Prevalence and phylogenetic characterizations of Enterovirus D68 strains
among respiratory infection cases in Beijing, 2018-2019
Abstract
Backdround: Enteroviruse-D68 (EV-D68) has been endemic in Beijing for
some years. This study analyz the prevalence and phylogenetic
characterizations of EV-D68 in Beijing during 2018 to 2019. Methods: The
clinical specimens were collected from respiratory infection cases of 30
sentinel hospitals in Beijing and subjected to EV and EV-D68 detection
by real-time PCR. Results: Of 15, 645 respiratory infection cases,
467(2.98%) cases were enterovirus positive and 14(0.09%) were EV-D68
positive. The detection rates of EV-D68 were 0.11% (9/7, 837) in 2018,
0.06% (5/7, 805) in 2019, respectively. Of these EV-D68 infection
patients, 7 cases were aged younger than 18 years, 3 were aged 18 to 60
years and 4 aged over 60 years. 4 cases (28.6%) were diagnosed as upper
respiratory tract infection and 10 (71.4%) as pneumonia, including one
with severe pnuemonia. The main symptoms for EV-D68 patients were fever
(10/14,71.4%) and cough (9/14, 64.3%). 7 cases were detected in summer
and the rest cases in the autumn. The phylogenetic analysis suggested
that EV-D68 strains from 2018 belonged to a major subclade B3 and a
minor subclade D3, while all strains in 2019 were clustered into
subclade D3. These subclade B3 or subclade D3 strains were located in a
separated evolutionary branches,respectively. Conclusions: Our research
further elucidate the continuous molecular evolution and genetic
variability of EV-D68 occured in Beijing, China.