Children who are being treated for cancer are significantly immunocompromised.
It is very important to assess possible infection early and treat quickly.
Several factors cause an increased susceptibility to infection:
- Chemotherapy induced neutropenia
- Underlying cancer
- Invasive procedures and foreign bodies - the placement of lines, catheters, biopsies
- Nutritional status
- Ulcerated mucosa
- Defects in immunity
- Humoral (produces an increase risk of infection with encapsulated bacteria)
- Cell mediated increased risk of infection with viruses, fungi and bacteria that replicate intracellularly.
Common Causes of Infection in children with cancer:
| Pathogen | |
| Bacteria | Gram Positive Staphlococci Streptococci Enterococci Clostridium difficile
|
Gram Negative Enterobacteriaceae (E Coli, Klebsiella) Psuedomonas aeruginosa Anaerobes
|
|
| Fungi | Candida Aspergillus Cryptococci |
| Viruses | Herpes simplex Varicella Zoster Cytomegalovirus Epstein-Barr virus Adenovirus Influenza virus Respiratory Syncytial virus |
| Other | Pneumocystis Carinii Toxoplasma gondii Cryptosporidium |
Chicken Pox
Chicken pox is a life threatening infection in the immunocompromised
- Mortality rate of 10% with varicella
- Mortality rate of 1 – 2% with zoster
- VZIG in “at risk” exposed patients
- Within 96 hours of chicken pox exposure
- 2nd dose if re-exposure occurs more than 3 weeks post-treatment
- IV Acyclovir early if any lesions are seen l1500 mg / m2 / day divided q8h
VZIG dosage:
| Weight (kg) | Dose(units) | # vials |
| 0 – 10 | 125 | 1 @ 125 |
| 10.1 – 20 | 250 | 2 @ 125 |
| 20.1 – 30 | 375 | 3 @ 125 |
| 30.1 – 40 | 500 | 4 @ 125 |
| Over 40 | 625 | 5 @ 125 or 1 @ 625 |
Neutropenia
- Is the biggest factor that increases the risk of infection with bacteria and fungi
- Depends on the severity and duration of the neutropenia
- Absolute Neutrophil count (ANC) is < 1000 / mm3
- Neutropenia is usually secondary to chemotherapy but can be due to bone marrow failure from leukemia or aplastic anemia.
Fever = Temp of more than 38 degrees - three times in 24 hours or more than 38.5 degrees once.
Fever in a neutropenic patient is a medical emergency.
Fever in a non-neutropenic patient should be carefully assessed
- Increased risk secondary to lymphocyte dysfunction
- History and physical
- Blood and urine cultures
- If focal signs of infection - throat swab, CXR, stool culture and sensitivity
- Treat if infection is documented
Splenectomy or hyposplenism
Pediatric cancer patients may have hyposplenism and may be at increased risk for life threatening infection in the long term because of this.
