Ultrasonographic diagnosis and medical treatment of human cystic echinococcosis in asymptomatic school age carriers: 5 years of follow-up.

Hydatidosis or cystic echinococcosis (CE) caused by Echinococcus granulosus is endemic in the Province of Río Negro, Argentina. The objective of this investigation was to evaluate the results of a program carried out in endemic areas of the Province of Río Negro, Argentina, in the years 1997-2002. Abdominal ultrasonography was used, classifying the cases detected according to WHO guidelines. A treatment algorithm was defined which included observation, albendazol therapy, PAIR or surgery, according to cyst type and size. A total of 5745 schoolchildren were evaluated, detecting hydatid cyst carriers in 70 (1.2%). Of these; 40 (57.1%) were included in follow-up protocol, 25 (35.7%) in treatment protocol with albendazol, 2 (2.9%) with PAIR and 3 (4.3%) with conventional surgery. After a mean of 44 months, among 25 cases treated with albendazol, in 2 (8%) cysts underwent total involution, in 17 (68%) they presented positive changes, in one (4%) they remained unchanged and in 4 (16%) they progressed to type II, while 1 (4%) displayed negative evolutionary changes. Out of 39 cases under observation alone protocol, in 8 cases (21%) cysts underwent total involution, in 7 (18%) they presented positive changes, in 11 (28%) they remained unchanged, in 2 (5%) they progressed to Type II and in 11 (28%) they presented negative evolutionary changes and had to be included in the other protocol types. In this study, conventional surgery, was applied to 10% of detected cases. The combination of ultrasonographic screening and albendazol treatment showed promising results.