[Molecular epidemiological analysis of ECHO7 virus isolated from sewage water in Yunnan Province, China]

To investigate the epidemic and evolutionary trends of enterovirus (EV) in the external environment of Yunnan Province, China, molecular typing was performed on 4 EV strains that were isolated from environmental sewage in Yunnan. The VP1 region of isolates was amplified by RT-PCR using universal enterovirus primers, and the amplified VP1 region was sequenced for GenBank BLAST search and genotype analysis. The 4 EV strains were identified as ECHO7. Their nucleotide and amino acid homologies with the VP1 sequences of 68 ECHO7 strains retrieved from GenBank were measured by Mega software analysis. Our findings showed that ECHO7 strains from environmental sewage and population samples were in different evolutionary branches. These strains showed typical geographical and temporal differences; In addition, there were different transmission chains at the same time and in the same area. ECHO7 strains isolated from sewage water and patients with acute flaccid paralysis during the same period in Yunnan belonged to different clusters and evolved at different speeds. Special concerns are needed for this problem. Continuous molecular biological surveillance of human EV in the external environment of Yunnan will provide strong support for early warning of EV diseases.