China
Africa
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Novel RNA Interference (RNAi)-Based Nanomedicines for Treating Viral Infections
Published in Dan Peer, Handbook of Harnessing Biomaterials in Nanomedicine, 2021
Nyree Maes, Skye Zeller, Priti Kumar
In 2004, two groups reported the results of in vivo administration of siRNAs that targeted NP and components of the RdRp. siRNAs directed against NP and/or PA were complexed with either PEI [41] or lipofectamine [110] and delivered to mice i.v. prior to infection. In both studies large reductions in viral titers up to 100-fold were observed against several strains of influenza including H1N1, H5N1, H7N7 and H9N2 and survival rates of mice were significantly increased. Treatment with a combination of these siRNAs was more potently inhibitory. Combinations of PEI complexed siRNAs targeting NP and M2 [132] or 2′O-methyl modified siRNAs complexed to lipofectamine targeting NP and NS1 [125] have also been explored in vivo with similar results. Treatment prior to infection increased survival of mice (i.v. treatment) or chickens (i.n. treatment) following challenge with lethal dose of H5N1 with significant reductions in viral titers.
Biological Agents
Published in Katarzyna Majchrzycka, Małgorzata Okrasa, Justyna Szulc, Respiratory Protection Against Hazardous Biological Agents, 2020
In recent years, influenza viruses type B and C, characteristic for humans, and type A, also found in animals (birds, swine and others), have been recognised as occupational hazards. These include the A/(H5N1) virus, responsible for avian influenza in domestic poultry and wild birds. This virus is highly pathogenic for humans. There have been reported infections with the A/(H1N1) virus, including numerous deaths in China and in Africa. Milder infections (flu-like symptoms, conjunctivitis) are caused by the (H7N7) subtype of avian influenza virus, which caused the epidemics in poultry farmers in the Netherlands and Canada in 2003–2004 [CDC 2019].
Mathematical modeling and nonstandard finite difference scheme analysis for the environmental and spillover transmissions of Avian Influenza A model
Published in Dynamical Systems, 2021
A. Feukouo Fossi, J. Lubuma, C. Tadmon, B. Tsanou
The avian influenza virus infection is caused by viruses adapted to birds and it normally affects wild birds and poultry. The wild birds are natural reservoir for all the sub-types of influenza A viruses. Influenza viruses are widespread and due to their high mutation rate many subtypes exist. Further, H5N1, H7N4, H7N7, H7N9, H9N2, and other avian influenza viruses with pathogenicity have great potential threat to human. Poultry farms are an important reservoir for the avian influenza virus (AIV) [28]. AIV transmission to humans is largely facilitated by contact with animals and excretion of contaminated droplets or aerosols [18], and to a lesser extent through transport of (dead) birds or contaminated objects (vehicles, humans, or fomites), water, food, and contact with infected wildfowl or insects [9]. Historically, the avian influenza splits into two classes: the High Pathogenic Avian Influenza (HPAI) and the Low Pathogenic Avian Influenza (LPAI). The HPAI can cause a series of systemic infections that can lead to high mortality. The LPAI causes mild or no symptoms. In general, the risk of direct transmission of avian influenza to human is very low. However, in 2014 a high mortality rate was recorded with around 38.7% of the patients infected with H7N9 virus dead [7]. H7N9 virus can cause pneumonia, respiratory failure, acute respiratory distress syndrome and multi-organ failure.