March 03, 2021 — Houston has had cases of every concerning variant of the virus that causes COVID-19, according to a large new genome sequencing study.
Public health authorities have flagged the six variants identified in the study as problematic, because they have gene changes that may make the virus more contagious or help it escape immunity from vaccines or past infections.
The new finding comes as Texas Governor Greg Abbott announced that he would lift the mask mandate there, and “open Texas 100%.”
The preprint study, which has not yet been fully vetted by outside scientists, decoded genomes of SARS-CoV2 viruses isolated from more than 20,400 COVID patients, a number that represents about 4% of all the COVID cases seen in that city over the past year.
Houston is the fourth largest city in the U.S. with an ethnically diverse population and an international port. It’s also home to some of the nation’s top virus hunters.
The study used a large enough sample of viruses to give a “deep and realistic” picture of the situation there, said Keith Jerome, MD, PhD, head of the virology division at the University of Washington, in Seattle.
“This is a very impressive piece of work,” said Jerome, who was not involved in the research. “It is one of the most comprehensive looks that we’ve had of the viruses in a given area anywhere in the United States.”
The study’s authors say that Houston may be the first city to find all the variants, but it probably isn’t the only one to have them.
“it’s likely that there are other cities in the country that have all these variants and simply aren’t aware,” said study author Wesley Long, MD, medical director of diagnostic microbiology at Houston Methodist Hospital.
The genomes analyzed for the study date back to March 2020. The Houston Methodist health system is part of a global network of genome sequencing labs called the ARTIC Network, which is always on the lookout for new viral variants.
The variants detected in the study first showed up in testing in December, Long says, and more cases were detected in January and February of this year.