Distribution of gene segments of the pandemic A(H1N1) 2009 virus lineage in pig populations.

Swine influenza viruses (SIVs) are important not only for pig farming, but also for public health. In fact, pandemic A(H1N1) 2009 viruses [A(H1N1)pdm09] were derived from SIVs. Therefore, timely characterization of locally circulating SIVs is necessary for understanding the global status of SIVs. To genetically characterize SIVs circulating in Japanese pig populations, we isolated 24 SIVs of three subtypes (17 H1N1, four H1N2 and three H3N2 strains) from 14 pig farms in Japan from 2013 to 2016. Genetic analyses revealed that the haemagglutinin (HA) and neuraminidase (NA) genes of the 17 H1N1 and the HA gene of one H1N2, A/swine/Aichi/02/2016 (H1N2), SIVs belonged to the A(H1N1)pdm09 lineage. More importantly, all of the remaining six gene segments (i.e., PB1, PB1, PA, NP, M and NS) of the 24 SIVs, regardless of the HA and NA subtype, were also classified as belonging to the A(H1N1)pdm09 lineage. These results indicate that gene segments of A(H1N1)pdm09 lineage are widely distributed in SIVs circulating in Japanese pig populations In addition, the NA gene of A/swine/Aichi/02/2016 (H1N2) shared less than 88.5% nucleotide identity with that of the closest relative A/swine/Miyagi/5/2003 (H1N2), which was isolated in Japan in 2003. These results indicate the sustained circulation of classical H1N2-derived SIVs with remarkable diversity in the NA genes in Japanese pig populations. These findings highlight the necessity of both intensive biosecurity systems and active SIV surveillance in pig populations worldwide for both animal and public health.

Kinetics, Longevity, and Cross-Reactivity of Antineuraminidase Antibody after Natural Infection with Influenza A Viruses.

The kinetics, longevity, and breadth of antibodies to influenza virus neuraminidase (NA) in archival, sequential serum/plasma samples from influenza A virus (IAV) H5N1 infection survivors and from patients infected with the 2009 pandemic IAV (H1N1) virus were determined using an enzyme-linked lectin-based assay. The reverse-genetics-derived H4N1 viruses harboring a hemagglutinin (HA) segment from A/duck/Shan Tou/461/2000 (H4N9) and an NA segment derived from either IAV H5N1 clade 1, IAV H5N1 clade 2.3.4, the 2009 pandemic IAV (H1N1) (H1N1pdm), or A/Puerto Rico/8/1934 (H1N1) virus were used as the test antigens. These serum/plasma samples were also investigated by microneutralization (MN) and/or hemagglutination inhibition (HI) assays. Neuraminidase-inhibiting (NI) antibodies against N1 NA of both homologous and heterologous viruses were observed in H5N1 survivors and H1N1pdm patients. H5N1 survivors who were never exposed to H1N1pdm virus developed NI antibodies to H1N1pdm NA. Seroconversion of NI antibodies was observed in 65% of the H1N1pdm patients at day 7 after disease onset, but an increase in titer was not observed in serum samples obtained late in infection. On the other hand, an increase in seroconversion rate with the HI assay was observed in the follow-up series of sera obtained on days 7, 14, 28, and 90 after infection. The study also showed that NI antibodies are broadly reactive, while MN and HI antibodies are more strain specific.

Adverse events following pandemic influenza A (H1N1) 2009 monovalent and seasonal influenza vaccinations during the 2009-2010 season in the active component U.S. military and civilians aged 17-44years reported to the Vaccine Adverse Event Reporting System.

BACKGROUND: No comparative review of Vaccine Adverse Event Reporting System (VAERS) submissions following pandemic influenza A (H1N1) 2009 and seasonal influenza vaccinations during the pandemic season among U.S. military personnel has been published. METHODS: We compared military vs. civilian adverse event reporting rates. Adverse events (AEs) following vaccination were identified from VAERS for adults aged 17-44years after pandemic (monovalent influenza [MIV], and seasonal (trivalent inactivated influenza [IIV3], live attenuated influenza [LAIV3]) vaccines. Military vaccination coverage was provided by the Department of Defense's Defense Medical Surveillance System. Civilian vaccination coverage was estimated using data from the National 2009 H1N1 Flu Survey and the Behavioral Risk Factor Surveillance System survey. RESULTS: Vaccination coverage was more than four times higher for MIV and more than twenty times higher for LAIV3 in the military than in the civilian population. The reporting rate of serious AE reports following MIV in service personnel (1.19 per 100,000) was about half that reported by the civilian population (2.45 per 100,000). Conversely, the rate of serious AE reports following LAIV3 among service personnel (1.32 per 100,000) was more than twice that of the civilian population. Although fewer military AEs following MIV were reported overall, the rate of Guillain-Barré Syndrome (GBS) (4.01 per million) was four times greater than that in the civilian population. (1.04 per million). CONCLUSIONS: Despite higher vaccination coverage in service personnel, the rate of serious AEs following MIV was about half that in civilians. The rate of GBS reported following MIV was higher in the military.

Differential proteomic analysis of respiratory samples from patients suffering from influenza.

The exact molecular pathways involved in the pathogenesis of influenza are yet unclear. In the present study we investigated the upper respiratory proteome in influenza patients. 200 nasal and throat swab samples were collected from patients suffering from acute respiratory illness. These samples were confirmed for influenza pandemic A/H1N1/2009 and influenza type B using qRT-PCR. 10 similar swabs were collected from healthy individuals and were used as controls. Proteins were extracted from the cell pellets and were subjected to 2-D gel electrophoresis. The differentially expressed proteins were identified using MALDI-TOF. Identified proteins were classified into different functional groups based on functions reported in the databases. 25 % of these proteins were involved in cytoskeletal formation, whereas 14 % were involved in signal transduction. Proteins involved in anti-viral responses, Ca-signaling, transport, and tumor suppression constituted 10 % each, where as 5 % of proteins each belong to Nicotinic acetylcholine receptor, Protein Synthesis and anti-bacterial proteins. 10 % of the proteins have not been described previously. This is the first report on respiratory proteome profile in Influenza patients. The study emphasizes the role of such profiling studies using multiple platforms for bio-marker discoveries, especially non-invasive diagnostic marker in Influenza and other infectious diseases.

Neurology of the H1N1 pandemic in Singapore: a nationwide case series of children and adults.

Neurologic complications have long been associated with influenza. A novel strain of influenza A (H1N1) first described in humans to have outbreak potential in 2009 in Mexico went on to become the first influenza pandemic of this century. We evaluated the neurologic complications of the novel influenza A (H1N1) 2009 in children and adults admitted to all public hospitals in Singapore during the influenza A (H1N1) 2009 pandemic between May 2009 and March 2010. All patients were positive for novel H1N1 infection and presented with neurologic symptoms prior to oseltamivir treatment. Ninety-eight patients (median age 6.6 years, range 0.4-62.6) were identified; 90 % were younger than 18 years; 32 % suffered from preexisting neurological, respiratory, or cardiac disease; and 66 % presented with seizures. Of those presenting with seizures, new onset seizures were the most common manifestation (n = 40, 61.5 %), followed by breakthrough seizures (n = 18, 27.7 %) and status epilepticus (n = 7, 10.8 %). Influenza-associated encephalopathy occurred in 20 %. The majority of children (n = 88) presented with seizures (n = 63, 71.6 %), encephalopathy (n = 19, 21.6 %), and syncope (n = 4, 4.5 %). Among adults, a wider range of neurological conditions were seen, with half of them presenting with an exacerbation of their underlying neurological disease. The neurological symptoms developed at a median of 2 days after the onset of systemic symptoms. The median length of hospital stay was 3 days, and 79 % were monitored in general wards. Neurologic complications associated with the novel influenza A (H1N1) 2009 strain were generally mild and had a good outcome. They occurred more frequently in patients with underlying neurological disorders. Seizures and encephalopathy were the most common manifestations, similar to other influenza virus strains.

Influenza A(H1N1)pdm09 resistance and cross-decreased susceptibility to oseltamivir and zanamivir antiviral drugs.

Neuraminidase inhibitors (NAIs) oseltamivir and zanamivir are currently the only effective antiviral drugs available worldwide for the management of influenza. The potential development of resistance is continually threatening their use, rationalizing and highlighting the need for a close and sustained evaluation of virus susceptibility. This study aimed to analyze and characterize the phenotypic and genotypic NAIs susceptibility profiles of A(H1N1)pdm09 viruses circulating in Portugal from 2009 to 2010/2011. A total of 144 cases of A(H1N1)pdm09 virus infection from community and hospitalized patients were studied, including three suspected cases of clinical resistance to oseltamivir. Oseltamivir resistance was confirmed for two of the suspected cases. Neuraminidase (NA) H275Y resistant marker was found in viruses from both cases but for one it was only present in 26.2% of virus population, raising questions about the minimal percentage of resistant virus that should be considered relevant. Cross-decreased susceptibility to oseltamivir and zanamivir (2-4 IC50 fold-change) was detected on viruses from two potentially linked community patients from 2009. Both viruses harbored the NA I223V mutation. NA Y155H mutation was found in 18 statistical non-outlier viruses from 2009, having no impact on virus susceptibility. The mutations at NA N369K and V241I may have contributed to the significantly higher baseline IC50 value obtained to oseltamivir for 2010/2011 viruses, compared to viruses from the pandemic period. These results may contribute to a better understanding of the relationship between phenotype and genotype, which is currently challenging, and to the global assessment of A(H1N1)pdm09 virus susceptibility profile and baseline level to NAIs.

A/H1N1 vaccine intentions in college students: an application of the theory of planned behavior.

OBJECTIVE: To test the applicability of the Theory of Planned Behavior (TPB) in college students who have not previously received the A/H1N1 vaccine. PARTICIPANTS: Undergraduate communication students at a metropolitan southern university. METHODS: In January-March 2010, students from voluntarily participating communication classes completed a hardcopy survey assessing TPB and clinically significant constructs. Hierarchical regression equations predicted variance in vaccine intentions of students who had not received a flu shot (N=198; 70% Caucasian). RESULTS: The TPB model explained 51.7% (p<.001) of variance in vaccine intentions. Controlling for side effects, self-efficacy and perceived comparative susceptibility predicted intentions when entered in the first block, whereas attitudes, subjective norms, and perceived behavioral control significantly contribute when entered in the second block. CONCLUSIONS: For students who have not previously received a flu vaccine, vaccine communication should utilize self-efficacy and perceived comparative susceptibility to employ the TPB to promote vaccine intentions.

Reassortant swine influenza viruses isolated in Japan contain genes from pandemic A(H1N1) 2009.

In 2013, three reassortant swine influenza viruses (SIVs)-two H1N2 and one H3N2-were isolated from symptomatic pigs in Japan; each contained genes from the pandemic A(H1N1) 2009 virus and endemic SIVs. Phylogenetic analysis revealed that the two H1N2 viruses, A/swine/Gunma/1/2013 and A/swine/Ibaraki/1/2013, were reassortants that contain genes from the following three distinct lineages: (i) H1 and nucleoprotein (NP) genes derived from a classical swine H1 HA lineage uniquely circulating among Japanese SIVs; (ii) neuraminidase (NA) genes from human-like H1N2 swine viruses; and (iii) other genes from pandemic A(H1N1) 2009 viruses. The H3N2 virus, A/swine/Miyazaki/2/2013, comprised genes from two sources: (i) hemagglutinin (HA) and NA genes derived from human and human-like H3N2 swine viruses and (ii) other genes from pandemic A(H1N1) 2009 viruses. Phylogenetic analysis also indicated that each of the reassortants may have arisen independently in Japanese pigs. A/swine/Miyazaki/2/2013 were found to have strong antigenic reactivities with antisera generated for some seasonal human-lineage viruses isolated during or before 2003, whereas A/swine/Miyazaki/2/2013 reactivities with antisera against viruses isolated after 2004 were clearly weaker. In addition, antisera against some strains of seasonal human-lineage H1 viruses did not react with either A/swine/Gunma/1/2013 or A/swine/Ibaraki/1/2013. These findings indicate that emergence and spread of these reassortant SIVs is a potential public health risk.

Adjuvanted A/H1N1 (2009) influenza vaccination during pregnancy: description of a prospective cohort and spontaneously reported pregnancy-related adverse reactions in the Netherlands.

BACKGROUND: During influenza pandemics, pregnant women have an increased risk of severe complications. Vaccination can diminish these complications. In the Netherlands, the adjuvanted vaccines Focetria® and Pandemrix® were used during the A/H1N1 (2009) influenza pandemic. The national vaccination scheme included pregnant women, but knowledge concerning the safety of adjuvants during pregnancy was lacking. The aim of the study is to assess safety of adjuvanted influenza vaccines during pregnancy. METHODS: The Dutch Teratology Information Service, part of the Netherlands Pharmacovigilance Centre Lareb, recruited 295 A/H1N1 (2009) vaccinated pregnant women through health care providers. Questionnaires were sent during the pregnancy to their health care providers and a second one 6 weeks after the estimated date of birth. Reported complications and adverse outcomes were compared with background rates. Additionally, the spontaneously reported pregnancy-related adverse reactions in the database of the Netherlands Pharmacovigilance Centre Lareb are described. RESULTS: Compared with the background rate, no increased risk of spontaneous abortions or congenital malformations was observed. There were three spontaneous abortions among 23 first trimester exposures. In the cohort of 281 pregnancies with known outcomes, three major malformations were observed after exposure at any time during pregnancy. In these cases exposure occurred once periconceptional, and twice in the second trimester. Furthermore, no increased risk of adverse pregnancy outcomes or neonatal problems were observed. The spontaneously reported pregnancy-related adverse events showed no unexpected pattern. CONCLUSION: The present study adds further reassurance for the safe use of adjuvanted vaccines during pregnancy and facilitates decision making in future pandemics.

Performance of the Directigen EZ Flu A+B rapid influenza diagnostic test to detect pandemic influenza A/H1N1 2009.

The Directigen EZ Flu A+B rapid influenza diagnostic test, as compared to real-time reverse transcriptase polymerase chain reaction, demonstrated suboptimal performance to detect pandemic influenza A/H1N1 2009. Age- and viral load-stratified test sensitivity ranged from 33.3 to 84.6% and 0 to 100%, respectively.

In vitro antiviral activity of hypothiocyanite against A/H1N1/2009 pandemic influenza virus.

Influenza virus spreads via small particle aerosols, droplets and fomites, and since it can survive for a short time on surfaces, can be introduced into the nasal mucosa before it loses infectivity. The hypothiocyanite ion (OSCN-), product of the lactoperoxidase/H2O2/SCN- system of central airways, is emerging as an important molecule for innate defense mechanism against bacteria, fungi and viruses. Here we demonstrated that OSCN(-) displays virucidal activity in vitro against the A/H1N1 2009 pandemic influenza virus. The concentration required to inhibit viral replication by 50% was 2 µM when virus were challenged directly with OSCN- before cell inoculation. These values were even lower when inoculated cells were maintained in contact with enzyme free-OSCN- in the culture medium. The last experimental conditions better reflect those of tracheobronchial mucosa, where HOSCN/OSCN- is retained in the air-liquid interface and inactivates both the viruses approaching the epithelium from outside and those released from the inoculated cells after the replication cycle. Importantly no OSCN- cytotoxicity was observed in the cellular system employed. The lack of toxicity in humans and the absence of damage on surfaces of fomites suggest a potential use of OSCN- to avoid mucosal and environmental transmission of influenza virus. Since hypothiocyanite is normally present in human airways a low risk of viral resistance is envisaged. In vivo confirmatory studies are needed to evaluate the appropriate dose, regimen and formulation.

Clinical diagnosis of pandemic A(H1N1) 2009 influenza in children with negative rapid influenza diagnostic test by lymphopenia and lower C-reactive protein levels.

BACKGROUND: The sensitivity of rapid influenza diagnostic test (RIDT) of children with influenza-like illness (ILI) remains low. OBJECTIVE: We compare the parameters between pandemic A(H1N1) 2009 influenza with negative RIDT and ILI not H1N1 for improving the low sensitivity of RIDT for children with ILI. METHODS: In a cohort of consecutive laboratory-confirmed H1N1 influenza, we identified 150 H1N1 children with positive RIDT, 152 H1N1 children with negative RIDT, and 75 children with ILI not H1N1. Viral load in throat, complete blood count (CBC), and C-reactive protein (CRP) levels between H1N1 children with negative RIDT and children with ILI not H1N1 were assessed. RESULTS: The diagnostic sensitivity of the RIDT was 45·5%. An analysis of CBC and CRP levels indicated that H1N1 children with negative RIDT had lower total leukocyte, neutrophil, lymphocyte, and basophil counts, and serum CRP levels (P < 0·01). Lymphocyte counts less than 1500 cells/mm(3) and CRP levels <15 mg/l, determined by a receiver operating characteristic curve, showed a diagnostic sensitivity of 52·5% and 80·7%, respectively. Combining the lymphocyte counts and CRP levels provided a diagnostic sensitivity of 91·5%. Moreover, H1N1 children with negative RIDT had a lower viral load than those with positive RIDT (3·33 versus 4·48 log10  copies/ml, P < 0·001); the viral load was negatively correlated to the lymphocyte count (P < 0·001). CONCLUSIONS: A combination of a low lymphocyte count and a low CRP level could, in the early disease phase, provide a useful screening for H1N1 children with false-negative RIDT, potentially facilitating differential diagnoses.

HA222 polymorphism in Influenza A(H1N1) 2009 isolates from Intensive Care Units and ambulatory patients during three influenza seasons.

Amino acid substitutions which can affect the receptor binding specificity of the influenza virus, like the substitution of aspartic acid with glycine in position 222 of the haemagglutinin (HA) of influenza virus A(H1N1) 2009, have been associated with increased viral pathogenicity and increased tropism for the lower respiratory tract. In this paper, the polymorphic site 222 and the site 223 of the HA1 polypeptide of H1N1 2009 viruses were analyzed in order to better clarify the role of these substitutions in H1N1 2009 virus virulence. Viral strains included in this study were collected in Tuscany during 3 different influenza seasons from patients with severe as well as with mild forms of influenza caused by A(H1N1) 2009 virus. In addition, the oseltamivir resistance of the H1N1 2009 strains circulating during the same seasons was monitored with the aim to evaluate whether these changes in the HA and in neuraminidase (NA) tend to be linked and to influence each other. Altogether, the results indicate that in severe forms of influenza viral population is more variable than in mild influenza, as regards the site 222. The frequency of such substitutions varied among the three seasons, it was highest in the season 2010-2011 and very low in the season 2012-2013. However these differences were not significant.

Guillain-Barré syndrome surveillance during National Influenza Vaccination Campaign, New York, U.S.A., 2009.

The New York State Department of Health (NYSDOH) collected information about hospitalized patients with Guillain-Barré syndrome (GBS) during October 2009-May 2010, statewide (excluding New York City), to examine a possible relationship with influenza A(H1N1)pdm09 vaccination. NYSDOH established a Clinical Network of neurologists and 150 hospital neurology units. Hospital discharge data from the Statewide Planning and Research Cooperative System (SPARCS) were used to evaluate completeness of reporting from the Clinical Network. A total of 140 confirmed or probable GBS cases were identified: 81 (58%) from both systems, 10 (7%) from Clinical Network only, and 49 (35%) from SPARCS-only. Capture-recapture methods estimated that 6 cases might have been missed by both systems. Clinical Network median reporting time was 12 days versus 131 days for SPARCS. In public health emergencies in New York State, a Clinical Network may provide timely data, but in our study such data were less complete than traditional hospital discharge data.

Trends of influenza infection in Suriname.

The trends of influenza infection in Suriname were assessed from February 2010 through February 2011. Testing of 393 patients with symptoms of acute respiratory infection (ARI) revealed 15.3% Influenza B and 18.6% could be identified as influenza A positive, consisting of 56% influenza A(H1N1)pdm09 and 44% seasonal A(H3N2). Influenza infection occurred throughout the year, and all three influenza types affected young children as the primary population. The annual incidence of A(H1N1)pdm09 was 6.88 per 100,000 inhabitants [CI] 4.87-9.45. The spread of influenza could neither be linked to tourist flow from the Netherlands nor to contact rates related to school schedules.

Conocimientos, actitudes y prácticas sobre la influenza A(H1N1) 2009 y la vacunación contra influenza pandémica: resultados de una encuesta poblacional / Knowledge, attitudes and practices about influenza A(H1N1) 2009, and influenza vaccine in Mexico: results of a population survey

OBJETIVO: Evaluar conocimientos, actitudes y prácticas respecto a la pandemia de influenza, con especial énfasis en la vacuna contra influenza estacional y pandémica. MATERIAL Y MÉTODOS: Estudio transversal con muestreo polietápico probabilístico, realizado durante diciembre de 2009 en residentes mayores de 18 años de la Ciudad de México (y área metropolitana), Monterrey, Guadalajara y Mérida. RESULTADOS: Se incluyeron 1 600 sujetos (48.9% masculino); 34% había recibido vacuna contra influenza estacional en años pasados, 90.6% estaba dispuesto a recibir la vacuna contra A(H1N1). La principal causa de rechazo a la vacunación fue no confiar en la vacuna (46.5%). Principales medidas preventivas identificadas por los encuestados: lavado de manos (47.5%), vacuna contra A(H1N1) (28%) y etiqueta respiratoria (19.4%). El nivel escolar (1.7, p=0.006) y edad (1.02, p<0.001) influyeron en el rechazo a la vacuna. El 82.9% de los encuestados calificó el manejo de la situación por el Gobierno Federal como bueno o muy bueno. CONCLUSIONES: La población refirió un alto porcentaje de aceptación para la vacuna de influenza pandémica durante el inicio de la campaña de vacunación en México, comparado con la reportada en otros países. La principal razón de aquéllos que la rechazan es la desconfianza hacia la vacuna.

OBJECTIVE: To assess knowledge, attitudes and practices regarding influenza pandemic, with special emphasis on issues related to influenza vaccine, seasonal and pandemic. MATERIALS AND METHODS: Cross-sectional study, probabilistic multistage sampling in patients over 18 years, residents of Mexico City (and metropolitan area), Monterrey, Guadalajara and Merida in December 2009. RESULTS: A total of 1.600 subjects (48.9% male) were interviewed, 34% had previously received seasonal flu vaccine, 90.6% were willing to be vaccinated against A(H1N1), 46.5% of those who would not receive the vaccine was because they did not trust A (H1N1), 68% considered influenza A (H1N1) as a risk for their family. Hand washing was the preventive measure most commonly reported (47.5%), secondly influenza vaccine (28%). Schooling (1.7, p=0.006) and age (1.02, p<0.001) influence rejection to get vaccine. 82.9% of respondents rate the federal government's management as good or very good. CONCLUSIONS: There was a high acceptance rate for the pandemic influenza vaccine in Mexico when compared to similar studies in other countries, the main reason for those who reject the vaccine was distrust in it.

Relationship between respiratory viral load and lung lesion severity: a study in 24 cases of pandemic H1N1 2009 influenza A pneumonia.

OBJECTIVE: To investigate the relationship between respiratory viral load and lung lesion severity of patients with pandemic H1N1 2009 influenza A pneumonia. STUDY DESIGN: Cross-sectional observation study. METHODS: 24 consecutive H1N1 influenza patients with viral pneumonia (13 males, 11 females, mean age: 17.5 years) during their presentation to hospital were retrospectively analysed. Viral load were first measured on average 5.2 days after the onset of symptoms. The initial CT and viral load measurement was carried on the same day in 13 patients. The rest were carried out with a mean interval time of 1.5 days. All patients had viral load follow-up till turned negative. Thirteen patients had radiological follow-up. RESULTS: There was no significant correlation between the initial lung lesion severity and viral load (P=0.4). Both viral load and lung lesion severity decreased over time, being highest value at initial presentation. The patients had higher initial viral load or higher initial lung lesion severity tended to be slower in resolving. The lung lesion decreased at a slower rate than viral load. CONCLUSIONS: While there was no correlation between the initial viral load and lung lesion severity, these two indices provide valuable information for epidemiological control.

Mass oseltamivir prophylaxis halts pandemic influenza A H1N1 2009 outbreak in a secondary school in Ashanti Region, Ghana.

OBJECTIVES: To describe the epidemiology and public health response to H1N1 outbreak and make recommendations to prevent future outbreaks. DESIGN: A descriptive study of an outbreak investigation. SETTING: A secondary school in Asante Akim South District. METHODS: Influenza A H1N1 2009 infection was laboratory-confirmed by Polymerase Chain Reaction (PCR) in clinically ill students after collecting throat swabs. Sixty students of the school had presented with fever, cough, headache and sore throat. The students' dormitories were also inspected to assess degree of ventilation and general level of cleanliness in the rooms. RESULTS: The outbreak followed a propagated transmission lasting 10 days with two peaks on 22(nd) and 24(th) June, 2010.The clinical attack rate was 9.9%. Secondary attack rates at the highly congested female dormitory were 28%, 31.3% and 17.8% for Rooms 1, 2 and 3 respectively. The generation time for the Influenza H1N1 a 2009 outbreak in the school was about two days. CONCLUSION: A mild form of Influenza A H1N1 2009 was confirmed in a secondary school affecting mainly those in the boarding house. Cases identified were treated, but post-exposure prophylaxis with oseltamivir administered to the remaining school population actually halted the outbreak, after social distancing interventions had not succeeded.

Guillain-Barre Syndrome With Treatment-Related Fluctuations

No abstract available.

Clinical and Laboratory Characteristics of Pandemic Influenza A/H1N1 2009 Infection among Patients with Malignancy in Korea / 감염과화학요법

BACKGROUND: Patients with malignancy are considered to be at high risk of severe pandemic influenza A/H1N1 2009. This study was conducted to identify the severity of pandemic influenza A/H1N1 2009 among patients with malignancy. MATERIALS AND METHODS: Between August 2009 and December 2009, we reviewed clinical data and medical records of 31 patients with malignancy and 63 hospitalized patients without malignancy. RESULTS: Eighty-three patients with laboratory-confirmed pandemic influenza A/H1N1 2009 were admitted. The rate of ICU admission was higher among patients with malignancy (without malignancy 13% vs with malignancy 35%, P=0.024). The mortality rate was higher among patients with malignancy (without malignancy 6% vs with malignancy 25%, P=0.033). Patients using immunosuppressants showed a higher rate of lower respiratory tract infection (83% vs 24%, P=0.013). CONCLUSIONS: Pandemic influenza A/H1N1 2009 in patients with malignancy was more severe than in patients without malignancy.