Portal de Periódicos da CAPES

Multimodality imaging in diagnosis and management of alveolar echinococcosis: an update

2016; Volume: 22; Issue: 3 Linguagem: Inglês

10.5152/dir.2015.15456

1305-3612

Mesut Bulakçı, Merve Gülbiz Kartal, Sabri Yılmaz, Erdem Yılmaz, Ravza Yilmaz, Dilek Şahın, Murat Aşık, Oğuz Bülent Erol,

Parasitic Infections and Diagnostics

chinococcosis is the general name given to zoonotic infections caused by tapeworms (cestodes) in the genus Echinococcus.The life cycle of this parasite occurs in two different mammalian organisms (definitive host and natural intermediate host).Humans are accidental or aberrant intermediate hosts and are not a part of the natural life cycle of the parasite (1).The invasion of different organs by metacestodes, primarily the liver and lungs, causes severe problems in the intermediate or accidentally intermediate hosts (1, 2).The metacestodes Echinococcus multilocularis invade different organs in humans and shows growth and infiltration patterns mimicking neoplastic processes.In addition, diagnostic difficulties are encountered since it is not a common disease, particularly in nonendemic regions (3).Early diagnosis of the disease, as well as appropriate treatment and follow-up is very important in improving the patient's quality of life.Imaging is essential in the diagnosis, follow-up, and management of the disease. Epidemiology and pathophysiologyIn humans, the E. granulosus cestodes causes cystic echinococcosis (CE), E. multilocularis cestodes causes alveolar echinococcosis (AE), and E. vogeli and E. oligarthrus cause polycystic echinococcosis (also termed as neotropical echinococcosis).Although CE is common worldwide, AE is a manifestation seen only in the northern hemisphere.AE is more common in Russia, Central Asia, China, Northern Japan, Central Western Europe, Eastern Europe, Turkey, and Alaska.The exposure to Echinococcus eggs is affected by occupational and behavioral factors.The incidence of CE is highest in regions where sheep breeding is common.The risk of encountering AE is increased in human groups who spend more time in the wilderness.Polycystic echinococcosis, which has less medical and economic importance, is limited to Central and South America and few cases are reported in humans (1, 2).AE infestation is almost equal in men and women.The peak age is reported between 50 and 70 years (2).The natural course of the disease consists of approximately 5-15 years of asymptomatic incubation period followed by a chronic period (1, 2).The disease is incidentally detected in more than one-third of the patients (3).The definite hosts are foxes, whereas rodents are intermediate hosts in the life cycle of E. multilocularis.The eggs produced by the adult parasite are released into the environment by the fox and the cycle continues with digestion of contaminated food by the intermediate host.The eggs penetrate the bowel wall and invade the lymphatic and portal systems, and from there 247