An extensive look at wastewater samples taken across the United States from May to July found traces of the H5N1 bird flu popping up -- but only in areas populated by farm animals.

On, south of the Jezreel Valley in northern Israel, in the second case of the season. The disease was traced to four poultry sheds housing some 34,000 hens used for breeding chickens for meat. The first bird flu was identified earlier this month at Moshav Nahalal in the Jezreel Valley.

Last week, a person in Missouri was infected with bird flu despite not having any exposure to animals. The state’s health department said the individual recovered from their illness but that a household contact of the patient had become ill with similar symptoms on the same day.

San Diego County is now the fifth location in California to detect the bird flu, county officials announced Monday.