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Emerging Infectious Diseases: A Threat to Global Public Health and Economic Security. S. Machado. Duane J Gubler Professor. EcoHealth , Kunming, 16 Oct, 2012. Signature Research Program in Emerging Infectious Diseases Duke-NUS Graduate Medical School, Singapore.
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Emerging Infectious Diseases: A Threat to Global Public Health and Economic Security S. Machado Duane J Gubler Professor EcoHealth, Kunming, 16 Oct, 2012 Signature Research Program in Emerging Infectious Diseases Duke-NUS Graduate Medical School, Singapore
Emerging Infectious Diseases: A Threat to Global Public Health and Economic Security • Background • Snapshot of recent epidemics • Reasons for emergence and spread • Prospects for the future • Challenges to reverse the trends
The Global Threat of Infectious DiseasesEmerging and re-emerging diseases A/H1N1 Dengue A/H1N1 Chikungunya Dengue Emerging diseases Re-emerging diseases Adapted from Morens, Folkers, Fauci 2004 Nature 430; 242-9
Major Infectious Disease Epidemics since 1980 • Dengue/DHF-1970s, SE Asia, global • HIV/AIDS-1980s-Africa,global • Drug resistant TB-1990s, US, global • Cholera-1991-Americas • Plague-1994-India, global • Foot & Mouth disease-1995,2000- Taiwan & UK • West Nile-1990s-Mediterranean, Americas • BSE-1990s- UK, Canada, US • Swine fever, 1996- Netherlands • H5N1 influenza-1997- HK-global • Nipah encephalitis-1998-Malaysia,Asia • SARS-2002- Asia, global • Chikungunya-2004-Africa, Asia • H1N1 influenza-2009-Mexico?,global
What did these Epidemic Infectious Diseases have in Common? • All were caused by zoonotic pathogens • All spread by modern transportation • Most had Asian origin • Laboratory and clinical diagnoses were problematic • Poor communication among countries • Major economic impact
Major Infectious Disease Epidemics since 1980 • Dengue/DHF-1970s, SE Asia, global • HIV/AIDS-1980s-Africa,global • Drug resistant TB-1990s, US, global • Cholera-1991-Americas • Plague-1994-India, global • Foot & Mouth disease-1995,2000- Taiwan & UK • West Nile-1990s-Mediterranean, Americas • BSE-1990s- UK, Canada, US • Swine fever, 1996- Netherlands • H5N1 influenza-1997- HK-global • Nipah encephalitis-1998-Malaysia,Asia • SARS-2002- Asia, global • Chikungunya-2004-Africa, Asia • H1N1 influenza-2009-Mexico?,global
Plague Pandemics • Justinian’s Plague (mid-6th Century A.D.) • Black Death (mid-14th Century A.D.) • Modern Pandemic (1894 – mid-1900s)
India Delhi Calcutta Madras Bombay Potential Spread of Pnuemonic Plague out of India, 1994
Pneumonic Plague in India • Indian outbreak was a major surprise – no plague confirmed in India since 1966 • Clinical and lab diagnosis • Media and panic driven epidemic • First epidemic to impact global air transportation • Caused huge economic loss for India (> $3 billion)
Chain of transmission among guests at Hotel M—Hong Kong, 2003 2 family members 2 close contacts Guangdong Province, China 4 family members 10 HCWs 4 HCWs* Hospital 2Hong Kong Canada F A A F G † G † 3 HCWs K † K † Ireland 156 close contacts of HCWs and patients A Hospital 3 Hong Kong H H I Hotel MHong Kong L§ J I United States E 99 HCWs (includes 17 medical students) J D B M§ Hospital 1 HK C C D E B Germany 0 HCWs Singapore HCW HCW B Vietnam Hospital 4 Hong Kong 34 HCWs 28 HCWs 2 family members 37 HCWs HCW 37 close contacts 4 other Hong Kong Hospitals Unknown number close contacts HCW * Health-care workers; † All guests except G and K stayed on the 9th floor of the hotel. Guest G stayed on the 14th floor, and Guest K stayed on the 11th floor; § Guests L and M (spouses) were not at Hotel M during the same time as index Guest A but were at the hotel during the same times as Guests G, H, and I, who were ill during this period. Bangkok Data as of 3/28/03
Economic Impact of Selected Infectious Diseases Plague, India $5-6 bn
Why Have we Seen Such a Dramatic Increase in Epidemic Infectious Diseases? • Complacency, Lack of Political Will • Policy Changes • Changes in Public Health • Changing Life Styles/Behavior • Microbial Adaptation • Technology • Intent to Harm • Climate Change
Why Have we Seen Such a Dramatic Increase in Epidemic Infectious Diseases? Major Drivers • Demographic Changes (Pop Growth) • Environmental Change • Uncontrolled Urbanization • Agricultural/Land Use Practices • Deforestation • Animal Husbandry • Modern Transportation (Globalization) • Increased Movement of People, Animals, Commodities • Lack of Public Health Infrastructure
Urban Growth in Asian(1) and American(2) Cities, 1950-2010 • Mean population of Dhaka, Bangkok, Jakarta, Manila and Saigon. • Mean population of Rio de Janeiro, Sao Paulo, San Juan, Caracas and Guayaquil.
Average annual number of global airline passengers by decade, 1950-2010 Million of Passenger (Mil) IATA 2010 Decade
Global distribution of dengue virus serotypes, 1970 Gubler, 1998
Global distribution of dengue virus serotypes, 1970-2000 1981 1977 1981 1979 1994 1980 1982 1975 1985 1971 DENV – 1; DENV – 2; DENV – 3; DENV – 4
Global distribution of dengue virus serotypes, 2012 Adapted from Gubler, 1998
West Nile Fever Dengue Fever Yellow Fever Mayaro Fever Chikungunya Epidemic Polyarthritis SARS Influenza Lassa Fever Monkeypox CJD/BSE HIV/AIDS Cholera E. coli O157 E. Coli 0104:H4 Malaria Leishmaniasis Chagas Disease Cyclospora Exotic Infectious Diseases That HaveRecently Been Introduced to the US
Live Animal Importation into the USA - 2002 • 47,000 mammals • 28 species of rodents • 379,000 birds • 2 million reptiles & Poisonous snakes • 49 million amphibians • 223 million fish Data from U.S. Fish & Wildlife Service
Exotic Mosquito Species Recently Introduced and Established in the US • Aedes (Stegomyia) albopictus • Ochlerotatus (Aedes Finlaya) togoi • Ochlerotatus (Aedes Finlaya) japonicus • Aedesbahamensis • Culex biscayensis
Global Threat of Epidemic Infectious Diseases • Disease and Trade-interwoven History • 14th century, Europe discovers exotic goods from Asia • Global Trade Flourishes • 18th, 19, 20th centuries • New Millennium • Integrated global economic system with a transnational flow of knowledge, capital, products, people, animals, and pathogens • Rapid spread of epidemic infectious disease from point of origin
Demographic Changes Technology/Globalization Socio-cultural organization Global climate change Agricultural, land use and animal husbandry changes/practices Habitat alteration Urbanization NATURAL ECOSYSTEM HUMAN ECOSYSTEM REGIONAL ENVIRONMENTAL CHANGE Species’ Ecological-evolutionary Dynamics Opportunistic habitat expansion/ecological release Vector (domestication) Vector/reservoir species Wildlife/reservoir transport/encroachment Human encroachment Host-Pathogen Dynamics Emergence Processes of ‘Host-Parasite Biology’ Host switching (host novelty) • Breaching of pathogen persistence thresholds Transmission amplification and genetic change (pathogen novelty) Disease Emergence ecosystem continuum
The Global Threat of Epidemic Infectious Diseases ProjectedGlobal Trends • Asian countries will lead in economic growth • Asian Cities will lead in population growth • Circular rural to urban migration • Increased globalization • Increased trade • Increased movement of people, animals and commodities • Increased movement of pathogens • Increased probability of epidemic disease • Increased threat to global economic security
Tuesday, Oct 16, 2012 • The Armageddon virus: Why experts fear a disease that leaps from animals to humans could devastate mankind in the next five years • Warning comes after man died from a Sars-like virus that had previously only been seen in bats • Earlier this month a man from Glasgow died from a tick-borne disease that is widespread in domestic and wild animals in Africa and Asia http://www.dailymail.co.uk/science
Pathogens of Tomorrow • From Whence They Will Come? • From Asia • From Animals • Mostly Viruses
Global Threat of Epidemic Infectious DiseasesChallenge to Reverse the Trend • Prevent movement of pathogens and vectors via modern transportation • Improve international cooperation and data sharing • Improve effective laboratory-based surveillance • Rebuild public health infrastructure to prevent & control vector-borne and zoonotic diseases • Trained personnel • Laboratory and epidemiologic capacity • Tools (vaccines, drugs, insecticides, mosquito control, etc) • Understanding disease ecology • Political will • Economic support • Regional prevention and control programs