[Observation on the change of anti-S. japonicum antibody level in population migrated from outside embankment to new town].

Objective: To detect the change of the anti-S. japonicum antibody level after people migrated from outside embankment to newly established town.
Methods: Three pilot spots were established for the investigation: one spot that both inhabitancy and cultivation disuse (A), one spot that only inhabitancy disuse but farming continued (B) and the third one served as control (C). DIGFA and ELISA were used to detect the antibody level in the populations from 2002 to 2005.
Results: The positive rate of anti-S. japonicum antibody declined significantly from 6.63% to 3.52% by DIGFA and from 7.26% to 3.71% by ELISA at spot A (chi2=5.2625, P<0.05; chi2=6.3296, P<0.05, respectively). There was no significant difference on the positive rate of antibody in spots B and C. The average A450 value of ELISA in the three spots was statistically analyzed by One-Way ANOVA. It was only in spot B that the average A450 value declined from 0.182 in 2003 to 0.147 in 2005 (P<0.01).
Conclusion: The anti-S. japonicum antibody level in human population has decreased at certain degree after they migrated from outside embankment to new town.