How can infection be spread

Some — but not all — infectious diseases spread directly from one person to another. Infectious diseases that spread from person to person are said to be contagious. Some infections spread to people from an animal or insect, but are not contagious from another human. Lyme disease is an example: You can't catch it from someone you're hanging out with or pass in the street. Many germs live in and on our bodies without causing harm and some even help us to stay healthy.

Only a small portion of germs are known to cause infection. An infection occurs when germs enter the body, increase in number, and cause a reaction of the body. A Source is an infectious agent or germ and refers to a virus, bacteria, or other microbe. In healthcare settings, germs are found in many places. People are one source of germs including:. People can be sick with symptoms of an infection or colonized with germs not have symptoms of an infection but able to pass the germs to others.

Germs are also found in the healthcare environment. Examples of environmental sources of germs include:. A susceptible person is someone who is not vaccinated or otherwise immune, or a person with a weakened immune system who has a way for the germs to enter the body. Devices like IV catheters and surgical incisions can provide an entryway, whereas a healthy immune system helps fight infection.

When patients are sick and receive medical treatment in healthcare facilities, the following factors can increase their susceptibility to infection. Transmission refers to the way germs are moved to the susceptible person. New research finds that cells in the ear are susceptible to infection with SARS-CoV2, causing symptoms that include dizziness, ear ringing, and….

As the wildfires rage on, people in the West now have to protect themselves not only from the novel coronavirus, but from wildfire smoke as well…. Getting scratched by your dog can happen, especially during feeding and playtime. Learn about possible health risks from dog scratches and how to….

People are renting pools via a new app this summer. Is this practice safe? There are hundreds of lymph nodes in the body that help fight infection, including the armpit. Learn more about what it looks like when they're….

Not all cat scratches are dangerous. But some circumstances may increase your risk of developing certain diseases and other health risks.

Learn more…. Health Conditions Discover Plan Connect. How Are Diseases Transmitted? Direct contact Indirect contact Preventing transmission Takeaway Overview Infectious diseases are transmitted from person to person by direct or indirect contact.

Direct contact. Indirect contact. How to prevent disease transmission. The takeaway. Read this next. Zoonosis Medically reviewed by Kaitlyn T. Walsh, DVM. Most Common Noncommunicable Diseases. Medically reviewed by Judith Marcin, M. Medically reviewed by Elaine K. Luo, M. Health Risks of a Dog Scratch. Medically reviewed by Emelia Arquilla, DO. Medically reviewed by Deborah Weatherspoon, Ph.

Medically reviewed by Angelica Balingit, MD.