Highly contagious Delta variant identified and dominant over AZ
The highly contagious Delta variant appears to be the dominant strain of the COVID-19 virus in Arizona and is a reflection of what is happening across the country.
“We find Delta almost everywhere now,” said David Engelthaler, director of the infectious diseases division at the Arizona-based Translational Genomics Research Institute. “It is officially our dominant strain and will likely stay that way until another variant emerges that can spread even faster than Delta.”
For Arizonans who are not vaccinated or who do not have immunity to COVID-19, it means they are at a higher risk of contracting the virus that is causing it. That’s because the Delta variant spreads so much more efficiently than other strains of the virus.
According to the U.S. Centers for Disease Control and Prevention, Arizona ranked seventh largest among U.S. states and territories for its seven-day rate of new COVID-19 cases behind Missouri, Arkansas, Florida, Louisiana, and the Virgin Islands on Monday Nevada.
In the past three weeks, the Delta variant, first detected in India and also known as B.1.617.2, has risen at a ratio of about 30% to about 50% of all sequenced COVID-19 cases in Arizona, Engelthaler said. In the US, Delta is the dominant variant of COVID-19, CDC data shows.
“If we take a closer look at our data, we can see that over the past three weeks it has likely been between 50 and 60%, which is in line with CDC predictions for current sequencing across the country,” Engelthaler said. “That really gives us some insight into how the virus has evolved and what is most successfully transmitted.”
Data shows that less than half of Arizona nationals are fully vaccinated
About 49% of the total US population was fully vaccinated as of Monday, That means two weeks before their last shot, according to the CDC. In Arizona, the CDC data shows that 44.5% of the total population was fully vaccinated on Monday and 52% of the Arizona population had received at least one dose.
The delta variant of the SARS-CoV-2 virus that causes COVID-19 has been discovered across Arizona, but primarily in Maricopa, Pinal, and Pima counties, where most of the people live and where most of the COVID-19 cases occur said Engelthaler.
The Arizona CDC and laboratories that perform genome sequencing of positive COVID-19 samples have also had Delta variant cases in Yuma counties, Cochise, according to officials at TGen, which maintains a COVID-19 variant dashboard, Identified Coconino, Mohave, and Navajo.
“At any point in time, around 10 to 13% of the cases are sequenced, so that we get a really good overview. And we’re getting sequenced data from across the state, ”Engelthaler said. “I would assume there are a few thousand, maybe several thousand, total cases of Delta in Arizona.”
The fast transfer of the Delta variant created what CDC Director Dr. Rochelle Walensky recently called “a pandemic of the unvaccinated”.
“It is very clear that the severe cases that are hospitalized or, worse, death are those that are not vaccinated,” Engelthaler said.
“Over 99% of hospital cases are people who have not been vaccinated, which is why the CDC director made this comment. I think it is an appropriate point and it just means that the concern does not apply to the people who are vaccinated. “
During a hearing for the U.S. Senate Committee on Health, Education, Labor and Pensions Tuesday, Walensky said the prevalence of the Delta variant in the U.S. had risen to about 83% of the cases sequenced.
“This is a dramatic increase from 50% for the week of July 3rd. In some parts of the country the percentage is even higher, especially in areas with low vaccination rates, ”she said.
“Every death is tragic and even more heartbreaking when we know that the majority of these deaths could be prevented with a simple, safe, and available vaccine.”
State: Most of AZ’s new COVID-19 cases are in unvaccinated people
About 95% of Arizona COVID-19 cases in May and 92% of reported cases in June were not fully vaccinated, according to the state Department of Health. Approximately 99% of Arizona COVID-19 deaths in 2021 were from people who were not fully vaccinated.
Arizona hospitals are reporting an increase in COVID-19 patient numbers and the number of cases has also increased. The current concern is people who lack immunity, either because they haven’t been vaccinated or because they haven’t had a previous infection.
“Wherever it appears, it becomes the dominant variety,” Engelthaler said of the Delta variant. “It just competes with the other varieties.”
Some so-called “breakthrough” cases of COVID-19 occur in people who are fully vaccinated, but they are rare. Federal, state and county health officials say the COVID-19 vaccine is the best way to prevent transmission of the Delta variant, which is causing waves of hospitalizations in parts of the country where vaccination rates are low .
State health officials said last week Arizona had recorded more than 3,500 breakthrough cases from more than 3.2 million fully vaccinated people. Twenty-eight of them had died.
There is some debate about whether the delta variant makes people sicker. Engelthaler said, following the evidence he’s seen, Delta doesn’t appear to be causing any more severe disease than any other COVID-19 strain.
“It’s just more effective to find the next person at risk. That is why we are seeing increasing case numbers. They don’t go up in height, but they do, and that’s because this is the most efficient strain of this virus out there and it’s like water. It finds the cracks, “said Engelthaler.
In an interview published on the Harvard TH Chan School of Public Health website, Harvard Associate Professor of Epidemiology William Hanage is quoted as saying that the delta variant is about 60% more transmissible than the previously dominant alpha variant derived from the United Kingdom originated and also known as B.1.1.7. He also said it appears to have a higher viral load earlier in the infection.
These higher viral loads “may mean it is even more contagious by the time people don’t realize they are infected,” Hanage is quoted as saying. “Delta’s greater virulence means that unvaccinated people who become infected will get sicker and put more stress on the health system.”
Without more immunity in the population, Delta could mutate into a more deadly variant
For the past week, there have been new case reports of more than 1,000 daily, according to the state, a level Arizona hasn’t seen since March.
The state’s seven-day average for new cases was 1,219 on Tuesday, the highest since mid-March and more than double the two weeks ago average of 543. The seven-day average had reached up to 9,800 inches in January, according to country sources.
“If you are not immune from a vaccination or previous infection, you are still at risk. In fact, there is now a higher risk of getting infected because this variant is such an efficient spreader, ”said Engelthaler.
Arizona Department of Health officials did not immediately respond when asked where in the state the Delta variant is most common. The department announced last month that there have been at least four potential outbreaks of COVID-19 involving 10 or more people since May, but did not confirm whether those potential outbreaks were the Delta variant.
A country western dance-related outbreak near Show Low in Navajo County has been linked to 24 positive COVID-19 cases, including two deaths. While many of those who attended the dance believe the Delta variant is to blame, state and county health officials say they cannot confirm whether this is true.
Less than 40% of the population in the zip code that Show Low belongs to and the area the dance hall is located in have received at least one dose of the COVID-19 vaccine, state data shows. And at the region’s hospital – Summit Healthcare Regional Medical Center – only about 30% of staff were vaccinated, hospital officials recently told the Arizona Republic.
The problem with continued transmission of the COVID-19 virus is that it continues to replicate, creating a higher risk of it mutating into a more deadly or vaccine-resistant variant.
And COVID-19 is a global problem, stressed Engelthaler. Stopping the spread of the variants will not be done through one country’s efforts alone, he said.
“(The US is) great compared to the rest of the world. In many countries in Africa we are seeing vaccination rates of less than 5%,” Engelthaler said. “That means there are many opportunities for additional mutations and potentially new variants that we may have to deal with.”
You can reach Stephanie Innes at [email protected] or at 602-444-8369. Follow her on Twitter @stephanieinnes
You can reach Alison Steinbach at [email protected] or at 602-444-4282. Follow her on Twitter @alisteinbach
Support local journalism. Subscribe to azcentral.com today.