Infection in Haematopoietic Stem Cell Transplantation & Cellular Therapy

Infection is the process by which germs enter our body, multiply and cause us to fall sick.

What are the germs we are concerned with during and after stem cell transplantation?

 1)  ​Bacterial infection 

Bacteria are microscopic organisms that can cause infection anywhere in our body. Bacterial infections are common in the first few weeks of transplant when your immune system is poor. It can happen and progress quickly, leading to life-threatening situations. 

2)  ​Viral infection 

Herpes simplex virus (HSV) & varicella-zoster virus (VZV) are viruses that can stay inactive in your nerve cells and become reactivated when your immune system weakens, causing painful blisters on your skin.

Another example is Cytomegalovirus virus (CMV), which may be present in healthy individuals, can cause serious damage to your lungs, gut and eyes when your immune system is poor. Also, BK virus can cause pain and difficulty urinating as well as bleeding in urine (red or brown urine). 

3)  ​Fungal infection 

Fungi are microscopic organisms that usually cause little trouble for people with healthy immune systems. But in those with poor immunity, fungal infections can be difficult to treat and life-threatening. 

4)  ​Pneumocystis infection (PCP) 

Pneumocystis jirovecci can affect your lungs causing difficult-to-treat and life-threatening infection, especially in people with poor immunity.

1)   Take medicines to prevent infections 

Antibiotic (against bacteria), anti-viral (against viruses), anti-fungal (against fungi) and anti-pneumocystis medicine are routinely given to prevent infections during and after HSCT. It is important to take these medicines as advised, even if you are feeling normal, as your new marrow will take time to produce sufficient blood cells to fight infections as in a healthy adult. However, look out for any drug allergy reactions such as red and itchy skin, swelling of face, lips, tongue or throat. If you suspect a drug allergy, stop the medicine and see a doctor immediately. 

2)   Receive injections to boost your immunity 

Granulocyte Colony Stimulating Factor (G-CSF) and immunoglobulins (IVIG) are body proteins that may be given to reduce the risk of infections. G-CSF is given by injecting under the skin in the belly area to boost white blood cell production while IVIG is given intravenously to boost your blood antibody levels. 

3)   Take your vaccinations as advised by your doctor 

Within weeks of HSCT, your antibody level against vaccine preventable diseases will be lowered and these diseases can be life-threatening. Therefore, you will be given a series of vaccinations when your immune system has recovered to prevent infections such as influenza, pneumococcal and hepatitis. It is important that you take the vaccinations as advised to lower your risk of infections. 

4)   Recognise the signs and symptoms of an infection early 

• Fever of more than 38°C
• Feeling drowsy and weak
• Low blood pressure
• Shortness of breath
• Runny nose, cough or sore throat
• Pain when passing urine
• Shivering and feeling cold
• Redness, swelling or warmth on the skin, especially around wound sites or catheters
• Stomach pain, diarrhea or vomiting
• Unable to see or think clearly
• Headache

 5)   See a doctor immediately if you are feeling unwell

Infections are medical emergencies, especially in those with poor immunity after stem cell transplant. Antibiotics need to be started immediately to prevent serious organ damage. Your blood may be taken to determine the identity and source of infection. Also, inform your doctor of any medicine or supplement that you are taking and your medical conditions such as allergies or G6PD deficiency. This will help your healthcare team to choose the most effective medicine for you. Finally, it is important that you take your medicines as advised, so that your infection can be treated completely.