SANTA FE, N.M. — The New Mexico Department of Health on Monday confirmed two more human cases of plague.

The recent cases involve a 52-year-old woman and a 62-year-old woman. The first case this year was reported in early June in a 63-year-old man.

All three patients, who live in Santa Fe County, were hospitalized but there have been no deaths.

State public health veterinarian Paul Ettestad said plague can be present in fleas that infest wild rodents in Santa Fe County, including within the city limits of Santa Fe and in other locations around New Mexico.

“Pets that are allowed to roam and hunt can bring infected fleas from dead rodents back into the home, putting you and your children at risk,” he said.

Health workers are conducting environmental investigations around the homes of the three patients to look for ongoing risk and to ensure the safety of immediate family members and neighbors.

Plague generally is transmitted to humans through the bites of infected fleas but can be transmitted by direct contact with infected animals including rodents and pets. Symptoms include sudden onset of fever, chills, headache and weakness.

According to the Centers for Disease Control and Prevention, plague is infamous for killing millions of people in Europe centuries ago. Antibiotics are now effective in treating the disease, but officials say without prompt treatment, it can cause serious illness or death.

The CDC reports that hundreds of cases have been documented over the last century in the western United States, typically in northern New Mexico, northwestern Arizona and southern Colorado.

In 2016, New Mexico had four human cases with no fatalities. Four cases were also reported in 2015 with one fatality.