As the delta variant of the coronavirus continues its surge, Harris County officials have once again raised the coronavirus threat level, this time to red, signifying a severe and uncontrolled level of the virus in the community.

Unvaccinated residents are asked to minimize contact with others whenever possible and avoid leaving home except for the most essential needs. Both vaccinated and unvaccinated residents are encouraged to wear masks, Harris County Judge Lina Hidalgo said during an Aug. 5 news conference.

“We find ourselves retracing our steps toward the edge of a cliff,” Hidalgo said. “It is very conceivable that we could see ourselves heading toward a public health catastrophe.”

Hidalgo called the situation a “perfect storm” of circumstances: strained nursing and hospital staff, a more transmissible variant and limited ability to implement health interventions at the local level.

The increased threat level comes just two weeks after the county raised the threat level from yellow to orange.

Harris County now has over 20,000 active cases of COVID-19, according to the Harris County Public Health dashboard, with a testing positivity rate over 15%. Just 22 days prior, that rate was below 5%. In addition, Aug. 2 data has shown that the positivity rate is doubling every 1.8 weeks, faster than at any other point in the pandemic, Hidalgo said.

Meanwhile, 65.1% of eligible Harris County residents age 12 and older have received at least one dose of the vaccine as of Aug. 5, according to public health data.

Still, hospitalizations have maintained a steep curve; according to Texas Medical Center data, coronavirus hospitalizations reached over 300 patients per day Aug. 4. Of those, 85%-90% are unvaccinated, said Dr. David Persse, chief medical officer and local health authority for the city of Houston.

“We have to shift that curve again and change those trends,” Hidalgo said.

Key to doing so: Get vaccinated if you are eligible and have not already received the vaccine. It was a message stressed repeatedly by Hidalgo, Persse and Houston Mayor Sylvester Turner.

“If you are currently unvaccinated in this community, you represent a danger to yourself and others, and in particular your own family members,” Persse said.

In the city of Houston, 89 municipal workers, 68 police officers, and 40 firefighters are positive for the coronavirus with three employees hospitalized, Turner said. Those positive test results mean the city is less able to provide services to its residents, he said.

With beds in intensive care units at surge levels—TMC reports 1,434 beds in use, over the 1,330-bed base capacity threshold—and services such as fire and emergency medical services similarly hampered, response times slow down, Persse said.

For example, as of 1 p.m. on Aug. 5, 26 of the 104 ambulances in the Houston Fire Department were at emergency departments, waiting to offload patients. Four of them had been there for over two hours.

“An ambulance that’s at the emergency department waiting to offload a patient is not available to take the next 911 call,” Persse said.