The Virochip was superior in performance to DFA , showing a 19 % increase in the detection of 7 respiratory viruses included in standard DFA panels , and was similar to virus - specific PCR ( sensitivity , 85 % to 90 % ; specificity , > 99 % ; positive predictive value , 94 % to 96 % ; negative predictive value , 97 % to 98 % ) in the detection of