Population-Based Serologic Survey of Vibrio cholerae Antibody Titers before Cholera Outbreak, Haiti, 2022

Abstract

A Vibrio cholerae O1 outbreak emerged in Haiti in October 2022 after years of cholera absence. In samples from a 2021 serosurvey, we found lower circulating antibodies against V. cholerae lipopolysaccharide in children <5 years of age and no vibriocidal antibodies, suggesting high susceptibility to cholera, especially among young children.

Keywords: Haiti; Vibrio cholerae; antibodies; bacteria; cholera; correlates of protection; dried blood spots; enteric infections; outbreaks; serosurveys; vibriocidal.

Figure 1

Vibrio cholerae–specific and functional antibodies among participants in a serologic study conducted before a cholera outbreak in Haiti, 2022. We performed ELISAs for both IgG and IgA serotypes on all 861 samples for LPS and CtxB. Horizontal lines indicate medians; error bars indicate interquartile ranges. CtxB, cholera toxin subunit B; LPS, lipopolysaccharide.

Figure 2

Antibody titers by age, vaccination status, and previous history of infection among participants in a serologic study conducted before a cholera outbreak in Haiti, 2022. We compared antibody titers for lipopolysaccharide (LPS) and cholera toxin subunit B (CtxB) between children <5 years of age (n = 112) and adults and children >5 years of age for LPS IgG (A), LPS IgA (B), CtxB IgG (C), and CtxB IgA (D). We made statistical comparisons between the <5- and ≥5-year age groups using an unpaired 2-tailed Student t test. Individual year-by-year comparisons were compared using 1-way analysis of variance. Horizontal lines indicate medians; error bars indicate interquartile ranges. Significant p values are indicated.