Nine people have been diagnosed with salmonella infections in an outbreak in New Mexico, Colorado, Kansas, Texas and Oklahoma. Of the nine cases, seven were children one year old or younger. There have been three salmonella cases in New Mexico, in Taos, Roosevelt and Curry counties.

Officials said six of the nine cases have been linked to young poultry from a hatchery in New Mexico. The New Mexico Department of Health said it won’t release the name of the hatchery until the investigation is completed.

Poultry can shed salmonella in their feces. Health officials said thorough hand-washing following contact with these animals is important to prevent salmonella infection. Human infection occurs when contaminated food, hands, or other objects are placed in the mouth.