Study: Arizona’s COVID outbreak began in late February 2020

By: - January 21, 2021 9:30 am
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COVID-19 continues to ravage Arizona, but a study of the genomes of a number of people who became infected with COVID-19 in Arizona has led researchers to believe that Arizona’s outbreak of COVID-19 likely began in late February 2020 and started with a strain of the virus that likely originated from either Washington or Europe. 

Arizona’s first confirmed case of COVID-19 appeared on Jan. 22, 2020 when an Arizona State University student returned from a trip to China. The 26-year-old student was quickly isolated and was only seen by public health officials and researchers. 

No additional cases would be confirmed until early March, leading researchers to believe that the outbreak likely had different origins than the ASU student — and that the answers would be hidden in the genetic makeup of the virus itself. 

Although the virus is generally known as COVID-19, there are different variants of it. Viruses naturally change over time as they infect new hosts, and it is some of the newer mutations that are scaring some in the scientific community. Back in early 2020, the novel coronavirus had only begun to mutate, and there were just a few variants. 

In Arizona, researchers found that the majority of the COVID-19 samples they collected during February and March were from the A.1 and B.1 lineage. In mid-February, the A.1 version of the virus was spreading rapidly in Washington

The A.1 lineage also is one of the more prevalent versions, and it quickly spread across the globe

“If these eight Arizona genomes stem from a single introduction of the A.1 lineage, this…estimate suggests the lineage was already present in Arizona prior to when community transmission was announced in Washington, on 29 February,” the study says. “However, it is likely that the eight A.1 lineage genomes from Arizona arose from multiple introductions into the state, given that the same lineage was being spread throughout the country.”

One of the A.1 lineages came from a person who was considered the first instance of known community spread. 

The majority of the people who were examined had the B.1 lineage which has been seen across the globe, especially in places like New York. However, the researchers were able to determine through gene sequencing that the lineage was more likely tied to Asia or Europe. 

“[T]his lineage was observed in multiple European countries, including the large Italian outbreak, before it was first documented in New York,” the study says. “In fact, just within Arizona, we have documented at least two instances in which B.1 lineage viruses were imported directly from Europe.”

In one case, a traveler came from France, attended multiple social gatherings and at least one person from one of those gatherings contracted the virus. 

In Coconino County, a traveler who came back from Rome was presumed to have been infected there. 

The B.1 strain is the version of the virus that has mutated recently that has caused alarms. 

The mutations being witnessed with COVID are allowing the virus to survive and reproduce more efficiently, particularly in two mutations that have been found in the United Kingdom and South Africa. Virus mutations can also make vaccines less effective, this is why the flu vaccine can be less or more effective depending on how the flu has mutated or which strain is active in a given flu season.  

“To date, the variants B.1.1.7, B.1.351, and P.1 have not been detected in Arizona,” Arizona Department of Health Services spokeswoman Holly Poynter said to the Arizona Mirror. “If these emerging variants were detected, the Arizona Department of Health Services (ADHS) would coordinate with the CDC and local partners to investigate these cases to determine epidemiologic and clinical characteristics and report this information to the public.” 

Since November, the agency has sequenced over 350 samples and has been working with the Utah Public Health Laboratory to do so, Poynter said. Every two weeks, ADHS also provides up to 27 specimens to the CDC for them to examine. Another 5,000 samples have been sent to the Translational Genomics Research Institute in Phoenix since November for additional sequencing. 

Researchers estimated that between there were at least 11 times COVID was introduced to Arizona February and March, although they suspect it was likely more. 

“[O]ur analyses indicate that community transmission likely did not occur within Arizona until at the earliest early- to mid-February, when viruses from lineages B.1 and A.1 may have been first introduced,” the study says. 

Those early days of the pandemic stand in stark contrast to today. Arizona is breaking all its previous records in regards to COVID, and just last week surpassed the record for the most people to die within a week from the virus. Between Jan. 10 and Jan. 16, there were 1,125 people who died from COVID in Arizona, according to researchers at John Hopkins University

As of Thursday, there have been 699,942 confirmed infections and over 11,772 deaths from COVID-19 in Arizona.

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Jerod MacDonald-Evoy
Jerod MacDonald-Evoy

Reporter Jerod MacDonald-Evoy joined the Arizona Mirror from the Arizona Republic, where he spent 4 years covering everything from dark money in politics to Catholic priest sexual abuse scandals. He brings strong watchdog sensibilities and creative storytelling skills to the Arizona Mirror.