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Order Articulavirales
Published in Paul Pumpens, Peter Pushko, Philippe Le Mercier, Virus-Like Particles, 2022
Paul Pumpens, Peter Pushko, Philippe Le Mercier
The order is of extremely high medical importance, because of the continuous healthcare concern associated with influenza infections. There are four types of influenza virus, namely types A, B, C, and D belonging to the genera Alphainfluenzavirus, Betainfluenzavirus, Gammainfluenzavirus, and Deltainfluenzavirus, respectively. The influenza A and B viruses are clinically relevant for humans. Influenza A viruses are responsible for annual epidemics and all known influenza pandemics. The influenza B virus is primarily a human pathogen, which is not associated with an animal reservoir. It causes similar symptoms and disease as the influenza A virus. However, the frequency of the severe cases of influenza B infections appears to be significantly lower than that of influenza A. As to the influenza C, well-defined outbreaks have rarely been detected in humans, and the virus is rarely associated with severe syndromes. Most people have antibody to the influenza C virus by early adulthood, and influenza C is not included in the current influenza vaccine formulations. For more information and references, reviews of Pushko et al. (2008), Pushko and Tumpey (2015), and Pushko and Tretyakova (2020) are recommended.
Biobased Products for Viral Diseases
Published in Mahendra Rai, Chistiane M. Feitosa, Eco-Friendly Biobased Products Used in Microbial Diseases, 2022
Gleice Ribeiro Orasmo, Giovanna Morghanna Barbosa do Nascimento, Maria Gabrielly de Alcântara Oliveira, Jéssica Missilany da Costa
Thus, new therapeutic agents that control the Influenza A Virus (IAV), the propagation and attenuation of excessive pro-inflammatory responses are needed. Polysaccharide extract from Radix isatidis L., a traditional Chinese herbal medicine, exerted potent in vitro anti-IAV activity against human seasonal influenza viruses (H1N1 and H3N2) and avian influenza viruses (H6N2 and H9N2) (Li et al. 2017). R. isatidis L. root polysaccharide extract therefore has the potential to be used as an adjunct to antiviral therapy for the treatment of IAV infection.
Severe Influenza Pneumonia and Its Mimics in the Critical Care Unit
Published in Cheston B. Cunha, Burke A. Cunha, Infectious Diseases and Antimicrobial Stewardship in Critical Care Medicine, 2020
Influenza A virus is considered a self-limited infection. However, a patient with an ILI can be subjected to severe pneumonia with respiratory failure. Influenza A mainly targets the lower respiratory tract but might present with other distinct clinical syndromic entities in the CCU. Among them, multi-organ failure with ARDS and septic shock are the most prominent. The consideration about the different infectious and non-infectious conditions that mimic influenza pneumonia at admittance must be sufficient. A history of travel and exposures at the earliest possible entry point is essential. In addition, the absence of symptoms of ILIs does not effectively rule out influenza infection, especially in the elderly and immunocompromised people. Knowing the wide spectrum of the presentation and severity of influenza infection, intensivists in the CCU will have to find what they seek to.
Emerging antiviral therapies and drugs for the treatment of influenza
Published in Expert Opinion on Emerging Drugs, 2022
Jinshen Wang, Yihang Sun, Shuwen Liu
Influenza is an acute respiratory infectious disease caused by influenza viruses divided into four types: A, B, C and D. Indeed, due to antigenic transformation and drift, influenza A virus (IAVs) possesses the strongest infectivity and the highest mortality rate. Unlike IAVs, influenza B viruses mutate less, causing seasonal epidemics but rarely pandemics. Influenza C and D viruses are highly antigenically stable and only lead to mild upper respiratory tract infections. According to the antigenic features of two glycoproteins on the virus surface, including hemagglutinin (HA) and neuraminidase (NA), IAVs can be divided into 18 subtypes of HA (H1–H18) and 10 subtypes of NA (N1–N10) [1,2]. There have been four influenza outbreaks in human history. The first pandemic (Spanish influenza 1918–1919) caused by the H1N1 virus was responsible for 50 to 100 million deaths [3,4]. The ‘Asian flu’ caused by the H2N2 virus in 1957–1959 appeared in China and then spread to more than 20 countries worldwide, resulting in about 45 million infections and 1.1 million deaths [5,6]. In 1968–1969, the H3N2 virus replaced the H2N2 virus causing the Hong Kong pandemic, leading to approximately 1 million deaths [7,8]. In 2009, the swine-derived H1N1 virus spread to more than 30 countries worldwide through human-to-human transmission, which caused about 19,000 deaths and posed a huge threat to global public health security [8,9]. It is worth noting that since 1997, several avian influenza viruses have exhibited cross-species transmission and spread to humans, such as H5N1 and H7N9 [10–13].
The roles of epidermal growth factor receptor in viral infections
Published in Growth Factors, 2022
Influenza A virus (IAV) is the most virulent type of influenza virus that causes seasonal epidemics as well as global pandemics. It is made up of eight negative sense, single stranded RNA segments that are surrounded by viral envelope (Samji 2009). Eierhoff et al. (2010) have reported that EGFR promotes internalisation of IAV into host cells via both clathrin- and caveolin-1 dependent endocytosis. They have demonstrated that modulations of expression and activity of EGFR using siRNA and PD153035 in the early stage of infection alter the virus uptake and progeny virion production. Their studies also suggested that IAV attachment causes clustering of lipid-rafts which brings EGFR and other RTKs in close proximity. EGFR is activated in response to the clustering and facilitates the viral endocytosis (Figure 2(i)) (Eierhoff et al. 2010).
Novel insights into the pathogenesis of virus-induced ARDS: review on the central role of the epithelial-endothelial barrier
Published in Expert Review of Clinical Immunology, 2021
Jun Feng, Lina Liu, Yang He, Min Wang, Daixing Zhou, Junshuai Wang
The immunopathogenesis of ARDS is associated with an imbalanced immune response, which may cause lung tissue damage, loss of alveolar structure, and loss of pulmonary epithelial and endothelial integrity [73]. Severe lung injury and cell death during influenza A virus infection are the result of an exuberant host inflammatory response [74,75]. TNF-α derived from CD8 + T cells can cause damage to bystanders by triggering the death of uninfected epithelial cells. If CD8+ cells fail to eliminate the virus, tremendous amounts of cytokines released from CD4 + T effector cells can also induce augmented inflammatory responses for pathogen clearance, as well as tissue damage [76,77]. By further stimulating inflammasome pathway activities, viral infections can exacerbate the impairment of the immunological response.