Texas Hospital Reports 50 Mu COVID Cases As Delta's Dominance Continues

Roughly 50 cases of the Mu variant of COVID have been detected in a Texas hospital, according to local news outlets.

It's the newest variant to be dubbed a variant of interest (VOI) by the World Health Organization (WHO), which updated its VOI list last week and officially gave Mu its name. The variant is also known as B.1.621.

Dr. Wesley Long, a clinical pathologist at the Houston Methodist Hospital, told news outlet Click2Houston Monday that staff had found "a few cases here and there dating back all the way till May" after the WHO granted Mu its classification.

Data on Mu is still thin on the ground, though experts have said it appears to have some mutations that are associated with virus advantages. Hundreds of Mu samples have been sequenced in the U.S., according to Outbreak.info.

Yet health officials have said they are more concerned about the rampaging Delta variant at the moment, which has out-competed all other variants in the U.S. to become almost the sole variant in the country.

Speaking to Fox 26 Houston, Dr. Long said the hospital was "pulling some data" on the cases but added that they "probably don't have what it takes to overtake the juggernaut that is the Delta variant," given a general lack of spread. The news outlet said the hospital had confirmed that around 50 Mu cases had been reported there.

According to Centers for Disease Control and Prevention (CDC) data, the Mu COVID variant was detected in roughly 0.1 percent of sequenced COVID samples in the U.S. in the week ending September 4.

The Delta variant, on the other hand, was detected in 98.9 percent of them. The Alpha variant made up another 0.1 percent and another classification listed as "Other" made up about 0.7 percent.

On Tuesday, Maria Van Kerkhove, COVID specialist for the WHO, said in a press event that the Mu variant was increasing in prevalence in some South American countries but decreasing in other parts of the world, CNBC has reported.

She added that the Delta variant remains the "most concerning" variant to her given its increased transmissibility. Meanwhile Dr. Mike Ryan, executive director of the WHO Health Emergencies Programme, said new variants would have to compete with the "best in class" that is Delta.

Similar comments were made by U.S. infectious disease expert Dr. Anthony Fauci last week, who said that although researchers were "paying attention" to Mu, it was not considered to be "an immediate threat" at the moment.

COVID variants emerge due to random mutations to the virus that happen wherever it is allowed to spread. Sometimes these mutations are useless or harmful to the virus, and other times they make it stronger. Not all variants will be as strong as, or worse than, Delta.

COVID sample
A COVID sample being tested at a testing site in Wantagh, New York, in April 2020. Delta is still the dominant variant in the U.S., CDC data shows. Al Bello/Getty