Plasma Endotoxin Levels Are Not Increased in Schistosoma mansoni-Infected Women without Signs or Symptoms of Hepatosplenic Disease

Elevated circulating endotoxin levels in the plasma of patients with advanced hepatosplenic schistosomiasis caused by Schistosoma mansoni have been reported, possibly caused by parasite egg-induced intestinal mucosal breaches facilitating bacterial access to the bloodstream. Neither endotoxin levels in people with S. mansoni but without hepatosplenic disease nor the impact of treatment on endotoxin levels have been described. We used a methodically optimized Limulus amebocyte lysate assay to measure plasma endotoxin in community-dwelling women from an S. mansoni-endemic area without clinical hepatosplenic disease. We found no difference in baseline mean plasma endotoxin levels between those with (n = 22) and without (n = 31) infection (1.001 versus 0.949 EU/mL, P= 0.61). Endotoxin levels did not change in schistosome-infected women after successful treatment (1.001 versus 1.093 EU/mL, P = 0.45) and were not correlated with circulating anodic antigen or stool egg burden. Our findings do not support the hypothesis that translocating eggs in S. mansoni infection introduce bacterial sources of endotoxin to the circulation.