Italian farmers say sales of choice "mozzarella di bufala", made from milk of water buffalo in the Campania region around Naples, had already dropped 40 percent because of the rubbish crisis when stories emerged about brucellosis among buffalo.
A bacterial disease causing fever, it spreads through contaminated or unpasteurized milk and can infect humans.
"We have seen a decrease in the consumption of fresh buffalo mozzarella," said Rome restaurateur Mahua Reset. "But it looks like nobody is worried about mozzarella on pizzas, because consumption of pizza has increased."
Authorities say controls already in place prevent infected milk from reaching cheese producers but took the precaution this week of naming a special commissioner to eradicate brucellosis.
His first task will be to supervise the slaughter of between 30 000 and 60 000 buffalos of a total Italian herd of 400 000 and pay Italian farmers millions of euros in compensation.
"There should be no concern about milk used for cheese because milk with brucellosis does not get into the production circuit of DOP mozzarella," said Vito Rubino, president of a mozzarella producers' association, in comments sent to Reuters.
DOP (Protected Designation of Origin) is the label Italian cheese producers jealous of their quality use to tell consumers mozzarella, parmesan, grana padano and other cheeses come from the original location and are made with traditional methods.
Mozzarella has been produced in Campania at least since the 12th century. The name first appears in a 16th-century cookbook by the papal chef Bartolomeo Scappi. It is mostly used to top pizzas or in Caprese salad with tomatoes and basil, but gourmands say real bufala cheese from Campania is best appreciated on its own.
Italian newspapers have reported that the Neapolitan mafia, known as the Camorra, has hindered eradication of brucellosis by peddling infected cheese. But Angelo Coletta of the buffalo herders' association said a police investigation came up with no evidence of links between mozzarella and the mob.
Authorities ruled out any threat to mozzarella and other products from the rubbish crisis in Naples, where political incompetence and mob interference have led to piles of uncollected garbage rotting in the streets.
"The rubbish crisis is limited to large metropolitan areas and doesn't affect mozzarella production," said Guido Tamperi, Italy's undersecretary for farm policy.