Reporting positive PCR tests without corresponding cycle (Ct) thresholds is a seriously flawed approach. A positive test above 30 cycles, for instance, is very different from one at 20 cycles. If you have this data, please post it, either by reported positive test ('case'), or an average next to the PCR test totals. If you don't have this data, you should demand it from the labs reporting to you.
Customer support service by UserEcho