Diagnosis, treatment, and management of echinococcosis.

Echinococcosis (hydatid disease) is caused by the larvae of dog and fox tapeworms (cestodes) of the genusEchinococcus (family Taeniidae).This zoonosis is characterised by long term growth of metacestode (hydatid) cysts in humans and mammalian intermediate hosts. The two major species that infect humans are E granulosus and E multilocularis, which cause cystic echinococcosis (CE) and alveolar echinococcosis (AE). A few reported cases of polycystic echinococcosis in Central and South America are caused by E vogeli and E oligarthrus. w1 w2 The clinical potential of two other Echinococcus species (E shiquicus and E felidis) is unknown. 2 Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are serious chronic diseases with poor prognosis and high mortality if managed inadequately. Of the estimated two to three million cases of echinococcosis globally, most are cystic. 4 Published reports and the Office International des Epizooties databases suggest that the global burden for human CE exceeds one million disability adjusted life years (DALYs), resulting in a loss of $760m (£490m; €612m) a year, although these figures are probably underestimates. Case series and small clinical trials show a mortality rate of 2-4% for CE, but this increases markedly with poor treatment and care. 6 There are 0.4 million cases of human AE, and survival analysis has shown that, if untreated or if treatment is limited, mortality exceeds 90% 10-15 years after diagnosis. 7 About 18 000 new cases of AE occur annually, with a total annual burden of 666 434 DALYs. Here, we introduce the Echinococcus parasites and the diseases they cause, and we discuss current methods for the diagnosis, treatment, and management of both types of echinococcosis. The life cycle characteristics of Echinococcus spp and the causes and immunology of echinococcosis have been described extensively. 9-14 w3-w16 Where and how is echinococcosis acquired?