The story begins with a bacterial infection: Brucellosis affects the reproductive system and reduces milk production in domestic animals. The disease, which can also be transmitted to humans via food, has broken out among water buffalo in Campania, and has gotten so bad that the Italian government has ordered the slaughter of between 30,000 and 60,000 head from among a total herd of 400,000 (that's 7.5-15 % for those counting). It's a long standing problem, but one that has gotten much worse recently because, as Italian newspapers and the BBC are reporting, "local vets who are supposed to test and put down infected animals have been intimidated by the local mafia - the Camorra - who also control some of the farms."
Add to the mix an ongoing refuse problem in Naples, also caused by mafia corruption, and you end up with some really rough times for buffalo milk mozzarella. However, even though the government has reassured people that the Brucellosis outbreak is unrelated to the garbage problem, consumption is still down. Moreover, it turns out that D.O.P. mozzarella is safe because pasteurization kills any brucella living in the milk.
I wonder whether any of this will have an effect on the American buffalo milk industry, if you can even call it that. Regardless, expect to see the price of D.O.P. mozzarella di bufala rise steeply in the coming weeks and months. And who knows if the Italian producers will ever recover from this. Losing up to 15 % of the herd (in an industry that's already relatively tiny) is surely a big blow.