We conducted a re-infection study in a S. haematobium endemic Malian population, to determine whether an equivalent to the boost in IL-5 that occurs after treatment of S. mansoni occurs after treatment for S. haematobium infections, and to model any such IL-5 boost against known key components of immunity to schistosomiasis, SWA-IgE and eosinophils. The gene discussed is IL5; the disease is schistosomiasis.