Q & A: Preventing Infections When You Have Cancer

sick senior woman in her bed

An increased risk of infection because of a weakened immune system is a major concern for people undergoing certain types of cancer treatment. According to the Centers for Disease Control and Prevention, 60,000 cancer patients in the US are hospitalized each year because of a dangerously low level of white blood cells – a condition called neutropenia. Neutropenia can lead to serious and sometimes fatal infections.

And the threat has grown as certain infections caused by bacteria have become more resistant to antibiotics over the years. Antibiotics are drugs that fight infections either by killing the bacteria or stopping the bacteria from growing.  Research has shown that more than 25% of infections after chemotherapy are caused by the kind of bacteria that are often resistant to standard antibiotics. Cancer patients should take extra precautions to keep from getting sick and have a plan in place to get help if they do get sick.

How does neutropenia increase infection risk?

White blood cells are part of the immune system. When the body doesn’t have enough white blood cells to kill germs, it’s much easier to get an infection. This is especially true for the type of white blood cells called neutrophils, which are generally the most numerous type of white blood cell when blood counts are in the normal range. Neutrophils are our first defense against infection, and the word neutropenia (or being neutropenic) means the neutrophil count is low.

Chemotherapy helps treat cancer by destroying cancer cells. But sometimes chemo also harms or kills normal cells. Neutrophils are some cells that are most commonly affected by chemo for a period of time until they can regrow And a decreased neutrophil count leaves the body vulnerable to infection during the time they are low. Radiation, surgery, stem cell transplant, bone marrow transplant, steroids, or even the cancer itself can also weaken the immune system, making infection more of a risk.

How do I know if I have neutropenia?

The only way to know you have neutropenia is through a blood test. Your health care team can track your neutrophil count, along with all your blood counts, through regular blood work. Cancer patients undergoing chemotherapy tend to be at greatest risk for developing neutropenia from the 7th day through the 12th day after treatment, but periods of neutropenia can sometimes be longer or shorter depending on the treatment and type of cancer.

While neutropenia itself has no warning signs, it’s important to know the signs of possible infection due to neutropenia. Ask your health care team to help you figure out when you are likely to be most at risk for neutropenia, what signs to look for, and when to report them.

How can I protect myself from infection?

  • Wash your hands a lot and encourage your caregiver and other people around you to wash their hands a lot too.
  • Talk to your health care team about getting a flu shot and ask your caregiver, family, and others near you to get one too. Do not get the nasal mist flu vaccine.
  • Take a bath or shower every day and use an unscented lotion so your skin won’t get dry or cracked.
  • Avoid large crowds of people.
  • Stay away from anyone with a fever, the flu, or another infection.
  • See Preventing Infections in People With Cancer for a more detailed list.

What should I do if I get sick?

  • Take your temperature whenever your doctor recommends it, and any time you don’t feel well.
  • If you have a fever, call your doctor right away, even if the office is closed.
  • If you go to the emergency room, tell the person who checks you in that you have cancer and what kind of treatment you are receiving.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.


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