Opportunistic Infections

Opportunistic Infections

People who have a weakened immune system are at risk of developing infections caused by common germs that are usually harmless. These infections are known as 'opportunistic'. One opportunistic organism is a type of fungus called pneumocystis, which can cause an infection called pneumocystis pneumonia. 

Key points to remember about 'opportunistic' infections and your child with cancer

This page is part of a whole section about childhood cancer.

  • if your child has a weakened immune system, they are at risk of developing infections caused by common germs that are usually harmless
  • one of the infections your child is at risk of developing is pneumocystis pneumonia
  • doctors can give your child medicine to reduce the risk of them developing pneumocystis pneumonia

How can my child with a weakened immune system develop an 'opportunistic' infection?

People who have a weakened immune system (infection-fighting system) are at risk of developing infections caused by common germs that are usually harmless. These infections are known as 'opportunistic'. This is because organisms which do not usually cause disease in healthy people use the opportunity created by lowered immunity to become infective.

Pneumocystis pneumonia

One opportunistic organism is a type of fungus called pneumocystis. This fungus can cause an infection called pneumocystis pneumonia (PCP).

How can doctors help prevent my child from developing pneumocystis pneumonia?

Doctors can reduce the risk of your child with a weakened immune system developing pneumocystis pneumonia (PCP). They do this by giving your child medicine that helps prevent this infection from developing. This medicine will either be:

  • cotrimoxazole (also known as Bactrim) - an oral medicine which your child will take twice a day for 2 days a week, usually on a Saturday and Sunday
  • pentamidine - an intravenous medicine which your child will have monthly, usually through a central line

All the pages in the childhood cancer section of this website have been written by health professionals who work in the field of paediatric oncology. They have been reviewed by the members of the National Child Cancer Network (NZ). Medical information is authorised by the clinical leader of the National Child Cancer Network.

This page last reviewed 16 July 2020.
Email us your feedback


On this page