Avian Flu Virus Essay Example | Topics and Well Written Essays - 2000 words

Avian Flu Virus - Essay Example Moreover, it has been known that this H5N1 virus is able to infect other animals other than birds and pigs, such as, cats and larger felines, and transmission of infection from other animals to human may occur unknowingly. An article published in the Journal of Virology in the year 2005, titled "Avian Influenza (H5N1) Viruses Isolated from Humans in Asia in 2004 Exhibit Increased Virulence in Mammals" and researched by Maines and co-workers investigates this in an isolate of the virus of the H5N1 strain, isolated from 2004 Asian epidemic, and in this work, that article will be critiqued. Research Questions: As is apparent from the epidemiologic patterns of the outbreak of these H5N1 infections, the virulence factors responsible for human disease need to be elucidated. The problem remains that the virulence factors of H5N1 viruses is poorly understood from the biologic and molecular perspectives, this being an avian virus transmitted to humans. It points to the need for mammalian models of studies, and since there is evidence that mammalian experiments in nonhuman primates such as ferrets and mice have been studied for influenza virus pathogenesis and other nonhuman mammals may also serve as carriers for human virus, nonhuman primate studies may serve as an acceptable model. In these models, the relative virulence of the H5N1 isolated from 2003-2004 outbreaks in both humans and avian species can be studied, and the authors can have the advantage of comparing them with earlier 1997 H5N1 human isolates to compare the virulence of the virus, so a molecular or biologic c orrelate is available that may be applied in the management of human epidemics. Relevance of the Question: From the public health point of view, the circulation of H5N1 virus in the poultry may cause more human cases with human-avian reassortant pandemics. Epidemiologic observations have demonstrated that from the time of first recognition and isolation, the virulence of this strain is increasing markedly over the years in terms of mortality and case fatality rates. Although the clinical presentations of the human cases were usual in the form of fever, respiratory symptoms, diarrhea, lymphopenia, and thrombocytopenia, in rare occasions, they indeed presented with just fever and gastrointestinal symptoms. This could have indicated a change in the pattern of virulence, despite the pattern of fatality remaining the same, that is, development of pneumonia with critical compromise in gas exchange, leading to respiratory failure and death despite assisted ventilations. Research in this area is necessary since there is a paucity of research answering this question abou t how an infection with this virus leads to acute respiratory distress and multiple organ dysfunctions in humans. Although studies in mammalian models do have constraints from the practical, ethical, and economic perspectives, it could be a valid option since ferret is a naturally susceptible host to influenza A virus, has been used in previous studies to evaluate H5N1 virulence and safety and efficacy of vaccine candidate preparations. Moreover, the same authors previously studied H5N1 virus virulence in ferrets and they have valid criteria for assessment, where they demonstrated earlier equivalence in