Public health officials in Germany say contaminated sprouts are the source of an E. coli outbreak that has claimed the lives of at least 30 people.

The head of the Robert Koch Institute, Reinhard Burger, says the pattern of the outbreak points to the sprouts as the source.

Health officials initially blamed the bacterial outbreak on Spanish sprouts and vegetables and then spread the blame to other European farmers, costing European Union farmers million of dollars as produce was left to rot in fields and warehouses.

The outbreak has sickened more than 2,800 people and sparked renewed tensions between the EU and Russia, where officials are refusing to back down on a total ban of all EU vegetables.

On Thursday, Russian President Dmitry Medvedev and other top officials began hosting top EU officials for a two-day food crisis summit in the Russian city of Nizhny Novgorod.

E. coli symptoms include stomach cramps, diarrhea, fever, vomiting, and in extreme cases kidney failure and death.