Serological and Molecular Epidemiology of Chikungunya Virus Infection in Vietnam, 2017-2019

Viruses. 2023 Oct 8;15(10):2065. doi: 10.3390/v15102065.

Abstract

Chikungunya fever is an acute febrile illness caused by the chikungunya virus (CHIKV), which is transmitted by Aedes mosquitoes. Since 1965, only a few studies with limited scope have been conducted on CHIKV in Vietnam. Thus, this study aimed to determine the seroprevalence and molecular epidemiology of CHIKV infection among febrile patients in Vietnam from 2017 to 2019. A total of 1063 serum samples from 31 provinces were collected and tested for anti-CHIKV IgM and IgG ELISA. The 50% focus reduction neutralization test (FRNT50) was used to confirm CHIKV-neutralizing antibodies. Quantitative real-time RT-PCR (RT-qPCR) was performed to confirm the presence of the CHIKV genome. The results showed that 15.9% (169/1063) of the patients had anti-CHIKV IgM antibodies, 20.1% (214/1063) had anti-CHIKV IgG antibodies, 10.4% (111/1063) had CHIKV-neutralizing antibodies, and 27.7% (130/469) of the samples were positive in RT-qPCR analysis. The E1 CHIKV genome sequences were detected among the positive RT-qPCR samples. Our identified sequences belonged to the East/Central/South/African (ECSA) genotype, which has been prevalent in Vietnam previously, suggesting CHIKV has been maintained and is endemic in Vietnam. This study demonstrates a high prevalence of CHIKV infection in Vietnam and calls for an annual surveillance program to understand its impact.

Keywords: Vietnam; chikungunya; molecular epidemiology; seroprevalence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Neutralizing / genetics
  • Antibodies, Viral
  • Chikungunya Fever*
  • Chikungunya virus* / genetics
  • Disease Outbreaks
  • Fever / epidemiology
  • Humans
  • Immunoglobulin G
  • Immunoglobulin M
  • Molecular Epidemiology
  • Seroepidemiologic Studies
  • Vietnam / epidemiology

Substances

  • Antibodies, Viral
  • Immunoglobulin M
  • Immunoglobulin G
  • Antibodies, Neutralizing

Grants and funding

This research was supported by AMED (Japan Agency of Medical Research and Development) under SCARDA grant number JP223fa627004h0001, JP233fa627004h0002; AMED under grant number, JP22wm0125006, JP22fk0108123 and JP20wm0225017; JSPS (Japan Society for the Promotion of Science) under grant number 22KK0115; the Japan Research Foundation for Clinical Pharmacology; The Naito foundation grant for the next generation researcher; Takeda Science Foundation; and e-Asia under grant number JP22jm0210079h003, JP23jm0210079h004.