Total 420 serum samples from twentyintensive pig farms were tested in different districts in Hainan province.The resultsshowed that PRDC was very common in pig farms, but infected rate different.

• 通过笔者对省内不同县、市的20个规模化猪场共420份血清进行的血清流行病学调查，结果表明，我省各地猪场普遍存在PRDC感染，但各场之间及各猪群之间PRDC的感染状况不尽相同。