As the world is slowly easing back to life post-COVID-19, a new strain is forcing countries to put up their defenses: the more infectious Delta Variant.
Even the director of the Centers for Disease Control and Prevention, Dr. Rochelle Walensky, said in a statement last July 22 that the COVID-19 delta variant is one of the most infectious respiratory diseases the scientific community has seen so far.
The Rising Global Threat of a New COVID-19 Strain
The Delta Variant is also known as the B.1.617.2 variant, a mutation that first appeared in India. According to a summary from Yale Medicine, it was first identified last December and since then, has seen a rapid spread and becoming the dominant form of COVID-19 in both India and Great Britain.
The delta variant has already spread to more than a hundred countries and has already accounted for more than 83 percent of confirmed cases in the United States alone. While researchers and medical experts agree that it spreads fast, there's still no concrete explanation as to why.
To this end, researchers from China examined the infection and transmission of the delta variant from the first known local transmission reported last May 21. They then presented their findings in a preprint study appearing on the online repository Virological last July 7, in an article titled "Viral infection and transmission in a large well-traced outbreak caused by the Delta SARS-CoV-2 variant."
Tracing the Spread of the Delta Variant in Mainland China
A collaborative effort between the local authorities in Guangdong Province, China, as wella s the Department of Zoology and the Big Data Institute at the University of Oxford, traced 167 infections to the first index case. They then conducted surveillance and screening processes on the delta variant cases, as well as their close contacts. Close contacts of the reported cases were also isolated and took COVID-19 polymerase chain reaction (PCR) tests daily.
Researchers then compared the data from the COVID-19 delta variant spread to the early days of the original pandemic, when the original SARS-CoV-2 variant began spreading in the mainland. It revealed that the average time it took for a person from exposure to testing positive on the PCT test, or the time it takes for the virus to replicate to detectable levels, was at an average of only 3.71 days for the delta variant, compared to the 5.61 days from the original strain.
According to John Connor, researcher from the National Emerging Infectious Diseases Laboratories at the Boston University who was not a part of the study, an important takeaway from the study is that the time from exposure to critical levels of the new COVID-19 strain is now shorter. He explains in an article from Live Science that this changes the window at which people are infectious.
Researchers in the study also examined the viral loads when the coronavirus first appeared in the PCR tests, finding that in the delta variant, the virus particles were as much as 1,260 times higher compared to the original.
Read also: COVID-19 Delta Variant: More Dangerous New Mutations Possible, Unvaccinated People at Risk
Check out more news and information on the COVID-19 Delta Variant in Science Times.
