Primary Children's H1N1 Flu Update for Physicians
What's New - October 21, 2009
Information to providers on testing and treating for H1N1
Since rapid testing for influenza viruses, including the pandemic H1N1, is unreliable, physicians seeing children in outpatient clinics may struggle with how to diagnose and treat H1N1 influenza. We offer the following advice:
Who should be tested?
- Testing should not be used to decided whether to start antiviral therapy in an at-risk patient.
- Therapy should be started empirically.
- Testing may be useful when results would alter future therapy or when failure to prove influenza would lead to additional studies such as blood cultures or CT scan.
- Testing may also prove useful for managing other family members or contacts who might become ill.
- Keep in mind that outpatient viral testing is not inexpensive.
What tests should be performed?
- Obtain a nasopharyngeal aspirate.
- The initial testing will be viral DFA, which can identify influenza A, influenza B, parainfluenza, RSV, adenovirus and human metapneumovirus.
- If the DFA is positive for influenza A, the virus will be subtyped by H1N1 PCR to determine if it is the 2009 H1N1.
- If the DFA is negative, the specimen will be sent for multiplex viral PCR (Luminex).
How much will it cost?
- $160 - If the DFA is positive for influenza, cost is for the combination of DFA and confirmatory PCR.
- $80 - If another respiratory virus is identified by DFA and influenza is not detected. The confirmatory PCR will not be needed.
- $380 - If the DFA is negative, multiplex PCR will be performed.
How do I obtain results?
- The physician or his/her office staff will be responsible for obtaining and communicating with the patient.
- Primary Children's will not provide results to patients.
- Results are posted on Help2 as soon as they are available.
- DFA results are available in a matter of hours.
- PCR may take up to 24 hours, depending on when the specimen is submitted.
Primary Children's resources are limited. Remember that you can obtain a specimen in the office and submit it to the IMed Central Lab, or ARUP for DFA or PCR. This will be easier for the family and reduce the stress on Primary Children's.
- If you order influenza PCR or multiplex respiratory viral PCR, an NP swab is an adequate specimen.
- NP aspirate or NP suction is better for DFA.
Testing recommendations
Who to test
- Everyone who is going to be admitted.
- Patients with high risk of complications.
- Testing can be considered selective for patients with mild disease.
What to use
- At Primary Children's standard testing involves DFA (with 2 hour turn around).
- Negative DFAs are sent for PCR.
- For patients who have been ill longer than 48 hours, PCR may be much more sensitive.
- Rapid tests have low sensitivity, and a negative test cannot be used to rule out infection.
- Rapid tests may give false positives. During periods of low flu activity, positive rapid tests may well be false positives.
Respiratory precautions recommendations (hospitalized patients)
- Assume Flu A until the results of the viral panel are known. These patients should be in Droplet Precautions for Flu A
- For patients with negative DFA, please assume Flu A until PCR or culture results are finalized. Do not take them out of Droplet Precautions for Flu A until culture is finalized
- In NICU and ICS, please contact Infection Prevention and Control (801-914-9184 on Schedule Pro) before discontinuing droplet precautions.
- N95 or PAPR mask recommended for the following procedures:
- Intubation
- Bronchoscopy
- Suctioning
- Nasopharyngeal swab
- Nasopharyngeal wash
Additional Resources
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