The Impact of Using Multiplex Real-time Polymerase Chain Reaction for Quick Diagnosis of Different Emerging Infectious Diseases

Rapid multiplex real-time polymerase chain reaction (PCR) is an all-in-one real-time pathogen detection method that integrates sample preparation, amplification, detection and analysis. It can simultaneously detect multiple targeted pathogens in a run. The system requires shorter laboratory processing time in comparing to the routine real-time PCR method and it has significantly shorter turn-a-round time than the traditional culturing method. In Queen Mary Hospital, two rapid multiplex PCR systems (Cepheid GeneXpert and BioFire FilmArray) have been installed in 2017 for rapid detection of pathogens causing emerging infectious diseases (e.g. Mycobacterium tuberculosis, respiratory viruses including MERS Coronavirus) and multi-drug resistant bacteria (e.g. MRSA, CPE, VRE) causing nosocomial infections in hospitals. During the recent influenza surge periods, the systems were also extensively used for rapid seasonal flu detection. By comparing the rapid multiplex PCR system with the routine real-time PCR method, the laboratory processing time in the laboratory can be significantly shortened from 5 hours to 1 hour for seasonal influenza virus and MERS coronavirus detection. Recent studies have shown that the introduction of rapid PCR can significantly reduce 21.5 hours of hospital stay in median among patients with positive rapid viral PCR testing results and significantly reduce the airborne infection isolation (AII) duration from 68.0 to 20.8 hours in comparing to the use of conventional smear microscopy for mycobacteria infection. This method can have positive effect to the control of medical inpatient bed occupancy rate. It can also improve the hospital infection control by reducing the risk of pathogen transmission. The rapid multiplex PCR is quick and simple to handle. Although the use of rapid multiplex PCR system will increase the laboratory running cost, the shortened turn-a-round time can significantly improve patient care. In conclusion, the introduction of rapid multiplex real-time PCR for diagnosis of emerging infectious diseases is highly recommended in public hospitals in Hong Kong.