Addressing Infectious Disease Threats
Developed by the Directors of Health Promotion and Education with support from the Centers for Disease Control and Prevention, National Center for Infectious Diseases
What Are Infectious Diseases?
Infectious diseases are human illnesses caused by viruses, bacteria, parasites, fungi and other microbes. They may be spread by direct contact with an infected person or animal, by ingesting contaminated food or water, by insects like mosquitos or ticks (disease vectors), or by contact with contaminated surroundings like animal droppings or even contaminated air.
A Problem That Won’t Go Away
With the advent of antibiotics 50 years ago, scientists made sweeping predictions heralding the end of death and suffering from infectious diseases. During the past 25 years, however, microbes have demonstrated their tremendous ability to adapt, survive and challenge us anew.
Once thought almost eliminated as a public health problem, infectious diseases remain the leading cause of death worldwide. In 1996, infectious diseases killed about one third of the more than 52 million people who died that year.
In the United States, two of the ten leading causes of death are infectious diseases (HIV and pneumonia/ influenza). The Centers for Disease Control and Prevention (CDC) reports that 160,000 Americans die each year with an infectious disease as the underlying cause of death. Ranging from childhood ear infections to measles to sexually transmitted diseases (STDs), infectious illnesses account for 25% of all physician visits each year, and antimicrobial agents are second only to pain relievers as the most frequently prescribed class of drugs.
Anticipating and coping with these microbial threats requires vigilance. We must maintain global surveillance and a strong public health infrastructure with state-of-the-art laboratories and solid partnerships with colleagues in medical, scientific, and policy arenas. Research and creativity are crucial, as is targeted public education at all levels of society to assure a well- informed public. Knowing that local threats can balloon into national or global problems, partnerships must be formed at all levels to develop both local and global prevention strategies.
A Financial Burden
Societal costs of infectious diseases are staggering. In the United States, treatment of non-AIDS STDs alone costs $5 billion annually. The yearly price tags of other infectious diseases are $30 billion for intestinal infections, $17 billion for influenza, $1 billion for salmonella, and $720 million for Hepatitis B. Altogether, the cost of treatment and lost productivity associated with illness from infectious agents tops $120 billion each year.
Although some infectious diseases, such as polio, have been nearly wiped out, the vast majority of these diseases will not be eliminated in our lifetime. Indeed, the World Health Organization reports that at least 30 new diseases have been scientifically recognized around the world in the last 20 years. These emerging diseases include sin nombre hantavirus, first identified in the US in 1993; cryptosporidiosis (a water-borne cause of diarrhea that recently affected more than 400,000 people in a single outbreak in the U.S.); the Ebola virus from Africa; and HIV.
Infectious diseases once thought under control are also reemerging. Diseases like tuberculosis, cholera, and even diphtheria are making a comeback.
Why Are Infectious Diseases Emerging and Reemerging?
Many factors are making it easier for infectious diseases to become an even bigger problem in the future.
The genetic makeup and reproductive ability of many infectious agents allows them to mutate or evolve into more deadly strains against which humans have little resistance. Mass migrations of refugees bring infectious diseases into new areas. Global travelers visiting exotic areas bring new diseases home with them. Growth of congested urban slums, lacking sanitation and clean water, result in large outbreaks of infections spread by food, water and environmental factors. Population shifts and urbanization disturb natural habitats and increase human contact with remote environments and poorly under-stood ecosystems that hide many unknown and dangerous microorganisms. Over time, animal infections can become transmissible to humans (zoonoses). The globalization of world commerce brings potential contaminants across our borders daily by way of food, plants, hitchhiking insects, and other products. Misuse and overuse have eroded the ability of once-dependable antibiotics to fight common infections. Many microorganisms have become resistant to our most powerful modern drugs. Likewise, disease-carrying insects are becoming resistant to pesticides. Human sexual behavior and substance abuse expedite the spread of infectious agents. Institutional settings, such as child care centers and hospitals, provide an ideal environment for transmission of infectious diseases because they bring susceptible individuals into close daily contact. Until recently, the commitment and resources needed to sustain an active community defense against infectious diseases were waning. Faith in antibiotics and vaccines led to a downward spiral in public health spending, and essential surveillance and laboratory systems did not keep pace with available technology. Cutbacks in prevention programs, lack of trained staff, and weak outbreak detection systems, for a time, allowed infectious diseases to gain a strong foothold in the United States and abroad.
The Good News About Infectious Disease Control
Many infectious diseases can be prevented through simple and inexpensive methods.
Wash Your Hands Often Routinely Clean and Disinfect Surfaces
Always wash your hands before, during and after preparing food, before eating, after using the bathroom or changing diapers, and after handling animals or animal waste.
Cleaning with soap and water removes dirt and most germs. Using a disinfectant kills additional germs. It is important to thoroughly clean areas where germs are likely to be transmitted, such as the kitchen and bathroom.
• Handle and Prepare Food Safely
Buy and refrigerate perishable foods quickly. Store food properly. Don’t allow juices from meat, seafood, and poultry or eggs to drip on other foods. Wash hands and kitchen surfaces and utensils while preparing food. Wash raw fruits and vegetables. Don’t eat raw eggs. Cook poultry and meat until the juices run clear. Use different dishes for raw foods and cooked foods. Keep cold foods cold and hot foods hot. Don’t leave leftovers out longer than 2 hours.
• Get Immunized
Children, adolescents and adults need immuni-zations. Make sure the members of your family get the right vaccines at the right time. Keep immunization records for the whole family.
• Use Antibiotics Properly
Unnecessary antibiotics can be harmful and, if misused, can cause bacteria to become resistant to treatment. Antibiotics don’t work against viruses like colds and flu. Use antibiotics exactly as prescribed by your provider.
• Practice Animal Safety
Keep pets healthy by following your veterinarian’s recommendations. Clean litter boxes daily and don’t let children play where animals urinate or defecate. Cover sandboxes. Use insect repellent if engaging in outdoor activities. Avoid contact with wild animals.
A Critical Role for Health Education Professionals
Thanks to modern technology, researchers continually have new answers to the age-old question: What makes people ill? As part of their trade, specialists in community and individual health education have an obligation to keep pace with such public health research. Recent findings, for example, show that some chronic diseases and conditions (including ulcers, certain heart diseases, C. pneumoniae, and chronic liver disease) may in fact have etiologic connections to infectious agents.
Since many infectious diseases cannot be prevented by vaccines or treated effectively once established, the only line of defense is often education so communities and individuals can take preventive measures. Health educators must be proactive in leading these prevention efforts or others may step in who lack the necessary skills and resources to do this critical job well.
Communicating About Disease Risk
Public health professionals must be conduits of information in times of complacency and crisis. When infectious disease outbreaks occur, there may be tension between the public’s right to know about potential health risks and the need to avoid undue alarm. The goals of risk communication are education, informed decision making about the acceptability of risks, persuasion to modify the behavior of individuals or communities, and cooperation among all involved parties (e.g., government, health experts, industry, and the public).
Strategies for Successful Risk Communication
Remember that risk communication is an interactive process. Trust is vital. Listen to people’s concerns and address real-life situations. As much as possible, explain what is known or suspected in terms that the public can easily understand. Strive to balance clarity and simplicity with accuracy and completeness. Avoid messages that are confusing or misleading. Public satisfaction and the perception that a message is helpful and truthful help establish trust. Recognize that public perceptions of risk are likely to differ from those of experts. The public may tend to overestimate the risk of sensationalized and infrequent events and underestimate the risk of more familiar causes of disease and death. Experts tend to define issues narrowly and technically, and to minimize the likelihood that something will go wrong. While media attention is given to dramatic illnesses, the public has little awareness of greater public health issues such as antimicrobial resistance. Health officials must be prepared to deal with the conflict between public complacency and crisis. They must not only understand the factors that promote the spread of different infectious diseases, but they must be able to communicate with diverse target audiences (such as parents of young children, the immune-compromised, the elderly, and migrants) without stigmatizing anyone.
Infectious Diseases, Agents, and Modes of Transmission
| AGENT TYPE || MODE OF TRANSMISSION || || |
| || Person-to-Person (direct contact, airborne or droplet, blood, sexual contact) || Ingestion || Contaminated Environment || Vector-Borne || Animal Contact |
| Bacteria || Chlamydia Diphtheria, || Botulism || Legionellosis || Lyme disease || Cat-scratch |
| || Gonorrhea H. influenzae b Meningococcal disease Pertussis, Syphilis Tuberculosis Group A & B streptococcus || Camphylobacter Cholera, E. coli. Salmonellosis Shigellosis Typhoid fever || || Plague || disease Q fever brucellosis |
| Parasites || Head lice Scabies Pinworms || Amoebiasis Cryptosporidiosis Cyclosporiasis Giardiasis Hookworm Tapeworm || Schistosomiasis || Malaria || Toxicara |
| Viruses || AIDS Chickenpox, Cold viruses Ebola haemorrhagic fever Hepatitis B and C Herpes, Influenza Measles, Mumps, Rubella || Hepatitis A Rotavirus || Hantavirus pulmonary syndrome || Encephalitis Dengue Yellow fever || Rabies Monkey-pox |
| Fungi || Ringworm || || Histoplasmosis || || |
| || || || Valley fever || |