An increasing trend of sensitivity , positive predictive value and PLR was found , with the lowest in IgM testing ( 7 . 4 % , 28 . 6 % and 1 . 45 ) , intermediate in FQ - PCR ( 40 . 7 % , 50 % and 3 . 63 ) , and highest in culture ( 55 . 6 % , 75 % and 10 . 9 ) .