Atlanta, Georgia - Amid a multi-state salmonella outbreak, federal health authorities have identified wild songbirds and bird feeders as the likely source.

The illness has affected 19 people across eight states, eight of whom have been hospitalized, the New York Times reported.

The patients are between 2 months and 89 years old.

The Atlanta-based Centers for Disease Control and Prevention (CDC) said the salmonella infections affected communities in California, Kentucky, Mississippi, New Hampshire, Oklahoma, Oregon, Tennessee, and Washington.

Six cases were reported in Washington and five in Oregon. No one has died so far.

Public health officials conducted interviews with the sick people, asking them about animals they had come in contact with before they fell ill.

All of the 13 interviewed said they had been in direct or indirect contact with wild birds, with nine of them stating they owned a bird feeder.

According to the CDC, salmonella can spread among birds, who then pass it on to pets and people.

The authorities warned they found strains of salmonella that has sickened people in wild songbirds, such as pine siskins – the small, streaked, yellow-tinged songbirds from the finch family.

To prevent further salmonella cases, the CDC recommends cleaning bird feeders and bird baths at least once a week or when they are dirty.

People should also avoid feeding wild birds with their bare hands, and should wash with soap and water after touching a bird feeder or bath, as well as after handling a bird.

Because many people don't get tested for salmonella, the CDC said the actual number of infections may be much higher than the number of reported cases.

About 1.35 million cases of salmonella are reported every year in the US. Of those infected, about 26,500 require hospitalization and about 420 people don't survive.