Lower respiratory tract hemorrhage associated with 2009 pandemic influenza A (H1N1) virus infection

Abstract

Please cite this paper as: Kennedy et al. for the 2009 Pandemic H1N1 Influenza‐Associated Lower Respiratory Tract Hemorrhage Working Group. (2012) Lower respiratory tract hemorrhage associated with 2009 pandemic influenza A (H1N1) virus infection. Influenza and Other Respiratory Viruses DOI: 10.1111/irv.12022. Background Influenza‐associated lower respiratory tract hemorrhage (LRTH) has been reported in previous pandemics and is a rare complication of seasonal influenza virus infection. We describe patients with LRTH associated with 2009 pandemic influenza A (H1N1) (pH1N1) virus infection identified from April 2009 to April 2010 in the United States. Methods We ascertained patients with pH1N1‐associated LRTH through state and local surveillance, the Emerging Infections Program, and CDCs Infectious Diseases Pathology Branch. All patients had influenza A, evidence of pneumonia, and evidence of LRTH. Results We identified 44 cases; the median number of days from illness onset to clinical signs of LRTH was one. Hemoptysis or respiratory tract bleeding was documented in 40% of pH1N1‐associated LRTH cases, often present early during the course of illness. Twenty‐one (48%) patients with LRTH had no other hemorrhagic diatheses. Seven (23%) patients with LRTH received antiviral treatment within two days of illness onset. Conclusions During influenza season, clinicians should consider influenza infection in the differential diagnosis for patients presenting with hemoptysis or other signs or symptoms of LRTH. While the impact of timing of antiviral therapy on this complication has not been studied, the rapid progression of LRTH may support use of early empiric therapy. Continued investigation is necessary to betterdefine the clinical spectrum of both seasonal influenza‐ and pH1N1‐associated LRTH.

The humanized DRAGA mouse (HLA-A2. HLA-DR4. RAG1 KO. IL-2R g c KO. NOD) establishes inducible and transmissible models for influenza type A infections

“…Acute viral pneumonia with alveolar hemorrhage in humans afflicted by seasonal IAV infections is a catastrophic clinical condition promoting bacterial superinfection and hypoxemic respiratory failure. 55,56 We found striking evolution toward alveolar hemorrhage in sub-lethal infections of DRAGA mice with H1N1/PR8 and H3N2/Aichi viruses. Since it is known that upper and lower respiratory viruses including influenza viruses can suppress host transcription for a number of genes, [57][58][59][60] we questioned whether pulmonary hemorrhage detected in H1N1/PR8-infected DRAGA mice may relate to virus-induced alterations of pro-coagulant processes in their lungs.…”

Public protests and environmental policy‐making: The cases of Xiamen antiparaxylene protests in China and the civic movement against Kodaikkanal mercury poisoning in India

“…In a special session of the Standing Committee of the National People's Congress of the P.R China on the social impact of environmental problems, Yang Chaofei, vice‐chairman of the Chinese Society for Environmental Sciences revealed that the number of environmental “mass incidents” grew at an average of 29% annually, between 1996 and 2011 (Kennedy, 2012). Similarly, the Chinese Academy of Social Sciences (CASS, 2014) found that environmental pollution triggered half of the “mass incidents” that happened in the country (群体性事件 quntixing shijian) that attracted 10,000 or more participants between 2000 and 2013.…”

The Importance of Vaccinating Children and Pregnant Women against Influenza Virus Infection

“…While gas-exchanging alveolar type I epithelial cells can generate an antiviral response, high viral loads can overwhelm this and lead to compromised lung function [87,88]. In some severe cases of influenza virus infection, virus and inflammation were noted in the lower respiratory tract or alveoli, with resulting cellular damage ( Figure 2) [8,9,[11][12][13]89]. Additionally, neutrophils have been implicated in the pathophysiology of alveolar damage following infection with influenza virus [90].…”

“…Several studies report that in fatal cases of influenza virus infection, increased inflammation, and virus are found in the alveoli [8][9][10][11][12][13]. Disruption of the alveolar region due to viral infection and increased inflammation can contribute to the development of acute respiratory distress syndrome (ARDS), which is a major health concern for children and pregnant women [14][15][16][17].…”