Another year, another flu season! The ED will soon fill with feverish, coughing, miserable kids. Last flu season was rough, with the CDC reporting the highest number of pediatric deaths since tracking began in 2004 (excluding the H1N1 pandemic). Half had underlying conditions, and 89% were not fully vaccinated. We know that kids can get really sick with the flu, but reassuringly, most otherwise healthy kids recover just fine with supportive care. While we’re encouraging flu vaccines for kids and their families, let’s review the guidelines of who actually should be tested.
What do the guidelines say?
According to both the CDC and AAP, testing for flu isn’t required to make the diagnosis. If flu is in the community and your patient has symptoms of flu…they most likely have the flu! Testing should be reserved for high-risk children for whom the results will change management – particularly for children who may benefit from antivirals such as oseltamivir (Tamiflu).
Children are considered high-risk if they:
- Are hospitalized with suspected flu
- Are <2 years of age (says the CDC – although the AAP notes that children <5 years of age, and especially those <2, can be considered high-risk)
- Were born premature
- Have an underlying medical condition (examples include: chronic lung disease, asthma, heart disease, kidney disease, liver disease, metabolic disease, hematologic disorders including sickle cell disease, or neurologic/neurodevelopmental conditions)
In otherwise healthy kids over age 2 (and especially over age 5) who are not hospitalized, testing for the flu is not recommended as it does not affect the management of these patients. The mainstay of care for the flu is still supportive care!
Also… tests have limitations! The guidelines recommend testing early in the illness and using molecular assays (RT-PCR) when possible. Keep in mind that a negative test does not always rule out flu, and a positive test doesn’t always explain a child’s symptoms.
Does Testing Prevent Overuse of Antibiotics or Other Workups?
Probably not. A meta-analysis found that rapid viral testing was not associated with decreased antibiotic use, ED length of stay, ED return visits, or hospitalization rates. Furthermore, overtesting exposes kids to potentially distressing nasal swabs, contributes to significant resource utilization (including laboratory and staff resources) and workflow inefficiencies, and risks diverting limited resources away from high-risk children. In an era of rising healthcare costs, diagnostic stewardship matters.
Let’s chat about Tamiflu.
Oseltamivir (Tamiflu) is the most common antiviral prescribed for flu, can shorten symptom duration by 12-36 hours, and may reduce complications or hospitalization duration if started within 48 hours of symptom onset. Both the CDC and AAP recommend early initiation for hospitalized or high-risk children, but emphasize that treatment should not wait for test results. The guidelines also recommend antivirals for those who are high-risk or those with complicated flu, regardless of the duration of symptoms. However, oseltamivir is not without side effects – vomiting is common in young children. As such, for patients who are not at increased risk of complications from flu, the risks of antivirals (such as adding vomiting to the mix in an already sick kid) may outweigh the benefits. A recent vignette-based study found variability in prescribing practices and nonadherence to national treatment recommendations – suggesting the uncertainty of perceived benefits of oseltamivir in relatively healthy kids.
Testing Take Homes
- Testing for flu should be purpose-driven. When it will affect what you do next, then test. If the result won’t change your management, it may be reasonable not to test.
- Testing is recommended for high-risk children (<2 years of age and sometimes <5 years of age, high-risk conditions, or requiring hospitalization).
- Confirming flu with a test is not required to prescribe antivirals in those who are eligible.
Dr. Lauren Klingensmith, MD, is a Pediatric Emergency Medicine Fellow at the Children’s Hospital of Philadelphia. She can be reached at klingensml@chop.edu.
