Genome Microevolution of Chikungunya Viruses Causing the Indian Ocean Outbreak
By I. Schuffenecker, I. Iteman, A. Michault, S. Murri, L. Frangeul, M. Vaney, R. Lavenir, N. Pardigon, J. Reynes, François Pettinelli and 13 more. PLoS Medicine, 2006
1,188 citations recorded by the source corpus.
Background A chikungunya virus outbreak of unprecedented magnitude is currently ongoing in Indian Ocean territories. In Réunion Island, this alphavirus has already infected about one-third of the human population. The main clinical symptom of the disease is a painful and invalidating poly-arthralgia. Besides the arthralgic form, 123 patients with a confirmed chikungunya infection have developed severe clinical signs, i.e., neurological signs or fulminant hepatitis. Methods and Findings We report the nearly complete genome sequence of six selected viral isolates (isolated from five sera and one cerebrospinal fluid), along with partial sequences of glycoprotein E1 from a total of 127 patients from Réunion, Seychelles, Mauritius, Madagascar, and Mayotte islands. Our results indicate that the outbreak was initiated by a strain related to East-African isolates, from which viral variants have evolved following a traceable microevolution history. Unique molecular features of the outbreak isolates were identified. Notably, in the region coding for the non-structural proteins, ten amino acid changes were found, four of which were located in alphavirus-conserved positions of nsP2 (which contains helicase, protease, and RNA triphosphatase activities) and of the polymerase nsP4. The sole isolate obtained from the cerebrospinal fluid showed unique changes in nsP1 (T301I), nsP2 (Y642N), and nsP3 (E460 deletion), not obtained from isolates from sera. In the structural proteins region, two noteworthy changes (A226V and D284E) were observed in the membrane fusion glycoprotein E1. Homology 3D modelling allowed mapping of these two changes to regions that are important for membrane fusion and virion assembly. Change E1-A226V was absent in the initial strains but was observed in >90% of subsequent viral sequences from Réunion, denoting evolutionary success possibly due to adaptation to the mosquito vector. Conclusions The unique molecular features of the analyzed Indian Ocean isolates of chikungunya virus demonstrate their high evolutionary potential and suggest possible clues for understanding the atypical magnitude and virulence of this outbreak.
Subfields: Endocrinology, Public Health, Environmental and Occupational Health, Virology
View Paper: https://www.semanticscholar.org/paper/fc32a82d04a47074566cdd317d94672ec6f477a2
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In Public Health, Environmental and Occupational Health
Citations in the corpus
- A Mouse Model for Chikungunya: Young Age and Inefficient Type-I Interferon Signaling Are Risk Factors for Severe Disease (2008, methodology): “Intra-dermal (ID) injection of 10(6) PFU of CHIKV-21, isolated from an individual from La Reunion with central nervous system (CNS) symptoms [4],”
- A Single Mutation in Chikungunya Virus Affects Vector Specificity and Epidemic Potential (2007, background): “These observations provide the basis for an explanation of the observed rapid shift among CHIKV genotypes to viruses containing the E1-A226V mutation during the Reunion outbreak [32].”
- IDseq—An open source cloud-based pipeline and analysis service for metagenomic pathogen detection and monitoring (2020, background): “Maintaining the ability to detect divergent viruses is of paramount concern, given their role in numerous recent outbreaks, including the recent emergence of SARS-CoV-2, the coronavirus responsible for the COVID-19 outbreak [44] [45] [46] [47] .”
- Two Chikungunya Isolates from the Outbreak of La Reunion (Indian Ocean) Exhibit Different Patterns of Infection in the Mosquito, Aedes albopictus (2007, background): “After December 2005, most patients harboured essentially CHIKV isolates with an amino-acid change at the position E1-226V [19].”
- Biology and pathogenesis of chikungunya virus (2010, background): “La Reunion, which is part of France, is an island in the Indian Ocean with a population of ∼785,000; strikingly, an estimated 300,000 cases of CHIKV infection”