Emerging and Re-emerging Infectious Diseases

Zika, Chikungunya Aedes aegypti, the yellow fever mosquito, is a mosquito that can spread dengue fever, chikungunya, Zika fever, and yellow fever viruses, and other diseases.

Aedes Egypti The mosquito can be recognized by white markings on its legs and a marking in the form of a lyre on the upper surface of its thorax. This mosquito originated in Africa, but is now found in tropical and subtropical regions throughout the world.

WNV

Monkeypox from Prairie Dogs

Are infectious diseases emerging more than before?

Institute of Medicine 1992 Report on Emerging Infections Defined emerging infections as: “New, reemerging or drug-resistant infections whose incidence in humans has increased within the past two decades or whose incidence threatens to increase in the near future.”

Major Factors Contributing to Emerging Infections: 2013 1. Human demographics and behavior 2. Technology and Industry Economic development and land use 4. International travel and commerce 5. Microbial adaptation and change 6. Breakdown of public health measures Institute of Medicine Report, 2013

More Factors Contributing to Emerging Infections: 2013 7. Human vulnerability Climate and weather Changing ecosystems Poverty and social inequality War and famine Lack of political will Intent to harm Institute of Medicine Report, 2013

Emerging Infections: Human Demographics, Behavior, Vulnerability More people, more crowding Changing sexual mores (HIV, STDs) Injection drug use (HIV, Hepatitis C) Changing eating habits (foodborne infections) More populations with weakened immune system: elderly, HIV/AIDS, cancer patients and survivors, persons taking antibiotics and other drugs

Emerging Infections: Technology and Industry Mass food production (Campylobacter, E.coli O157:H7, etc…) Use of antibiotics in food animals (antibiotic-resistant bacteria) New drugs for humans (prolonging vulnerability)

Emerging Infections: Economic Development, Land Use, Changing Ecosystems Changing ecology influencing waterborne, vectorborne transmission (e.g. dams, deforestation) Contamination of watershed areas by cattle (Cryptosporidium) More exposure to wild animals and vectors (Lyme disease)

Emerging Infections: International Travel and Commerce Persons infected with an exotic disease anywhere in the world can be into major US city within hours (SARS, VHF,…) Foods from other countries imported routinely into US (Cyclospora,….) Vectors hitchhiking on imported products (Asian tiger mosquitoes on lucky bamboos,….)

Speed of Global Travel in Relation to World Population Growth From: Murphy and Nathanson. Semin. Virol. 5, 87, 1994 CDC

Emerging Infections: Microbial Adaptation and Change Increased antibiotic resistance with increased use of antibiotics in humans and food animals (VRE, VRSA, penicillin- and macrolide-resistant Strep pneumonia, multidrug-resistant Salmonella, TB,….) Jumping species from animals to humans (avian influenza, HIV, SARS?)

Emerging Infections: Poverty, Social Inequality, Breakdown of Public Health Measures Lack of basic hygienic infrastructure (safe water, foods) Inadequate vaccinations (measles, diphtheria) Discontinued mosquito control efforts (dengue, malaria) Lack of monitoring and reporting (SARS

Emerging Infections: Intent to Harm Bioterrorism: Anthrax in US 2001 Bio-Crimes: Salmonella in OR, Shigella in TX. Potential agents: Smallpox, Botulism toxin, Plague, Tularemia, ….

CDC

Prevention of Emerging Infectious Diseases Will Require Action in Each of These Areas Surveillance and Response Applied Research Infrastructure and Training Prevention and Control The plan is organized around four interdependent goals: Surveillance and Response, Applied Research, Infrastructure and Training, and Prevention and Control. Surveillance systems at the state and national levels monitor emerging microbes and detect outbreaks of disease. When surveillance data or other information uncover a change in the occurrence of distribution of a disease, or when a new strain of a microbe becomes a health threat, public health workers investigate, assess the potential public health implications, and mount a rapid response. Through applied research, they provide answers to questions about the disease’s causes, transmission, diagnosis, prevention, and control. A specialized infrastructure supports and equips their work and links them in national and global communications network. Training the next generation of scientific experts is a crucial component of this public health strategy. All of these efforts are ultimately directed toward disease prevention--the institutionalization of public awareness and behavior change, and disease control--the application of the most effective tools and technologies to strengthen personal and community capacities to prevent infectious diseases. CDC

Preventing Emerging Infectious Diseases: More to Do Enhance communication: locally, regionally, nationally, globally Increase global collaboration Share technical expertise and resources Provide training and infrastructure support globally Ensure political support Ensure judicious use of antibiotics Vaccines for all The culmination of all of these efforts is the prevention and control of infectious diseases. Disease prevention alerts people to the threats of new and reemerging diseases and teaches them how to protect themselves and their families. Disease control applies the most effective tools and technologies to counteract infectious microbes and strengthen personal and national protections against emerging diseases.

Rosenthal SR, Ostfeld RS, McGarvey ST, Lurie MN, and Smith KF Rosenthal SR, Ostfeld RS, McGarvey ST, Lurie MN, and Smith KF. The Overlooked Pathways to Infectious Disease Emergence. Emerging Infectious Diseases; under review.

Rosenthal SR, Ostfeld RS, McGarvey ST, Lurie MN, and Smith KF Rosenthal SR, Ostfeld RS, McGarvey ST, Lurie MN, and Smith KF. The Overlooked Pathways to Infectious Disease Emergence. Emerging Infectious Diseases; under review.

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Preventing Emerging Infectious Diseases Surveillance and Response Detect, investigate, and monitor emerging pathogens, the diseases they cause, and the factors influencing their emergence, and respond to problems as they are identified. Surveillance means watchfulness: recognizing the pathogen, tracking its location, monitoring its activity, sizing up the risk. What is the threat? What caused it? Where is it appearing? How is it moving? Surveillance detects large and small changes in disease patterns soon after they occur and alerts us to take preventive actions. It is the basis for timely public health responses and sound public health decisions. CDC

Preventing Emerging Infectious Diseases Applied Research Integrate laboratory science and epidemiology to increase the effectiveness of public health practice. A sustained, timely, and forward-thinking applied research program enables scientists to uncover the vulnerabilities of emerging microbes, create novel ways to counter the effects of microbes, and evaluate the preventive potential of new tools. Research has already provided effective means to reduce the numbers of outbreaks of some infectious diseases, as well as unexpected new knowledge with more far-reaching implications. CDC’s strategy for conducting applied research involves translating laboratory and epidemiologic knowledge into practical tools for preventing disease. A renewed and expanded commitment to knowledge through applied research can ensure continued progress and stimulate the discovery of new biomedical and behavioral approaches to counteract emerging and resurgent infectious diseases. CDC

Preventing Emerging Infectious Diseases Infrastructure and Training Strengthen public health infrastructures to support surveillance, response, and research and to implement prevention and control programs. Provide the public health work force with the knowledge and tools it needs. Rebuilding the public health infrastructure will require an ongoing and sizable investment in modernization and training to boost local, state, national, and global disease-monitoring power and to augment outbreak-response expertise. These improvements are the only way to guarantee that the United States, and the world, are prepared with trained experts, well-equipped laboratories, and cutting-edge technology to head off emerging microbes in the decades to come. Public health infrastructure and training support public health actions. Nations, states, and communities need strong infrastructure to sustain disease surveillance, research, and prevention and to prepare for the unexpected. They need modern laboratories that are equipped to recognize widespread microbial agents like Helicobacter pylori and E. coli O157:H7. They need people, equipment, and know-how to perform jobs as diverse as disease surveillance, microbe identification, restaurant inspections, water-supply tests, vaccination campaigns, and public health education. They need communications technologies to link scientists in national and global networks. They need training to teach laboratory researchers how to perform diagnostic tests and process hazardous specimens, to instruct workers about new tools and techniques, and to prepare the next generation of scientists to confront emerging disease challenges. CDC

Preventing Emerging Infectious Diseases Prevention and Control Ensure prompt implementation of prevention strategies and enhance communication of public health information about emerging diseases. The culmination of all of these efforts is the prevention and control of infectious diseases. Disease prevention alerts people to the threats of new and reemerging diseases and teaches them how to protect themselves and their families. Disease control applies the most effective tools and technologies to counteract infectious microbes and strengthen personal and national protections against emerging diseases. CDC

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