Follow up study of symptomatic human cystic echinococcosis treatment with albendazole and praziquantel, in Uruguay

Background: Cystic echinococcosis (CE) is a chronic disease considered a neglected one. Cystic echinococcosis is endemic in Uruguay and the region. Surgery, using various technical approaches, has the potential to safely remove the cyst(s) and lead to a complete cure in a high number of patients with simple forms of CE. However, surgery may be impractical in patients with multiple cysts in several organs, high surgical risk, or in patients with previous multiple surgeries. In these cases, the pharmacological treatment with the benzimidazolic drug Albendazole (ABZ) alone or combined with Praziquantel (PZQ), has been promising as the best choice to achieve improvement or cure.

Methods: In this study, we analyze the results obtained on the anti-parasitic treatment of 43 patients diagnosed with CE between the years 2003 and 2020. Patients were treated before and/or after surgery with ABZ or the combination ABZ/PZQ. The standardize protocol of the anti-parasitic drug treatment before surgery was 7 days, 15 days or 1 month depending on the urgency and availability of the surgical procedure. All cases that involved confirmed locations on lungs underwent immediate surgery with minimal pre-treatment when possible. After surgery, the standardize protocol of anti-parasitic drug treatment consisted of six cycles of 30 days each and resting intervals of 15 days in between. ABZ was used in all cases, administered orally, twice daily, at a total dosage of 15 mg/kg/day, with food high in fat content for improved absorption. The follow up was carried out according to WHO-IWGE guidelines for 5 years.

Results: Of the 43 patients fourteen were ≤ 15 years of age and had a differentiated pre-surgical treatment. From the ≥ 16 years of age, 36 completed the treatments and the 5 years follow up. Four patients changed geographical locations, without a forwarding contact, after the post-surgery treatment. No patient died during the study. Of the 36 patients that completed the study, 32 were treated only with ABZ; 93.75% achieved treatment success as determined by improvement or cure, and 6.25% treatment failure determined by no change or worsening. The last four patients received the ABZ/PZQ combination therapy and achieved 100% treatment success.

Conclusion: The pharmacological treatment resulted in a good option not only as palliative but also as potentially curative. The main relevance of its use was in cases with previous multiple surgeries or surgeries with potential life-threatening complications due to the number and location of cysts and concurrent comorbidities. A follow-up of at least 5 years would be recommended to assure remission and control of the transmission. More randomized trials are needed to provide clear clinical evidence of different pharmacological treatments for CE.