Songbirds such as sparrows and thrushes carry various forms of bird flu and could potentially spread the viruses to pigs and poultry, US researchers have reported.
The birds carried low-pathogenic avian influenza – the less dangerous form of bird flu – but flu viruses can and do swap genes and mutate into more dangerous forms, the researchers said.
A major risk is that the birds would infect pigs, which are suspected ‘mixing vessels’ for new strains of influenza – notably the ongoing pandemic of H1N1 swine flu, the researchers wrote in the Biomed Central journal BMC Infectious Diseases.
“What is significant about the work is that for a long time folks thought this was just an issue in shorebirds and ducks,’ Tom Smith of the University of California Los Angeles, who directed the study. ‘We haven’t been doing surveillance on wild passerines. Most of the money for doing disease work in birds comes when one works on game species.”
Using National Science Foundation and National Institutes of Health funds, Smith and colleagues teamed up with David DeSante at the California-based Institute for Bird Populations to test songbirds for avian influenza viruses at the same time they were banding the birds for other research.
They tested more than 13,000 birds from 225 different species in 41 US states, and found low-pathogenic avian influenza in 22 species, notably fox sparrows, Cassin’s finches, Swainson’s thrush and Western tanagers.
Source: Straits Times