Influenza A (H1N1) Virus Outbreak in the Districts of Chhattisgarh: A Cross-Sectional Study

Background The H1N1 flu is a subtype of the influenza A virus, also known as the swine flu. An entirely new strain of the H1N1 virus started sickening people in the 2009-2010 flu season. It was a novel influenza virus combination that can infect humans, pigs, and birds. It was frequently referred to as the "swine flu." The virus may be able to spread for a little while longer in children and individuals with compromised immune systems. Objective The objective is to investigate the outbreaks of H1N1 among young adults in the Bastar District of Chhattisgarh. Methods Collection of the blood samples of 342 individuals between December 2015 and November 2017 was done. Thirty-one cases of Influenza A (H1N1) PDM09 virus infection were identified and confirmed. The molecular relationship between viruses is identified by the real-time polymerase chain reaction (RT-PCR) method. Result The majority of samples (n=13) were sourced from Raipur Medical College, followed by contributions from Durg District Hospital (n=5), Raigarh Medical College (n=4), Rajnandgaon District Hospital (n=3), Jagdalpur Medical College (n=2), Bilaspur Medical College (n=2), and smaller contributions from Dhamtari District Hospital and Gariyabandh Primary Health Care. Among these, 31 samples tested positive for Influenza A (H1N1) PDM 2009 virus, with a slightly higher prevalence among 19 female patients. Age-wise distribution revealed higher proportions of positive cases in the age groups of 0-10 years, 31-40 years, and 21-30 years. In the molecular analysis, 154 samples showed no target amplification, while 125 samples exhibited amplification of only Influenza A without subtype (H1) amplification. Remarkably, 31 patients who tested positive for Influenza A (H1N1) died from the virus; most of the deaths were in children under five and middle-aged adults. Conclusion The detection of Influenza A (H1N1) PDM 2009 virus, especially among females, indicates its persistent circulation. Positive cases were prevalent among younger and middle-aged individuals. Molecular analysis showed subtype variations, with significant fatalities observed in children under five and middle-aged adults, emphasizing the severity of the virus across different age groups. It is advised that in order to keep Indian influenza surveillance up to date and robust, more epidemiological data should be gathered, along with information on risk factors like immunization status, hospitalization, and mortality rates should be estimated, and influenza case subtyping should be improved.

Response of Human Retinal Microvascular Endothelial Cells to Influenza A (H1N1) Infection and the Underlying Molecular Mechanism

Purpose

Whether H1N1 infection-associated ocular manifestations result from direct viral infections or systemic complications remains unclear. This study aimed to comprehensively elucidate the underlying causes and mechanism.

Method

TCID50 assays was performed at 24, 48, and 72 hours to verify the infection of H1N1 in human retinal microvascular endothelial cells (HRMECs). The changes in gene expression profiles of HRMECs at 24, 48, and 72 hours were characterized using RNA sequencing technology. Differentially expressed genes (DEGs) were validated using real-time quantitative polymerase chain reaction and Western blotting. CCK-8 assay and scratch assay were performed to evaluate whether there was a potential improvement of proliferation and migration in H1N1-infected cells after oseltamivir intervention.

Results

H1N1 can infect and replicate within HRMECs, leading to cell rounding and detachment. After H1N1 infection of HRMECs, 2562 DEGs were identified, including 1748 upregulated ones and 814 downregulated ones. These DEGs primarily involved in processes such as inflammation and immune response, cytokine-cytokine receptor interaction, signal transduction regulation, and cell adhesion. The elevated expression levels of CXCL10, CXCL11, CCL5, TLR3, C3, IFNB1, IFNG, STAT1, HLA, and TNFSF10 after H1N1 infection were reduced by oseltamivir intervention, reaching levels comparable to those in the uninfected group. The impaired cell proliferation and migration after H1N1 infection was improved by oseltamivir intervention.

Conclusions

This study confirmed that H1N1 can infect HRMECs, leading to the upregulation of chemokines, which may cause inflammation and destruction of the blood-retina barrier. Moreover, early oseltamivir administration may reduce retinal inflammation and hemorrhage in patients infected with H1N1.

Identifying H1N1 and COVID-19 vaccine hesitancy or refusal among health care providers: a scoping review

OBJECTIVES

The objective of this review was to describe and map the evidence on COVID-19 and H1N1 vaccine hesitancy or refusal by physicians, nurses, and pharmacists in North America, the United Kingdom and the European Union, and Australia.

INTRODUCTION

Since 2009, we have experienced two pandemics: H1N1 "swine flu" and COVID-19. While severity and transmissibility of these viruses varied, vaccination has been a critical component of bringing both pandemics under control. However, uptake of these vaccines has been affected by vaccine hesitancy and refusal. The vaccination behaviors of health care providers, including physicians, nurses, and pharmacists, are of particular interest as they have been priority populations to receive both H1N1 and COVID-19 vaccinations. Their vaccination views could affect the vaccination decisions of their patients.

INCLUSION CRITERIA

Studies were eligible for inclusion if they identified reasons for COVID-19 or H1N1 vaccine hesitancy or refusal among physicians, nurses, or pharmacists from the included countries. Published and unpublished literature were eligible for inclusion. Previous reviews were excluded; however, the reference lists of relevant reviews were searched to identify additional studies for inclusion.

METHODS

A search of CINAHL, MEDLINE, PsycINFO, and Academic Search Premier databases was conducted April 28, 2021, to identify English-language literature published from 2009 to 2021. Gray literature and citation screening were also conducted to identify additional relevant literature. Titles, abstracts, and eligible full-text articles were reviewed in duplicate by 2 trained reviewers. Data were extracted in duplicate using a structured extraction tool developed for the review. Conflicts were resolved through discussion or with a third team member. Data were synthesized using narrative and tabular summaries.

RESULTS

In total, 83 articles were included in the review. Studies were conducted primarily across the United States, the United Kingdom, and France. The majority of articles (n=70) used cross-sectional designs to examine knowledge, attitudes, and uptake of H1N1 (n=61) or COVID-19 (n=22) vaccines. Physicians, medical students, nurses, and nursing students were common participants in the studies; however, only 8 studies included pharmacists in their sample. Across health care settings, most studies were conducted in urban, academic teaching hospitals, with 1 study conducted in a rural hospital setting. Concerns about vaccine safety, vaccine side effects, and perceived low risk of contracting H1N1 or COVID-19 were the most common reasons for vaccine hesitancy or refusal across both vaccines.

CONCLUSIONS

With increased interest and attention on vaccines in recent years, intensified by the COVID-19 pandemic, more research that examines vaccine hesitancy or refusal across different health care settings and health care providers is warranted. Future work should aim to utilize more qualitative and mixed methods research designs to capture the personal perspectives of vaccine hesitancy and refusal, and consider collecting data beyond the common urban and academic health care settings identified in this review.

Discrete Stochastic Optimization for Public Health Interventions with Constraints

Many public health threats exist, motivating the need to find optimal intervention strategies. Given the stochastic nature of the threats (e.g., the spread of pandemic influenza, the occurrence of drug overdoses, and the prevalence of alcohol-related threats), deterministic optimization approaches may be inappropriate. In this paper, we implement a stochastic optimization method to address aspects of the 2009 H1N1 and the COVID-19 pandemics, with the spread of disease modeled by the open-source Monte Carlo simulations, FluTE, and Covasim, respectively. Without testing every possible option, the objective of the optimization is to determine the best combination of intervention strategies so as to result in minimal economic loss to society. To reach our objective, this application-oriented paper uses the discrete simultaneous perturbation stochastic approximation method (DSPSA), a recursive simulation-based optimization algorithm, to update the input parameters in the disease simulation software so that the output iteratively approaches minimal economic loss. Assuming that the simulation models for the spread of disease (FluTE for H1N1 and Covasim for COVID-19 in our case) are accurate representations for the population being studied, the simulation-based strategy we present provides decision makers a powerful tool to mitigate potential human and economic losses from any epidemic. The basic approach is also applicable in other public health problems, such as opioid abuse and drunk driving.

Clinical study of invasive pulmonary aspergillosis following influenza A H1N1

This study to analyze the clinical characteristics of patients with invasive pulmonary aspergillosis (IPA) following influenza A (H1N1) infection.We retrospectively analyzed 10 cases with IPA following H1N1 infection. The clinical manifestations, laboratory examination results, chest computed tomography, and treatments were analyzed.Clinical manifestations: all 10 cases had typical flu-like symptoms at the onset of the disease, among which 7 patients developed dyspnea in the late stage, and 8 patients had hemoptysis. Laboratory examination: the absolute and percentage of peripheral blood lymphocytes in all 10 patients were declined, among which 5 cases were with decreased CD3+ CD4+ T cells/lymphocytes; 9 cases with increased bronchoalveolar lavage fluid galactomannan; 6 cases with increased serum galactomannan; 1 case with bronchoalveolar lavage fluid cultured aspergillus fumigatus; and 2 cases with aspergillus by second-generation sequencing. Chest computed tomography: all patients showed multiple diffused ground-glass opacities at the beginning, along with linear or reticular interstitial changes. Two cases had multiple subarachnoid nodules with halo signs, 3 cases had consolidation in multiple segments of both lungs, 2 cases had cavities, and 4 cases were with pleural effusion. Treatment: 10 patients were treated with antiviral and anti-Aspergillus drugs after admission. Four patients received respiratory support. All 10 cases were cured and discharged.Early diagnosis of IPA in influenza A (H1N1) patients is the key to successful treatment.

Extracorporeal membrane oxygenation for respiratory failure in children: the years before and after the 2009 H1N1 pandemic

OBJECTIVE

To evaluate whether there was any impact on the number of pediatric extracorporeal membrane oxygenation runs and survival rates in the years subsequent to the 2009 pandemic.

METHODS

We studied two different periods of extracorporeal membrane oxygenation support for respiratory failure in children by analyzing datasets from the Extracorporeal Life Support Organization. Autoregressive integrated moving average models were constructed to estimate the effect of the pandemic. The year 2009 was the year of intervention (the H1N1 epidemic) in an interrupted time series model. Data collected from 2001 - 2010 were considered preintervention, and data collected from 2010 - 2017 were considered postintervention.

RESULTS

There was an increase in survival rates in the period 2010 - 2017 compared to 2001 - 2010 (p < 0.0001), with a significant improvement in survival when extracorporeal membrane oxygenation was performed for acute respiratory failure due to viral pneumonia. The autoregressive integrated moving average model shows an increase of 23 extracorporeal membrane oxygenation runs per year, prior to the point of the level effect (2009). In terms of survival, the preslope shows that there was no significant increase in survival rates before 2009 (p = 0.41), but the level effect was nearly significant after two years (p = 0.05), with a 6% increase in survival. In four years, there was an 8% (p = 0.03) increase in survival, and six years after 2009, there was up to a 10% (p = 0.026) increase in survival.

CONCLUSION

In the years following 2009, there was a significant, global incremental increase in the extracorporeal membrane oxygenation survival rates for all runs, mainly due to improvements in the technology and treatment protocols for acute respiratory failure related to viral pneumonia and other respiratory conditions.

Evaluation of Pregnancy, Younger Age, and Old Age as Independent Risk Factors for Poor Hospitalization Outcomes in Influenza A (H1N1)pdm09 Virus a Decade After the Pandemic

Introduction The influenza A (H1N1)pdm09 virus infection was first reported in Mexico in 2009 and quickly became the first flu pandemic of the 21st century. Statistics show that the prevalence of H1N1 infection was higher among young adults during the pandemic while the elderly were at more risk of death. However; many studies have shown a gradual change over the years, with attack rates increasing in older adults as compared to young adults. The other significant vulnerable group for this infection seems to be pregnant women. Over the years, many authors have found that pregnancy may not be a significant risk factor for increased hospitalization and poorer outcomes. This study aims to perform a comparative analysis and thereby assess pregnancy, younger age, and old age as independent risk factors for poor hospitalization outcomes. Materials and methods The hospital records of all patients with H1N1 infection admitted between January 1, 2018, to December 31, 2018, were screened. The patients included in the study were young adults (18-31 years), pregnant women, and the elderly (≥65 years). Comparative analysis was done between them. Nominal variables were compared using the chi-square test. Results A total of 379 patients were admitted to our hospital with H1N1 infection from January 1, 2018, to December 31, 2018. There were 75 elderly (19.7%), 224 (59%) middle-aged adults, 55 (14.5%) young adults, and 25 (6.5%) pregnant women. Fever (90%, 84%, and 96%) and cough with expectoration (72%, 67.3%, and 40%) were the most prevalent symptoms. The elderly reported more dyspnoea (28% vs. 5.5%, 4 %). Diabetes mellitus was found in 73.3 % of the elderly, 3.6% of the young adults, and 12% of pregnant women. Hypertension was present in 45% of the elderly, 1.8% of young adults, and 4% of pregnant women. Coronary artery disease was seen in 22.7% of the elderly and 1.8% of young adults. Chronic kidney disease (5.3%) and chronic obstructive pulmonary disease (13.3%) were seen only in the elderly group. Relative lymphopenia was prevalent in all groups and was more in pregnant women (76% vs. 61.8% and 41.8%) as compared to other groups. Serum creatinine was elevated in 38% of the elderly, 2% of young adults, and 0% of pregnant women. Abnormal chest radiograph was reported for 48% of the elderly, 30.9% of young adults, and 12% of pregnant women. Twenty-six point seven percent (26.7%) of the elderly needed more than a weeks' stay as compared to 7.3% of young adults and 20% of pregnant women. Thirty-two percent (32%) of the elderly required intensive care as compared to 1.5% of young adults and none of the pregnant women. More of the elderly (26.7%) required ventilator support than other groups (7.3% and 4%). About 25.3% of the elderly had a superinfection. Eight percent (8%) of the elderly died in the study while none died in the other groups. Conclusion Age representation and poor hospitalization outcomes due to H1N1 seem to have shifted from young adults to older age groups. The elderly are at more risk for a prolonged stay, intensive care, ventilator support, and death as compared to young adults and pregnant women. Pregnancy may not be associated with poor hospitalization outcomes for H1N1 as has been earlier thought.

H1N1 Influenza Virus in Patients With Cystic Fibrosis: A Literature Review Examining Both Disease Entities and Their Association in Light of the 2009 Pandemic

The novel coronavirus (COVID-19) that is challenging the health sector and negatively impacting the global economy takes us back to the 2009 influenza A (H1N1) virus pandemic that brought the world to a standstill. In 2009, H1N1 became a significant health concern for several months. It mainly affected people under the age of 65 hyears who had no prior immunity, including children. Among the high-risk populations were pregnant patients and those with chronic cardiac, pulmonary, or respiratory diseases. These patients were at risk of developing severe pneumonia and respiratory complications. Cystic fibrosis (CF) represents a form of severe chronic lung disease in young adults and is the major fatal hereditary disorder of Caucasians in the United States. An online search of PubMed and Google Scholar was conducted to find relevant literature that explicitly examines patients with CF and H1N1.

H1N1 Influenza Causing Fulminant Myocarditis Requiring Extracorporeal Membrane Oxygenation

Influenza infection is a known cause of global morbidity and mortality. Most cases of influenza A (H1N1) influenza infection are mild and do not require hospitalization. Although the most common presentation is with upper respiratory tract symptoms, hemodynamic instability requiring vasoactive drugs and ventilatory support use is unusual. We present a case of acute fulminant myocarditis that presented with dyspnea, which was confirmed with laboratory tests, chest X-ray, and echocardiogram. The test for H1N1 in nasopharyngeal secretions was positive. The patient evolved to refractory cardiogenic shock despite the clinical measures applied.

Clinical profile & outcome of H1N1 infected pregnant women in a tertiary care teaching hospital of northern India

BACKGROUND & OBJECTIVES

H1N1 influenza is a recognized cause of febrile respiratory infection worldwide. There are not many studies to show its impact on pregnancy. In the present study we aimed to assess clinical characteristics, obstetric and perinatal outcome of pregnant women with H1N1 infection.

METHODS

A retrospective observational study was conducted at a tertiary care teaching hospital in New Delhi, India. A total of 24 pregnant women microbiologically positive for H1N1 were included. Maternal characteristics and outcome were recorded. Perinatal outcome which was defined as presence of any of the indicators such as abortion, preterm delivery, intrauterine death and neo natal death was noted.

RESULTS

The mean age of the study group was 25.2 ± 3 yr with a mean gestational age of 34.9 ± 4.6 wk. Six patients (25%) had associated co-morbidities. Nine patients (37.5%) presented within 48 h of onset of symptoms and 15 (62.5%) reported after 48 h. In 17 (70.83%) patients treatment was delayed by >48 h. ICU admission was needed in 20.8 per cent patients and mortality rates was 8.3 per cent. There were seven cases of adverse perinatal outcome.

INTERPRETATION & CONCLUSIONS

The presenting symptoms of pregnant women with H1N1 were similar to that of general population. Acquiring infection in late trimester, late initiation of antiviral treatment and presence of co-morbid illness were high risk factors for developing critical illness. Pregnant women with suspected H1N1 influenza should be started on antiviral therapy at the earliest. This is likely to help reduce the ICU admission rates and mortalities in this group of women.

Asthma and severity of 2009 novel H1N1 influenza: a population-based case-control study

BACKGROUND

Asthma has been shown to be associated with an increased risk of the 2009 novel H1N1 influenza (H1N1) infection among children. However, little is known about the role of asthma in severity of H1N1 infection.

OBJECTIVE

To determine the association between asthma and other atopic conditions and severity of H1N1 infection.

PATIENTS AND METHODS

We conducted a population-based case-control study. Cases were all Olmsted County, MN residents admitted to the hospital within a week of a positive test for H1N1. Controls who had a positive H1N1 but were not admitted to hospital were individually matched to cases with regard to birth day, gender, clinic registration date, diagnostic method, and calendar month of influenza testing. Asthma was ascertained using predetermined criteria. Data were fit to conditional logistic regression models.

RESULTS

There were 46 eligible individuals admitted to hospitals with H1N1 infection during the study period. Ninety-seven controls were individually matched to their corresponding cases. Among cases, 23 (50%) were male and 29 (63.0%) were Caucasians. The median age at hospitalization was 20.7 years. Twenty-five (54.4%) cases had asthma before the date of hospitalization, compared to 33 (34.0%) controls (matched OR: 2.31; 95% CI, 1.13-4.73; p = 0.02). This association approached statistical significance after adjusting for all pertinent covariates (adjusted matched OR: 2.55; 95% CI, 0.98-6.64; p = 0.055).

CONCLUSION

Asthma may be associated with severe H1N1 infection. In addition to timely influenza vaccination for asthmatics, consideration for prophylactic treatment for unimmunized asthmatics with significant exposure to influenza and immunized asthmatics with early flu-like symptoms should be given.

Comparison of the use of H1N1 and seasonal influenza vaccinations between veterans and non-veterans in the United States, 2010

BACKGROUND

Veterans of the U.S. armed forces tend to be older and have more chronic health problems than the general adult population, which may place them at greater risk of complications from influenza. Despite Centers for Disease Control and Prevention (CDC) recommendations, seasonal influenza vaccination rates for the general adult population remain well below the national goal of 80%. Achieving this goal would be facilitated by a clearer understanding of which factors influence vaccination.

METHODS

Using the 2010 U.S. National Health Interview Survey (NHIS), this study estimates models of two types of vaccinations (H1N1 and seasonal flu), assesses if the correlates differ for these vaccinations, and analyses the distribution of the correlates by veteran status.

RESULTS

Veterans, women, non-Hispanic whites, non-smokers, those at high risk, educated, with health insurance, and who use clinics as a usual source of care were more likely to receive both types of vaccinations. Those who were older, married, and with higher income were more likely to get vaccinated for seasonal flu, but not for H1N1. Age and number of children living in the household were found to have different effects for H1N1 compared to seasonal flu.

CONCLUSION

Veterans are more likely to get vaccinated for seasonal influenza and H1N1 compared to the general population. This might be due to Veterans having better access to care or Veterans participating in better health care practices. Future studies should examine potential differences in flu vaccination use among Veterans using Veterans Affairs (VA) health care system vs. non-VA users.

Hospitalizations from pandemic Influenza [A(H1N1)pdm09] infections among type 1 and 2 diabetes patients in Spain

OBJECTIVES

To describe and analyze the clinical characteristics and outcomes for all patients with diabetes who were hospitalized with laboratory-confirmed A(H1N1)pdm09 infections in Spain during 2009.

METHODS

Observational retrospective study using data collected by the Spanish National Hospital Discharge Database. We selected all admissions with diagnosis ICD-9-CM code 488·1 [A(H1N1)pdm09]. Discharges were grouped as follows: no diabetes, Type1 and Type 2 diabetes. Underlying medical conditions and risk factors included all those that constitute an indication for annual influenza vaccination, pregnancy, and obesity. The outcome variables analyzed were in-hospital case fatality risk, length of hospital stay, and costs.

RESULTS

The total number of persons hospitalized with A(H1N1)pdm09 was 11,499. Of those, 97 suffered Type 1 and 936 Type 2, giving an overall prevalence of diabetes of 9%. The most common underlying medical condition among Type 2 subjects was obesity (26·8%), and for Type 1 renal disease (10·3%). In-hospital mortality was 2·1% among Type 1 patients, 3·8% among Type 2 patients, and 2·3% among non-diabetics; after multivariate analysis, diabetes was not a factor independently associated with dying during hospitalization for A(H1N1)pdm09. Independent factors increasing the risk of death among diabetic patients included age (OR 1·03; 95% CI1·01-1·05), hematological disorders (OR 3·49; 95% CI, 1·46-8·37), and obesity (OR 1·88; 95% CI1·07-3·92).

CONCLUSIONS

Among individuals hospitalized in Spain with A(H1N1)pdm09 infections, the age-specific prevalence of diabetes was higher than the general population in most age groups. The results of multivariate analysis suggest that possibly concomitant conditions such as obesity increase the risk of dying from the infection, but not diabetes itself.

Processing of Novel Electronic Health Data to Support Public Health Surveillance

Objective

To describe data management and analytic processes undertaken to rapidly acquire and use previously unavailable data during a public health emergency response.

Introduction

Accurately gauging the health status of a population during an event of public health significance (e.g. hurricanes, H1N1 2009 pandemic) in support of emergency response and situation awareness efforts can be a challenge for established public health surveillance systems in terms of geographic and population coverage as well as the appropriateness of health indicators. The demand for timely, accurate, and event-specific data can require the rapid development of new data assets to “fill-in” existing information gaps to better characterize the scope, scale, magnitude, and population health impact of a given event within a very narrow time-window. Such new data assets may be concurrently under development and evaluation while being used to support response efforts. Recent examples include the “drop-in” surveillance processes deployed at evacuation centers following Hurricane Katrina1 and the illness and injury surveillance systems established for response workers during the Deepwater Horizon Oil spill response. During the 2009 H1N1 pandemic response, CDC acquired access to data from several national-level health information systems that previously had been un-vetted as public health information sources. These sources provided data extracts from massive administrative or electronic medical records (EMR) based in hospital and primary care settings. It was hoped that such data could supplement existing influenza surveillance systems and aid in the characterization of the pandemic. Few of these new data sources had formal documentation or concise information on the underlying populations and geographies represented.

Methods

Throughout CDC’s H1N1 response; epidemiologists, data managers, and IT specialists collaborated to develop standardized methods to rapidly characterize, process, store, and provision these new data for analysis and reporting by subject matter experts.These new data were not part of a formally designed sample so each data source needed to undergo extensive empirical review to understand, representativeness, unique nuances, and facilitate the interpretation of analytic results and accurate reporting to public health decision makers.

Results

Such work requires a multi-disciplinary approach that cyclically reviews incoming data iteratively while concurrently documenting findings, modifying initial business rules (e.g. extraction, binning, or coding logic), and analytic techniques to produce the most interpretable and informative results. To elucidate the underlying complexity for these sequential and contingent activities occurring across information technology, informatics, and epidemiology domains, we retrospectively described the intersection of the discrete tangible tasks and workforce roles via a TaskFlow diagram (Figure 1). Vertical “swim lanes” represent discrete tasks: On-boarding/Documentation, Analysis/Visualization, and Visualization/Reporting. Workforce roles such as Data management, Epidemiological Analysis, and Communications are broken into three horizontal “swim lanes” as each requires dramatically different skillsets and are accomplished by different individuals. Each of the steps (1–9) in the diagram were leveraged to produce supplemental artifacts (e.g. code books, extraction guides, defined analytic methods, etc.) to support ongoing analysis, interpretation, reporting, and over process improvement. The totality of all of these interrelated activities have an a priori purpose of characterizing population health during an event of public health significance to support disease prevention and control efforts in a timely fashion.

Conclusions

This presentation describes the underlying business processes, activities, and roles used in transforming novel data sources, during the H1N1 response, into informative assets to support public health surveillance. By formally articulating and describing each of these steps, in a structured manner, we hope to contribute to the dialogue of developing useful practices for leveraging electronic health data to meet public health surveillance challenges.

Microsimulation of financial impact of demand surge on hospitals: the H1N1 influenza pandemic of fall 2009

OBJECTIVE

Microsimulation was used to assess the financial impact on hospitals of a surge in influenza admissions in advance of the H1N1 pandemic in the fall of 2009. The goal was to estimate net income and losses (nationally, and by hospital type) of a response of filling unused hospital bed capacity proportionately and postponing elective admissions (a "passive" supply response).

METHODS

Epidemiologic assumptions were combined with assumptions from other literature (e.g., staff absenteeism, profitability by payer class), Census data on age groups by region, and baseline hospital utilization data. Hospital discharge records were available from the Healthcare Cost and Utilization Project Nationwide Inpatient Sample (NIS). Hospital bed capacity and staffing were measured with the American Hospital Association's (AHA) Annual Survey.

RESULTS

Nationwide, in a scenario of relatively severe epidemiologic assumptions, we estimated aggregate net income of $119 million for about 1 million additional influenza-related admissions, and a net loss of $37 million for 52,000 postponed elective admissions.

IMPLICATIONS

Aggregate and distributional results did not suggest that a policy of promising additional financial compensation to hospitals in anticipation of the surge in flu cases was necessary. The analysis identified needs for better information of several types to improve simulations of hospital behavior and impacts during demand surges.

Analysis of 2009 pandemic influenza A/H1N1 outcomes in 19 European countries: association with completeness of national strategic plans

OBJECTIVE

To describe changes in reported influenza activity associated with the 2009 H1N1 pandemic in European countries and determine whether there is a correlation between these changes and completeness of national strategic pandemic preparedness.

DESIGN

A retrospective correlational study.

SETTING

Countries were included if their national strategic plans had previously been analysed and if weekly influenza-like illness (ILI) data from sentinel networks between week 21, 2006 and week 20, 2010 were more than 50% complete.

OUTCOME MEASURES

For each country we calculated three outcomes: the percentage change in ILI peak height during the pandemic relative to the prepandemic mean; the timing of the ILI peak and the percentage change in total cases relative to the prepandemic mean. Correlations between these outcomes and completeness of a country's national strategic pandemic preparedness plan were assessed using the Pearson product-moment correlation coefficient.

RESULTS

Nineteen countries were included. The ILI peak occurred earlier than the mean seasonal peak in 17 countries. In 14 countries the pandemic peak was higher than the seasonal peak, though the difference was large only in Norway, the UK and Greece. Nine countries experienced more total ILI cases during the pandemic compared with the mean for prepandemic years. Five countries experienced two distinct pandemic peaks. There was no clear pattern of correlation between overall completeness of national strategic plans and pandemic influenza outcome measures and no evidence of association between these outcomes and components of pandemic plans that might plausibly affect influenza outcomes (public health interventions, vaccination, antiviral use, public communication). Amongst the 17 countries with a clear pandemic peak, only the correlation between planning for essential services and change in total ILI cases significantly differed from zero: correlation coefficient (95% CI) 0.50 (0.02, 0.79).

CONCLUSIONS

The diversity of pandemic influenza outcomes across Europe is not explained by the marked variation in the completeness of pandemic plans.

Determinants of 2009 A/H1N1 influenza vaccination among pregnant women in Hong Kong

During the 2009–2010 A/H1N1 influenza pandemic, pregnant women infected with the virus experienced excess morbidity and mortality when compared with other groups. Once a vaccine was available, pregnant women were a priority group for vaccination. Only a few studies have reported on the uptake of 2009 A/H1N1 influenza vaccine among pregnant women during the pandemic and none were from Asia. The purpose of this study was to examine factors associated with 2009 A/H1N1 influenza vaccine uptake among pregnant women in Hong Kong. Using a multi-center, cross-sectional design, we recruited 549 postpartum women from four post-natal wards in Hong Kong over a 4-month period during the second wave of the A/H1N1 influenza pandemic in the winter and spring of 2010. Only 6.2% (n = 34) of participants had received the 2009 A/H1N1 influenza vaccine and 4.9% (n = 27) had received the seasonal influenza vaccine. The most common reasons for not receiving the 2009 A/H1N1 vaccine were fear of causing harm to themselves or their fetus. A high knowledge level (OR = 19.06; 95% CI 5.55, 65.48), more positive attitudes (OR = 3.52; 95% CI 1.37, 9.07), and having a family member who had the 2009 A/H1N1 influenza vaccine (OR = 7.69; 95% CI 2.92, 20.19) were independently and positively associated with vaccination. Study results show an unacceptably low uptake of the pandemic A/H1N1 influenza vaccine among pregnant women in Hong Kong. Interventions to increase influenza vaccine knowledge and uptake among this group should be a priority for future pandemic planning and seasonal vaccination campaigns.

Deriving behavior model parameters from survey data: self-protective behavior adoption during the 2009-2010 influenza A(H1N1) pandemic

In this paper, we demonstrate how public opinion surveys can be designed to collect information pertinent to computational behavior modeling, and we present the results of a public opinion and behavior survey conducted during the 2009-2010 H1N1 influenza pandemic. The results are used to parameterize the Health Belief Model of individual health-protective decision making. Survey subjects were asked questions about their perceptions of the then-circulating influenza and attitudes towards two personal protective behaviors: vaccination and avoidance of crowds. We empirically address two important issues in applying the Health Belief Model of behavior to computational infectious disease simulation: (1) the factors dynamically influencing the states of the Health Belief Model variables and (2) the appropriateness of the Health Belief Model in describing self-protective behavior in the context of pandemic influenza.

Adjuvant effect of docetaxel on the immune responses to influenza A H1N1 vaccine in mice

BACKGROUND

Vaccination remains one of the most effective approaches to prevent the spread of infectious diseases. Immune responses to vaccination can be enhanced by inclusion of adjuvant in a vaccine. Paclitaxel extracted from the bark of the Pacific yew tree Taxus brevifola was previously demonstrated to have adjuvant property. Compared to paclitaxel, docetaxel is another member of taxane family, and is more soluble in water and easier to manipulate in medication. To investigate the adjuvant effect of this compound, we measured the immune responses induced by co-administration of a split inactivated influenza H1N1 vaccine antigen with docetaxel.

RESULTS

When co-administered with docetaxel, lower dose antigen (equivalent to 10 ng HA) induced similar levels of IgG and IgG isotypes as well as HI titers to those induced by higher dose antigen (equivalent to 100 ng HA). Docetaxel promoted splenocyte responses to H1N1 antigen, ConA and LPS, mRNA expressions of cytokines (IFN-gamma, IL-12, IL-4 and IL-10) and T-bet/GATA-3 by splenocytes. The enhanced immunity was associated with up-expressed microRNAs (miR-155, miR-150 and miR-146a) in docetaxel-stimulated RAW264.7 cells. Docetaxel promoted similar IgE level to but alum promoted significantly higher IgE level than the control.

CONCLUSION

Docetaxel has adjuvant effect on the influenza H1N1 vaccine by up-regulation of Th1/Th2 immune responses. Considering its unique vaccine adjuvant property as well as the safe record as an anti-neoplastic agent clinically used in humans during a long period, docetaxel should be further studied for its use in influenza vaccine production.

Recent advances in the diagnosis and treatment of influenza pneumonia

A potentially fatal complication of influenza infection is the development of pneumonia, caused either directly by the influenza virus, or by secondary bacterial infection. Pneumonia related to the 2009 influenza A pandemic was found to be underestimated by commonly used pneumonia severity scores in many cases, and to be rapidly progressive, leading to respiratory failure. Confirmation of etiology by laboratory testing is warranted in such cases. Rapid antigen and immunofluorescence testing are useful screening tests, but have limited sensitivity. Confirmation of pandemic H1N1 influenza A infection can only be made by real-time reverse-transcriptase polymerase chain reaction (rRT-PCR) or viral culture. The most effective preventive measure is annual influenza vaccination in selected individuals. Decisions to administer antiviral medications for influenza treatment or chemoprophylaxis should be based upon clinical and epidemiological factors, and should not be delayed by confirmatory laboratory testing results. Neuraminidase inhibitors (NI) are the agents of choice.

Emergence of pandemic 2009 influenza A H1N1, India

BACKGROUND & OBJECTIVES

Pandemic H1N1 caused deluge of cases from 74 countries and prompted World Health Organization to raise warning to phase 6. The present study was conducted on throat and nasal swab samples received and tested at National Centre for Disease Control, Delhi, India during 2009-2010 to collect epidemiological and clinical information on positive cases.

METHODS

Throat and nasopharyngeal swabs from category C influenza A H1N1 patients during May 2009-September 2010 along with their clinico-epidemiological details were collected from identified hospitals from Delhi and other States. Samples were tested by Real time reverse transcriptase PCR using primers and probes developed at CDC, Atlanta for four influenza target genes.

RESULTS

A total of 33,751 samples, both throat and nasal swab samples from each patient were tested for H1N1 influenza virus, of which, 7943 (23.5%) were positive for pandemic influenza A H1N1 and 3759 (11.1%) were positive for influenza A (seasonal flu). Maximum number of positive cases (N=2792, 35.1%) were from 20-39 yr age group, comprising 1790 (22.5%) males and 1182 (14.8%) females. Only 2620 (33%) positive cases were close contact of influenza A H1N1 positive patient. Majority cases presented (N=2792, 35.1%) with fever 7005 (88.1%), followed by 6133 cases (77.2%) exhibiting fever and cough, 377 (4.7%) complained of fever, cough, nasal catarrh and 362 (4.5%) cases had fever with shortness of breath.

INTERPRETATION & CONCLUSIONS

The study showed a peak of cases of pandemic influenza A H1N1 in December 2009 and indicated predominance of H1N1 positive cases among 20-39 yr age group and among males compared to females.

Virus-like particle (VLP)-based vaccines for pandemic influenza: performance of a VLP vaccine during the 2009 influenza pandemic

The influenza pandemic of 2009 demonstrated the inability of the established global capacity for egg-based vaccine production technology to provide sufficient vaccine for the population in a timely fashion. Several alternative technologies for developing influenza vaccines have been proposed, among which non-replicating virus-like particles (VLPs) represent an attractive option because of their safety and immunogenic characteristics. VLP vaccines against pandemic influenza have been developed in tobacco plant cells and in Sf9 insect cells infected with baculovirus that expresses protein genes from pandemic influenza strains. These technologies allow rapid and large-scale production of vaccines (3-12 weeks). The 2009 influenza outbreak provided an opportunity for clinical testing of a pandemic influenza VLP vaccine in the midst of the outbreak at its epicenter in Mexico. An influenza A(H1N1)2009 VLP pandemic vaccine (produced in insect cells) was tested in a phase II clinical trial involving 4,563 healthy adults. Results showed that the vaccine is safe and immunogenic despite high preexisting anti-A(H1N1)2009 antibody titers present in the population. The safety and immunogenicity profile presented by this pandemic VLP vaccine during the outbreak in Mexico suggests that VLP technology is a suitable alternative to current influenza vaccine technologies for producing pandemic and seasonal vaccines.

[Severe forms of influenza A (H1N1) 2009 in pregnant women: experience of the University Hospital of Fez, Morocco and literature review]

Introduction

Le but de cette étude est de décrire les caractéristiques épidémiologiques, cliniques, paracliniques ainsi que l’évolution des femmes enceintes ou en post partum atteintes de formes graves de Grippe A(H1N1) 2009.

Méthodes

C’est une étude prospective observationnelle monocentrique, menée au sein de notre service de réanimation mère et enfant au centre hospitalier universitaire Hassan II à Fès, sur une période de 3 mois, allant de novembre 2009 à janvier 2010.

Résultats

L’âge moyen était de 28 ans, dans 85% des cas la grossesse se situaient au troisième trimestre, le syndrome grippal était constant, la SpO2 initiale était en moyenne de 86%. A la radiographie thoracique, un syndrome alvéolaire bilatéral était toujours présent. L’infection virale était confirmée dans tous les cas par la polymerase chain reaction. Chez 3 patientes la PaO2/FiO2 était inférieure à 300. L’Oseltamivir était l’antiviral utilisé chez toutes les parturientes. Un syndrome de détresse respiratoire aigu a été développé chez 28% des parturientes, elles ont été ventilées artificiellement avec des niveaux de pressions expiratoires positives à 14 +/- 1 cmH2O. L’évolution était favorable dans 71% des cas, cependant, 2 décès ont été déplorés.

Conclusion

Les résultats rejoignent les données de la littérature, à savoir, un risque accru pour la femme enceinte de développer une forme grave, une présentation clinique similaire au reste de la population, l’intérêt de la vaccination et d’un traitement antiviral précoce et le rôle de l’ECMO dans le traitement des hypoxémies réfractaires.

Computed tomography findings from patients with ARDS due to Influenza A (H1N1) virus-associated pneumonia

PURPOSE

The purpose of this study was to retrospectively evaluate whether computed tomography (CT) findings have prognostic value for the prediction of mortality and severity of the clinical course in patients presenting with early stage of acute respiratory distress syndrome (ARDS) due to swine-origin influenza A (S-OIV).

MATERIALS AND METHODS

Chest CT (16-/64-row multidetector CT) of 23 patients (of whom 9 patients died) were retrospectively reviewed by three independent blinded observers. The CT findings were graded on a 3-point scale (1: normal attenuation, 2: ground-glass attenuation, 3: consolidation). The extent of each abnormality was determined by visually estimating the percentage (to the nearest 10%) of the affected lung parenchyma in each zone and multiplied by the CT-score described above.

RESULTS

All patients presented with a mixture of bilateral patchy consolidations and ground glass opacities. Spearman rank correlation in evaluation of the presence and extent of lung abnormalities by the three different observers was good (correlation coefficient, 0.876-0.922; p < 0.001). The overall CT-score in survivors (mean, 96.0 (± 26.2); range, 53-158) was significantly lower than that in non-survivors (mean, 116.2 (± 14.0); range, 101-139). ROC analysis revealed an area under curve of 0.79 (p = 0.021) for the CT score with an optimal cutoff value of a CT-score of 100 for prediction of survival, with a sensitivity of 100% and a specificity of 64% (accuracy, 78%). For this optimal cutoff, Kaplan-Meier estimator showed a significant difference for the survival ratio (p = 0.011).

CONCLUSION

In patients with severe ARDS due to S-OIV-infection, the CT-score has a prognostic value in the prediction of mortality.

H1N1 preventive health behaviors in a university setting

BACKGROUND

When H1N1 emerged in 2009, institutions of higher education were immediately faced with questions about how best to protect their community from the virus, yet limited information existed to help predict student preventive behaviors.

METHODS

The authors surveyed students at a large urban university in November 2009 to better understand how students perceived their susceptibility to and the severity of H1N1, which preventive behaviors they engaged in, and if policies impacted their preventive health decisions.

RESULTS

Preventive health behavior messaging had a mixed impact on students. Students made simple behavior changes to protect themselves from H1N1, especially if they perceived a high personal risk of contracting H1N1. Although policies were instituted to enable students to avoid classes when ill, almost no student self-isolated for the entire duration of their illness.

CONCLUSIONS

These findings can help inform future decision making in a university setting to best influence preventive health behaviors.

Findings in children severely infected with a novel influenza A virus of swine origin: pulmonary imaging

BACKGROUND

This article reviews the chest radiography of children with severe infection caused by a novel influenza A (H1N1) virus of swine origin (S-OIV). We analyzed the role of their pulmonary images in predicting the severity and diagnosis of the disease.

METHODS

Among 97 patients with confirmed novel H1N1 infection, 42 patients treated with mechanical ventilation formed group 1, and the remaining 55 patients constituted group 2. The initial and subsequent radiograhic findings in groups 1 and 2 were compared with respect to the pattern, distribution, and extent of the abnormality.

RESULTS

In group 1, 24 patients presented with three or more lung zone diseases, whereas only 5 patients in group 2 demonstrated these findings (P<0.001). A pneumomediastinum or pneumothorax was observed in 24/42 patients in group 1 and in 18/55 patients in group 2 (P=0.019). Twelve patients in group 1 and 5 in group 2 developed a ground-glass opacity cyst with a honeycomb appearance (P=0.007).

CONCLUSIONS

The most common radiographic and computed tomography findings in children who were severely infected with S-OIV included unilateral or bilateral ground-glass opacities with or without associated focal or multifocal areas of consolidation. Children with bilateral involvement or with greater opacity on the chest radiographs were more likely to worsen and require the mechanical ventilation.

Chest computed tomography findings in severe influenza pneumonia occurring in neutropenic cancer patients

OBJECTIVE

To describe the chest computed tomography findings for severe influenza H1N1 infection in a series of hospitalized neutropenic cancer patients.

METHODS

We performed a retrospective systematic analysis of chest computed tomography scans for eight hospitalized patients with fever, neutropenia, and confirmed diagnoses of influenza H1N1. The clinical data had been prospectively collected.

RESULTS

Six of eight patients (75%) developed respiratory failure and required intensive care. Prolonged H1N1 shedding was observed in the three mechanically ventilated patients, and overall hospital mortality in our series was 25%. The most frequent computed tomography findings were ground-glass opacity (all patients), consolidation (7/8 cases), and airspace nodules (6/8 cases) that were frequently moderate or severe. Other parenchymal findings were not common. Five patients had features of pneumonia, two had computed tomography findings compatible with bronchitis and/or bronchiolitis, and one had tomographic signs of chronicity.

CONCLUSION

In this series of neutropenic patients with severe influenza H1N1 infection, chest computed tomography demonstrated mainly moderate or severe parenchymatous disease, but bronchiolitis was not a common feature. These findings associated with febrile neutropenia should elicit a diagnosis of severe viral infection.

Pneumonia induced by swine-origin influenza A (H1N1) infection: chest computed tomography findings in children

PURPOSE

The purpose of this study was to determine the features of chest computed tomography (CT) in children with swine-origin influenza A (H1N1) virus (S-OIV).

MATERIALS AND METHODS

The study population consisted of 16 children with laboratory-confirmed S-OIV infection (12 boys, 4 girls), with an age range of 5-10 years (mean 6.3 years). Pneumonia was suspected in these patients based on clinical features or confirmed by radiography. All subjects underwent CT for close evaluation of pneumonia, including characteristics, distribution, extent, and other findings such as pleural effusion, pneumothorax, and pneumomediastinum.

RESULTS

The predominant CT finding was consolidation plus ground-grass opacity (GGO) (11/16, 69%). The consolidation-dominant pattern was found in 10 of 16 (66%) patients, and 1 (6%) was GGO-dominant. One (6%) had only GGO. In all, 7 of the 16 patients had segmental or lobar consolidation. Abnormal opacities were primarily distributed in the central lung zone (8/16, 50%) and were multifocal (15/16, 94%). Four showed atelectasis (4/16, 25%). Pneumomediastinum was observed in 4 of 16 (25%). One patient had negative radiographic findings but was positive on CT.

CONCLUSION

Multifocal consolidation with central distribution is a common CT finding in children with S-OIV, but there are few GGO-dominant cases. Widespread consolidation (segmental or lobar) is also common.

Clinical characteristics of adult patients with influenza-like illness hospitalized in general ward during Influenza A H1N1 pandemic 2009/2010

OBJECTIVE

To investigate clinical and laboratory features of patients with Influenza A H1N1 virus infection hospitalized during 2009/2010 pandemic.

METHODS

Prospective observational study comparing clinical and laboratory characteristics of Influenza A H1N1 positive and negative patients with influenza-like illness (ILI).

RESULTS

From October 21, 2009 to February 14, 2010 196 ILI patients were admitted, of which 66 tested positive for Influenza A H1N1. The patients with H1N1 infection were younger (43 years vs. 65 years; P < 0.01), more patients were pregnant (P < 0.01), had allergies (P < 0.05) or, asthma (P < 0.01). H1N1 positive patients were more often febrile (91% vs. 72.9%; P < 0.01) and had a higher prevalence of headache (31.8% vs. 18.5%; P < 0.05). Lower values of C-reactive protein (88 pg/dl vs. 126 pg/dl; P < 0.01), procalcitonine (0.42 µg/l vs. 3.98 µg/l; P < 0.05), leukocyte count (7.4*10(9)/l vs. 11.7*10(9)/l; P < 0.01) and higher values of troponin (0.162 µ/l vs. 0.146 µg/l; P < 0.01) were found in H1N1 positive patients. More bacterial infections were found in H1N1 negative group (68.8% vs. 89.2%; P < 0.05).

CONCLUSIONS

In this study patients infected with Influenza A H1N1 differed from H1N1 negative ILI patients in several clinical and laboratory characteristics. The same was observed also by other investigators. The results of the study suggest some other specific features, such as a higher incidence of headache and higher values of troponin in Influenza A H1N1 infected patients.

Influenza preparedness and response: involvement of African Field Epidemiology and Laboratory Training Programs, 2009

BACKGROUND

The capacity of public health professionals to rapidly detect and respond to disease pandemics is critical to understand and control global disease spread. On June 11, 2009, the World Health Organization (WHO) declared H1N1 virus infection as pandemic. In May 2009, we assessed the participation of Field Epidemiology and Laboratory Training Programs (FELTPs) based in sub-Saharan Africa on pandemic influenza preparedness and response.

METHODS

We administered an electronic survey to directors and resident advisors of African Field Epidemiology Network (AFENET) member and associate FELTPs. The survey included questions on the following attributes: program involvement in suspected H1N1 investigations, experience in influenza outbreak investigations, national influenza surveillance and response plans, and H1N1 outbreak preparedness.

RESULTS

Nine countries (100%) responded to the survey; all had existing national influenza response plans. Six programs reported their trainees had participated in past pandemic preparedness and response exercise, five (83%) of them were influenza specific.

CONCLUSION

FELTPs played an important role in H1N1 surveillance and response in sub-Saharan Africa. Continued technical assistance and support to these programs is vital to foster their capacity to monitor and control public health threats.

Analysis of influenza A viruses of subtype H1 from wild birds, turkeys and pigs in Germany reveals interspecies transmission events

BACKGROUND

Despite considerable host species barriers, interspecies transmissions of influenza A viruses between wild birds, poultry and pigs have been demonstrated repeatedly. In particular, viruses of the subtypes H1 and H3 were transmitted between pigs and poultry, predominantly turkeys, in regions with a high population density of both species. The recovery of a swine influenza H1N1 virus from a turkey flock in Germany in 2009 prompted us to investigate molecularly the subtype H1 viruses recently detected in wild birds, pigs and poultry.

OBJECTIVES

The goal of this study was to investigate the relationship between H1N1 viruses originating from wild and domestic animals of Germany and to identify potential trans-species transmission or reassortment events.

METHODS

Hemagglutinin and neuraminidase gene or full-length genome sequences were generated from selected, current H1N1 viruses from wild birds, pigs and turkeys. Phylogenetic analyses were combined with genotyping and analyses of the deduced amino acid sequences with respect to biologically active sites. Antigenic relationships were assessed by hemagglutination inhibition reactions.

RESULTS

Phylogenetic analysis of the hemagglutinin sequences showed that viruses from distinct H1 subgroups co-circulate among domestic animals and wild birds. In addition, these viruses comprised different genotypes and were distinguishable antigenically. An H1N1 virus isolated from a turkey farm in northern Germany in 2009 showed the highest similarity with the avian-like porcine H1N1 influenza viruses circulating in Europe since the late 1970s.

CONCLUSIONS

The data demonstrate the genetic and antigenic heterogeneity of H1 viruses currently circulating in domestic and wild animals in Germany and points to turkeys as a possible bridge between avian and mammalian hosts.

Successful use of venovenous extracorporeal membrane oxygenation for complicated H1N1 pneumonia refractory to mechanical ventilation

In April 2009, novel H1N1 influenza A pneumonia was initially identified in young adults by the Mexican Health Ministry. Previously healthy patients progressing to multisystem organ failure were common. Worldwide, hospitals reported surges in intensive care admissions during the initial phase of the pandemic. In patients with H1N1 pneumonia refractory to mechanical ventilation, centers were initially reporting low survival rates despite the use of extracorporeal membrane oxygenation (ECMO). The initial poor outcomes and protracted ECMO treatment epochs resulted in centers limiting or withholding the use of ECMO in this population. With respect to children with H1N1 infection there was uncertainty concerning optimal incorporation of ECMO as a therapeutic option. In children with rapidly progressive pneumonia and hypoxia refractory to mechanical ventilation, venovenous (VV) ECMO has been successfully used with survival ranging from 40-60% depending on the etiology. We report the successful use of VV ECMO in two children with confirmed novel H1N1 complicated by bacterial pneumonia or morbid obesity. Our Institutional Review Board waived the need for consent. Prompt initiation of VV ECMO resulted in rapid clinical improvement, radiographic resolution of diffuse consolidation, and return of full neurocognitive function. For children with rapidly progressive respiratory distress on conventional ventilation, VV ECMO can be used to improve outcomes when initiated early in the disease process even in children with a significant co-morbidity.

Coupling sensitive in vitro and in silico techniques to assess cross-reactive CD4(+) T cells against the swine-origin H1N1 influenza virus

The outbreak of the novel swine-origin H1N1 influenza in the spring of 2009 took epidemiologists, immunologists, and vaccinologists by surprise and galvanized a massive worldwide effort to produce millions of vaccine doses to protect against this single virus strain. Of particular concern was the apparent lack of pre-existing antibody capable of eliciting cross-protective immunity against this novel virus, which fueled fears this strain would trigger a particularly far-reaching and lethal pandemic. Given that disease caused by the swine-origin virus was far less severe than expected, we hypothesized cellular immunity to cross-conserved T cell epitopes might have played a significant role in protecting against the pandemic H1N1 in the absence of cross-reactive humoral immunity. In a published study, we used an immunoinformatics approach to predict a number of CD4(+) T cell epitopes are conserved between the 2008-2009 seasonal H1N1 vaccine strain and pandemic H1N1 (A/California/04/2009) hemagglutinin proteins. Here, we provide results from biological studies using PBMCs from human donors not exposed to the pandemic virus to demonstrate that pre-existing CD4(+) T cells can elicit cross-reactive effector responses against the pandemic H1N1 virus. As well, we show our computational tools were 80-90% accurate in predicting CD4(+) T cell epitopes and their HLA-DRB1-dependent response profiles in donors that were chosen at random for HLA haplotype. Combined, these results confirm the power of coupling immunoinformatics to define broadly reactive CD4(+) T cell epitopes with highly sensitive in vitro biological assays to verify these in silico predictions as a means to understand human cellular immunity, including cross-protective responses, and to define CD4(+) T cell epitopes for potential vaccination efforts against future influenza viruses and other pathogens.

Extreme efficiency of airway pressure release ventilation (APRV) in a patient suffering from acute lung injury with pandemic influenza A (H1N1) 2009 and high cytokines

The authors report a Japanese boy with severe pandemic influenza A(H1N1) 2009-associated pneumonia and deteriorating oxygenation. He dramatically recovered after the use of Airway Pressure Release Ventilation (APRV) mode. There was no improvement by using any conventional ventilation, however, APRV immediately led to an improvement of his clinical symptoms and laboratory findings.

Neurological complications of pandemic influenza A H1N1 2009 infection: European case series and review

Neurological manifestations and outcomes of children with the 2009 H1N1 virus infection have been reported in three American series and from smaller cohorts and case reports worldwide. Of the 83 children admitted between April 2009 and March 2010 with H1N1 virus infection to a tertiary children's hospital in a European setting, five children aged between 2 and 10 years had neurological symptoms. Four patients had seizures and encephalopathy at presentation. One patient presented with ataxia; one developed neuropsychiatric manifestations, and two developed movement disorders during the disease course. Early neuroimaging showed evidence of acute necrotising encephalopathy (ANE) in one case and non-specific white matter changes in another. Initial neuroimaging was normal for the other three, but interval MRI showed increased signal in bilateral periventricular distribution in one and significant cerebral volume loss in the other. Clinical outcomes varied: two recovered fully while three had residual seizures and/or significant cognitive deficits. Conclusion An analysis of our patients along with all reported cases reveal that seizures and encephalopathy were common neurological presentations associated with pandemic 2009 H1N1 influenza virus infection in children requiring hospital admission. Neuroimaging suggestive of ANE, basal ganglia involvement and volume loss appears to be associated with worse neurological outcome.

Vaccination of patients with mild and severe asthma with a 2009 pandemic H1N1 influenza virus vaccine

BACKGROUND

Asthma was the most common comorbidity of patients hospitalized with 2009 H1N1 influenza.

OBJECTIVE

We sought to assess the immunogenicity and safety of an unadjuvanted, inactivated 2009 H1N1 vaccine in patients with severe versus mild-to-moderate asthma.

METHODS

We conducted an open-label study involving 390 participants (age, 12-79 years) enrolled in October-November 2009. Severe asthma was defined as need for 880 μg/d or more of inhaled fluticasone equivalent, systemic corticosteroids, or both. Within each severity group, participants were randomized to receive intramuscularly 15 or 30 μg of 2009 H1N1 vaccine twice 21 days apart. Immunogenicity end points were seroprotection (hemagglutination inhibition assay titer ≥40) and seroconversion (4-fold or greater titer increase). Safety was assessed through local and systemic reactogenicity, asthma exacerbations, and pulmonary function.

RESULTS

In patients with mild-to-moderate asthma (n = 217), the 2009 H1N1 vaccine provided equal seroprotection 21 days after the first immunization at the 15-μg (90.6%; 95% CI, 83.5% to 95.4%) and 30-μg (95.3%; 95% CI, 89.4% to 98.5%) doses. In patients with severe asthma (n = 173), seroprotection 21 days after the first immunization was 77.9% (95% CI, 67.7% to 86.1%) and 94.1% (95% CI, 86.8% to 98.1%) at the 15- and 30-μg doses, respectively (P = .004). The second vaccination did not provide further increases in seroprotection. Participants with severe asthma who are older than 60 years showed the lowest seroprotection (44.4% at day 21) with the 15-μg dose but had adequate seroprotection with 30 μg. The 2 dose groups did not differ in seroconversion rates. There were no safety concerns.

CONCLUSION

Monovalent inactivated 2009 H1N1 pandemic influenza vaccine was safe and provided overall seroprotection as a surrogate of efficacy. In patients older than 60 years with severe asthma, a 30-μg dose might be more appropriate.

Prioritization of delayed vaccination for pandemic influenza

Limited production capacity and delays in vaccine development are major obstacles to vaccination programs that are designed to mitigate a pandemic influenza. In order to evaluate and compare the impact of various vaccination strategies during a pandemic influenza, we developed an age/risk-structured model of influenza transmission, and parameterized it with epidemiological data from the 2009 H1N1 influenza A pandemic. Our model predicts that the impact of vaccination would be considerably diminished by delays in vaccination and staggered vaccine supply. Nonetheless, prioritizing limited H1N1 vaccine to individuals with a high risk of complications, followed by school-age children, and then preschool-age children, would minimize an overall attack rate as well as hospitalizations and deaths. This vaccination scheme would maximize the benefits of vaccination by protecting the high-risk people directly, and generating indirect protection by vaccinating children who are most likely to transmit the disease.

[Suspicion of rheumatoid purpura post influenza vaccination (H1N1) complicated by acute intussusception in a child of four years]

Abstract

Le purpura rhumatoïde représente la vascularite immunoallergique la plus fréquente de l’enfant. Sa survenue dans les suites d'une vaccination antigrippale est exceptionnelle. Nous rapportons l’observation d’une fille de 4ans qui présente une suspicion de purpura rhumatoïde post vaccination antigrippale A(H1N1) compliqué d’invagination intestinale aiguë ayant bénéficié d’une réduction chirurgicale. L’évolution était favorable avec un recul de un an. L’invagination intestinale aiguë constitue la complication digestive la plus redoutable du purpura rhumatoïde. Dont le diagnostic doit être toujours évoqué devant des douleurs abdominales aigues chez un enfant porteur de cette vascularite.

Extracorporeal life support for pandemic influenza: the role of extracorporeal membrane oxygenation in pandemic management

The recent global threat of a severe pandemic influenza outbreak has suggested that extracorporeal life support will begin to play an evolving role in the care of critically ill influenza stricken patients. The highly communicable attributes of influenza could result in widespread infection and an associated increased need for advanced life support. Supply and demand equilibrium may be abruptly disrupted, and ethical decisions regarding the allocation of life saving resources will inevitably need to be made. Protocol oriented planning, research analysis, and advanced technologies are critical factors in averting catastrophe. This review article details the epidemiology, diagnostic techniques, and interventions for the influenza A virus, including H1N1.

Low-dimensional clustering detects incipient dominant influenza strain clusters

Influenza has been circulating in the human population and has caused three pandemics in the last century (1918 H1N1, 1957 H2N2 and 1968 H3N2). The 2009 A(H1N1) was classified by World Health Organization as the fourth pandemic. Influenza has a high evolution rate, which makes vaccine design challenging. We here consider an approach for early detection of new dominant strains. By clustering the 2009 A(H1N1) sequence data, we found two main clusters. We then define a metric to detect the emergence of dominant strains. We show on historical H3N2 data that this method is able to identify a cluster around an incipient dominant strain before it becomes dominant. For example, for H3N2 as of 30 March 2009, the method detects the cluster for the new A/British Columbia/RV1222/2009 strain. This strain detection tool would appear to be useful for annual influenza vaccine selection.

Serological analysis of human pandemic influenza (H1N1) in Thailand

The study was aimed at determining the prevalence of pandemic influenza (H1N1) 2009 among patients with respiratory tract diseases during July-December 2009 using real-time reverse transcription polymerase chain reaction. Haemagglutination inhibition (HI) assay was performed to detect antibody titres against pandemic influenza in 255 medical personnel, 307 members of the general population during the second week of December 2009 in Khon Kaen province, Thailand, and in 100 stored sera collected from people of different age-groups during 2008. The results showed that the pandemic (H1N1) 2009 had occurred during July-December 2009. The results of the HI test after the wave of this outbreak showed that 123 (48%) of the 255 sera collected from the medical personnel, 109 (36%) of the 307 sera obtained from the general population, and only two of the 100 stored sera from 2008 contained antibodies (HI titres > or = 40) against pandemic influenza. Antibody against the pandemic (H1N1) 2009 was found in at least one-third of the population. In conclusion, the prevalence of virus and serological data obtained from the study can be used as the serological background level of the Thai population after the July-December pandemic. Finally, the serological data might be useful for outbreak-prevention and control strategies and for the management of vaccination for the pandemic (H1N1) 2009 in Thailand.

Clinical profile of swine flu in children at Puducherry

OBJECTIVE

To study the clinical profile and outcome of children screened and diagnosed for Swine flu at a tertiary care hospital.

METHODS

All Children with suspicion of swine flu infection attending our hospital during the epidemic from August 2009 through January 2010 were screened and categorized into A, B and C as per guidelines of National Health and family welfare. Patients in Category A were advised home quarantine, Category B tested and treated with ostelamivir and Category C were hospitalized.

RESULTS

Among 424 cases screened for Swine flu, 79 were children in the age group 0-12 years of age (18.6%). The median age of presentation was 5 years. Children belonging to Category A were 43(54.4%), Category B were 31(39.2%) and Category C were 5(6.3%). Out of the cases that were screened, 19 children were confirmed positive for H1N1 infection(30.2%).Out of positive cases 8 were in category A (42%), eight were in category B (42%) and five were in category C (26.3%).

CONCLUSIONS

During the epidemic of swine flu at puducherry, majority of cases were category A with mild symptoms. Home quarantine and preventive measures during the epidemic were found to be far more important than testing and treating with Oseltamivir.

The successful use of extra-corporeal membrane oxygenation in the management of a pregnant woman with severe H1N1 2009 influenza complicated by pneumonitis and adult respiratory distress syndrome

We report a case of H1N1 2009 influenza A, in a previously fit woman at 24 weeks of gestation, who presented atypically with abdominal pain. The infection was complicated by severe respiratory failure and acute respiratory distress syndrome, requiring ventilatory support, including extra-corporeal membrane oxygenation (ECMO). This was one of the first cases of severe H1N1 disease presenting in the UK. Use of extra-corporeal membrane oxygenation for the complications of H1N1 resulted in full maternal recovery and subsequent delivery of a healthy infant.

Influenza and parainfluenza associated pediatric ICU morbidity

OBJECTIVES

To investigate if morbidity in young children admitted to a pediatric intensive care unit (PICU with a laboratory proven diagnosis of influenza and parainfluenza infection) had increased.

METHODS

Retrospective study from January 2003 through December 2009 was carried out. Every child in the PICU with a laboratory-confirmed influenza or parainfluenza infection was included.

RESULTS

18 influenza (influenza A =13 and influenza B = 5) and 17 parainfluenza admissions were identified over the 7-year period. Parainfluenza type 3 (n = 9) was the commonest subtype of parainfluenza infection. The median age of children admitted with influenza was higher than parainfluenza (4.5 vs 1.7 years, p = 0.044). Admissions associated with proven influenza and parainfluenza infections accounted for 2% of PICU annual admissions. There was only one death in 2003. 51% of these patients required ventilatory support, 45% received systemic corticosteroids, and 91% received initial broad spectrum antibiotic coverage. Bacterial co-infections were identified in 25% of these patients. The incidence of influenza admissions had not increased significantly in 2009 (H1N1 pandemic) when compared with 2003 (SARS epidemic) (p = 0.3). There were only two PICU cases of pandemic H1N1 in 2009 and both survived. The annual incidence of severe PICU cases of influenza and parainfluenza were 0.94 and 0.88 per 100,000 children per annum, respectively.

CONCLUSIONS

Pandemic H1N1, influenza and parainfluenza viruses may be associated with significant childhood morbidity and PICU admissions.

Simple respiratory protection--evaluation of the filtration performance of cloth masks and common fabric materials against 20-1000 nm size particles

A shortage of disposable filtering facepiece respirators can be expected during a pandemic respiratory infection such as influenza A. Some individuals may want to use common fabric materials for respiratory protection because of shortage or affordability reasons. To address the filtration performance of common fabric materials against nano-size particles including viruses, five major categories of fabric materials including sweatshirts, T-shirts, towels, scarves, and cloth masks were tested for polydisperse and monodisperse aerosols (20-1000 nm) at two different face velocities (5.5 and 16.5 cm s⁻¹) and compared with the penetration levels for N95 respirator filter media. The results showed that cloth masks and other fabric materials tested in the study had 40-90% instantaneous penetration levels against polydisperse NaCl aerosols employed in the National Institute for Occupational Safety and Health particulate respirator test protocol at 5.5 cm s⁻¹. Similarly, varying levels of penetrations (9-98%) were obtained for different size monodisperse NaCl aerosol particles in the 20-1000 nm range. The penetration levels of these fabric materials against both polydisperse and monodisperse aerosols were much higher than the penetrations for the control N95 respirator filter media. At 16.5 cm s⁻¹ face velocity, monodisperse aerosol penetrations slightly increased, while polydisperse aerosol penetrations showed no significant effect except one fabric mask with an increase. Results obtained in the study show that common fabric materials may provide marginal protection against nanoparticles including those in the size ranges of virus-containing particles in exhaled breath.

Neonates investigated for influenza-like illness during the outbreak of pandemic H1N1 2009: trivial infections but major triage implications

We report eight cases of neonates (from birth to 25 days) admitted to the neonatal service of a teaching hospital with influenza-like illness during the outbreak of pandemic H1N1 2009, and discuss their management and infection control issues. Empirical antibiotics were often promptly initiated and timely stopped when sepsis was ruled out. Also, there was no pandemic H1N1-09 but influenza A (H3N2, n = 1), parainfluenza (type 3, n = 3) and respiratory syncytial virus (n = 1) have been isolated. The infants recovered spontaneously without any antiviral therapy. There was no outbreak of the respiratory infections in the neonatal service during the admissions. Respiratory viral infections can occur in neonates although the clinical course may be milder and nonspecific. Emergency room and frontline staff must be vigilant of the non-specific clinical features of infections with respiratory viruses in the neonates so that prompt triage and isolation can be implemented to avoid outbreaks in the neonatal service.

2009 H1N1 influenza: a twenty-first century pandemic with roots in the early twentieth century

A swine-origin H1N1 triple-reassortant influenza A virus found to be a distant relative of the 1918 "Spanish flu" virus emerged in April 2009 to give rise to the first influenza pandemic of the 21st century. Although disease was generally mild and similar to seasonal influenza, severe manifestations including respiratory failure were noted in some, particularly those with underlying conditions such as asthma, pregnancy and immunosuppression. Children and younger adults accounted for most cases, hospitalizations and deaths. A reverse transcriptase-polymerase chain reaction assay was superior to antigen-based rapid tests for diagnosis. All 2009 H1N1 pandemic influenza strains were susceptible to 1 or more neuraminidase inhibitors. Monovalent, unadjuvanted 2009 H1N1 vaccines were licensed in the United States in September 2009 and initially targeted to younger individuals, pregnant women, caretakers of infants and healthcare providers. The 2009 H1N1 pandemic highlights the need for modernization of influenza vaccines, improved diagnostics and more rigorous evaluation of mitigation strategies.

Pandemic (H1N1) 2009 surveillance for severe illness and response, New York, New York, USA, April-July 2009

On April 23, 2009, the New York City Department of Health and Mental Hygiene (DOHMH) was notified of a school outbreak of respiratory illness; 2 days later the infection was identified as pandemic (H1N1) 2009. This was the first major outbreak of the illness in the United States. To guide decisions on the public health response, the DOHMH used active hospital-based surveillance and then enhanced passive reporting to collect data on demographics, risk conditions, and clinical severity. This surveillance identified 996 hospitalized patients with confirmed or probable pandemic (H1N1) 2009 virus infection from April 24 to July 7; fifty percent lived in high-poverty neighborhoods. Nearly half were <18 years of age. Surveillance data were critical in guiding the DOHMH response. The DOHMH experience during this outbreak illustrates the need for the capacity to rapidly expand and modify surveillance to adapt to changing conditions.