Rapid Molecular Diagnosis of Parechovirus Infection Using the Reverse Transcription Loop-Mediated Isothermal Amplification Technique

Objectives Human parechovirus (HPeV), especially HPeV A3 (HPeV3), causes sepsis-like diseases and sudden infant death syndrome in neonates and young infants. However, commercial laboratory tests for HPeVs, including HPeV3, do not exist.Methods We originally designed inner primers, outer primers, and loop-primers on the 5′ untranslated region of HPeV3. We used HPeV3 ribonucleic acids (RNAs), other viral RNAs, and clinical stool samples to confirm whether our designed primers would allow the detection of HPeV3 with the reverse transcription loop-mediated isothermal amplification (RT-LAMP) technique.Results We created three combinations of primers and confirmed that all primer sets allowed the detection of HPeV3 RNAs in only 60 minutes. These primer sets had cross-reactivity with HPeV type 1 (HPeV1), but all sets showed negative results when we applied Coxsackievirus, Echovirus, Enterovirus, Norovirus, and Adenovirus genomes. Four of six stool samples, which were obtained from newborn and infant patients with sepsis-like symptoms, showed positive results with our RT-LAMP technique.Conclusions This report is the first showing that HPeVs can be detected with RT-LAMP. Based on this finding, HPeV infection can be diagnosed faster, more easily, and with less cost. This technique is clinically useful for newborn and infants who have sepsis-like symptoms.