The government is reinforcing disinfection measures after a highly infectious strain of the avian influenza(AI) involving migratory birds was detected for the first time in seven months. 

According to the Ministry of Agriculture, Food and Rural Affairs on Tuesday, samples from 17 wild birds collected in Gokgyo Stream in Cheonan, South Chungcheong Province, were examined on Monday. One of them was found to contain a highly pathogenic H5N1 strain of AI. 

Officials are raising the possibility of secondary infections via migratory birds, adding other regions in the nation may also have been affected. 

The ministry assessed that it is a grave situation, noting the discovery of a highly infectious strain involving migratory birds is often followed by the discovery of similar strains at domestic poultry farms, including those far away. 

The ministry also raised its AI watch level to "serious" on Monday and strengthened quarantine measures.