title: Reasons for the increase in emerging and re-emerging viral infectious diseases.
abstract: In the past two decades, humans have faced many new viral infectious agents in emerging and re-emerging infectious diseases (EIDs). Many factors contribute to the appearance of EIDs. These factors are complex but can be classified into three different categories: virus factors, human factors, and ecological factors. The factors contributing to the cause of such viral infectious diseases will be systematically reviewed in this article.
authors.affiliation: Department of Microbiology, Immunology and Molecular Genetics, UCLA School of Medicine, Los Angeles, CA 90095-1747, USA. ekwhui@ucla.edu
authors.forename: Eric Ka-Wai
authors.initials: EK
authors.lastname: Hui
mesh_terms: D000818:Animals; D021821:Communicable Diseases, Emerging / Q000453:epidemiology* / Q000209:etiology / Q000821:virology*; D004463:Ecology; D006801:Humans; D014777:Virus Diseases / Q000453:epidemiology* / Q000209:etiology / Q000821:virology*