Perspectives of public health laboratories in emerging infectious diseases

Chua, Kaw Bing; Gubler, Duane J

Infectious diseases have affected humans since the first recorded history of man. Infectious diseases remain the second leading cause of death worldwide despite the recent rapid developments and advancements in modern medicine, science and biotechnology. Greater than 15 million (.25%) of an estimated 57 million deaths that occur throughout the world annually are directly caused by infectious diseases. Millions more deaths are due to the secondary effects of infections. Moreover, infectious diseases cause increased morbidity and a loss of work productivity as a result of compromised health and disability, accounting for approximately 30% of all disability-adjusted life years globally. 1, 2 Compounding the existing infectious disease burden, the world has experienced an increased incidence and transboundary spread of emerging infectious diseases due to population growth, urbanization and globalization over the past four decades. [3] [4] [5] [6] [7] [8] Most of these newly emerging and re-emerging pathogens are viruses, although fewer than 200 of the approximately 1400 pathogen species recognized to infect humans are viruses. On average, however, more than two new species of viruses infecting humans are reported worldwide every year, 9 most of which are likely to be RNA viruses. 6 Emerging novel viruses are a major public health concern with the potential of causing high health and socioeconomic impacts, as has occurred with progressive pandemic infectious diseases such as human immunodeficiency viruses (HIV), the recent pandemic caused by the novel quadruple re-assortment strain of influenza A virus (H1N1), and more transient events such as the outbreaks of Nipah virus in 1998/1999 and severe acute respiratory syndrome (SARS) coronavirus in 2003. [10] [11] [12] [13] [14] In addition, other emerging infections of regional or global interest include highly pathogenic avian influenza H5N1, henipavirus, Ebola virus, expanded multidrug-resistant Mycobacterium tuberculosis and antimicrobial resistant microorganisms, as well as acute hemorrhagic diseases caused by hantaviruses, arenaviruses and dengue viruses.