Communicable Diseases

A communicable disease is one that is spread from one person to another through a variety of ways that include: contact with blood and bodily fluids; contact with a contaminated surface or object; breathing in an airborne virus; or by being bitten by an insect. They can be caused by viruses, bacteria, and fungi and are often called “infectious” or “transmissible” diseases. 


Take the following measures regularly to help prevent the spread of communicable diseases:

  1. Avoid close contact with those who are sick, and if you’re sick limit your contact with others.
  2. Cover coughs and sneezes.
  3. Wash your hands often with soap and water or use alcohol-based hand sanitizer, especially before preparing and handling food.
  4. Avoid touching your eyes, nose and mouth.
  5. Clean and disinfect surfaces that get a lot of use, especially doorknobs and food areas.
  6. Avoid eating spoiled food.
  7. Avoid touching wild animals.
  8. Take antiviral drugs and get available vaccines if your doctor recommends them.
  9. Adopt business/school practices that encourage employees/students to stay home when they have flu symptoms.
  10. Practice good health habits to strengthen your body’s fight against infection. Eat a balanced diet, drink plenty of fluids, exercise daily, manage stress, and get enough rest and sleep.

 Take the following measures regularly to help prepare yourself for cold and flu season:

  1. Learn how diseases spread to help protect yourself and others.
  2. Take everyday preventive actions to prevent the spread of diseases.
  3. Prepare for the possibility of schools, workplaces and community centers being closed. Investigate and prepare for virtual coordination for school, work (telework) and social activities.
  4. Gather supplies in case you need to stay home for several days or weeks. Supplies may include cleaning supplies, non-perishable foods, prescriptions and bottled water. Buy supplies slowly to ensure that everyone has the opportunity to buy what they need.
  5. Create an emergency plan so that you and your family know what to do and what you will need in case an outbreak happens. Consider how a pandemic may affect your plans for other emergencies.
  6. Review your health insurance policies to understand what they cover, including telemedicine options.
Keep a well-stocked and updated influence kit at home every cold and flu season.

Stay Alert

Medical News Today has a list of some of the most common communicable diseases, including:

  • Rhinoviruses: a virus also known as the common cold. It spreads through coughs and sneezes, or touching eyes, nose, or mouth after touching surfaces that are contaminated with the virus
  • Salmonella and Escherichia coli: bacteria that infect the digestive system. They spread through contaminated foods. 
  • Ringworm and Athlete’s foot: fungal infections that infect the skin. They spread through direct contact with people or surfaces carrying the fungus.

There are different types of flu outbreaks, as defined by the Red Cross:

  • Seasonal flu: a contagious respiratory illness caused by influenza (flu) viruses occurring every year. It affects an average of 5-20% of the U.S. population.
  • Epidemic: the rapid spread of a disease that affects some or many people in a community or region at the same time.
  • Pandemic: an outbreak of a disease that affects large numbers of people throughout the world and spreads rapidly.
  • H1N1 Influenza (swine flu): a respiratory disease of pigs caused by type A influenza viruses that cause regular outbreaks in pigs. People do not normally get H1N1 influenza, but human infections can and do happen. H1N1 influenza viruses have been reported to spread from person-to-person.
  • Avian Influenza: Commonly known as bird flu, this strain of influenza virus is naturally occurring in birds.

During Cold and Flu Season

Follow everyday healthy preventive measures to prevent the spread of viruses.

During Pandemics

A pandemic is a communicable disease outbreak that spans several countries and affects a large number of people. Viruses like COVID-19, which can easily spread from person to person, most often cause pandemics. A new virus can emerge from anywhere and quickly spread around the world. It is hard to predict when or where the next new pandemic will emerge.

If a pandemic is declared:

  1. Wash your hands often with soap and water for at least 20 seconds and try not to touch your eyes, nose or mouth.
  2. Keep a distance of at least six feet between yourself and people who are not part of your household.
  3. Cover your mouth and nose with a mask when in public.
  4. Clean and disinfect high-touch objects and surfaces.
  5. Stay at home as much as possible to prevent the spread of disease.
  6. Follow the guidance of the Centers for Disease Control and Prevention (CDC).

Stay healthy during a pandemic:

  1. 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.
  2. 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. 
  3. Take actions to prevent the spread of disease. Cover coughs and sneezes. Wear a mask over your nose and mouth in public. Stay home when sick, except to get medical care. Disinfect surfaces.
  4. 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.
  5. 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.
  6. Share accurate information about the disease with friends, family and people on social media. Sharing bad information about the disease or treatments for the disease may have serious health outcomes. Remember that stigma hurts everyone and can cause discrimination against people, places or nations.
  7. Know that it’s normal to feel anxious or stressed. Engage virtually with your community through video and phone calls. Take care of your body and talk to someone if you are feeling upset.
  8. Get vaccinated once available. Vaccines stimulate your immune system to produce antibodies, so vaccines actually prevent diseases.

The Williamson County Health Department Testing Site During the COVID-19 Pandemic

Williamson County COVID-19 Testing Site in 2020 at the Ag Center.

Alert Systems

Using an alert system is crucial to being informed before and during the spread of disease. Our alert systems page has resources for a number of alert options.

Local Communicable Disease Risks

History of communicable diseases in Williamson County

Communicable diseases pose one of the most flexible and rapidly evolving public health threats in Tennessee. The scope of these threats make protocols and timely dissemination of public health information of particular importance. 

Communicable diseases fall into two broad categories: human or zoonotic. Examples of human-spread diseases with a history of local impacts include a variety of forms of influenza, HIV/AIDS, and hepatitis. Zoonotic diseases, transferred from animals to humans, include avian influenza, COVID-19, the West Nile virus, and rabies.

In 2012, Tennessee was listed by the CDC as one of the highest influenza burdened states in the nation. On average, 20% of the nation’s population will contract seasonal influenza every year, and carries a higher than average mortality and morbidity rate for influenza and associated pneumonia.

For More Info

Lists of communicable diseases: 

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