Treatment of Influenza A in a Young Adult with COVID-19 Exposure
The treatment plan is appropriate: oseltamivir 75mg twice daily for 5 days should be initiated immediately, combined with isolation for 5 days or until fever-free for 24 hours without antipyretics, with acetaminophen (not NSAIDs) for symptom management, and critical monitoring for COVID-19 development since a positive influenza test does not exclude concurrent or subsequent COVID-19 infection. 1, 2
Antiviral Therapy
Oseltamivir 75mg twice daily for 5 days is the correct treatment for this 19-year-old with confirmed influenza A, particularly since he presents within 48 hours of symptom onset (symptoms started yesterday evening). 2, 3
The benefit of oseltamivir is greatest when started within 24 hours of symptom onset, decreasing illness duration by approximately 24 hours and potentially reducing risk of serious complications. 3
Treatment efficacy diminishes after 48 hours, making immediate initiation essential in this case where the patient is still within the optimal treatment window. 2, 3
Isolation Requirements
Isolation for 5 days or until fever-free for 24 hours without antipyretic medication and symptoms improve is appropriate, but given COVID-19 exposure, isolation precautions should be maintained beyond the standard influenza period if symptoms persist or worsen. 1
The American Thoracic Society specifically recommends extended isolation monitoring in patients with COVID-19 exposure, as this patient has had close contact with a COVID-19-positive relative 3 days ago. 1
Symptomatic Management
Acetaminophen is the correct first-line antipyretic (not ibuprofen) for temperatures above 38.5°C (101.3°F), dosed at 650mg every 4-6 hours as needed, maximum 4 times in 24 hours. 1
Target temperature reduction to below 38°C, as excessive temperature reduction may interfere with immune response. 1
Supportive care with rest, hydration, bland diet for GI symptoms, and humidifier/oral lozenges for cough is appropriate. 3
Critical Monitoring for COVID-19
The most important pitfall to avoid: A positive Influenza A test does NOT rule out COVID-19. 1
Repeat COVID-19 testing should be strongly considered if:
- Symptoms worsen or fail to improve within 48-72 hours of oseltamivir initiation 1
- New symptoms develop, particularly respiratory distress (respiratory rate ≥30/min, oxygen saturation decline, shortness of breath) 1
- Persistent high fever despite antivirals, chest pain, altered mental status, or inability to maintain oral hydration 1
COVID-19 and influenza coinfection, while rare (0.54% in one series), does occur and can result in more severe outcomes including ICU admission and death. 4, 5
The patient's exposure to a COVID-19-positive relative 3 days ago places him within the typical incubation period for COVID-19, and GI symptoms (vomiting, diarrhea) can precede respiratory COVID-19 symptoms by several days. 6
Asymptomatic COVID-19 transmission is a critical factor that makes screening based solely on symptoms unreliable. 7
Red Flags Requiring Immediate Re-evaluation
- Development of respiratory distress (respiratory rate ≥30/min, oxygen saturation decline below 95%, shortness of breath) 1
- Persistent high fever despite 48-72 hours of oseltamivir 1
- Chest pain, altered mental status, or inability to maintain oral hydration 1
- Worsening symptoms after initial improvement (suggesting secondary bacterial infection or COVID-19 development) 6
Follow-up Strategy
The plan to return if condition worsens or new symptoms arise is appropriate, but should be more specific: instruct the patient to seek immediate care for any red flag symptoms listed above. 1
Consider scheduled telephone follow-up at 48-72 hours to assess response to oseltamivir and screen for COVID-19 symptom development. 6, 1