A botched vaccine intended to protect Paraguay's livestock against foot-and-mouth disease was responsible for transmitting the ailment to hundreds of animals that later had to be destroyed, the government said Tuesday.
After extensive laboratory tests, Paraguayan and international scientists concluded that "human error" and "negligence" in the production of the vaccine caused the outbreak last September, a top veterinary official here said.
"After the most recent laboratory analysis, we have confirmed that the outbreak of foot and mouth disease... came about as a result of problems with the vaccination of animals," said Daniel Rojas, head of Paraguay's National Service for Animal Health and Quality.
"There now is no doubt that it was human error that led to the outbreak of foot-and-mouth," he said.
The affected animals were at the Santa Helena ranch, a hacienda some 400 kilometers (250 miles) northeast of Asuncion, in the department of San Pedro.
Authorities said all told, more than a thousand cattle had to be sacrificed during the outbreak, which sent tremors through a region that prizes its meat industry.
Officials said they have not yet determined who would be held accountable for the costly mistake..
"We still have to identify at what stage in the process the problem occurred, determine who was responsible for the mistake and punish them," Rojas said, adding that the outbreak "led to significant economic losses for the country."
The outbreak prompted neighboring countries to ban the import of Paraguayan meat, livestock, and meat by-products to prevent the spread of the disease across international boundaries.
The export ban was a major blow to tiny, mostly rural Paraguay, where beef is the number two export, totaling $650 million last year.
Officials estimate that the ban costs the economy some $70 million each month.
One of the most contagious animal diseases known to scientists, foot-and-mouth (also known as hoof-and-mouth) disease infects mainly cattle and swine but also sheep and goats.
The disease can be spread with dust, animal-to-animal in herds, through consumption of contaminated animal products and even with farm implements and vehicles.
Although adult animals normally do not die from the disease, they must be destroyed once infected to keep it from spreading.