@article{758c64d696fb44eb83590bc0a1e9ce46,
title = "Vi SEROLOGY IN DETECTION OF CHRONIC SALMONELLA TYPHI CARRIERS IN AN ENDEMIC AREA",
abstract = "A passive haemagglutination assay measuring antibody to highly purified Vi antigen, known to be sensitive and specific for the detection of chronic Salmonella typhi carriers in a non-endemic area, was assessed in an endemic area. A reciprocal serum Vi antibody titre of 160 was found to have a sensitivity of 75%, specificity of 92%, and a high predictive value in screening for chronic S typhi carriers in high-risk population groups (eg, women over 40 years). This simple assay can screen for chronic S typhi carriers even in areas where typhoid fever is highly endemic.",
author = "Lanata, {Claudio F.} and Conrado Ristori and Luis Jimenez and Julio Garcia and Levine, {Myron M.} and Black, {Robert E.} and Mario Salcedo and Viviana Sotomayor",
note = "Funding Information: suggested that the passive haemagglutination assay with highly purified Vi antigen had no greater sensitivity or specificity than direct bacterial agglutination and more elaborate techniques, such as fluorescent Vi antibody test,23,24 counter-immunoelectrophoresis, or solid-phase radioimmunoassay25 have been advocated. However, these more sophisticated techniques require expensive equipment and their use in less-developed countries where typhoid fever is endemic is limited. The practical application of the simple passive haemagglutination assay with highly purified Vi antigen in detecting chronic S typhi carriers in an endemic area depends not only on the sensitivity and specificity of the titre used as cut-off but also on its predictive value. 18 Since the predictive value of each titre cut-off is greater in populations with higher chronicS typhi carrier rates, screening high-risk groups of the population will be justifiable. We thank Mr Charles Young for technical assistance and Dr Merrill Snyder for reviewing the manuscript. This work was partly supported by grants from the World Health Organisation, the Pan American Health Organisation, and the HDC Corporation, Mountain View, California, and by research contract C-1115 from the US Army Medical Research and Development Command. Correspondence should be addressed to C. F. L., Center for Vaccine Development, Division of Infectious Diseases, University of Maryland School of Medicine, 29 South Greene Street, Baltimore, Maryland 21201, USA.",
year = "1983",
month = aug,
day = "20",
doi = "10.1016/S0140-6736(83)90401-4",
language = "English (US)",
volume = "322",
pages = "441--443",
journal = "The Lancet",
issn = "0140-6736",
publisher = "Elsevier Limited",
number = "8347",
}