SCHISTOSOMA MANSONI INFECTION AND THE ASSOCIATED ANTIBODY IMMUNE RESPONSE AMONGST RESIDENTS OF KIGUNGU ENTEBBE, UGANDA.

UNLABELLED: BACNKGROUND: There are many foci endemic for Schistosoma (S.) mansoni in Uganda. The immune responses to infection with the parasites in these areas have been found to vary with host sex, age and infection intensity.

OBJECTIVE

To determine the profile of antibody isotypes responses against S. mansoni crude soluble egg antigens (SEA) and soluble adult worm protein (SWAP) antigens that determine the host resistance or susceptibility to reinfection.

DESIGN

Cross Sectional, cohort study.

SETTING

Kigugu fishing village in Entebbe, Uganda.

SUBJECTS: Nine hundred and forty five (945) Kigungu residents reported forpre-treatment screening and enrolment and 626 cohorts report for post-treatment screening and enrolment 18 months later.

RESULTS

Pearson's Chi-sq2 showed thatincrease in titres of anti (SWAP IgE, SEA IgE, and SEA IgG2) was not significant, but increase in anti SEA IgG3 was significant. Decrease in titres of anti (SWAP IgG1, SEA IgG1, and SEA IgG4) was not significant but decrease of anti (SWAP IgG2, SWAP IgG3 and SWAP IgG4) was significant. Positive correlation existed between age and anti SWAP IgE in before and after treatment sera. On the contrary, age was positively correlated with anti SWAP IgG4 in pre-treatment sera but was negatively correlated with anti SWAP IgG4 in the post-treatment sera. In addition there were positive correlation between higher egg counts and the immunoglobulin levels of anti SWAP IgG4 and anti SEA IgG4 but negative correlations were observed between anti SWAP IgE and anti SEA IgE. Conversely low egg counts were associated with high levels of anti SWAP IgE. Furthermore, IgG1-4, IgE antibody to SEA and SWAP antigens did not differ significantly according to sex.

CONCLUSION

We concluded that praziquantel treatment of S. mansoni infected persons alter the immune responses that are influenced by age and intensity. A phenomenon that is useful in the effort to produce vaccine against schistosome.