Antibody Study Of Tularemia Patients In Twenty Years

Objective: To study the maintainable time of humoral immunity against Francisella tularensis and influence factors after infection and the recessive infection situation in healthy people. To set up Nested PCR for diagnosing tularemia patients as soon as possible.Methods: Thirty-one subjects with acute tularemia and the same area healthy people were st udied for antibodies to Francisella tularensis by using Immuno-Chromatographic Assay (ICA) i n third week(Jan. of 1986), sixth month(July of 1986), second year(1987), third year(1988), si xth year(1991), seventh year(1992), eighth year(1993), ninth year(1994), twentieth year(2005). Special antibody was detected in the cohort study. And the subjects were retrospectively studi ed in Jan. of 2005. Thirteen subjects' blood was collected in Jan. of 1986 and was detected by Nested PCR in April of 2005.Results: The GMT of subjects decreased from ll,890(in 1986) to 46.94(in 2005). The rate of decay was 58.1%. A correlation was known between the titer of early phase and that of the late phase (r=0.659, P<0.05). There was no statistically significant difference between the content of questionnaire and the late phase titer. The control group was negative result during 20 years. The Francisella tularensis positive rate was 84.6% in Nested PCR.Conclusion: The study show the special antibody in partial patients can last for a long time with a gradual reducing trend. The titer of the early phase influence significantly that of the late phase without other factors. And there is no recessive infection in the healthy people. Nested PCR are convenient and precise for clinical apply.