Winter Respiratory Illness Surge Creates Diagnostic Challenge for Families

Similar Symptoms, Different Viruses

As winter tightens its grip across the country, families face a familiar yet frustrating dilemma: determining whether that persistent cough, fever, or fatigue signals COVID-19, influenza, or just a seasonal cold. You cannot tell the difference between flu and COVID-19 by the symptoms alone because many of the signs and symptoms are the same , creating a diagnostic puzzle that has become increasingly complex this season.

Both COVID-19 and flu can cause varying degrees of symptoms. You may experience no symptoms (called asymptomatic cases) or you could develop severe symptoms . The overlap extends to nearly every common respiratory symptom: fever, fatigue, cough, sore throat, runny nose, shortness of breath, body aches, headaches, vomiting, and diarrhea .

However, medical experts have identified key differences that can help distinguish between these illnesses. The loss of taste and smell is specific to COVID-19 and is not seen in people who have the flu . Additionally, some patients have anecdotally reported a new and intense symptom: a "razor blade throat," characterized by a sharp, scraping sensation when swallowing. This particularly severe sore throat is linked to NB.1.8.1, or "Nimbus," a subvariant of Omicron .

Current Winter Season Outlook

As of December 13, overall respiratory virus activity is moderate nationally , with distinct patterns emerging for each illness. Nationally, seasonal influenza activity continues to increase across the country. As of December 10, epidemic trend estimates indicate that influenza virus infections are growing or likely growing in 39 states .

COVID-19 activity shows a different trajectory. COVID-19 activity is beginning to increase from low levels in some areas of the nation. COVID-19-associated emergency department (ED) visits and hospitalizations remain at low levels . Meanwhile, nationally, RSV activity is moderate and continues to increase in most areas of the United States, particularly in young children .

The CDC's latest projections offer cautious optimism. CDC expects the upcoming fall and winter respiratory disease season will likely have a similar or lower number of combined peak hospitalizations due to COVID-19, influenza, and RSV compared to last season .

Testing and Treatment Strategies

Given the symptom overlap, healthcare professionals emphasize that testing is needed to confirm a diagnosis . The good news is that diagnostic technology has improved significantly. The nose swab can be used to test for both COVID-19 and the flu , streamlining the testing process for patients and healthcare providers.

For most COVID-19 testing needs, home antigen tests are a quick and easy way to find out whether you have COVID-19 . However, flu and RSV tests are usually only given to people who are hospitalized with severe symptoms .

Treatment approaches differ significantly between viruses. Viruses can't be treated by antibiotics. Those only help treat bacterial infections . Instead, FDA has authorized or approved several antiviral medications used to treat mild-to-moderate COVID-19 in people who are more likely to get very sick. Treatment must be started within five to seven days of when symptoms first start .

Prevention and Future Preparedness

Vaccination remains the cornerstone of prevention strategy. You can help prevent serious illness, hospitalization and death of both viruses by getting vaccinated. You can get both the flu vaccine and the COVID-19 vaccine in the same doctor's visit . This dual approach is particularly important as testing can also reveal if someone has both flu and COVID-19 at the same time, although this is uncommon. People with flu and COVID-19 at the same time can have more severe illness than people with either flu or COVID-19 alone .

The timing differences between illnesses also matter for families planning their response. COVID-19 symptoms can take longer than flu symptoms to develop, she explains. Someone with flu usually has symptoms 1 to 4 days after being infected. A person with COVID-19 typically shows symptoms about 5 days after infection, although this can range from 2 to 14 days .

As respiratory season progresses, the key for families lies in staying informed about local disease activity, maintaining good hygiene practices, and seeking prompt testing when symptoms arise. With multiple viruses circulating simultaneously, the ability to quickly identify and appropriately treat each illness becomes crucial for both individual recovery and community health protection.