Disease Outbreak

Infectious diseases are illnesses caused by germs such as bacteria, viruses, parasites, and fungi that enter the body and multiply, causing an infection. Some infectious diseases are communicable (i.e. contagious) and can spread easily from one individual to another. Other infectious diseases can be spread by germs carried in air, water, food, or soil. They can also be spread by vectors (like biting insects), from animals to humans, or transferred via a "fomite" (e.g., utensils, countertops, door handles.) Infectious disease outbreaks often occur after natural disasters like floods and hurricanes.

From influenza to coronavirus, malaria, measles, pox viruses, tuberculosis, West Nile, and Lyme disease, outbreaks of contagious diseases can have serious impacts on human health. When a disease outbreak is rapidly spreading in a community, it is called an epidemic. An epidemic that is spreading in multiple regions around the globe is known as a pandemic. Pandemics are usually caused by new or novel viruses; they have occurred throughout human history, including these devastating and noteworthy diseases:

The Plague of Justinian in 541 A.D. was attributed to the bubonic plague and wiped out more than 25 million people in just one year.
The Black Plague killed more than 75 million people in Europe, the Middle East, China, and India from 1347 to 1351.
The 1918 Spanish Flu pandemic killed well over 50 million people in one year, including 675,000 Americans.
The first Cholera pandemic spread across the world from its original reservoir in the Ganges delta in India. Six subsequent pandemics killed millions of people across all continents. The current (seventh) pandemic started in South Asia in 1961, reached Africa in 1971, and the Americas in 1991.
The Smallpox pandemic of the 20th century claimed between 300 and 500 million lives. In 1980, smallpox was declared eradicated following a massive campaign launched by the World Health Organization (WHO) in 1959. It is the only human disease that has ever been eradicated.
The Tuberculosis pandemic continues to kill over 1.5 million people annually. Despite the availability of effective treatment, the bacteria that causes tuberculosis is increasingly resistant to drugs used to treat it.
The HIV pandemic killed over 39 million people since 1982. Now that there are effective treatments, HIV is no longer considered a pandemic; however, it is still an epidemic in some regions of the world.
The Swine Flu pandemic began as an outbreak of H1N1 influenza in the United States in 2009. Over 60 million Americans were affected, resulting in nearly 275,000 hospitalizations and 12,500 deaths.
The COVID-19 pandemic caused by the SARS-CoV-2 virus claimed approximately 7 million lives worldwide between December 2019 and May 2023. The WHO declared it a pandemic on March 11, 2020, prompting shutdowns across the globe. In May 2023, the WHO downgraded SARS-CoV-2 from a global public health emergency to an ongoing health concern.

FEMA info-graphic describing a pandemic as a widespread disease outbreak that can be spread directly or indirectly, even by people who have no symptoms, and vaccines or treatments for the disease might not be available for some time.

The health and diseases of animals, people, plants, and the environment are all interconnected. Understanding that healthy communities are more resilient to any disaster, a "One Health" approach is being adopted around the world to holistically address communicable diseases in people and pets, biosecurity on farms and in food production, emerging diseases (those that increased recently or are threatening to increase in the near future), and superbugs (i.e. strains of bacteria, viruses, parasites, and fungi that are resistant to antibiotics and other medications commonly used to treat the infections they cause.)

Individuals everywhere can do their part to prevent diseases by using simple infection control measures every day: staying home when sick to avoid infecting others, covering coughs and using good hand hygiene to reduce the spread of germs, safe food handling to prevent food-borne illnesses, and removing standing water outdoors to eliminate mosquito breeding grounds.

Graphic heading says Prepare Now surrounded by a Blue Circle

Before

During

After

Learn how diseases spread to help protect yourself and others.
Take action to prevent the spread of infectious diseases.
- Cover coughs and sneezes.
- Stay home when sick (except to get medical care).
- Wash hands with soap and water frequently, scrubbing for at least 20 seconds.
- Clean and disinfect grimy or frequently touched surfaces like door handles, kitchen counters, light switches, and remote controls.
- Drain and cover outdoor containers that can hold standing water where mosquitos can breed.
Make a Plan. Know what to do and what you will need to keep safe and healthy in case an outbreak happens.
Plan to take special infection control precautions in daycare, schools, workplaces, and other group settings, including canceling in-person social activities and working remotely.
Consider how a local infectious disease outbreak or a pandemic can affect your plans for other emergencies.
Gather supplies in case you need to stay home for several days or even weeks, including cleaning supplies, nonperishable foods, prescriptions, and bottled water. Don't "panic purchase" or hoard items. Buy supplies slowly to ensure that everyone has the opportunity to buy what they need.
Review your health insurance policies to understand what they cover, including telemedicine options.

Follow the latest guidelines from the CDC and state and local authorities to prevent the spread of disease. Refer to your local and state public health departments for vaccine and testing updates.
Maintain good personal health habits and public health practices. Proper handwashing and disinfecting surfaces help to slow the spread of disease. If soap and water are not available, use a hand sanitizer that contains at least 60 percent alcohol.
Limit close, face-to-face contact with others. Stay at home as much as possible to prevent the spread of disease.
Practice social distancing while in public. Keep a distance of at least six feet between yourself and people who are not part of your household. Avoid crowds and large groups of people.
If you believe you’ve been exposed to the disease, contact your doctor, follow the quarantine instructions from medical providers, and monitor your symptoms.
If you’re experiencing a medical emergency, call 9-1-1 and shelter in place with a mask, if possible, until help arrives.
Share only confirmed, accurate information about the disease with friends, family, and people on social media. Sharing rumors or bad information about the disease or treatments for the disease may have serious negative health outcomes.
Remember that stigma hurts everyone and can cause discrimination against people, places, or nations.
Know that it’s normal to feel anxious or stressed. Take care of your body and talk to someone if you are feeling upset.

Continue taking protective actions to reduce the spread of germs:
- Staying home when you are sick, especially if you have a fever.
- Cover coughs and sneezes with a tissue.
- Wash hands frequently, using soap and water for at least 20 seconds.
- Follow the guidance of your healthcare provider.
Follow official guidance on the re-opening of businesses, schools, community-based organizations, houses of worship, and workplaces. Be sure to evaluate your family emergency plan and make timely updates.
Watch out for scams and fraud, especially on social media where rumors can be very convincing and quickly go viral. Trust the science experts.
Work with your community to talk about the lessons you learned from the pandemic. Decide how you can use these experiences to be more prepared for future pandemics.