Antigen-specific antibody isotype patterns to schistosoma japonicum recombinant and native antigens in a defined population in Leyte, the Philippines.

We describe antibody isotype patterns resulting from Schistosoma japonicum infection among 155 individuals 5-76 years old from a community in Leyte, The Philippines. Their exposure, infection, and reinfection status had been observed in a previously described water contact study used to categorically classify them as putative resistant or susceptible individuals. Antigens tested for specific antibody isotype responses were soluble worm antigen preparation (SWAP) and soluble egg antigen (SEA) and a panel of recombinant molecules.

Immune correlate study on human Schistosoma japonicum in a well-defined population in Leyte, Philippines: II. Cellular immune responses to S. japonicum recombinant and native antigens.

Cellular immune responses to specific Schistosoma japonicum recombinant and native antigens were investigated in a defined study population of 155 individuals in the Philippines, where data collected from a 3-year observation of exposure, infection and reinfection pattern were used to categorically classify putative 'resistant' and 'susceptible' individuals. Using peripheral blood mononuclear cells (PBMC) of individuals enrolled in the study, in vitro lymphocyte proliferation and cytokine (IFN-gamma, IL-5 and IL-10) production in response to defined recombinant antigens (97 kDa paramyosin, 22 kDa tegumental antigen, 37 kDa glyceraldehyde-3-phosphate dehydrogenase, 14 kDa fatty acid binding protein and 28 kDa gluthathione-S-tranferase) and native antigen soluble worm antigen preparation (SWAP) were measured. Cellular responses to the recombinant and SWAP antigens suggest that Th1 type of response appear to be important in predicting resistance in this population.

Immune correlate study on human Schistosoma japonicum in a well-defined population in Leyte, Philippines: I. Assessment of 'resistance' versus 'susceptibility' to S. japonicum infection.

This study describes the categorical classification of 155 individuals living in an endemic village in Macanip, Leyte, Philippines as 'resistant' or 'susceptible' to Schistosoma japonicum infection using available exposure, infection and reinfection data collected from a 3-year water contact (WC) study. Epidemiological parameters including age, sex, and infection intensities in relation to observed reinfection patterns are also described. This classification was used in subsequent immunological studies described in two accompanying papers to identify protective immune mechanisms among resistant individuals induced by defined candidate vaccine molecules for S.

Difficulties and strategies in the control of schistosomiasis in the Philippines.

Schistosomiasis japonica continues to remain a public health problem in the Philippines affecting 10 out of 16 regions with 6.7 million people at risk mostly farmers and fisher folks. Early efforts focused on snail control in the absence of an effective drug against the disease.