Antibodies to the Vi capsule of Salmonella Typhi in the serum of typhoid patients and healthy control subjects from a typhoid endemic region.

Journal article

BACKGROUND: There is very little published data on the antibody response to the Vi capsular polysaccharide (Vi-CPS) of S. Typhi during naturally acquired typhoid fever in an endemic area. METHODOLOGY: An indirect ELISA, using tyraminated, purified Vi-CPS, was used to assay anti-Vi-CPS antibodies from typhoid fever cases and controls living in the Ho Chi Minh City and Mekong Delta region of Viet Nam. RESULTS: Antibody response to Vi-CPS is significantly higher in typhoid patients who have been ill for more than two weeks than those who are in the first two weeks of illness. The anti-Vi-CPS response is similar for adults and children. Anti-Vi-CPS antibodies can be detected in the sera of non-typhoid patients. The frequency with which this occurs increases with age, probably reflecting increased exposure to S. Typhi. CONCLUSIONS: Anti-Vi_CPS is elicited in persons infected with S. Typhi but only after a prolonged duration of illness. Vaccine trials have shown anti-Vi-CPS antibodies to be protective; thus early treatment of typhoid patients, i.e. in the first two week of illness before the Vi-CPS response is elicited, may inhibit the development of this protective immune response.

Authors: House, D; Ho, V; Diep, T; Chinh, N; Bay, P

• Publication status: Published
• Journal: Journal of infection in developing countries
• Volume: 2
• Issue: 4
• Pages: 308-312
• Publication date: 2008-01-01
• EISSN: 1972-2680
• ISSN: 2036-6590
• Language: English
• Keywords: Endemic Diseases; Young Adult; Child, Preschool; Polysaccharides, Bacterial; Child; Antibodies, Bacterial; Typhoid Fever; Adult; Enzyme-Linked Immunosorbent Assay; Age Factors; Humans; Case-Control Studies; Salmonella typhi; Adolescent; Vietnam