Diagnosis of Novel H1N1 Vs. Seasonal Flu Viral Infection

Fall flu season is approaching and many are wondering, "If I get sick, how do I know if it is seasonal influenza or swine flu?" Only a flu test can tell.

What Is H1N1 Swine Flu?

In the spring of 2009, a novel H1N1 swine flu hit the scene; novel meaning that this influenza virus previously only caused symptoms in animals, but has now made the jump to humans. Novel viruses can be especially dangerous, because, unlike the seasonal flu, the human immune system has no established acquired defense against them.

Both Novel H1N1 Flu and Seasonal Influenza are Dangerous

Although seasonal influenza vaccines are slated to be available in late summer or early fall, there may be a shortage of vaccines for the H1N1 pandemic flu, which would mean that only those with the highest risk of becoming ill from swine flu would be vaccinated.

But don't let concern over swine flu distract from the importance of getting vaccinated for the more common seasonal flu. Every year in the United States, about 36,000 people, mostly the elderly, die from seasonal influenza. Any type of influenza that effects humans is cause for concern.

Differentiating between Novel H1N1 and Seasonal Influenza

Populations at Highest Risk from Influenza

Seasonal Influenza: Those most vulnerable to the seasonal flu include the elderly, young children, and people with certain health conditions such as asthma, pregnancy and immune suppression.

Novel H1N1 Pandemic Flu: Young children, young adults, and those with health conditions that make them vulnerable, appear to be at greatest risk of becoming ill with the new swine flu. Epidemiologists suspect that some adults, over the age of 65, have a more experienced immune system which may provide some built in resistance to the novel H1N1.

Typical Symptoms of Influenza

Seasonal Influenza: Symptoms of seasonal flu often comes on suddenly and may include high fever, headache, extreme tiredness, dry cough, sore throat, runny or stuffy nose, and muscle aches. Stomach symptoms-like nausea, vomiting, and diarrhea-may also occur, but are more common in children than adults.

Novel H1N1 Pandemic Flu: Unfortunately, symptoms of novel H1N1 influenza are very similar to the symptoms of seasonal flu. It is not possible to know which you have by your symptoms alone.

How Are H1N1 Pandemic Flu Infections Diagnosed?

In addition to symptoms, the methods of prevention and treatment of novel H1N1 viral infection are very similar to those for seasonal flu. Therefore, it is likely that only those patients that have a high risk of serious complications will actually be tested for H1N1.

To test for novel H1N1 influenza virus, an upper respiratory specimen, such as a nasal swab, is collected. The CDC is recommending that all specimens be sent to the state public health laboratory.

If you do get tested, how quickly the results are available depends on the type of testing done. There are rapid flu tests that can help identify the type of virus in less than a half-hour, however, not all family practice offices may offer this quick test, and if an office does, it will likely only test in cases where knowing the viruses identity will make a difference in the treatment course chosen.

Sources

CDC "Flu Symptoms and Severity"
CDC "Key Facts about Swine Flu"
CDC (Aug, 2009) "Interim Guidance for the Detection of Novel Influenza A Virus Using Rapid Influenza Diagnostic Tests"
CDC (May, 2009) "Interim Guidance for Clinicians on Identifying and Caring for Patients with Swine-origin Influenza A (H1N1) Virus Infection"

* Please note: The information in this article is not to be followed as medical advice, diagnosis or treatment. Please consult with your physician or primary health practitioner for information regarding your own personal health and necessary treatments.