Comparison of hemagglutination and hemadsorption tests for influenza detection

Hemagglutination (HA) testing of the supernatant of primary rhesus monkey kidney cell culture tubes inoculated with clinical specimens was compared with hemadsorption (HAd) of the same tube for identifying the presence of hemagglutinin activity due to influenza. A total of 476 respiratory specimens were screened for influenza by this method. The 127 influenza or parainfluenza positive cultures showed 100% concordance between the two tests. All negative cultures were both also negative by HA and HAd. In contrast to the HAd method, HA testing was performed with less tube manipulation, less hands-on time, and less potential for cell culture tube contamination.