Migratory birds were found to have been the source of highly pathogenic avian influenza (HPAI) in South Korea this year and last year.
 
The Animal and Plant Quarantine Agency said Thursday that it found in the carcasses and feces of migratory birds an extensive amount of the HPAI virus, which was similar to the virus found in farms.
 
Epidemiological research also found that there is a low probability that HPAI entered the country through other routes such as imported livestock or overseas visits by farmers.
 
HPAI spread among farms due to a number of reasons such as movements by vehicles, farmers and middle merchants.
 
The agency said it doesn't expect HPAI to recur as it has been implementing strong quarantine measures and there have been no recurrences since June 10.