How are diseases spread from person to person?

Short Answer

Vaccine-preventable diseases spread in a variety of ways, including coughing or sneezing, touching the skin of an infected person, touching a surface that has the virus or bacteria on it, or drinking contaminated water. Sharing things like soda cans and drinking glasses can also spread diseases that are found in saliva. Some diseases can be spread in several of these ways.

Mucus & saliva

Many viruses spread by saliva and mucus, which are released by kissing and as droplets dispersed into the air when people with a disease cough, sneeze, or talk. These droplets can land in the mouths or noses of people who are nearby and infect those people.

Diseases that can be spread this way include:

Pertussis/whooping cough

Measles

Mumps

Flu

Meningitis

Pneumococcal disease

Hib

Chickenpox

Polio

Smallpox

Other bodily fluids

Some diseases are spread through bodily fluids other than saliva, such as eye secretions, genital secretions, or blood and discharge that comes from skin lesions. When someone comes in contact with these infected fluids and then touches their own eyes, nose, or mouth, they can contract the disease.

Diseases that can be spread this way include:

Diphtheria

Hepatitis B

Chickenpox

Smallpox

Feces

Bacteria and viruses that cause some infectious diseases can be found in the feces (stool) of an infected person. Those bacteria and viruses can spread the diseases when the fecal matter accidentally contaminates water, food, or an infected person’s hands. The disease then enters another person’s body when they consume contaminated food or water, or when they touch contaminated hands and then touch their own mouth.

Diseases that can be spread this way include:

Hepatitis A

Rotavirus

Polio

Infected surfaces

When people infected with certain diseases cough, sneeze, or talk, not only do infected saliva or mucus droplets travel through the air and reach the mouths and noses of people nearby, they can also land on surfaces and survive for short periods of time. Some diseases can be spread when someone touches an infected surface, and then touches their mouth, nose, or eyes. Tetanus is a special case; the bacteria can live on sharp objects and enter the skin through cuts, but can’t be spread from person to person.

Diseases that can be spread this way include:

Measles

Mumps

Flu

Tetanus

Pneumococcal disease

Smallpox