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

Autores: House Deborah, Ho Vo A., Diep To S, Chinh Nguyen T, Bay Phan V, Vinh Ha, Wain John, et al


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.

Palabras clave: Vi capsule Salmonella Typhi typhoid fever antibodies Viet Nam Vietnam

2008-09-21   |   769 visitas   |   Evalua este artículo 0 valoraciones

Vol. 2 Núm.4. Agosto 2008 Pags. 308-312. J Infect Developing Countries 2008; 2(4)