@article{fdi:010048276,
  title = {{E}stimating {C}hikungunya prevalence in {L}a {R}{\'e}union {I}sland outbreak by serosurveys : two methods for two critical times of the epidemic},
  author = {{G}{\'e}rardin, {P}. and {G}uernier, {V}. and {P}errau, {J}. and {F}ianu, {A}. and {L}e {R}oux, {K}. and {G}rivard, {P}. and {M}ichault, {A}. and de {L}amballerie, {X}avier and {F}lahault, {A}. and {F}avier, {F}.},
  editor = {},
  language = {{ENG}},
  abstract = {{B}ackground: {C}hikungunya virus ({CHIKV}) caused a major two-wave seventeen-month-long outbreak in {L}a {R}eunion {I}sland in 2005-2006. {T}he aim of this study was to refine clinical estimates provided by a regional surveillance-system using a two-stage serological assessment as gold standard. {M}ethods: {T}wo serosurveys were implemented: first, a rapid survey using stored sera of pregnant women, in order to assess the attack rate at the epidemic upsurge (s1, {F}ebruary 2006; n = 888); second, a population-based survey among a random sample of the community, to assess the herd immunity in the post-epidemic era (s2, {O}ctober 2006; n = 2442). {S}era were screened for anti-{CHIKV} specific antibodies ({I}g{M} and {I}g{G} in s1, {I}g{G} only in s2) using enzyme-linked immunosorbent assays. {S}eroprevalence rates were compared to clinical estimates of attack rates. {R}esults: {I}n s1, 18.2% of the pregnant women were tested positive for {CHIKV} specific antibodies (13.8% for both {I}g{M} and {I}g{G}, 4.3% for {I}g{M}, 0.1% for {I}g{G} only) which provided a congruent estimate with the 16.5% attack rate calculated from the surveillance-system. {I}n s2, the seroprevalence in community was estimated to 38.2% (95% {CI}, 35.9 to 40.6%). {E}xtrapolations of seroprevalence rates led to estimate, at 143,000 and at 300,000 (95% {CI}, 283,000 to 320,000), the number of people infected in s1 and in s2, respectively. {I}n comparison, the surveillance-system estimated at 130,000 and 266,000 the number of people infected for the same periods. {C}onclusion: {A} rapid serosurvey in pregnant women can be helpful to assess the attack rate when large seroprevalence studies cannot be done. {O}n the other hand, a population-based serosurvey is useful to refine the estimate when clinical diagnosis underestimates it. {O}ur findings give valuable insights to assess the herd immunity along the course of epidemics.},
  keywords = {},
  booktitle = {},
  journal = {{B}mc {I}nfectious {D}iseases},
  volume = {8},
  numero = {},
  pages = {99},
  ISSN = {1471-2334},
  year = {2008},
  DOI = {10.1186/1471-2334-8-99},
  URL = {https://www.documentation.ird.fr/hor/fdi:010048276},
}