As the latest surge of COVID-19 coronavirus has begun spiking in Mississippi, the state’s long-term care facilities, chiefly nursing homes, have seen massive spikes in outbreaks.

“We’re seeing rapid growth in nursing home outbreaks,” Mississippi State Epidemiologist Dr. Paul Byers said Wednesday.

On December 1, the Mississippi State Department of Health (MSDH) reported 31 ongoing outbreaks in long-term care facilities. On Thursday MSDH reported 163 long-term care facility outbreaks, a more than five-fold increase in approximately four weeks.

Through Thursday, the last date MSDH expects to report number for the month of December, the state reported just under 30,000 total new cases, more than two-thirds of which were found in the last 10 days of the month.

Federal health officials on Thursday pressed nursing home workers to get their booster shots amid a spike in COVID-19 cases among staffers and a concerning lag in booster vaccination for residents and staff.

Federal statistics show that less than 2 out of 10 nursing home staff members in Mississippi have been fully vaccinated and boosted through last week.

The omicron variant “is lightning fast, and we can’t afford another COVID-19 surge in nursing homes,” Health and Human Services Secretary Xavier Becerra said in a livestreamed appeal to the industry. “You know that. I know that. Higher numbers of COVID cases would likely once again have a devastating impact on our loved ones … and we know we just have to work doubly hard to keep them safe.”

Nursing homes are a testing ground for President Joe Biden’s assertion that the United States is much better prepared to handle a surging virus than it was last winter. Although residents are a tiny proportion of the population, they represent a disproportionate share of Americans who have died in the coronavirus pandemic.

Earlier this year the advent of vaccines brought the virus under control in nursing homes and allowed them to reopen to visitors. But that return to normalcy could be in jeopardy as omicron pushes COVID-19 cases to new highs for the nation.

Cases among nursing home staffers jumped to 10,353 for the week ending Dec. 27, a rise of nearly 80% from the previous week, according to data from the Centers for Disease Control and Prevention. Staff deaths increased to 58, tripling from the previous week. Among residents, who are more heavily vaccinated, cases went up slightly and the data showed no increase in deaths.

The Associated Press contributed to this report.