Ultrasound findings and associated factors to morbidity in Schistosoma haematobium infection in a highly endemic setting

Abstract

Objective: To evaluate the usefulness of the WHO classification of ultrasound pathological changes and to establish risk factors for morbidity in a highly endemic setting.

Methods: One hundred and fifty-seven ultrasounds were performed on school-aged children previously diagnosed with urinary schistosomiasis in Cubal, Angola. The findings were analysed according to the WHO guidelines. Factors for morbidity were studied.

Results: Mean age of the children was 8.7 (SD 3.2) years. Pathological changes were found in 85.3% (84.7% in the bladder, 34.4% the ureter and 6.3% kidney lesions). The global score according to the WHO classification was 5.74. Male gender [OR 2.61 (1.04-6.58); P 0.043] and older age [OR 2.96 (1.17-7.46); P 0.023] were associated with a higher risk of developing any kind of urinary abnormality. Proteinuria was present in 61.7% of the children. Macroscopic haematuria [OR 2.48 (1.11-5.58); P = 0.02)] and a high level of proteinuria > 300 mg/dl [OR 5.70 (2.17-14.94); P 300 mg/dl)] were associated with abnormalities of the upper urinary tract and showed good positive and negative predictive values for the detection of pathology in the upper urinary tract (65.5% and 71.1%, respectively).

Conclusions: Severe urinary tract pathology was found in a high percentage of the children in our setting. Microhaematuria and proteinuria were good markers of morbidity, proteinuria being more precise for severe alterations of the upper urinary tract. We suggest initial and evolutive ultrasound in children diagnosed with schistosomiasis, and close monitoring including periodic controls. As schistosomiasis control efforts are currently focused on reducing morbidity, tests that detect the presence or degree of morbidity are essential for targeting treatment and tracking the progress of control campaigns.

Keywords: Angola; paediatrics; pédiatrie; schistosomiase; schistosomiase urinaire; schistosomiasis; ultrasound; urinary schistosomiasis; échographie.