ABSTRACT
A survey of 12 schools in Cabo Delgado, northern Mozambique, was performed to assess the extent of schistosomiasis infection. Questionnaires validated by parasitological examination of stools and urine were used. Very high prevalences of Schistosoma haematobium infection were found in all schools (77.5% was the lowest recorded), so the questionnaires did not distinguish 'high risk' schools. However, they clearly indicated a good knowledge of the infection by students and teachers. The disease was recognized by teachers to be a public health problem in the area. S. mansoni infection was rare. It had not been reported in previous surveys, but its vector Biomphalaria was discovered in the area. Revised mapping of the disease is advisable in view of probable changes after many years of conflict.