SPRINGFIELD, Mo. (AP) — The spike in COVID-19 cases is leading to a surge of critical illnesses in southwestern Missouri.

The Springfield-Greene County Health Department on Friday reported the largest number of critical care and intensive care unit patients since the pandemic began, KYTV reported.

Yesterday (June 23rd) we reported 158 new cases of COVID-19. As of this morning, 167 COVID-19 patients are in Greene County hospitals. These are the highest numbers we’ve had in Greene County since mid-January. Complete data available at https://t.co/0vnxh30xxy pic.twitter.com/3dGmQQC3Si

— S-GC Health Dept. (@SGCHD) June 24, 2021

Health officials in Missouri’s third-largest city say 44% of the 167 COVID-19 patients there are considered critical care or are being treated in the ICU.

The delta variant of the virus is believed responsible for much of the spread in Missouri, especially in the southwestern and northern parts of the state.

With 158 new cases recorded in Greene County Mo yesterday, (population 295,000) we had more new cases than 30 states including DC and PR. (My quick math) The Delta Variant appears far more transmissible. If you have been waiting to vaccinate, I would go now before its too late.

— Steve Edwards (@SDECoxHealth) June 25, 2021

Officials also cite low vaccination rates.