Infection Precautions for Children During Cancer Treatment

A fever in a child on cancer treatment is not a wait-and-see problem. It can be the only sign of a bloodstream infection, and it can turn serious in hours.

St. Jude gives these thresholds for children older than 2 months:

• A single oral temperature of 100.9 °F (38.3 °C) or higher. Many centers round this to 101 °F.
• An oral temperature of 100.4 °F (38.0 °C) or higher that lasts for 1 hour.
• Taking it under the arm instead? The matching numbers are 99.9 °F (37.7 °C) for a single reading, or 99.4 °F (37.4 °C) held for 1 hour.

St. Jude's instruction is to contact the provider or go to the emergency room right away. CDC uses a slightly lower call-in number, 100.4 °F (38 °C). Centers differ by a few tenths of a degree, so write your team's exact number on the refrigerator and use theirs.

Other signs of infection that should trigger the same call, per St. Jude: chills, sweats, sores or pain anywhere, runny nose or congestion, a new kind of cough, sore throat, shortness of breath, neck stiffness, stomach pain, vomiting, pain or increased frequency with urination, vaginal discharge or irritation, sores or pain around the rectum, and diarrhea.

This is the instruction families most often get wrong, and it matters.

NCI says to talk with the doctor or nurse before giving any medicine for fever, including aspirin, acetaminophen such as Tylenol, and ibuprofen. Those drugs can mask a serious problem. A child who looks fine because the fever was knocked down is still a child with a possible bloodstream infection, and now nobody can see it.

If your team has already told you not to give fever medicine before being seen, follow that. If nobody has told you either way, ask at the next visit and write the answer down.

The route matters more than parents expect.

St. Jude says an oral temperature is generally the most accurate. If a child is too young or has painful mouth sores, take it under the arm, placing the thermometer high into the center of the armpit with the arm held at the side.

Do not use a rectal thermometer. St. Jude is explicit: it can damage the thin skin around the anus and raise infection risk in a child whose immune system is weak. The same logic applies to rectal suppositories and enemas, so ask before using any.

For an accurate oral reading, wait at least 15 minutes after a hot or cold drink, keep candy and gum out of the mouth, place the tip under the tongue toward the back, and keep the lips closed until it beeps.

Neutrophils are the white blood cells that fight bacteria. The absolute neutrophil count, or ANC, is calculated as part of a complete blood count.

St. Jude gives these bands:

• Normal for a healthy child: above 1,500.
• Mild neutropenia: 1,000 to 1,500.
• Moderate neutropenia: 500 to 1,000.
• Severe neutropenia: below 500.
• Profound neutropenia: below 100.

The lower the ANC, the higher the risk, and St. Jude notes that with neutropenia even minor infections can become serious. When counts are low, teams commonly advise staying home from school, avoiding public places, and wearing a mask.

Ask for your child's ANC at every visit, and ask what number changes the plan. That single question converts a vague warning into a rule you can follow.

These two deserve their own plan because both have a treatment window that closes.

Chickenpox and shingles. CDC lists children with leukemia or lymphoma, and people on immune-suppressing medicines, among those at highest risk of severe varicella. The virus is very contagious. CDC puts the secondary attack rate among susceptible household contacts between 61% and 100%, and says a person is contagious from 1 to 2 days before the rash appears until every blister has crusted over. Incubation runs 14 to 16 days, with a range of 10 to 21.

For an exposed immunocompromised child without evidence of immunity, CDC recommends VariZIG, a varicella-zoster immune globulin. It should be given as soon as possible after exposure, and can be given within 10 days.

Measles. CDC's post-exposure options are MMR vaccine within 72 hours of exposure, or immune globulin within 6 days. Live MMR is not given during chemotherapy, so immune globulin is the route the team will consider for a child in treatment.

Practical version: if your child is in the same room as someone with chickenpox, shingles, or measles, call the oncology line that day. Do not wait for symptoms. Tell the school and daycare that you must be called the same day for these three, not sent a newsletter next week.

CDC's guidance on altered immunocompetence is clear on both halves.

The child. Live, attenuated vaccines are not given during chemotherapy, and should not be given for at least 3 months after immunosuppressive therapy ends. The live list includes MMR, varicella, MMRV, live attenuated influenza vaccine, rotavirus, yellow fever, oral typhoid, BCG, and smallpox. Inactivated vaccines may be given, but CDC notes the antibody response may be poor during chemotherapy or radiation, so doses often need repeating after the immune system recovers. Ask which of your child's shots will need redoing.

The household. CDC states that MMR, varicella, and rotavirus vaccines should be given to susceptible household and close contacts when indicated. Vaccinating siblings protects the patient. One precaution: if a household member develops a rash after varicella vaccine, keep them away from the patient until the rash clears. NCI's general advice for people with neutropenia also mentions avoiding people who recently received a live vaccine, so confirm the household plan, including flu vaccine choice, with your team.

A central line is a catheter placed in a large vein, and CDC notes it can stay for weeks or months. It is also a direct route into the bloodstream for germs.

St. Jude's home rules:

• Wash hands for at least 20 seconds before and after touching the line.
• Keep the dressing clean and dry. Change it every 7 days, or sooner if it gets wet, dirty, or loose.
• Use aseptic technique and scrub the hub exactly as your team taught you.
• Cover the line and dressing with a waterproof cover for bathing.
• Only family or caregivers trained by hospital staff should handle the line. Visitors do not touch it.

Call right away for redness, pain, warmth, or swelling at the site, a temperature of 100.4 °F or above, fluid, blood, or pus leaking, or a line that is blocked, leaking, will not flush, or has moved.

NCI's prevention list is short and boring, which is a sign it works: wash hands often with soap and warm water, especially before eating; keep catheter sites clean; brush teeth daily; clean and treat cuts and scrapes promptly; stay away from sick people and crowds; and handle food safely by cooking meat, fish, and eggs thoroughly and washing or peeling produce.

Two things that usually do not help: a whole-house deep clean, and banning every visitor. One well person who washed their hands is safer company than isolation, and children on treatment still need friends.

Call the oncology line immediately, or go to the emergency department if you cannot get through, and say the child is on chemotherapy, for:

• A single oral temperature of 100.9 °F (38.3 °C) or higher, or 100.4 °F (38.0 °C) held for 1 hour, or whatever number your team gave you.
• Shaking chills, even without fever.
• Redness, swelling, or drainage at a central line site.
• Trouble breathing, a stiff neck, confusion, or a new rash of blisters.

Do not give fever medicine first unless your team has told you to. Bring the medicine list and the date of the last chemotherapy dose.

See Neutropenic Fever During Cancer Treatment for what happens after you arrive, and Childhood Cancer Overview for the wider picture. Also useful: Helping a Child Take Medicine During Cancer Treatment, School 504 Plans During Childhood Cancer, Transition to Adult Follow-Up After Childhood Cancer, and Childhood Cancer Scans and Scanxiety.

• Infection and Neutropenia during Cancer Treatment, National Cancer Institute
• Fever and Signs of Infection, Together by St. Jude
• How to Take a Temperature, Together by St. Jude
• Absolute Neutrophil Count (ANC) and Neutropenia, Together by St. Jude
• Central Line Associated Bloodstream Infections (CLABSI), Together by St. Jude
• About Central Line-associated Bloodstream Infections, Centers for Disease Control and Prevention
• Altered Immunocompetence, Vaccines and Immunizations, Centers for Disease Control and Prevention
• Clinical Guidance for People at Risk for Severe Varicella, Centers for Disease Control and Prevention
• Pink Book Chapter 22: Varicella, Centers for Disease Control and Prevention
• Measles Vaccine Recommendations, Centers for Disease Control and Prevention
• Food Safety for Older Adults and People with Cancer, U.S. Food and Drug Administration