Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Jul 15;17(7):e0271439.
doi: 10.1371/journal.pone.0271439. eCollection 2022.

Multiple chikungunya virus introductions in Lao PDR from 2014 to 2020

Elodie Calvez  1 , Phaithong Bounmany  1 , Somphavanh Somlor  1 , Thonglakhone Xaybounsou  1 , Souksakhone Viengphouthong  1 , Sitsana Keosenhom  1 , Paul T Brey  2 , Vincent Lacoste  1 , Marc Grandadam  1
Affiliations

Multiple chikungunya virus introductions in Lao PDR from 2014 to 2020

Elodie Calvez et al. PLoS One. .

Abstract

The first documented chikungunya virus (CHIKV) outbreak in Lao People's Democratic Republic (Lao PDR) occurred in 2012-2013. Since then, several imported and a few autochthonous cases were identified by the national arbovirus surveillance network. The present study aimed to summarize the main genetic features of the CHIKV strains detected in Lao PDR between 2014 and 2020. Samples from Lao patients presenting symptoms compatible with a CHIKV infection were centralized in Vientiane Capital city for real-time RT-PCR screening. Molecular epidemiology was performed by sequencing the E2-6K-E1 region. From 2014 to 2020, two Asian lineage isolates (e.g. French Polynesia; Indonesia), one ECSA-IOL lineage isolate (e.g. Thailand) and one unclassified (e.g. Myanmar) were imported in Vientiane Capital city. Sequences from the autochthonous cases recorded in the Central and Southern parts of the country between July and September 2020 belonged to the ECSA-IOL lineage and clustered with CHIKV strains recently detected in neighboring countries. These results demonstrate the multiple CHIKV introductions in Lao PDR since 2014 and provide evidence for sporadic and time-limited circulation of CHIKV in the country. Even if the circulation of CHIKV seems to be geographically and temporally limited in Lao PDR, the development of international tourism and trade may cause future outbreaks of CHIKV in the country and at the regional level.

PubMed Disclaimer

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Geographical location of chikungunya cases, at the province level, in Lao PDR.
Data based on the analysis of the samples collected by the Institut Pasteur du Laos arbovirus surveillance network between 2012 and 2020. The provinces indicated in yellow correspond to those where at least one sample was found positive for chikungunya virus during the study period (2014–2020). The red triangle indicates the province where the chikungunya outbreak occurred in 2012–2013.
Fig 2
Fig 2. Maximum-likelihood phylogenetic tree of CHIKV sequences from Lao PDR based on E2-6K-E1 region.
Only bootstrap values >70 are shown. The Lao strains sequenced in this study are indicated in red, the previously identified ones in blue.
See this image and copyright information in PMC

References

    1. Higgs S, Vanlandingham D. Chikungunya Virus and Its Mosquito Vectors. Vector-Borne and Zoonotic Diseases. 2015;15: 231–240. doi: 10.1089/vbz.2014.1745 - DOI - PubMed
    1. Schwartz O, Albert ML. Biology and pathogenesis of chikungunya virus. Nature Reviews Microbiology. 2010;8: 491–500. doi: 10.1038/nrmicro2368 - DOI - PubMed
    1. World Health Organization. Chikungunya update 15 September 2020. https://www.who.int/news-room/fact-sheets/detail/chikungunya (accessed 21 December 2020). 2020. Available: https://www.who.int/news-room/fact-sheets/detail/chikungunya
    1. Robinson MC. An epidemic of virus disease in Southern Province, Tanganyika territory, in 1952–1953. Transactions of the Royal Society of Tropical Medicine and Hygiene. 1955;49: 28–32. doi: 10.1016/0035-9203(55)90080-8 - DOI - PubMed
    1. Sharif N, Sarkar MK, Ferdous RN, Ahmed SN, Billah MdB, Talukder AA, et al.. Molecular Epidemiology, Evolution and Reemergence of Chikungunya Virus in South Asia. Frontiers in Microbiology. 2021;12: 1411. doi: 10.3389/fmicb.2021.689979 - DOI - PMC - PubMed

Publication types