Sailo said that the cases of PRRS have decreased during the past one month and samples have been taken so far from 1,621 pigs even as the Centre had asked the state government to collect samples from all the pigs in Mizoram.
"There are around 2.5 lakh pigs in the state out of which 75 per cent were affected by the PRRS," Sailo said, adding that the infection rate has reduced considerably now.
The PRRS was propagated by pigs imported from neighbouring Myanmar where it was prevalent, he said.
Though the state government, through the district magistrates of the districts adjoining Myanmar issued prohibitory orders, smugglers continued to smuggle pigs and piglets from Myanmar through the porous 404-km-long international border with that country, he said.