LB-21. TITLE: A Novel Method to Determine Immunity to Vibrio Cholerae In A Previously Immunologically-Na´ve Population
Session: Poster Abstract Session: Late Breaker Posters
Saturday, October 22, 2011
Room: Poster Hall B1
Handouts
  • IDSAPOSTER9 (2).pdf (607.7 kB)
  • Background: The non-invasive characteristic of V. cholerae and its ability to enhance mucosal immunity is thought to be important for protection. The relationship between oral gingival secretions and serum antibody titers has been well established and has been adapted for HIV and other infectious diseases. Oral mucosal sampling for cholera immunosurveys has yet to be investigated and would represent a highly innovative method of collection in resource limited settings.

    Method: Humoral immune responses in oral gingival secretions and serum of 13 patients with culture confirmed cholera (CCC) were compared to those of 13 healthy controls (HCs). IgG and IgA responses to the recombinant cholera toxin B subunit (rCTB) were assessed by kinetic enzyme-linked immunosorbent assay (kELISA). Vibriocidal IgG was measured in sera and oral gingival secretions in serially diluted samples, using described methods for the Haitian isolate serotype of V. cholerae O1 Ogawa (BAA-2165) and four additional strains.

    Results: Serum Anti-Cholera Toxin B rCTB IgG was detected at dilutions of 1:400 in all CCCs and none of HCs for a sensitivity of 100% with 95% confidence interval 0.77-1.0. Serum rCTB IgA was detected in 8/13 CCCs at a dilution of 1:400.Serum Vibriocidal IgG: Detected in 12/13 CCCs for a sensitivity of 92% with 95% confidence interval of 0.67-0.98 p= 0.00029. Vibriocidal IgG was cross-reactive between representative cholera strains. Oral Gingival Anti-Cholera Toxin B IgG : Cholera toxin B IgG in oral secretions was detected with a sensitivity of 76.9% with mean oD/min 10.03 and 95% confidence interval (0.49-0.92) p=0.007.Oral Gingival Vibriocidal IgG: Vibriocidal IgG was detected in neither of the samples from patients with culture-confirmed cholera nor the HCs.

    Conclusion: The absence of prior cholera in Haiti allows for determination of immune responses to primary infection. The serum IgG kELISA results uniformly differentiated between CCC and HC at a screening dilution of 1:100 and thus provide a clear marker of infection with a readily performed assay. Antibodies were detected in oral secretions in ¾ of those sampled but was not a sufficiently reliable marker of prior infection to use in seroepidemiologic studies.


    Subject Category: E. Innate and adaptive immunity to infections, including vaccine immunology

    Claude-lyne Valcin, MD1, Colette Guiteau, MD2, Patrice Joseph, MD3, Peter Wright, MD4, Jean William Pape, MD5,6,7, Ronald Taylor8, Mike Son8, Molly Housman9 and Paul Modern, BS10, (1)Infectious Disease and International Health, Dartmouth Medical School, Lebanon, NH, (2)GHESKIO Medical Center, Port-au-Prince, Haiti, (3)GHESKIO, Port-au-Prince, Haiti, (4)Pediatrics, Dartmouth Medical School, Lebanon, NH, (5)GHESKIO, New York, NY, (6)Centres GHESKIO, Port-au-Prince, Haiti, (7)Weill Cornell Medical College , New York, NY, (8)Dartmouth Medical School, Lebanon, NH, (9)Dartmouth College, Lebanon, NH, (10)Dartmouth-Hitchcock Medical Center, Lebanon, NH

    Disclosures:

    C. L. Valcin, None

    C. Guiteau, None

    P. Joseph, None

    P. Wright, None

    J. W. Pape, None

    R. Taylor, None

    M. Son, None

    M. Housman, None

    P. Modern, None

    See more of: Late Breaker Posters
    See more of: Poster Abstract Session

    Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.