Objective: To evaluate 2017 poliovirus surveillance in Qinghai Province. Methods: According to the World Health Organization (WHO) 4 th edition of the polio laboratory manual procedure for virus isolation, the isolated L20B positive strain was identified as intratypic differentiation (ITD) by the China Center for Disease Control and Prevention, CDC). The National Polio Laboratory performed the nucleotide sequence determination of the capsid protein VP1 coding region of poliovirus (PV) and analyzed the poliovirus surveillance and the result of analysis of the cases with acute flaccid paralysis (AFP) reported in Qinghai Province in 2017 and stool samples of healthy children. Results: In 2017, Qinghai CDC Polio Laboratory received specimens of 211 AFP cases and healthy stool samples. PV2 strains were isolated with a separation rate of 0.95%. Non-polio enterovirus (NPEV) strains were isolated from 25 strains with the isolation rate of 11.85%. Two PVs were used for ITD. All of them were vaccine-associated strains. Conclusions In 2017, the Qinghai CDC Polio Laboratory did not find any poliovirus and vaccine-derived poliovirus in the AFP cases and stool samples from healthy persons, maintaining the polio-free status.

Objective: To evaluate the running status of Qinghai provincial hand foot and mouth disease (HFMD) laboratory network in 2017. Methods: The surveillance database developed in Qinghai provincial HFMD laboratory network in 2017 were analyzed, and the indicators for the running status of HFMD laboratory network in Qinghai province were evaluated. Results: It was shown that 574 samples of suspected HFMD cases were detected by real time RT-PCR in 2017, and 368 were positive, the positive rate was 64.11%. Then 121 virus strains were isolated, the results of sequencing and analysis showed that 100 strains were EV71 with C4a genotype, 16 strains were CA16 with B1b genotype, and 5 strains belonged to the other enterovirus. In addition, Qinghai provincial HFMD network labs passed all the confirmatory test and proficiency test, and on-site review held by national HFMD laboratory in 2017, respectively. Conclusions Qinghai provincial HFMD laboratory network has been established and running well. It provided important scientific basis for HFMD surveillance in Qinghai province.

Objective: To evaluate the running status of Qinghai provincial measles laboratory network during 2012—2017. Methods: To analyze serological and virological surveillance database developed in Qinghai provincial measles laboratory network in 2012—2017, and evaluate the indicators for the running status of measles laboratory network in Qinghai Province. Results: It was shown that 5 763 suspected measles cases were reported in Qinghai Province during 2012—2017, and 4 167 serum samples were collected from suspected measles cases, the collection rate is 72.31%; among them, 3 697 were IgM positive for measles and the positive rate was 88.72%; 68 were IgM positive for rubella and the positive rate was 1.63%. And 515 throat swab specimens were collected from suspected measles cases, 82 measles virus isolates were obtained and the positive rate was 15.92%. The result of sequencing and analysis showed that all the measles viruses belonged to genotype H1 and subgenotype H1a, which were predominant genotype circulated in China in recent years. In addition, Qinghai provincial measles network labs passed all the serological confirmatory test and proficiency test, and on-site review held by national or provincial measles laboratory and WHO during 2012—2017, respectively. Conclusions Qinghai provincial measles laboratory network has been established and running well. It provided important scientific basis for measles elimination in Qinghai province.

Objective: To investigate the genetic characteristics of enterovirus A 71 (EV-A71) and etiological features of hand, foot and mouth disease (HFMD) in Qinghai province from 2016 to 2017. Methods: Specimens were collected from HFMD patients in Qinghai province, and detected by real-time reverse transcription-polymerase chain reaction (RT-PCR). For EV-A71 positive samples, virus was isolated and RNA was extracted, and then VP1 coding region was amplified by RT-PCR. The phylogenetic tree was constructed by comparing with other genotypes and sub-genotypes strains of EV-A71. Results: It was shown that 114 strains of EV-A71 were isolated in Qinghai province from 2016 to 2017, which all belonged to genotype C4a, and could be divided to two different lineages by phylogenetic analysis. From 2016 to 2017, the epidemic strains of EV-A71 in the different transmission chains of Qinghai province was closely related to other provinces of China. Conclusions C4a was the dominant genotype of EV-A71 in Qinghai province from 2016 to 2017, and no other genotype was detected. In addition, EV-A71 isolated from Qinghai province co-evolved with EV-A71 in other provinces of China.