Ask A Scientist

How do you get an infection?

Asked by: David Holleran
School: Thomas Jefferson Elementary School
Grade: 4
Teacher: Mrs. Jahelka
Hobbies/Interests: Sports
Career Interest: Football Player

Answer from Debra Bohunicky

Clinical Instructor, Decker School of Nursing

Research area: : Spirituality and Health, Applied Hypnotherapy.

PhD school: PhD Candidate, Capella University

Interests/hobbies: Writing, gardening, needlecraft, music, walking my dog, re-exploring the tri-cities area after a 20 yr absence and recent re-location from Seattle, WA

An infection happens when a harmful microbe or germ enters the body and the body’s natural defenses, also called the immune system, cannot control or wipe them out. Usually the body does a great job of killing off harmful microbes, but sometimes these germs grow faster than the body’s killer defenses can keep up.  So you become sick. There are several kinds of microbes that can make you sick.  The three main types are protozoa (small), bacteria (smaller) and virus (smallest). You can’t see any of these around you without a microscope. The body’s first line of defense against germs includes “protectors” that either block the germs from entering your body (skin, mucous membranes of the mouth and throat, and nose hairs), make it too hot for germs to stick around (fever), or washes germs away (bleeding, peeing and sweating). If the germs get past these protectors, then a second line of defense, the “immune system”, goes to work. When the germs enter the bloodstream, the immune system sends out an alert calling up attack cells called macrophages (white blood cells). The macrophages come forward to gobble up and destroy these harmful germs. Our bodies also produce antibodies that go after specific germs.  Your doctor may give you a vaccine against a certain germ, such as for whooping cough, to help your body create antibodies so you won’t get that infection. People come in contact with germs many different ways. Picking up these germs or spreading them is called transmission. Some germs get into the body from contaminated blood through the bloodstream. This is why doctors, nurses, and dentists wear gloves when treating you when you are sick or cleaning your teeth. You can ingest germs by eating or drinking harmful microbes in food that is uncooked or unwashed and water that is untreated.  This is why we wash our fruits and vegetables before we eat them, why we always cook our food thoroughly, and why we don’t drink water we are unsure about or that is untreated, such as from creeks or streams. Harmful microbes may enter the body through close contact with infected creatures or other people.  The best defense against infections is to wash your hands often and especially after using the bathroom, before eating and handling food, and after handling any animals. Finally you can breathe in germs from the air through your nose and mouth, which is usually how colds are spread.  We cover our nose and mouth when we cough or sneeze, and wash our hands afterwards to minimize spreading these germs.

Last Updated: 3/1/17