That's what's happening in North Dakota, one of 31 states suffering more new Covid-19 cases this past week compared to the previous week.

Contact tracing is crucial to finding possible carriers of coronavirus, so they can quarantine and break the chain of infection.

But a "sharp increase" in new cases has engulfed contact tracers, leading to delays and "a backlog of positive cases that have yet to be assigned to a case investigator," the North Dakota Department of Health said this week.

"Close contacts will no longer be contacted by public health officials; instead, positive individuals will be instructed to self-notify their close contacts and direct them to the NDDoH website, where landing pages will be created ...

explaining the recommended and required actions for both positive patients and close contacts."

The North Dakota National Guard has shifted 50 soldiers from contacting close contacts to notifying people who have tested positive, the state health department said.

As many as half of all people who have COVID-19 don't show symptoms, so it's critical to wear a mask because you could be carrying the virus and not know it," the CDC said.