Infection and cancer - Maggie's Centres

Infection and cancer


Infection can be a serious side effect of cancer treatment. Many treatments that destroy cancer cells also lower the level of infection fighting white blood cells (neutrophils) in your body. This leaves you vulnerable to picking up infections caused by bacterial viruses or fungi (all commonly referred to as bugs)

During and after cancer treatment, infections, that you may normally manage without problems, can become serious and even life threatening, very quickly.  A less serious infection may still require medical treatment and cause delays with your treatment plan. 

 It is important to recognise the signs of infection and report them promptly to your Healthcare team. This means you will get treated quickly to avoid serious infection and will also reduce the chance of delaying cancer treatments

Cancer and infections - what’s the connection?

Neutrophils (a type of white blood cell)  are produced in the body by the bone marrow.  Chemotherapy drugs and some radiotherapy e.g. radiotherapy to your spine, pelvis or sternum (breastbone) can damage your bone marrow. 

Your risk of infection begins to increase if your neutrophil count falls below normal. Neutrophils in the blood are measured as part of a full blood count test (FBC). The normal range is 1.5-7.5 x 109 per litre of blood (your healthcare team may shorten this to 1.5-7.5)

When neutrophils are low this is called neutropenia. If your levels are less than 1.5 you are considered to be ‘neutropenic’ and very vulnerable to infections and developing  a  serious condition called  neutropenic sepsis or septicaemia  (blood poisoning) where large amounts of bacteria enter the bloodstream.

The type or dose of chemotherapy you are having may increase your risk of developing neutropenia. You are also more at risk if you  already have low white blood counts, another condition that affects the immune system, are over 65 or have previously received chemotherapy or radiotherapy .

There are certain times during each cycle of a course of treatment where the bone marrow, which produces the white blood cells,  is most affected . This usually  starts around a week after treatment  and lasts until the  bone marrow gradually recovers 3-4 weeks after treatment .  Your specialist nurse/doctor will be able tell you about the effects of your particular treatment.,  

You will be at risk of infection for as long as your neutrophil count is low. You may feel particularly tired, and also low, during this time as well.

Your blood count will be checked regularly throughout your course of treatment, sometimes chemotherapy treatment may be delayed to allow neutrophil counts to recover. Often a week's delay is enough but sometimes the dose of chemotherapy is reduced to allow treatments to continue safely.

If you do develop an infection you will usually  have a blood test and be treated with antibiotics. In some cases admission to hospital for stronger intravenous (via a drip or a syringe into a vein) antibiotics may be necessary.

Not all infections can be prevented however, reporting any signs of infection early to your healthcare team will allow you to have prompt treatment and will reduce the risk of serious problems.

Managing infections:  

There are three main things to remember:

  • Recognise signs  of infection
  • Report any promptly and 
  • Prevent infections occurring where you can.

 Recognise the symptoms (signs) of infection

Knowing what to look out for can be reassuring  for you and also those around you. Ask your specialist nurse/doctor what to expect after each  course of treatment

  • Fever (high temperature) This is the body’s natural response against invaders such as viruses, bacteria and fungus and is often one the first symptoms of infection. Take your temperature if you feel unwell . Your healthcare team will give you instructions about the level your temperature should reach, however,  as a general rule,  if it is higher than 38⁰C (100.4F) you should call your healthcare team immediately (day or night) because it could mean you have an infection.  

Whilst fever is  a common sign of infection it is not always present Some medication can mask or hide a fever. Other signs of infection which you should also report straight away include:

  • Chills, shivers, shaking, sweating
  • Cough, sore throat, shortness of breath, chest pain
  • Redness, warm skin, pain, swelling or oozing around any wounds or catheter sites (where a cannula, PICC line, Hickman line or other central line has been used)
  • Loose bowels or diarrhoea for more than 24 hours
  • Pain in the back above the waist or burning sensation when passing urine
  • Mouth ulcers, furry tongue
  • Unusual vaginal discharge or itching

Report signs of infection promptlyWhilst you are on cancer treatment, you will be given detailed instructions of symptoms to look out for by your medical team and a number to call out of hours if you develop them and you should follow these instructions carefully. 

Remember infections can get worse much quicker than normal  and can become very serious if you delay. It is far better to phone and check  your symptoms with  your hospital team, whatever the time of day or night, rather than waiting to see if symptoms improve. 

If you are telling a different doctor or team, or are having to go to an emergency department (perhaps because you are away from home), you should reinforce the fact that you are having treatment for cancer as this will highlight the need for you to be treated quickly.

Preventing infection where you can

Most infections during or after cancer treatment are not from other people but are from normal bacteria (flora) hosted by your gut or skin. 

  • Wash your hands and get those around you to wash theirs.  This is the most important way to avoid the spread of infection causing bacteria. wash your hands often and with extra care before eating, and before and after bathroom use or stroking pets. Take the time to scrub your hands thoroughly with soap and warm water.  It’s the friction that kills bacteria.
  • Take your temperature as recommended by your healthcare team and call your healthcare team immediately (day or night)  if your temperature is higher than 100.40F or 38 ⁰C
  • Clean the rectal area (around your back passage) thoroughly after each bowel movement wiping gently from front to back. A moist toilet tissue is helpful for better cleansing and to avoid skin irritation (check with healthcare team before using if you  are receiving radiotherapy to the rectal area )
  • Have a warm bath or shower every day and pat your skin dry. Use a water based lotion if skin becomes dry, an electric shaver instead of a razor and warm soapy water and antiseptic to clean cuts and scrapes. (seek specific skincare advice if you are having radiotherapy) 
  • Mouthcare:  Follow any specific  mouth care  advice you are given by your healthcare team but, in general,  brush your teeth twice a day with a soft toothbrush. Check with your healthcare team if it is ok to floss. 
  • Food: Make sure that all foods are properly handled, stored, used within expiry dates and thoroughly cooked. Wash  fresh fruit and vegetables before eating.  Ask your healthcare team  if there are any specific foods you should to avoid.
  • Wear protective gloves when gardening or cleaning up after pets.
  • Clean any cuts scratches with antiseptic and keep an eye on them (contact your healthcare team  before using any creams/lotions on an area being treated with radiotherapy)
  • If you have any dressings/bandages over surgical wounds make sure they are clean and dry. 

If your chemotherapy treatment is particularly likely to cause neutropenia your healthcare team may recommend treatment with medicine called growth factors. These stimulate the bone marrow to produce white blood cells and help prevent infection. Growth factors can also be used to enable higher doses of chemotherapy to be given without increasing the risk of infection. They are not used routinely for all people receiving cancer treatment as they are not suitable for all drugs and can also have side effects of their own (bone pain, fatigue, fever and appetite loss)

Things to avoid when your counts are low

  • Crowds and people with infections, infectious illnesses eg chickenpox or heavy colds. social contact is important for your emotional health but by avoiding crowds and people with obvious infections you are reducing your risk of infection.
  • Eating soft cheeses, pate, pro- biotic drinks or pro-biotic yoghurts
  • Vaccinations unless you check first with you healthcare team
  • Aspirin or other medication to reduce fever unless you check first with your healthcare team.
  • Dusty areas or  places where there is digging/building work taking place
  • Situations where you may bruise or break your skin

Having an infection or a low neutrophil count can make it necessary to delay your treatment or to reduce your chemotherapy dose. Not all infections can be prevented. However, avoiding those that you can and reporting any signs of infection early to your healthcare team will allow you to have prompt treatment and will reduce the risk of serious problems.


What now?

Talk to your specialist nurse/doctor and find out whether your cancer treatment is likely to raise your risk of infection and to find out any special precautions you may need to take. Tell them promptly about any side effects you have following treatment. 

Have a read through the links to blogs and information we have suggested on this page.

Drop into one of our Centres or get in touch online via our forum to talk things over with other visitors and ourcancer support specialists.


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