The Influenza A + B Antigen Rapid Test Kit is a rapid visual immunoassay tool suitable for the qualitative and presumptive detection of influenza A and B virus antigen and nasopharyngeal swab specimens formed by throat swabs. This test is intended as a rapid differential diagnosis of acute influenza A and beta antigen infections. Influenza is a highly contagious acute respiratory viral infection. The causative agent of the disease is immunologically diverse single-stranded RNA known as influenza virus. There are three types of influenza viruses: A, B, A viruses are the most prevalent and are associated with the most severe virus epidemics. Diseases produced by B viruses are generally milder than those caused, and C viruses have never been associated with large-scale human epidemics.