The United States Centers for Disease Control and Prevention reports that backyard chickens have sickened 163 people in 43 states with salmonella bacteria.
Thirty-four required hospitalization.
The CDC said the outbreak may be more widespread and have infected more people than the official count because not all salmonella infections are recognized as such or become severe enough to require medical assistance.
The outbreak encompasses salmonella infections with the serotypes Enteritidis, Hadar and Infantis, according to the CDC.
State and local public health officials have interviewed 92 people and found that 81 (88 per cent) reported contact with backyard poultry before getting sick, the CDC said.
Many Ontario municipal councils have been lobbied by residents wanting bylaw changes so they can keep backyard chickens.