The Global Burden of Alveolar Echinococcosis

Human alveolar echinococcosis (AE), caused by the larval stage of the fox tapeworm Echinococcus multilocularis, is amongst the world's most dangerous zoonoses. Transmission to humans is by consumption of parasite eggs which are excreted in the faeces of the definitive hosts: foxes and, increasingly, dogs. Transmission can be through contact with the definitive host or indirectly through contamination of food or possibly water with parasite eggs. We made an intensive search of English, Russian, Chinese and other language databases. We targeted data which could give country specific incidence or prevalence of disease and searched for data from every country we believed to be endemic for AE. We also used data from other sources (often unpublished). From this information we were able to make an estimate of the annual global incidence of disease and disease burden using standard techniques for calculation of DALYs. Our studies suggest that AE results in a median of 18,235 cases globally with a burden of 666,433 DALYs per annum. This is the first estimate of the global burden of AE both in terms of global incidence and DALYs and demonstrates the burden of AE is comparable to several diseases in the neglected tropical disease cluster

Population studies for AE in rural China.

<p>*Total of studies in the last 10 years.</p><p>+Study from 1992.</p

The life cycle of <i>Echinococcus multilocularis</i>.

<p>Man is infected as an aberrant intermediate host.</p

The relative numbers of CE∶AE cases in various studies from Turkey.

<p>*Intracranial echinococcosis only. Case searching from 47 neurosurgical units between 1994 and 1999.</p><p>**Intracranial echinococcosis only. Reported literature cases from Turkey from 1940s–1990s.</p

Flow chart illustrating the search methods and processing of information.

<p>Flow chart illustrating the search methods and processing of information.</p

Published case report series from Russia.

<p>*These data are from districts of Siberia where AE relative incidence might be expected to be higher.</p

Countries believed to be endemic for <i>E. multilocularis</i> over at least part of their territory.

<p>*Both European and Asian parts of Russia include large endemic areas.</p

Estimated annual incidence of AE in Asia, by country.

<p>*Including European Russia.</p

Global distribution of AE.

<p>Global distribution of AE.</p