Signs, symptoms and treatment of echinococcosis
Cystic echinococcosis is characterized by an asymptomatic incubation period that can last many years until cysts the parasite grows to an extent that triggers clinical signs, depending on the location and size of the cysts and the pressure exerted on the surrounding tissues. In cystic echinococcosis, The larval stages of the parasite develop as one or more cysts mainly in the liver and lungs, and less frequently in the bones, kidneys, spleen, muscles, central nervous system, and eyes. Abdominal pain, nausea and vomiting are commonly seen when cysts occur in the liver. If the lung is affected, clinical signs include chronic cough, chest pain and shortness of breath.
Alveolar echinococcosis is characterized by an asymptomatic incubation period of 5–15 years and the slow development of a primary tumour-like lesion which is usually located in the liver. Lesions may also involve other organs such as the spleen, lungs and brain following dissemination of the parasite via the blood and lymphatic system. Clinical signs include weight loss, abdominal pain, general malaise and signs of hepatic failure. If left untreated, alveolar echinococcosis is progressive and fatal.
Both cystic echinococcosis and alveolar echinococcosis can be expensive and complicated to treat, sometimes requiring extensive surgery and/or prolonged drug therapy.
Four options exist for the treatment of abdominal cystic echinococcosis: i) percutaneous treatment of the hydatid cysts with the PAIR (Puncture, Aspiration, Injection, Re-aspiration) technique; ii) surgery; iii) anti-infective drug treatment; iv) expectant management (‘watch and wait’). The choice must primarily be based on the ultrasound images of the cyst, following a stage-specific approach, and also on the medical infrastructure and human resources available to treat patients.
For alveolar echinococcosis, early diagnosis and radical (tumour-like) surgery followed by anti-infective prophylaxis remain the key elements. If the lesion is confined, radical surgery offers cure. Unfortunately, in many patients the disease is diagnosed at an advanced stage, and palliative surgery, if carried out without or with incomplete anti-infective treatment, frequently results in relapses.