title: Observations on investigations prior to schistosomiasis control.
mesh_terms: D003153:Community Health Services; D006275:Health Facility Planning; D006306:Health Surveys; D006801:Humans; D008722:Methods; D011315:Preventive Medicine; D011647:Puerto Rico; D012499:Sanitation; D012552:Schistosomiasis / Q000517:prevention & control*