@article{fdi:010070071,
  title = {{V}aline/isoleucine variants drive selective pressure in the {VP}1 sequence of {EV}-{A}71 enteroviruses},
  author = {{D}uy, {N}. {N}. and {H}uong, {L}. {T}. {T}. and {R}avel, {P}. and {H}uong, {L}. {T}. {S}. and {D}wivedi, {A}. and {S}essions, {O}. {M}. and {H}ou, {Y}. and {C}hua, {R}. and {K}ister, {G}. and {A}felt, {A}. and {M}oulia, {C}. and {G}ubler, {D}. {J}. and {T}hiem, {V}. {D}. and {T}hanh, {N}. {T}. {H}. and {D}evaux, {C}hristian and {D}uong, {T}. {N}. and {H}ien, {N}. {T}. and {C}ornillot, {E}. and {G}avotte, {L}. and {F}rutos, {R}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground: {I}n 2011-2012, {N}orthern {V}ietnam experienced its first large scale hand foot and mouth disease ({HFMD}) epidemic. {I}n 2011, a major {HFMD} epidemic was also reported in {S}outh {V}ietnam with fatal cases. {T}his 2011-2012 outbreak was the first one to occur in {N}orth {V}ietnam providing grounds to study the etiology, origin and dynamic of the disease. {W}e report here the analysis of the {VP}1 gene of strains isolated throughout {N}orth {V}ietnam during the 2011-2012 outbreak and before. {M}ethods: {T}he {VP}1 gene of 106 {EV}-{A}71 isolates from {N}orth {V}ietnam and 2 from {C}entral {V}ietnam were sequenced. {S}equence alignments were analyzed at the nucleic acid and protein level. {G}ene polymorphism was also analyzed. {A} {F}actorial {C}orrespondence {A}nalysis was performed to correlate amino acid mutations with clinical parameters. {R}esults: {T}he sequences were distributed into four phylogenetic clusters. {T}hree clusters corresponded to the subgenogroup {C}4 and the last one corresponded to the subgenogroup {C}5. {E}ach cluster displayed different polymorphism characteristics. {P}roteins were highly conserved but three sites bearing only {I}soleucine ({I}) or {V}aline ({V}) were characterized. {T}he isoleucine/valine variability matched the clusters. {S}patiotemporal analysis of the {I}/{V} variants showed that all variants which emerged in 2011 and then in 2012 were not the same but were all present in the region prior to the 2011-2012 outbreak. {S}ome correlation was found between certain {I}/{V} variants and ethnicity and severity. {C}onclusions: {T}he 2011-2012 outbreak was not caused by an exogenous strain coming from {S}outh {V}ietnam or elsewhere but by strains already present and circulating at low level in {N}orth {V}ietnam. {H}owever, what triggered the outbreak remains unclear. {A} selective pressure is applied on {I}/{V} variants which matches the genetic clusters. {I}/{V} variants were shown on other viruses to correlate with pathogenicity. {T}his should be investigated in {EV}-{A}71. {I}/{V} variants are an easy and efficient way to survey and identify circulating {EV}-{A}71 strains.},
  keywords = {{VP}1 ; {HFMD} ; {E}nterovirus ; {EV}-{A}71 ; {V}ietnam ; {VIET} {NAM}},
  booktitle = {},
  journal = {{BMC} {I}nfectious {D}iseases},
  volume = {17},
  numero = {},
  pages = {art. 333 [12 p.]},
  ISSN = {1471-2334},
  year = {2017},
  DOI = {10.1186/s12879-017-2427-4},
  URL = {https://www.documentation.ird.fr/hor/fdi:010070071},
}