Sensitivity, Specificity and Positive Predictive Value of Selected Clinical Sings and Symptoms Associated with Schistosomiasis Mansoni

Abstract

Proietti F A (Department of Clinical Medicine, School of Medicine, Federal University of Minas Gerais State, Brasil) and Antunes C M F. Sensitivity, specificity and positive predictive value of selected clinical signs and symptoms associated with schistosomiasis mansoni. International Journal of Epidemiology 1989, 18: 681–683. The signs and symptoms classically asociated with Schistosoma mansoni infection were analysed in relation to their senstitivity, specificity and positive predictive value in identifying S. mansoni patients as well as more severe forms of the disease under field conditions. Data was collected in a survey conducted in a small urban area in the south east of Brazil (14.3% infection in the studied sample with a geometrical mean excretion of 95.5 S. mansoni eggs/gram of faeces). ‘Blood in the stool’ and a ‘palpable and hardened liver’ showed the higest positive predictive value; their presence, even in relatively low prevalence areas may be used by the health field workers as an indication of the existence of more advanced clinical forms of the disease.