Rapid Diagnosis Of Measles Virus Using Reverse Transcription Loop-mediated Isothermal Amplification Coupled With A Disposable Lateral Flow Dipstick

Measles is a highly respiratory contagious disease characterised by fever and rash, due to high mobility and mortality, measles is the important reason that resulted in the deaths of children in developing countries. Since the 1960 s, mobility and mortality of measles have been further reduced after the implementation of an Expanded Programme on Immunisation, but there are still more than 20 million measles cases a year in the world. The measles virus laboratory diagnosis is an important part of measles surveillance.In this study, a reverse transcription loop-mediated isothermal amplification combined with a lateral flow dipstick(RT-LAMP-LFD) assay to rapidly detect measles virus was developed and evaluated. The RT-LAMP primers and probe were designed to target the haemagglutinin(HA) gene of measles virus,5 ’ end of the inner primers and probe were tagged with biotin and fluorescein isothiocyanate, respectively. Through the optimization of testing system, the measles virus of RT-LAMP- LFD rapid detection assay was developed to detect the clinical specimens within 1 hour including nucleic acid extraction. Sensitivity evaluation showed the RT-LAMP-LFD can detect 10 copies/μL of synthetic RNA, as sensitive as real-time RT-PCR which is routinely used. Furthermore, the assays showed 100% clinical specificity for identification of measles virus, and there was no cross reaction with other common respiratory infectious virus.A total of 494 clinical specimens were used to validate the RT-LAMP-LFD assay, comparing with real-time RT-PCR method at the same time. There were no significant differences in the results obtained using RT-LAMP-LFD or real-time RT-PCR. The advantages of RT-LAMP-LFD are rapidity and no requirement for expensive specialist equipment, which could be used for the cost effective, routine monitoring of measles in laboratories.