An infection is caused when a tiny living organism enters the body and multiplies, sometimes causing illness.² Infections can be caused by bacteria, viruses, fungi, or parasites.² Usually, the white blood cells of the immune system find and destroy these organisms, but this process is weakened in people living with multiple myeloma.³

In fact, frequent or recurring infections are a common symptom of multiple myeloma due to the combined impact of disease, treatment and patient related factors.^1,4

If you have multiple myeloma, you are more likely to get infections because the multiple myeloma weakens the immune system.³ Multiple myeloma cells multiply in the bone marrow, which is also where normal blood cells are made.³ Multiple myeloma cells then limit the production of normal blood cells, so there are fewer normal blood cells, including white blood cells that fight infection.³

White blood cells usually produce different types of proteins called antibodies to help fight infections.³ However, multiple myeloma cells produce only a single type of abnormal antibody that cannot fight infections.³ As the number of white blood cells and the number and type of normal antibodies are reduced, your body cannot destroy the disease-causing organisms.³

Some of the treatments for multiple myeloma can also prevent the immune system from working properly.^1,3 This is because they can reduce the number of a type of white blood cell called a neutrophil.⁵ During an infection, neutrophils act quickly to destroy invading bacteria or microorganisms by capturing and ingesting them. When the number of neutrophils gets too low, this is called ‘neutropenia’.⁵ Neutropenia can increase your risk of infection and make it harder for your body to fight them.^5,6 Neutropenia is closely monitored during treatment by your healthcare team.⁶
 

It is important to recognize the signs and symptoms of an infection and report any suspected infection to your healthcare team immediately.³

Common signs of infection may include:^3,6

• Fever (temperature of 38°C or higher)
• Chills, sweats, shivers or shakes
• Sore throat, cough or cold
• Shortness of breath
• Headache or stiffness in neck
• An area of redness, tenderness, or swelling
• Diarrhoea or new abdominal pain
• Sores or white patches in the mouth
• Burning, pain or blood when passing urine
• Vomiting that lasts more than a few hours
• Unusual bleeding, blood in urine or bowel motions
• Any sudden deterioration in health

The way an infection is treated depends on what is causing it, where it is in your body, and how severe it is.² If your healthcare team suspects you have an infection, they will carry out examinations and tests to find out what is causing it.¹ Common treatments include antibiotics, antivirals and antifungals.² The treatment that will be prescribed depends on what has caused the infection.²