September 2009

Testing for H1N1

The Exponent has done an excellent job of helping alert students about H1N1 Type A influenza. Fortunately, the virus so far has not been any worse than what we'd expect from seasonal flu. Many under age 25, however, are thought to have little if any immunity, and that means it will spread more easily than seasonal flu on college campuses.

A few details about testing, though, need clarification.

The Centers for Disease Control and the Indiana State Board of Health both have stated that it is not necessary to determine if all people with flulike symptoms have H1N1. This is by far the predominant influenza circulating, and seasonal flu is not expected until later this year. Because H1N1 has not been any worse than seasonal flu, the treatment is no different. Consequently, we have been advised to treat all flu right now as if it were H1N1 and only test when patients and a health provider concur that testing is appropriate for the case.

Testing requires two steps. First, we do a test to screen for Type A influenza, of which H1N1 is a subset. It requires that a small, flexible swab set be inserted through the nasal cavity to collect a sample. Given that, many do not want the test because the results will not change their treatment. Normally there are charges for the test. For some this will be covered by insurance. This week, however, the Indiana State Department of Health provided Purdue with a supply of more than 200 screening test kits, which we are making available to students at no cost while the supply lasts. This information was made public on the Purdue H1N1 site Tuesday.

Test results are generally available in about 45 minutes. Unfortunately, the test may produce many false negative results. In other words, a student testing negative for the illness might actually have Type A influenza.

To definitely determine if a patient has H1N1, part of the swab set may be sent to Indianapolis for further typing. There is no charge to students for this test. We're told these results normally would take two to three days but it's been running longer, results often arriving after the patients have recovered.

So far the Purdue Student Health Center has seen 224 students with flulike illness since Aug. 31. Four others were reported by other area health providers. PUSH has conducted 149 screening tests for Type A influenza. Twenty-two have come back positive. We have sent 36 samples to the state for H1N1 typing. So far we have received reports back on 28 of them showing that 18 were H1N1 and five were negative for H1N1. Four were inconclusive and sent to the CDC for type identification.

Currently, H1N1 vaccine has not been released to the state or county. The CDC has not determined priority groups for receiving the vaccine.

Updates are posted on our Web site, https://www.purdue.edu/fluinfo  

James Westman, director, Purdue Student Health Center
Co-chair, Purdue Pandemic Preparedness Committee

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