(H3N2) and influenza B, respectively. CONCLUSIONS: Influenza vaccination did not show effective protection against hospitalization with influenza in 2015/16 season in Beijing.

Prevention and control of emergent infectious disease with high specific antigen sensor.

This study aims to evaluate the application of a new type of high specificity antigen sensor in detecting the viruses in sudden infectious diseases. Influenza A (H1N1) virus immunosensor was used for the respective determination of the six kinds of antigens of H1N1, H3N2 viral protein, HA protein of H7N9, influenza B virus, adenovirus, and EV71 virus of same dilution degree on the Screen Printed Carbon Electrode (SPCE), so as to test the specificity of the detection method. In addition, various batches of chick embryo allantoic saliva dilution simulation samples were also detected on their recovery (accuracy), repeatability (precision), and stability. The results were as follows: the linear equation was y = 121.33x + 168; the slope of the linear equation was 121.33 nA/HA unit, representing the sensitivity; correlation coefficient was R2=0.9921 > 0.90. Using Statistical Analysis System (SAS) software, we found that: the W values of seven sets of data after Shapiro-Wilk detection were 0.853, 0.991, 0.901, 0.906, 0.825, 0.974, and 0.992, respectively; P values were 0.247, 0.831, 0.386, 0.405, 0.174, 0.691, and 0.821, respectively, all of which were greater than 0.05, suggesting that normality was met. The results of homogeneity test for variance were as follows: F = 2.44, P = 0.0775 > 0.05, suggesting that homogeneity of variance was met. The parametric test results were as follows: F = 19114.0, P < 0.0001, suggesting that there were obvious differences between testing data of the seven groups. The determination recovery rate of electrochemical immunosensor was 80-110%. Relative Standard Deviation (RSD) values of repeatability (precision) test of H1N1 influenza virus electrochemical immunosensor were 7.74%, 3.54%, and 2.01%, all of which were smaller than 10%. The signal response of H1N1 electrochemical immune biological sensor could still maintain more than 85% of the original signal within 30 days of storage. In conclusion, H1N1 electrochemical immune biosensor has good specificity and the test results are not affected by other viruses of the same type. Besides, it has good accuracy which can realize the accurate determination of A (H1N1) influenza virus in actual detection. Thus, the requirement of precision measurement of A (H1N1) flu virus detection can be met. Therefore, H1N1 electrochemical immune biosensors can be used in actual detection with good stability.

Detection of Antigenic Variants of Subtype H3 Swine Influenza A Viruses from Clinical Samples.

A large population of genetically and antigenically diverse influenza A viruses (IAVs) are circulating among the swine population, playing an important role in influenza ecology. Swine IAVs not only cause outbreaks among swine but also can be transmitted to humans, causing sporadic infections and even pandemic outbreaks. Antigenic characterizations of swine IAVs are key to understanding the natural history of these viruses in swine and to selecting strains for effective vaccines. However, influenza outbreaks generally spread rapidly among swine, and the conventional methods for antigenic characterization require virus propagation, a time-consuming process that can significantly reduce the effectiveness of vaccination programs. We developed and validated a rapid, sensitive, and robust method, the polyclonal serum-based proximity ligation assay (polyPLA), to identify antigenic variants of subtype H3N2 swine IAVs. This method utilizes oligonucleotide-conjugated polyclonal antibodies and quantifies antibody-antigen binding affinities by quantitative reverse transcription-PCR (RT-PCR). Results showed the assay can rapidly detect H3N2 IAVs directly from nasal wash or nasal swab samples collected from laboratory-challenged animals or during influenza surveillance at county fairs. In addition, polyPLA can accurately separate the viruses at two contemporary swine IAV antigenic clusters (H3N2 swine IAV-α and H3N2 swine IAV-ß) with a sensitivity of 84.9% and a specificity of 100.0%. The polyPLA can be routinely used in surveillance programs to detect antigenic variants of influenza viruses and to select vaccine strains for use in controlling and preventing disease in swine.