Immunoepidemiologic studies of Strongyloides stercoralis and human T lymphotropic virus type I infections in Jamaica.

Epidemiologic investigations of Strongyloides stercoralis and human T lymphotropic virus type I (HTLV-I) infections were conducted. Of 312 persons contacted, 209 (67%) provided blood and stool samples. Prevalences of S. stercoralis and HTLV-I antibodies were 26.8% and 8.1% (n = 198), respectively, and S. stercoralis larvae were detected in 4%. HTLV-I antibodies were significantly more common in persons positive for S. stercoralis larvae (10 [58.8%] of 17) compared with seropositive larva-negative (4 [8.9%] of 45) or seronegative persons (9 [6.2%] of 145) (P < .002). IgE levels increased with age in S. stercoralis-seropositive persons who were HTLV-I negative (P < .002). However, there was an age-related depression of serum IgE in HTLV-I-positive positive persons (P < .003) that was sufficient to annul the IgE level-raising effect of S. stercoralis seropositivity. The data provide evidence that HTLV-I infection is associated with increased frequency of larvae in the stool of S. stercoralis-infected persons and suggest that the mechanism may involve suppression of the IgE response.