What is the most effective way in determining whether someone has been infected with H1N1 influenza virus?

The most effective way to determine whether someone has been infected with the H1N1 influenza virus is through a laboratory test known as a polymerase chain reaction (PCR) assay. This test can detect the presence of viral RNA in respiratory specimens, such as nasal swabs or throat swabs, collected from the individual being tested. The PCR assay amplifies and detects specific genetic sequences of the H1N1 influenza virus, allowing for a rapid and accurate diagnosis of the infection.