Q: Should my child get another flu test? The first test was negative, but we have two flu patients at home.
- Myeongchan Kim
- Jul 7
- 3 min read
Medically reviewed by Sang Hyun Ahn, MD
Content edited by Myeongchan Kim, MD
This post is a dramatization of a question and answer session experienced by our actual medical reviewers. Please note that this content is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
Question:
My child started having a fever in the evening two days ago. We did a flu test the next day, but it came back negative. However, the fever returned that evening, reaching up to 39°C (102.2°F). After taking a fever reducer, it dropped to 37.3°C (99.1°F) within two hours. It has been exactly two weeks since my child received the flu vaccine. We were told that a flu fever doesn't drop easily, but my child's fever does respond to medication.
Currently, we have two other family members with the flu at home. When my older child had it, their fever also dropped with medication, but they struggled a lot with the symptoms. The child who is currently sick isn't struggling much, but they are absolutely terrified of the nasal swab test. Should we test for the flu again today? Right now, their temperature is normal at 36.5°C (97.7°F).
Answer:
I completely understand your dilemma regarding whether to retest, especially with two other family members already having the flu at home.
To summarize your current situation: the fever started on the first evening, followed by a negative flu test the next day. The fever responds well to medication, dropping from 39°C to 37.3°C. The flu vaccination was exactly two weeks ago, there is known exposure to the flu at home, and thankfully, your child is not currently in severe discomfort.
Here is what you should consider regarding a retest:
Flu tests are generally most accurate when performed 12 to 48 hours after symptoms begin. Testing too early can sometimes result in a false negative.
A retest is helpful if:
Symptoms worsen or persist.
An antiviral prescription (like Tamiflu) is needed, which is most effective when started within 48 hours of symptom onset.
A confirmed diagnosis is necessary to protect other vulnerable family members.
An immediate retest may not be necessary if:
The child is not overly distressed and their general condition is good.
The fever is well-controlled with standard fever reducers.
The child is severely afraid of the test, which can cause unnecessary trauma if their symptoms are mild.
Actionable Recommendations for Today:
Monitor General Condition: Check your child's overall state, paying close attention to their activity levels, appetite, and hydration.
Observe at Home: If there is no worsening of symptoms and their condition remains stable with a normal temperature, it is reasonable to continue observing them at home.
Prevent Family Transmission: Continue practicing strict hygiene, including mask-wearing and frequent hand-washing, to prevent further spread within the household.
When to visit a doctor immediately:
Seek emergency medical care if your child experiences difficulty breathing, chest pain, decreased consciousness, signs of severe dehydration, or a persistent fever over 40°C (104°F) that does not respond to fever reducers.
If your child is terrified of the test, observing their symptoms and only retesting if absolutely necessary is a reasonable and gentle approach. However, given the known flu exposure in your household, please consult your pediatrician (either via phone or in-person) to discuss whether starting antiviral medication might be clinically appropriate even without a second test.
For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.
