The Division of Consolidated Laboratories (DCLS) will no longer be offering testing for H1N1 novel influenza. This testing was not intended for diagnostic testing purposes but for public health surveillance purposes only. Recent DCLS testing has confirmed the presence of H1N1 novel flu strains in our communities therefore further surveillance testing is not justified at this time.
Should you be using the rapid influenza protein antigen as a means of diagnosis consider patients at this time who have a clinical presentation for flu with a positive rapid influenza A result to potentially have H1N1 novel flu.
Be aware however of the unreliability of this rapid test. False-negative results are more likely to occur when influenza is common in the community, which is typically at the height of an outbreak.
Specificities of rapid diagnostic tests for influenza are approximately 90-95%.
Sensitivity and specificity of these tests for detection of the novel H1N1 flu virus are unknown.
Antiviral treatment should be based on clinical presentation and patient risk rather than rapid testing result.
Clinical presentation may include: fever, chills, headache, upper respiratory tract symptoms (cough, sore throat, rhinorrhea, shortness of breath), myalgias, arthralgias, fatigue, vomiting, or diarrhea.
High risk groups include children less than 5 years old; persons aged 65 years or older; children and adolescents (less than 18 years) who are receiving long-term aspirin therapy and who might be at risk for experiencing Reye syndrome after influenza virus infection; pregnant women; adults and children who have chronic pulmonary, cardiovascular, hepatic, hematological, neurologic, neuromuscular, or metabolic disorders; adults and children who have immunosuppression (including immunosuppression caused by medications or by HIV); residents of nursing homes and other chronic-care facilities.
If you believe that confirmation of H1N1 is important clinically for your patient this confirmation can only be obtained utilizing Focus Diagnostics Laboratories via Mayo Clinic Reference Lab. This test would be ordered through Centra Lab as a miscellaneous lab order "Influenza A/H1N1 confirmation: Mayo/Focus Diagnostics".