Upsurge of Enterovirus D68 and Circulation of the New Subclade D3 and Subclade B3 in Beijing, China, 2016

Lingyu Shen,Maozhong Li,Aihua Li,Tiegang Zhang,Cheng Gong,Ming Luo,Zichun Xiang,Fang Huang

doi:10.1038/s41598-019-42651-7

Lingyu Shen, Maozhong Li + Show 6 more

Open Access

https://doi.org/10.1038/s41598-019-42651-7

Copy DOI

Abstract

We conducted a surveillance among acute respiratory tract infection (ARTI) cases to define the epidemiology, clinical characteristics and genetic variations of enterovirus D68 (EV-D68) in Beijing, China from 2015 to 2017. Nasopharyngeal swabs and sputum were collected from 30 sentinel hospitals in Beijing and subjected to EV and EV-D68 detection by real-time PCR. The VP1 gene region and complete genome sequences of EV-D68 positive cases were analyzed. Of 21816 ARTI cases, 619 (2.84%) were EV positive and 42 cases were EV-D68 positive. The detection rates of EV-D68 were 0 (0/6644) in 2015, 0.53% (40/7522) in 2016 and 0.03% (2/7650) in 2017, respectively. Two peaks of EV-D68 infections occurred in late summer and early-winter. Ten cases (23.81%) with upper respiratory tract infection and 32 cases (76.19%) presented with pneumonia, including 3 cases with severe pneumonia. The phylogenetic analysis suggested 15 subclade D3 strains and 27 subclade B3 strains of EV-D68 were circulated in China from 2016 to 2017. A total of 52 amino acid polymorphisms were identified between subclades D1 and D3. These data suggest an upsurge of EV-D68 occurred in Beijing in 2016, the new subclade D3 emerged in 2016 and co-circulated with subclade B3 between 2016 and 2017.

Highlights

Enteroviruses (EV) are small, non-enveloped viruses with a single-stranded, positive-sense RNA in the family Picornaviridae[1,2]
Among 21, 816 cases, 619 (2.84%) cases were enterovirus positive and 42 (0.19%) cases were enterovirus D68 (EV-D68) positive. 359 cases were successfully amplified among 619 enterovirus positive cases, including 326 cases belonging to EV-A to D, 26 cases and 7 cases belonging to RV-A and RV-C respectively, and no case belonging to RV-B
Of 326 cases belonging to EV-A to D, they were genotyped to 30 serotypes including 9 of EV-A, 16 of EV-B, 4 of EV-C and 1 of EV-D and the dominant serotypes were CVA6, EV-D68, CVA4, CVA2, CVA10, CVA5 and CVA12, accounting for 16.27%, 12.88%, 11.83%, 11.54%, 8.28%, 5.62% and 5.03%, respectively (Fig. 1)

Summary

Introduction

Enteroviruses (EV) are small, non-enveloped viruses with a single-stranded, positive-sense RNA in the family Picornaviridae[1,2]. The length of enteroviruses is approximately 7.5 kilobases, and divided into 15 species (EV-A to L and rhinovirus A to C)[3,4,5,6]. EV-D68 infections have been rarely reported until the worldwide outbreaks[10,11,12,13,14,15,16,17,18]. A nationwide outbreak of EV-D68 associated with severe respiratory tract infection was reported in the USA from mid-August 2014 to January 15, 2015 and 1,153 cases were confirmed with clinical characteristics of patients mainly resembling pneumonia with severe dyspnea syndrome during this epidemic[19]. In China, sporadic cases of EV-D68 were reported between 2006 and 201413,20–23. To raise awareness of this upsurge of EV-D68 infection, we performed an EV-D68 surveillance study on ARTI cases from the Respiratory Virus Surveillance System (RVSS) in Beijing and analyzed the epidemiological and clinical characteristics of EV-D68 infections from 2015 to 2017 in Beijing

Methods

Results

Conclusion