Window Rock, Ariz. • Navajo Nation health officials have reported 38 additional cases of COVID-19 and one more known death.

Tribal Department of Health officials said 7,840 people on the vast reservation that spans parts of Arizona, New Mexico and Utah have tested positive with 378 known deaths as of Sunday night.

Health officials also said reports from all 12 health care facilities on and near the Navajo Nation indicate 58,768 people have been tested and 5,581 have recovered from COVID-19.

The number of infections is thought to be far higher because many people have not been tested, and studies suggest people can be infected with the virus without feeling sick.

The coronavirus causes mild or moderate symptoms such as fever and cough for most people.

But for some — especially older adults and people with existing health problems — it can cause more severe illness including pneumonia, and death.

Tribal police and the New Mexico National Guard are enforcing weekend curfews on the Navajo Nation as officials continue to try to contain the coronavirus outbreak.