Evaluation of the features of cystic echinococcosis with concurrent super-infection: a retrospective study in Southern Iran

OBJECTIVE: Superinfection of cystic echinococcosis (CE) is a life-threatening complication with significant morbidities, which can be prevented with early diagnosis and treatment. This study aims to examine the clinical characteristics, diagnostic methods, and treatment options for superinfected CE, as there is currently limited information available on the differences between superinfected and non-infected CE in terms of clinical features, serological and radiologic findings. METHODS: This cross-sectional study was conducted on hospital records of patients who were diagnosed with hydatid cysts in a 15-year period (2004 to 2018) in two main university-affiliated referral centers in Fars province, southern Iran. Patients’ information regarding the demographical and clinical features related to CE, age, sex, previous history of CE or recurrence, size and location of CE, and length of hospital stay were collected. Moreover, the characteristics of concurrent infections with hydatid cysts were recorded. RESULTS: A total of 586 surgeries due to CE were performed on 501 patients, of which 67 (11.43%) had reoperations due to the recurrence of the disease. A total of 30 (5.99%) incidences of superinfection were observed. There were no statistically significant differences in terms of laboratory and imaging findings between CE patients with concurrent infections and other CE patients (p-value > 0.05). Among the patients with super-infection, four had fungal infections of the lungs. Aspergillus fumigatus was the causative pathogen in all four patients that were diagnosed with fungal superinfection. All patients underwent surgical excision with favorable long-term outcomes. CONCLUSION: Our study revealed a 5.99% incident rate of CE superinfection. Regarding the concurrent fungal infections in hydatid cysts, the patient’s symptoms and laboratory and imaging findings are inconclusive and histopathological evaluation seems to be the most reliable option. Surgical resection is the gold-standard treatment option with favorable outcomes and potentially can be curative.