Original Article
Laboratory diagnosis and molecular tracing of dengue bordline cases in Henan Province, 2017
Yanhua Du, Yi Li, Ruolin Wang, Haifeng Wang, Jia Su, Bianli Xu, Xueyong Huang
Published 2018-11-06
Cite as Chin J Prev Med, 2018, 52(11): 1164-1167. DOI: 10.3760/cma.j.issn.0253-9624.2018.11.013
Abstract
ObjectiveTo confirm the laboratory diagnosis of dengue bordline cases reported in Henan Province and trace its origin from molecular level in 2017.
MethodsThe study samples were blood samples (3-5 ml), which came from 8 suspected cases of dengue fever reported in the 2017 direct reporting system of Henan provincial infectious disease monitoring network. Meanwhile, case investigation was conducted according to National dengue fever surveillance programme. Serum were separated from blood samples and tested for Dengue NS1 antigen, IgM & IgG antibodies, and dengue RNA. According to dengue diagnosis criteria, confirmed cases were identified by testing results. Samples carried dengue RNA performed for real-time PCR genotyping and amplification of E gene. Then, the amplicons were sequenced and homological and phylogenetic analyses were constructed.
Results8 serum samples of suspected dengue cases were collected in Henan Province, 2017. Six of them were diagnosed as dengue confirmed cases. All the dengue confirmed cases belonged to outside imported cases, 5 of them were positive by dengue RNA testing. Genotyping results showed there were 1 DENV1 case, 2 DENV2 cases and 2 DENV3 cases. A DENV2 case and a DENV3 case of this study were traced its origin successfully. The sequence of Pakistan imported DENV2 case belongs to cosmopolitan genotype, which was the most consistent with Pakistan's DENV2 KJ010186 in 2013 (identity 99.0%). The sequence of Malaysia imported DENV3 case belongs to genotype I, which was the most consistent with Singapore's DENV3 KX224276 in 2014(identity 99.0%).
ConclusionThe laboratory diagnosis and molecular traceability of dengue cases in Henan Province in 2017 confirmed that all cases were imported and did not cause local epidemics.
Key words:
Dengue virus; Genotype; Diagnosis; Molecular tracing; Phylogenetic analysis
Contributor Information
Yanhua Du
Henan Center for Disease Control and Prevention, Institute of Infectious Disease Prevention and Control, Henan Key Laboratory of Pathogenic Microorganisms, Zhengzhou 450016, China
Yi Li
Ruolin Wang
Haifeng Wang
Jia Su
Bianli Xu
Xueyong Huang