Fulminant myocarditis in an adult with 2009 pandemic influenza A (H1N1 influenza) infection

ABSTRACT Human influenza pandemics occur when influenza viruses to which the population has little or no immunity emerge and acquire the ability to achieve human-to-human transmission. In April 2009, cases of a novel H1N1 influenza virus in children in the southwestern United States were reported. It was retrospectively shown that these cases represented the spread of this virus from an ongoing outbreak in Mexico. The emergence of the pandemic led to a number of national vaccination programs. Surprisingly, early human clinical trial data have shown that a single dose of nonadjuvanted pandemic influenza A (H1N1) 2009 monovalent inactivated vaccine (pMIV) has led to a seroprotective response in a majority of individuals, despite earlier studies showing a lack of cross-reactivity between seasonal and pandemic H1N1 viruses. Here we show that previous exposure to a contemporary seasonal H1N1 influenza virus and to a lesser degree a seasonal influenza virus trivalent inactivated vaccine is able to prime for a higher antibody response after a subsequent dose of pMIV in ferrets. The more protective response was partially dependent on the presence of CD8+ cells. Two doses of pMIV were also able to induce a detectable antibody response that provided protection from subsequent challenge. These data show that previous infection with seasonal H1N1 influenza viruses likely explains the requirement for only a single dose of pMIV in adults and that vaccination campaigns with the current pandemic influenza vaccines should reduce viral burden and disease severity in humans.

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Clinical impact of influenza – lessons learnt from the pandemic influenza A (H1N1) 2009

Microbiology Australia ◽

10.1071/ma11029 ◽

2011 ◽

Vol 32 (1) ◽

pp. 29

Author(s):

Alex Dierig ◽

Gulam Khandaker ◽

Robert Booy

Keyword(s):

Clinical Features ◽

Pandemic Influenza ◽

Influenza A ◽

Influenza Pandemic ◽

Gastrointestinal Symptoms ◽

H1n1 Influenza ◽

World Health ◽

Pandemic H1n1 ◽

Pandemic H1n1 Influenza ◽

Influenza A H1n1

Influenza is generally an acute, self-limiting, febrile illness without further complications in the majority of people. However, it can be associated with severe morbidity and mortality and the burden of the disease on society is likely to be underestimated. In 2009 an outbreak of H1N1 influenza A virus infection was detected in Mexico with further cases soon observed worldwide. Subsequently, in June 2009, the first influenza pandemic of the 21st century due to influenza A (H1N1) was declared by the World Health Organization (WHO). There were many uncertainties regarding the virulence, clinical symptoms and epidemiological features of this newly evolved influenza A strain. Over time, many similarities, but also some differences between the pandemic H1N1 influenza A and seasonal influenza were identified. We recently performed a systematic review of the literature, looking at articles published between 1 April 2009 and 31 January 2010, to identify the epidemiological and clinical features of the pandemic H1N1 influenza. In this current article we compare our findings with others from the international literature. There was more severe impact on young and healthy adults, children, pregnant women and the obese. Clinical features in general were similar between seasonal and pandemic influenza; however, there were more gastrointestinal symptoms associated with pandemic H1N1 influenza. Shortness of breath was characteristic of more severe pH1N1 2009 infection with a higher possibility of being admitted to an intensive care unit (ICU).

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Selenium Nanoparticles Inhibited H1N1 Influenza Virus Induced Apoptosis By Improving The Level of Gpx1

10.21203/rs.3.rs-1070042/v1 ◽

2021 ◽

Author(s):

Xia Liu ◽

Danyang Chen ◽

Jingyao Su ◽

Rulin Zheng ◽

Zhihui Ning ◽

...

Keyword(s):

Influenza A ◽

Mdck Cells ◽

Influenza Infection ◽

Chromatin Condensation ◽

H1n1 Influenza ◽

Influenza Viruses ◽

Selenium Nanoparticles ◽

Influenza A H1n1 ◽

Mechanistic Investigation ◽

Induced Apoptosis

Abstract Influenza A (H1N1) viruses are distributed around the world and pose a threat to public health. Vaccination is the main treatment strategy to prevent influenza infection, but antiviral drugs also play an important role in controlling seasonal and pandemic influenza. Currently, influenza viruses may emerge antiviral resistance, new agents with different modes of action are being investigated. Recently, selenium nanoparticles (SeNPs) which have antiviral effects attracted more and more attention in biomedical interventions. The appearance of nanotechnology attract great attention in the nanomedicine field. SeNPs constitute an attractive vector platform for delivering a variety of drugs to action targets. SeNPs is being explored for potential therapeutic efficacy in a variety of oxidative stress and inflammation-mediated diseases, such as cancer, arthritis, diabetes, and kidney disease. SeNPs could inhibit infection of Madin Darby Canine Kidney (MDCK) cells with H1N1 and prevent chromatin condensation and DNA fragmentation. ROS play a key role in physiological processes on apoptosis. SeNPs significantly inhibited the production of reactive oxygen species (ROS) in MDCK cells. Mechanistic investigation revealed that SeNPs inhibited the apoptosis induced by H1N1 virus infection in MDCK cells by improving the level of GPx1. Our results suggest that SeNPs is an effective selenium source to obtain H1N1 influenza antiviral candidate.

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SALIENT FEATURES OF CIRCULATING RESPIRATORY VIRUSES IN THE PRE– AND PANDEMIC INFLUENZA AND COVID–19 SEASONS

Russian Journal of Infection and Immunity ◽

10.15789/2220-7619-sfo-1662 ◽

2021 ◽

Author(s):

I. V. Kiseleva ◽

N. V. Larionova ◽

E. P. Grigorieva ◽

A. D. Ksenafontov ◽

M. Al Farroukh ◽

...

Keyword(s):

Pandemic Influenza ◽

Influenza A ◽

Influenza Infection ◽

Opportunity To Learn ◽

Respiratory Viruses ◽

Influenza Viruses ◽

Effective Prevention ◽

Pdm09 Virus ◽

Influenza A H1n1 ◽

Syncytial Virus

Abstract. A wide variety of zoonotic viruses that can cross the interspecies barrier promote the emergence of new, potentially pandemic viruses in the human population that was often accompanied by the disappearance of existing circulating strains. Among the various reasons underlying this phenomenon is the strengthening of populational immunity by expanding the immune layer of the population and improving the means and methods of medical care. However, “Natura abhorret vacuum”, and new pathogens come to replace disappearing pathogens. In the past ten years, there have been two critical events – the pandemic spread of the swine influenza A (H1N1) pdm09 virus in 2009 and the novel SARS–CoV–2 coronavirus in 2019, providing scientists with a unique opportunity to learn more about a relationship between respiratory viruses and their pathogenesis. Together with viruses of pandemic significance, a large number of seasonal respiratory viruses circulate, which contribute to the structure of human morbidity, and co–infections aggravate the condition of the illness. In the conditions of the spread of new viruses with unexplored characteristics, in the absence of means of prevention and therapy, it is especially important to prevent the aggravation of morbidity due to mixed infections. Here we review the mutual involvement of pandemic influenza A(H1N1)pdm09 and SARS–CoV–2 coronavirus and seasonal respiratory viruses in the epidemic process, discuss some issues related to their spread, potential causes affecting the spread and severity of the morbidity. The given facts, testify to the existence of seasonality and temporal patterns of the beginning and end of the circulation of respiratory viruses. Interestingly, the beginning of the circulation of the pandemic influenza A(H1N1)pdm09 virus led to a shift in the timing and intensity of circulation of some respiratory viruses, which is probably caused by the existence of "replication conflicts" between them, and did not affect others. Co–infection with SARS–CoV–2–19 and other respiratory viruses, especially respiratory syncytial virus and rhinoviruses, was quite often observed. At the current stage, no aggravating effect of influenza on the course of COVID–19 in mixed infection has been established. Whether this is due to the mild course of influenza infection in the 2020 epidemic season, or the competitive impact of SARS–CoV–2 on influenza viruses is not yet clear. Experts are still at the stage of accumulating facts and working on creating means of effective prevention and treatment of the new coronavirus infection.

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Seasonal influenza vaccination and the risk of infection with pandemic influenza: a possible illustration of non-specific temporary immunity following infection

Eurosurveillance ◽

10.2807/ese.15.47.19722-en ◽

2010 ◽

Vol 15 (47) ◽

Cited By ~ 23

Author(s):

H Kelly ◽

S Barry ◽

K Laurie ◽

G Mercer

Keyword(s):

Influenza Vaccine ◽

Pandemic Influenza ◽

Influenza A ◽

Seasonal Influenza ◽

Influenza Infection ◽

Risk Of Infection ◽

Seasonal Influenza Vaccine ◽

Influenza A H1n1 ◽

Seasonal Infection ◽

Temporary Immunity

Four Canadian studies have suggested that receipt of seasonal influenza vaccine increased the risk of laboratory-confirmed infection with 2009 pandemic influenza A(H1N1). During the influenza season of 2009 in Victoria, Australia, this virus comprised 97% of all circulating influenza viruses for which sub-typing was available. We found no evidence that seasonal influenza vaccine increased the risk of, or provided protection against, infection with the pandemic virus. Ferret experiments have suggested protection against pandemic influenza A(H1N1) 2009 from multiple prior seasonal influenza infections but not from prior seasonal vaccination. Modelling studies suggest that influenza infection leads to heterosubtypic temporary immunity which is initially almost complete. We suggest these observations together can explain the apparent discrepant findings in Canada and Victoria. In Victoria there was no recent prior circulation of seasonal influenza and thus no temporary immunity to pandemic influenza. There was no association of seasonal influenza vaccine with pandemic influenza infection. In Canada seasonal influenza preceded circulation of the pandemic virus. An unvaccinated proportion of the population developed temporary immunity to pandemic influenza from seasonal infection but a proportion of vaccinated members of the population did not get seasonal infection and hence did not develop temporary immunity to pandemic influenza. It may therefore have appeared as if seasonal vaccination increased the risk of infection with pandemic influenza A(H1N1) virus.

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Persistence of the 2009 Pandemic Influenza A (H1N1) Virus on N95 Respirators

Applied and Environmental Microbiology ◽

10.1128/aem.03850-12 ◽

2013 ◽

Vol 79 (7) ◽

pp. 2148-2155 ◽

Cited By ~ 30

Author(s):

A. D. Coulliette ◽

K. A. Perry ◽

J. R. Edwards ◽

J. A. Noble-Wang

Keyword(s):

Pandemic Influenza ◽

Influenza A ◽

H1n1 Virus ◽

Close Contact ◽

Influenza Infection ◽

The United States ◽

Control Measures ◽

Enzyme Linked Immunosorbent Assay ◽

Influenza A H1n1 ◽

N95 Respirators

ABSTRACTIn the United States, the 2009 pandemic influenza A (H1N1) virus (pH1N1) infected almost 20% of the population and caused >200,000 hospitalizations and >10,000 deaths from April 2009 to April 2010. On 24 April 2009, the CDC posted interim guidance on infection control measures in health care settings explicitly for pH1N1 and recommended using filtering face respirators (FFRs) when in close contact with a suspected- or confirmed-to-be-infected individual, particularly when performing aerosol-generating procedures. The persistence and infectivity of pH1N1 were evaluated on FFRs, specifically N95 respirators, under various conditions of absolute humidity (AH) (4.1 × 105mPa, 6.5 × 105mPa, and 14.6 × 105mPa), sample matrices (2% fetal bovine serum [FBS], 5 mg/ml mucin, and viral medium), and times (4, 12, 24, 48, 72, and 144 h). pH1N1 was distributed onto N95 coupons (3.8 to 4.2 cm2) and extracted by a vortex-centrifugation-filtration process, and the ability of the remaining virus to replicate was quantified using an enzyme-linked immunosorbent assay (ELISA) to determine the log10concentration of the infectious virus per coupon. Overall, pH1N1 remained infectious for 6 days, with an approximately 1-log10loss of virus concentrations over this time period. Time and AH both affected virus survival. We found significantly higher (P≤ 0.01) reductions in virus concentrations at time points beyond 24 to 72 h (−0.52-log10reduction) and 144 h (−0.74) at AHs of 6.5 × 105mPa (−0.53) and 14.6 × 105mPa (−0.47). This research supports discarding respirators after close contact with a person with suspected or confirmed influenza infection due to the virus's demonstrated ability to persist and remain infectious.

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Hospitalisation associated with the 2009 H1N1 pandemic and seasonal influenza in Hong Kong, 2005 to 2010

Eurosurveillance ◽

10.2807/ese.17.45.20309-en ◽

2012 ◽

Vol 17 (45) ◽

Author(s):

L Yang ◽

X L Wang ◽

K P Chan ◽

P H Cao ◽

H Y Lau ◽

...

Keyword(s):

Hong Kong ◽

Chronic Diseases ◽

Pandemic Influenza ◽

Influenza A ◽

Seasonal Influenza ◽

H1n1 Influenza ◽

Morbidity Burden ◽

Increased Risk ◽

Influenza A H1n1 ◽

2009 H1n1

Reliable estimates of the morbidity burden caused by the 2009 pandemic influenza (pH1N1) are important for assessing the severity of the pandemic. Poisson regression models were fitted to weekly numbers of cause-specific hospitalisation in Hong Kong from 2005 to 2010. Excess hospitalisation associated with the 2009 pandemic and seasonal influenza was derived from the model by incorporating the proxy variables of weekly proportions of specimens positive for the pandemic influenza A(H1N1)pdm09, seasonal influenza A (subtypes H3N2 and H1N1) and B viruses. Compared with seasonal influenza, pH1N1 influenza was associated with higher hospitalisation rates for acute respiratory disease (ARD) among children younger than 18 years and adults aged between 18 and 64 years, but among the elderly aged 65 years and older the hospitalisation rates were lower for pH1N1 than for seasonal H3N2 and H1N1 influenza. Hospitalisation rates for chronic diseases associated with pH1N1 influenza were generally higher than those associated with seasonal influenza. The reported hospitalised cases with laboratory-confirmed pandemic infections accounted for only 16% of pH1N1 influenza-associated hospitalisations for ARD in the age group 75 years and older, and 5?66% of hospitalisations for chronic diseases in those older than 40 years. The 2009 H1N1 influenza pandemic was associated with a dramatically increased risk of hospitalisation among children and young adults. The morbidity burden of pandemic was underreported in old people and in those with chronic conditions.

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Pandemic Influenza A(H1N1)2009 in Hospital Healthcare Workers in New Zealand

Infection Control and Hospital Epidemiology ◽

10.1086/663705 ◽

2012 ◽

Vol 33 (2) ◽

pp. 196-199 ◽

Cited By ~ 2

Author(s):

Nigel J. Raymond ◽

Neville Berry ◽

Tim K. Blackmore ◽

Sarah Jefferies ◽

Katherine Norton ◽

...

Keyword(s):

New Zealand ◽

Pandemic Influenza ◽

Healthcare Workers ◽

Influenza A ◽

H1n1 Influenza ◽

Rapid Diagnosis ◽

Infect Control Hosp ◽

Diagnosis And Treatment ◽

Influenza A H1n1

We evaluated A/H1N1 influenza in healthcare workers (HCWs) and in a flu room during the 2009 pandemic. The flu room aided HCW care and management by facilitating rapid diagnosis and treatment. Absence of fever was common, and symptoms were nonspecific. A higher rate of H1N1 occurred in HCWs deployed in acute services.Infect Control Hosp Epidemiol2012;33(2):196-199

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Effectiveness of seasonal 2010/11 and pandemic influenza A(H1N1)2009 vaccines in preventing influenza infection in the United Kingdom: mid-season analysis 2010/11

Eurosurveillance ◽

10.2807/ese.16.06.19791-en ◽

2011 ◽

Vol 16 (6) ◽

Cited By ~ 1

Author(s):

R Pebody ◽

P Hardelid ◽

D M Fleming ◽

J McMenamin ◽

N Andrews ◽

...

Keyword(s):

United Kingdom ◽

Influenza Vaccine ◽

Pandemic Influenza ◽

Influenza A ◽

Influenza Infection ◽

Vaccine Effectiveness ◽

The United Kingdom ◽

Trivalent Influenza Vaccine ◽

Monovalent Vaccine ◽

Influenza A H1n1

This study provides mid-season estimates of the effectiveness of 2010/11 trivalent influenza vaccine and previous vaccination with monovalent influenza A(H1N1)2009 vaccine in preventing confirmed influenza A(H1N1)2009 infection in the United Kingdom in the 2010/11 season. The adjusted vaccine effectiveness was 34% (95% CI: -10 - 60%) if vaccinated only with monovalent vaccine in the 2009/10 season; 46% (95% CI: 7 - 69%) if vaccinated only with trivalent influenza vaccine in the 2010/11 season and 63% (95% CI: 37 - 78%) if vaccinated in both seasons.

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The 2009 pandemic H1N1 influenza and indigenous populations of the Americas and the Pacific

Eurosurveillance ◽

10.2807/ese.14.42.19366-en ◽

2009 ◽

Vol 14 (42) ◽

Cited By ~ 80

Author(s):

G La Ruche ◽

A Tarantola ◽

P Barboza ◽

L Vaillant ◽

J Gueguen ◽

...

Keyword(s):

Influenza A ◽

Influenza Infection ◽

Severe Disease ◽

H1n1 Influenza ◽

Indigenous Populations ◽

Chronic Obstructive ◽

Pandemic H1n1 ◽

Pandemic H1n1 Influenza ◽

The Pacific ◽

Influenza A H1n1

There are few structured data available to assess the risks associated with pandemic influenza A(H1N1)v infection according to ethnic groups. In countries of the Americas and the Pacific where these data are available, the attack rates are higher in indigenous populations, who also appear to be at approximately three to six-fold higher risk of developing severe disease and of dying. These observations may be associated with documented risk factors for severe disease and death associated with pandemic H1N1 influenza infection (especially the generally higher prevalence of diabetes, obesity, asthma, chronic obstructive pulmonary disease and pregnancy in indigenous populations). More speculative factors include those associated with the risk of infection (e.g. family size, crowding and poverty), differences in access to health services and, perhaps, genetic factors. Whatever the causes, this increased vulnerability of indigenous populations justify specific immediate actions in the control of the current pandemic including primary prevention (intensified hygiene promotion, chemoprophylaxis and vaccination) and secondary prevention (improved access to services and early treatment following symptoms onset) of severe pandemic H1N1 influenza infection.

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