Study: COVID-19 Reinfection Rate Less Than 1% for Those Who Had Severe Illness

A study conducted by researchers from the University of Missouri School of Medicine and MU Health Care found that among more than 9000 patients who had severe COVID-19, less than 1% contracted the illness again at approximately 3.5 months after an initial positive test.

In a collaboration with MU Institute for Data Science and Informatics and the Tiger Institute for Health Innovation, researchers assessed data from 62 US health care facilities. The findings showed that 63 of the 9119 patients with severe COVID-19 infection contracted the virus a second time, with an average reinfection period of 116 days. The findings also showed that among 63 patients reinfected, 2 of them died.

“Our analysis also found asthma and nicotine dependence were associated with reinfection,” said lead researcher Adnan I. Qureshi, MD, professor of clinical neurology at the MU School of Medicine, in the press release. “However, there was a significantly lower rate of pneumonia, heart failure and acute kidney injury observed with reinfection compared with primary infection.”

Qureshi defined reinfection by 2 positive tests separated by a period of greater than 90 days after the initial infection resolved, and as confirmed by 2 or more consecutive negative tests. He investigated data from patients who received serial tests between December 2019 and November 2020, according to the press release.

“This is one of the largest studies of its kind in the U.S., and the important message here is that COVID-19 reinfection after an initial case is possible, and the duration of immunity that an initial infection provides is not completely clear,” Qureshi said in the press release.

REFERENCE

Study finds COVID-19 reinfection rate less than 1% for those with severe illness. University of Missouri School of Medicine. Published June 15, 2021. Accessed June 16, 2021. https://medicine.missouri.edu/news/study-finds-covid-19-reinfection-rate-less-1-those-severe-illness