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The 2009 novel H1N1 influenza A virus (H1N1) became a global pandemic. Data on antiviral prescriptions by location from 2008 to 2010 have not been reported. The purpose of this study was to assess antiviral geographic trends and correlation with influenza-like illness (ILI) over 3 years. Percent of outpatient ILI visits and antiviral prescriptions from 1 January 2008 to 31 December 2010 were included. Linear regression was used to assess correlation. In total, 14 million antivirals were dispensed during this period. A 115% increase was observed in 2009 compared with prescriptions dispensed in 2008, and an 84% decrease was observed in 2010 compared with 2009. The rate of antivirals was 1.32 prescriptions/100 persons in 2008, 2.85/100 persons in 2009 and 0.435/100 persons in 2010. 2009 regional growth was observed in most states and was highest in the West (293%) and the Northeast (272%). A positive correlation was observed between antivirals and ILI visits (R(2)=0.7853; P0.0001). With the 2009 H1N1 pandemic, antivirals increased compared with 2008 or 2010. Without the concern of H1N1, antivirals decreased in 2010 to levels lower than 2008. Geographic trends were also observed, which may be a result of the different intensity of influenza transmission and difference practice patterns. ILI diagnoses correlate with influenza antiviral prescription use in the USA.

In April 2009, Mexican health authorities announced an outbreak of a novel H1N1 influenza virus, which subsequently caused a pandemic. The world is now moving into the post-pandemic period. The experience gained in handling this pandemic at various levels under different settings has provided us many lessons for the future.To study the profile of various activities undertaken at flu screening centre as a response to pandemic influenza in a tertiary care hospital.Record-based study conducted in a tertiary care hospital of Pune. Required data was collected from records of flu OPD, ward and local health authority and interviewing related staff. Study included data from October 2009 to October 2010.A total of 8020 people presenting with influenza like illness (ILI) were screened in the flu OPD under study. Out of these, only 388 (4.84%) met clinical criteria where throat samples were collected, out of which only 81 were found to be positive (20.88%). Total three fatalities (3.7%) occurred out of 81 who had tested positive. Most cases of flu were managed at home (76.54%) while only 19 (23.4%) lab confirmed cases of H1N1 required hospitalisation.Majority of cases of H1N1 (2009) were managed at home. Early diagnosis, quick initiation of treatment, infection control measures, and good care at the hospital can effectively reduce morbidity and mortality in H1N1 pandemic.

Previous studies reported that the most common chronic condition found among hospitalized patients due to the novel 2009 H1N1 influenza was asthma. However, these studies did not include a concurrent control group. Thus, we investigated the association of asthma status and severity of H1N1 influenza in adults.The study was designed as a multi-site case-control study. Cases were patients who had positive PCR for H1N1 influenza and were admitted to the ICU or general ward with a diagnosis of H1N1 influenza from 1 January 2009 to 31 December 2009. Controls were patients who had positive PCR for H1N1 influenza, but were not admitted to hospitals.There were 91 H1N1 cases admitted to either ICU (n = 41) or general hospital ward (n = 50), and 56 controls who met the matching criteria were available. Of the 91 cases, the mean age was 47.3 years, 59% were female, and 38% had comorbid conditions. Of the 91 cases, 12 (13%) had asthma. Stratified analysis by comorbid conditions showed that among those without any comorbid conditions, 8 of 56 cases (14%) and 2 of 49 controls (4%) had asthma, (OR: 3.92, 95% CI: 0.79-19.42, p = 0.095) whereas, among the 39 subjects with one or more comorbid conditions, one of 7 controls (14%) had asthma and 4 of 35 (11%) cases had asthma (p = 0.83).Asthma may be associated with severity of H1N1 influenza among those without any non-asthma comorbid conditions. However, the limited sample size did not allow this study to fully establish statistical significance. We still recommend asthmatics as a priority group for influenza vaccination and treatment.

ObjectiveWe compared attack rates for novel H1N1 influenza A (H1N1) among various groups aboard an aircraft carrier as influenced by characteristics of their living arrangements.MethodsDuring an outbreak of H1N1 on board the USS George Washington (GW), group affiliation (department or squadron membership) data were obtained on all patients who were placed in respiratory isolation based on their diagnosis with presumptive H1N1. Because berthing spaces are assigned by department and various characteristics of each department's berthing spaces are known, analysis of attack rates in comparison to these characteristics was possible. Attack rates were compared with the square feet of living space per sailor, occupancy rate of the berthing areas, and size of the berthing areas. These results were further correlated with the mission of the various departments or squadrons.ResultsThe average attack rate was 3%, with the highest rates occurring in departments or squadrons whose mission required ongoing contact with civilian populations ashore. The attack rate among officers was 2.04 versus 3.19 among enlisted personnel; this difference was not significant (P = .21). The attack rate for women was 1.90 versus 3.09 for men, which was significant (P = .05). Although attack rates varied considerably based on organizational mission, no correlation was found between attack rate and square feet of living space per person or occupancy rate or size of berthing spaces.ConclusionsThe attack rate of the outbreak overall was limited to 3%. Smaller and more crowded berthing configurations did not contribute to higher attack rates, suggesting that transmission occurs most frequently elsewhere while engaged in other activities such as working, eating, or relaxing. Further studies are necessary to filter out potential correlations or variables not identified in this study, such as the difference between the number of men and women isolated. (Disaster Med Public Health Preparedness. 2012;0:1-5)

Please cite this paper as: Shin et al. (2012) Practices and predictors of 2009 H1N1 vaccination in cancer patients: a nationwide survey in Korea. Influenza and Other Respiratory Viruses 6(601), e120–e128. Background Because patients with cancer are considered to be at high-risk for influenza infection and related complications, annual vaccination is recommended. The emergence of the novel H1N1 influenza virus in 2009 complicated the medical care of patients with cancer. The present study examined H1N1 vaccination practices among patients with cancer during the pandemic season and investigated factors related to the vaccination. Methods A national multicenter cross-sectional survey of patient–doctor dyads was performed; A total of 97 oncologists (response rates of invited participants, 87·4%) and 495 patients (response rates of recruited participants, 86·5%) were included. Patients with cancer provided information concerning vaccination practices and reasons for/against it. Oncologists answered questions about their recommendations and knowledge of H1N1 vaccination. Mixed logistic regression was used to identify patient-level and physician-level predictors of H1N1 vaccination. Results Only 34·1% of the patients had received H1N1 vaccination, and 53·5% had not considered the need for vaccination. The H1N1 vaccine was proactively recommended by physicians in only a small fraction of patients (8·3%). Increasing age, higher educational status, longer time since the cancer diagnosis, comorbidities, and greater knowledge of H1N1 vaccination among oncologists were significant predictors of patients being vaccinated. Conclusions The present results showed low levels of utilization and poor interaction between patients and physicians with regard to the need for vaccination. In addition, the oncologist’s level of knowledge affected the adoption of preventive services. Intervention strategies are needed to maximize the rapid adoption of preventive methods to confront future pandemic threats in the cancer patient population.

SUMMARY The menu of diagnostic tools that can be utilized to establish a diagnosis of influenza is extensive and includes classic virology techniques as well as new and emerging methods. This review of how the various existing diagnostic methods have been utilized, first in the context of a rapidly evolving outbreak of novel influenza virus and then during the different subsequent phases and waves of the pandemic, demonstrates the unique roles, advantages, and limitations of each of these methods. Rapid antigen tests were used extensively throughout the pandemic. Recognition of the low negative predictive values of these tests is important. Private laboratories with preexisting expertise, infrastructure, and resources for rapid development, validation, and implementation of laboratory-developed assays played an unprecedented role in helping to meet the diagnostic demands during the pandemic. FDA-cleared assays remain an important element of the diagnostic armamentarium during a pandemic, and a process must be developed with the FDA to allow manufacturers to modify these assays for detection of novel strains in a timely fashion. The need and role for subtyping of influenza viruses and antiviral susceptibility testing will likely depend on qualitative (circulating subtypes and their resistance patterns) and quantitative (relative prevalence) characterization of influenza viruses circulating during future epidemics and pandemics.

ACADEMIC EMERGENCY MEDICINE 2012; 19:274–279 © 2012 by the Society for Academic Emergency Medicine Abstract Objectives: The objective was to determine child caregiver satisfaction with a nontraditional pediatric emergency department (ED) venue during the 2009 novel H1N1 influenza outbreak. Methods: Between May 1 and 7, 2009, the Texas Children’s Hospital (TCH) ED used a six-bed outdoor facility, the Mobile Pediatric Emergency Response Team (MPERT), to evaluate patients with suspected novel H1N1 influenza. Parents and caregivers of patients evaluated in the MPERT were surveyed by telephone using a validated questionnaire to evaluate satisfaction with the facility. Results: Of 353 patients, 155 caregivers (44%) completed questionnaires; 127 had wrong numbers, 71 did not answer, and 15 were on a no-call list. Survey responders felt that nurses and doctors explained concepts well (nurses 92%, doctors 94%), 91% felt TCH prepared them well for taking care of their children at home, 94% were satisfied with the medical care received, and 88% were not bothered by the outdoor setting. When asked to rate their MPERT experience on a scale of 0 (worst possible) to 10 (best possible), the median score was 9 (range 1 to 10). Conclusions: The MPERT facility alleviated patient volume surge and potentially prevented transmission during H1N1 outbreak. While these were health care provider goals, caregiver expectations were also met. Caregivers perceived MPERT as an acceptable alternative to receiving care in the regular ED, felt that physicians and nurses communicated well, and felt that medical care was good to excellent. Use of the MPERT did not negatively affect overall caregiver satisfaction with TCH. These findings suggest that families of pediatric patients are amenable to nontraditional ED venues during periods of ED crowding.

SUMMARYThe 2009 novel H1N1 influenza pandemic had a significant impact on Shenzhen's population with 2063 laboratory-confirmed human H1N1 cases and five deaths being reported. We used parameters from two population-based surveys and the Shenzhen Influenza Surveillance System to estimate the total number of H1N1 influenza infections in Shenzhen in the 2009 pandemic. The attack rate of influenza-like illness (ILI) in family households was 11·2% (95% CI 9·4–13·0), with 80·2% (95% CI 77·8–82·5) seeking medical care. The ILI attack rate in workers was 38·1% (95% CI 34·3–41·7) with 72·5% (95% CI 66·9–78·0) seeking medical care. The average H1N1 positive rate in individuals reporting ILI and testing by polymerase chain reaction was 22·7%. A total of 611 000–768 000 people, or 4·7–5·9% of the Shenzhen population, are estimated to have experienced H1N1 influenza. The estimated total number of cases of H1N1 is likely to be 330 times greater than the number of laboratory-confirmed cases.

The advent of the novel H1N1 virus prompted the Houston Department of Health and Human services (HDHHS) to use the existing sentinel surveillance system to effectively monitor the situation of novel H1N1 virus in the Houston metropolitan area. The objective of this study was to evaluate the demographic characteristics and common symptoms associated with confirmed cases of seasonal influenza and Novel H1N1 virus reported to HDHHS between October 2008 and October 2009. A total of 30 providers were randomly selected using the probability proportional to size (PPS) sampling technique to participate in a sentinel surveillance system. The system was used to effectively monitor both seasonal and novel H1N1 virus in the Houston metropolitan area. These providers collected and submitted specimens for testing at HDHHS laboratory from patients with influenza-like illness (ILI) symptoms who visited their clinics during the period, October 2008 and October 2009. These data formed the basis of the current study. Data obtained were subjected to both descriptive and inferential statistical analyses using SAS software version 9.1.3. Overall a total of 1,122 ILI cases were reported to HDHHS by sentinel providers and tested by HDHHS laboratory. Of this number 296 (67.5%) specimens tested positive for influenza A; 140 (32.0%) for influenza B, and 2 (0.46%) for influenza A/B. Two hundred and fifty-nine (59%) were confirmed cases of seasonal influenza and 179 (41%) were novel H1N1 subtype, respectively. The median ages for seasonal influenza and novel H1N1 virus were 7 and 8 years, with majority of the cases reported among children of age 5-9 years. Fever was the most common symptom reported among patients with seasonal flu and novel H1N1 virus, followed by cough. Twenty-three percent (23%) of patients who were vaccinated against seasonal flu prior to the epidemic were infected with seasonal flu virus. The sentinel surveillance system provided timely data on the circulating ILI that assisted in making decisions regarding response activities for both seasonal and novel H1N1 influenza.

With the continuous emergence of new infectious diseases and new strains of current diseases, such as the novel H1N1 influenza in 2009, in combination with expanding competition in the vaccine marketplace, the pressure to develop vaccine formulations right the first time is increasing. As vaccines are complex, costly, and have high risk associated with their development, it is necessary to maximize the potential for development of a successful formulation quickly. To accomplish this goal, the historical empirical approach to formulation development needs to be updated with a rational, systematic approach allowing for more rapid development of safe, efficacious, and stable vaccine formulations. The main components to this approach are biophysical characterization of the antigen, evaluation of stabilizers, investigation of antigen interactions with adjuvants, evaluation of product contact materials, and monitoring stability both in real time and under accelerated conditions. An overview of investigations performed for each of these components of formulation development is discussed. The information gained in these studies is valuable in forming the base of knowledge for the design of a robust formulation. With the use of continually advancing technology in combination with maintaining a rational, systematic approach to formulation development, there is a great increase in the probability of successfully developing a safe, effective, and stable vaccine formulation.

A novel influenza A (H1N1) has been spreading worldwide. Early studies implied that international air travels might be key cause of a severe potential pandemic without appropriate containments. In this study, early outbreaks in Mexico and some cities of United States were used to estimate the preliminary epidemic parameters by applying adjusted SEIR epidemiological model, indicating transmissibility infectivity of the virus. According to the findings, a new spatial allocation model totally based on the real-time airline data was established to assess the potential spreading of H1N1 from Mexico to the world. Our estimates find the basic reproductive number R0 of H1N1 is around 3.4, and the effective reproductive number fall sharply by effective containment strategies. The finding also implies Spain, Canada, France, Panama, Peru are the most possible country to be involved in severe endemic H1N1 spreading.

The sudden appearance of the novel H1N1 influenza virus in North America highlights the importance of planning for such an event. Although the severity of this influenza is currently low, many lessons can be learned from the initial response by health care organizations.

The response to the novel H1N1 influenza (swine flu) pandemic has been overwhelmingly biological and epidemiological in scope. While plans are moving forward on a vaccine, few of the social effects of a truly massive global catastrophe-or the issues of communication, responding to predictable inappropriate reactions, preparation of populations for these effects, or using local population resources in the epidemic-have been well considered. Anthropology can play an important and underutilized role in planning and responding to influenza and other global emergencies. This editorial discusses these issues and makes some preliminary recommendations.

The novel H1N1 influenza virus that emerged in humans in Mexico in early 2009 and transmitted efficiently in the human population with global spread has been declared a pandemic strain by WHO. Here we reviewed the role of ethical issue in the prevention of H1N1. Studies with original data related to the ethical issues in the prevention of diseases (published 1996-2012) were identified via searching electronic databases to extract related information. The role of ethical issues in the prevention of diseases must be understood. This comprises work on how the society understands about a disease and what are their individuals’ tasks to conquer the outbreak. Such understanding feeds into health damaging or health promoting behavior which eventually will help in the implementation of various disease control measures. The promises of ethical issue in the various control measures that may be taken to fight the danger of pandemic H1N1 are great.

We report a surveillance method for influenza that is based on automated hospital laboratory and pharmacy data. During the 2009 H1N1 influenza pandemic, this method was objective, easy to perform, and utilized readily available automated hospital data. This surveillance method produced results that correlated strongly with influenza-like illness surveillance data.

Guidelines from the CDC recommend the use of an N95 filtering facepiece respirator. Drs. Kenneth Shine, Bonnie Rogers, and Lewis Goldfrank discuss the efficacy of personal respiratory protection measures, medical masks, and respirators.

In 2006, the Centers for Disease Control and Prevention recommended discontinuing the use of adamantanes (amantadine and rimantadine) to treat influenza because of high levels of resistance to this class of antivirals. We examined changes in prescribing practices resulting from this recommendation and found that prescribing of adamantanes declined nationwide, with these drugs accounting for approximately 40% of the antivirals prescribed for influenza from 2000 to 2005 and only 2% in 2006. This finding provides evidence of a rapid change in clinical practice associated with the dissemination of treatment guidelines. Evaluating the effectiveness with which public health recommendations are translated into practice is important given the ongoing emergence of resistance to antiviral drugs and a novel H1N1 influenza virus.

We evaluated the ability of direct fluorescent antigen (DFA) influenza tests to identify novel H1N1 influenza virus. DFA results were compared with polymerase chain reaction results. The negative predictive value of DFA testing was at least 96%. Therefore, when performed on specimens of adequate quality, DFA tests can effectively rule out infection due to novel H1N1 virus.

In response to the 2009 H1N1 influenza pandemic, the governments of Japan and the United States for the first time authorized the emergency use of unapproved drugs. In this article, we comprehensively review the different regulatory approaches of Japan and the United States, countries with advanced regulatory and healthcare systems, to emergency authorization of the use of medical products as a countermeasure to public health emergencies. We outline the legal system, range of targeted products, requirements for the application dossier, legal stance for authorization, product availability, and termination of the Japanese Emergency Approval (EA), and we compare characteristics with those of the US Emergency Use Authorization (EUA). We also review the actual cases of these 2009 emergency authorizations. The Japanese EA importation of novel H1N1 influenza vaccines with adjuvant is presented, with lessons learned, and contrasted with the US EUA of peramivir.

A level 1 pediatric emergency department (ED) in a public hospital of South Bronx rapidly encountered a significant surge in ED patient census over several days as the novel H1N1 influenza outbreak occurred. Our aim was to identify ill patients with influenza-like illness and evaluate and treat them as expeditiously as possible without failing in our responsibility to treat all patients. We describe the ED response to the outbreak during 2009 H1N1-related visits.The objective of this study was to describe and compare pediatric ED visits during the fall 2009 H1N1 to that in the previous year.The department reorganized patient flow in the ED to maximize the understanding of where to best apportion our resources and to minimize walkout and return visit rates. We developed staging of the flow of patients. This included, but was not limited to, a rapid screening at pretriage stage, early registration before the formal triage, and expanding the service. We compared walkout rates during fall 2009 and fall 2008. Return visits for asthmatic patients within 7 days were also compared.Over a period of 48 days, 8841 patients visited the pediatric ED. The average number of visits during this outbreak was 184 per day (usual visits per day, 80-110). Overall ED visits increased by 93.6% (95% confidence interval [CI], 78.2%-109.6%; P0.001). Fifty-two patients tested positive for H1N1. The walkout rate was 2.9% (95% CI, 1.9%-4.0%) in 2009 compared with the walkout rate of 1.5% (95% CI, 1.0%-2.0%) in 2008. There were no statistically significant differences between walkouts (P = 0.06) and 7-day asthma revisits (P = 0.07) in 2008 and 2009 despite the almost doubling of the ED visits. Admission rates from 2009 did not significantly differ from 2008 (11.2% [990/8841] vs 10.2% [464/4560], P = 0.07).Staging of a surge volume allows ED administrators to maintain a strong control of a multipatient event to ensure an effective response and appropriate use of limited resources. The implementation of the reorganized measures during the fall 2009 H1N1-related surge in patient's visits resulted in improved patient flow without significant increase in walkout and 7-day asthma revisit rates. Our strategies accommodated the surge of patients in the ED.

Background Effective communication is critical to formulating responses to emergent events in health care settings. However, the range of factors that influenced communication in health care settings during the 2009 H1N1 influenza pandemic has received limited attention. Methods Cross-sectional semistructured interviews were conducted by telephone with 33 infection control key informants at nationally dispersed Veterans Affairs health care facilities. Interviews were guided by an interview script that addressed topics on infection control practices, including information sources, methods of dissemination, barriers and facilitators to effective communication, and recommendations for future practices. Results Communication was facilitated when information was timely, organized, disseminated through multiple channels, and included educational materials. Barriers to effective communication included feeling overwhelmed by the amount of information received, encountering contradictory information, and restrictions on information dissemination because of uncertainty and inconsistent information. Participants offered recommendations for future pandemics, including the need for standardized educational content, clearer guidance from national organizations, and predefined communication plans for hospital staff. Conclusion The findings of the present study provide insight about improving communication efforts within Veterans Affairs health care facilities during emergent events. The communication experiences discussed—and barriers and facilitators identified—can also be used in planning for future pandemics and other emergent situations.

SUMMARYThe spring of 2009 witnessed the emergence of a novel influenza A(H1N1) virus resulting in the first influenza pandemic since 1968. In autumn of 2010, the 2009 novel H1N1 influenza strain re-emerged. We performed a retrospective time-series analysis of all patients with laboratory-confirmed H1N1 influenza who presented to our institution during 2009. Cases of influenza were assembled into 3-day aggregates and forecasting models of H1N1 influenza incidence were created. Forecasting estimates of H1N1 incidence for the 2010–2011 season were compared to actual values for our institution to assess model performance. Ninety-five percent confidence intervals calculated around our model's forecasts were accurate to ±3·6 cases per 3-day period for our institution. Our results suggest that time-series models may be useful tools in forecasting the incidence of H1N1 influenza, helping institutions to optimize distribution of resources based on the changing burden of illness.

Molecular methods are becoming more widely used for the detection of respiratory pathogens, in part because of their superior sensitivity, relatively rapid turnaround time, and ability to identify pathogens that are slow growing or difficult to culture. The recent novel H1N1 influenza A pandemic served to underscore how quickly new molecular tests can become available for clinical use. Over the years PCR has been the dominant amplification method. Recently, modifications of this technology have emerged, some of which allow for the rapid detection of multiple pathogens in a single test. This review will focus on emerging multiplex molecular technologies and their clinical utility for the detection of respiratory pathogens.

The recent pandemic of a novel H1N1 influenza virus has stressed the importance of effective approaches to prevent viral infection. The innate immune system is our first line of defense against invading viruses. This review aims to give a brief summary of recent findings on the response of the innate immune system to influenza virus.Three families of pattern recognition receptors, toll-like receptors (TLRs), retinoic acid-inducible gene 1 protein like helicases (RLRs) and nucleotide-binding domain and leucine-rich-repeat-containing proteins (NLRs), are involved in recognition of influenza virus and they cooperatively operate to respond to the virus in cell culture or mouse models. Influenza virus mainly induces two types of innate immune cytokine responses: a proinflammatory response and an antiviral response. Recently, the NLRP3 inflammasome has proved to be an essential component in the host defense against influenza infection. The mitochondrion, traditionally recognized for its key role in respiration, metabolism and apoptosis, is becoming recognized as an important organelle for regulation of innate immune responses to influenza virus.The NLRP3 inflammasome is an essential component in the host defense against influenza infection. Further investigations are required to elucidate whether NLRP3 is associated with the adaptive response and to identify the components of influenza virus that activate this important mediator. The role of mitochondria as a potential central platform of innate response is becoming appreciated.

Community-acquired pneumonia (CAP) is a leading cause of morbidity and mortality worldwide, affecting approximately 5.6 million patients annually in the USA, where the annual cost exceeds US$12 billion. Optimal management should be based on knowledge of the most likely etiologic pathogens for each patient, based on an assessment of specific risk factors. It is also essential to assess severity of illness, to determine the appropriate site of care, and to order appropriate diagnostic testing. New developments in CAP management have focused on recognizing newly identified pathogens, such as methicillin-resistant Staphylococcus aureus and novel H1N1 influenza, understanding when to utilize new microbiological diagnostic techniques, and how to use biomarkers to direct the appropriate utilization of antibiotics and to define the duration of therapy. This paper reviews recent advances in our knowledge about the diagnosis and optimal management of CAP.

Analysis of pediatric deaths associated with pandemic A H1N1 influenza shows that fatal outcome is more likely in young children, under the age of 5. Neonates, because of the immaturity of their immune system, could represent a high-risk group for severe disease and fatal outcome. We present a group of five neonates with confirmed novel influenza A H1N1 infection. This report indicates that the full spectrum of influenza A H1N1 infection ranging from mild febrile illness with spontaneous recovery to severe disease with fatal outcome may be expected even in neonates. Journal of Perinatology (2011) 31, 446-448; doi:10.1038/jp.2010.194

While we often see Influenza infections as part of our daily lives during winter in the United States, it is a virus with significant potential for manipulation into an agent that may be used in the framework of Bioterrorism. The Novel H1N1 outbreak of 2009 highlighted what our response is to such an unsuspected outbreak both on a national and global scale. The responses to this outbreak allowed us to avert significant damage from the Pandemic, but retrospective analysis suggests that if the outbreak had been more virulent, greater impact would have been felt on a global scale. This short review attempts to briefly summarize our response to the Novel H1N1 outbreak in the United States and to apply the knowledge gleaned from this analysis to a hypothetical Bioterrorism attack that employs a modified Influenza virus, an event that is unlikely but not impossible.

In 2009 a novel H1N1 influenza virus emerged and spread rapidly. Soon after vaccine lots were released, however, the shelf life was revised downward due to an unexpected decrease in HA potency. In this study, we found differences in both stability and antigenic content of two monovalent H1N1/2009 vaccine preparations. These appear to have arisen due to differences in the A/California/7/2009-like influenza strain used to prepare vaccine.

In 2009, the World Health Organization recognized the novel H1N1 influenza A virus as a pandemic infection. Since April 2009, thousands of cases of novel H1N1 influenza A infection have been reported worldwide, and they have resulted in thousands of deaths. South American countries were affected by this infection during their winter season, and Chile presented one of the highest incidence rates. We have recently managed a liver transplant patient who presented with a severe novel H1N1 influenza A infection in the early postoperative period and required prolonged mechanical ventilation. The early suspicion of this infection during the current pandemic influenza in Chile made possible a timely treatment with oseltamivir. We decided to report this case because no other cases of liver transplant patients affected by H1N1 influenza A have been reported so far. We intend to alert clinicians about this potentially devastating viral infection in view of the current pandemic scenario, and here we review some of the recommendations for its prevention, diagnosis, therapy, and possible complications.

In June 2009, the World Health Organization declared that novel influenza A (nH1N1) had reached pandemic status worldwide. The response to the spread of this virus by the public and by the public health community was immediate and widespread. Among the responses included voluntary avoidance of public spaces, closure of schools, the ubiquitous placement of hand sanitizer, and the use of face masks in public places. Existing forecasting models of the epidemic spread of nH1N1, used by public health officials to aid in making many decisions including vaccination policy, ignore avoidance responses in the formal modeling. In this paper, we build a forecasting model of the nH1N1 epidemic that explicitly accounts for avoidance behavior. We use data from the U.S. summer and the Australian winter nH1N1 epidemic of 2009 to estimate the parameters of our model and forecast the course of the epidemic in the U.S. in 2010. We find that accounting for avoidance responses results in a better fitting forecasting model. We also find that in models with avoidance, the marginal return in terms of saved lives and reduced infection rates of an early vaccination campaign are higher.

The recent emergence of a novel H1N1 influenza A virus in humans caused the first influenza pandemic of this century. Many clinical diagnostic laboratories are overwhelmed by the testing demands related to the infection. Three novel H1N1-specific primer-probe sets reported during the early phase of the pandemic were tested in three commercial real-time RT-PCR mixtures. The amplification efficiencies and detection limits of these assays were determined. A ready-to-use premixed RT-PCR stored in a lyophilized format was developed. The detection limits of the studied assays were highly variable, ranging from 1.68E-01 to 1.68E-05 TCID50 per reaction. The detection limit of the lyophilized reaction mixture was found to be 1.68E-05 TCID50 per reaction, but the amplification efficiency of the assay was lower than those deduced from the other assays. All respiratory samples from infected patients and all control nasopharyngeal aspirates were positive and negative, respectively, in the newly developed assay. The results highlighted that, to enhance the sensitivity of an assay, it is essential to evaluate a primer-probe set with different commercial RT-PCR assays. This study also demonstrated the feasibility of using lyophilized reaction mixtures for the molecular diagnosis of novel H1N1. © 2010 Elsevier B.V., link_to_OA_fulltext

In April 2009, novel H1N1 influenza was first detected in Mexico. This was a new influenza caused from a new type of virus that was originally referred to as “swine flu” because laboratory testing showed that many of the genes in this new virus were very similar to those in influenza viruses that normally occur in swine.

Recombinant hemagglutinin (HA) from a novel H1N1 influenza strain was produced using an alphavirus replicon expression system. The recombinant HA vaccine was produced more rapidly than traditional vaccines, and was evaluated as a swine vaccine candidate at different doses in a challenge model utilizing the homologous influenza A/California/04/2009 (H1N1) strain. Vaccinated animals showed significantly higher specific antibody response, reduced lung lesions and viral shedding, and higher average daily gain when compared to non-vaccinated control animals. These data demonstrate that the swine vaccine candidate was efficacious at all of the evaluated doses.

The first influenza pandemic of the 21st century is now well upon us and several articles published in prominent journals in the past three months provide us with some information about the characteristics of H1N1 infection in the pregnant population. Although data from previous pandemics have significant limitations, it has repeatedly been shown that pregnant women are particularly prone to severe cases of influenza.1,2 The following three reports appear to confirm this pregnancy-associated increase in influenza virulence and suggest the wisdom of early antiviral treatment for pregnant women with influenza-like illness. A summary of their findings can be found in Table 1.

To the Editor: The medical community should be made aware of the serious potential for dosing errors in children prescribed Tamiflu (oseltamivir) oral suspension, as illustrated in the case described below. After the diagnosis of novel H1N1 influenza, a 6-year old received a prescription for Tamiflu (oseltamivir) oral suspension (12 mg per milliliter) at a dose of 3/4 teaspoon PO BID. However, the parents, one a primary care physician and the other one of the authors, had great difficulty determining the correct dose to administer to their child. The medication bottle was accompanied by a prepackaged syringe with markings of . . .