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.
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.
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Authors: Conall H Watson; Stephen Baker; Colleen L Lau; Kitione Rawalai; Mere Taufa; Jerimaia Coriakula; Nga Tran Vu Thieu; Tan Trinh Van; Dung Tran Thi Ngoc; Niel Hens; John H Lowry; Ruklanthi de Alwis; Jorge Cano; Kylie Jenkins; E Kim Mulholland; Eric J Nilles; Mike Kama; W John Edmunds Journal: PLoS Negl Trop Dis Date: 2017-07-20
Authors: Pham Thanh Duy; Nga Tran Vu Thieu; To Nguyen Thi Nguyen; Ho Ngoc Dan Thanh; Sabina Dongol; Abhilasha Karkey; Megan Carey; Buddha Basnyat; Gordon Dougan; Maia A Rabaa; Stephen Baker Journal: PLoS Pathog Date: 2020-10-21 Impact factor: 6.823