Back in November of last year I attended a meeting convened by the Foodborne Disease Burden Epidemiology Reference Group (FERG) which aims to assess the burden of all the major different foodborne illnesses worldwide. The WHO Initiative to Estimate the Global Burden of Foodborne Diseases was set up in 2007 and the first publication from this initiative is now available in PLoS Neglected Tropical Diseases.
The global burden of echinococcosis study was commissioned by FERG and carried out by Paul Torgerson and colleagues and the paper is available (free to download and open access as with all PLoS papers) here. Human alveolar echinococcosis (AE) is caused by the larval stage of the fox tapeworm Echinococcus multilocularis and is transmitted to humans by consumption of parasite eggs which are present in the faeces of foxes and dogs. If untreated, clinical signs such as abdominal mass and/or pain, jaundice, and ultimately liver failure can occur. Limited and expensive treatment options include liver resection to remove the parasite mass and chemotherapy but according to the authors lifetime chemotherapy is sometimes needed and without treatment the disease is usually fatal.
The authors found that there are approximately 18,235 (CIs 11,900–28,200) new cases of AE per annum globally with 16,629 (91%) occurring in China and 1,606 outside China. China and Russia have the most endemic cases. The mountainous regions of Kazakhstan, Kyrgystan, Uzbekistan, and Tadjikistan are all endemic for the disease too. They also calculated that AE results in a median of 666,434 DALYs per annum (CIs 331,000-1.3 million). They suggest that in some rural parts of China echinococcosis could be one of the most important diseases.
One stunning finding was that ‘annual mortality due to AE of approximately 18,000 is greater than one tenth of the total mortality of 177,000 as a result of the 10 diseases of the neglected tropical disease cluster (trypanosomiasis, Chagas disease, schistosomiasis, leishmaniasis, lymphatic filariasis, onchocerciasis, intestinal nematode infections, Japanese encephalitis, dengue, and leprosy )’.
Next steps include assessing the contribution of different transmission pathways (dogs, foxes, water and food contamination) to this burden of disease, and working out which methods of control will be most cost-effective.