Three patterns that need attention
1. Better, then worse again
A fever or cough that improves and then comes back or gets worse is one of CDC's emergency warning signs, in adults and in children.[1] It can mean a second infection, often bacterial, has set in. IDSA advises clinicians to check for and treat a bacterial infection in people who get worse after first improving, particularly those who already took an antiviral.[3] This is sometimes called a "second sickening."
A fever that returns after a course of Tamiflu falls in this group. Get seen the same day.
2. Not improving
Most people recover in a few days to less than two weeks.[1] If you are not improving after 3 to 5 days of antiviral treatment, IDSA suggests clinicians consider a bacterial infection.[3] Without an antiviral, a week of steady or worsening illness is also worth a visit.
3. Steadily getting worse
CDC recommends antiviral treatment for anyone whose illness is severe, complicated, or progressive, no matter how many days it has lasted.[4] Is it too late for Tamiflu?
What the complication might be
- Pneumonia from the flu virus itself, or from bacteria on top of flu.[1] The bacteria most often involved are Staphylococcus aureus (including MRSA), Streptococcus pneumoniae, and group A strep.[3]
- Ear and sinus infections.[2][1]
- A flare of a long-term condition such as heart failure, asthma, or diabetes.[2]
- Less common: inflammation of the heart, brain, or muscles, and sepsis.[1]
Antibiotics do not treat flu itself. They are used when a clinician finds a bacterial complication.[5]
Where to go
| Situation | Where |
|---|---|
| Any emergency warning sign | Emergency department, or call 911 |
| Better, then worse again, without trouble breathing | In-person care today: urgent care or your clinician, where you can be examined and checked for pneumonia |
| Not improving after several days | Your clinician or urgent care, today or tomorrow |
| A child with any of these | The child's pediatrician today, or an emergency department for warning signs |