Data shows that a new type of Covid virus, which has led to a sharp rise in the number of cases in India, has already reached more than half of the states in the United States.
Health chiefs first detected ‘Arcturus’, a highly contagious sub-disease of Omicron, in New York in late January. But it has since spread to 26 other states and caused 235 cases, with hot spots emerging in California, New Jersey and Virginia.
The variant – known scientifically as XBB.1.16 – is believed to be the most infectious version of Omicron to date, but there is no evidence that it is more deadly than other strains currently circulating.
In India, it is believed to have single-handedly increased the number of cases 13-fold in the space of a month. Hospitals in the country are on high alert, and some states have reinstated masking restrictions that were thrown in over a year ago.
The map above shows the cases where the highly contagious variant has been detected so far

The new variant of Covid ‘Arcturus’ has led to a significant increase in cases in India over the past month
US data is available on the global genome sequence database GISAID, which monitors the spread of Covid variants.
It shows that in total, XBB.1.16 has been detected in 27 states with a total of 235 cases recorded so far.
These are likely underestimations because only a few positive tests are analyzed for variants.
California is the hotspot for the new variant in the United States, with 54 sequences recorded so far.
Rounding out the top five are New Jersey, with 38 cases, Virginia (25), Texas (23), and New York (21).
Other states where the strain has been detected are: Washington, Illinois, Florida, Pennsylvania, Georgia, Utah, Ohio, Minnesota, Maryland, North Carolina, Nevada, Iowa, Indiana, Hawaii, Delaware, and Connecticut, Wisconsin, Oregon, Michigan, Massachusetts, Louisiana, and Colorado.
Dr Paul Hunter, an infectious disease expert at the University of East Anglia in England, said he was not concerned about the strain.
“Yeah, this variant seems to spread more easily than the variants currently in circulation,” he told DailyMail.com.
“But, on the other hand, it has been around for quite some time, and was first seen in the UK in early February.”
He added, “Although it has taken off in India in the last few weeks now, it has not been rapidly increasing globally.
From what I can gather in reports from India, there is currently no evidence that it causes more serious illness.
“I suspect we will see a wave of infections of this type, but I doubt it will cause a large wave, perhaps not as large as (the previous one).”
Internationally, XBB.1.16 has been detected in 28 countries and Aruba – including the United Kingdom, Australia and Canada.
But India was the most affected by its emergence.
Officials there believe the alternative is driving the latest wave single-handedly.
This week, the country’s health ministry conducted a mock exercise to check how prepared its hospitals were for another possible influx of patients.
And some states have reinstated face masks in public, the first time in more than a year in some areas.
India’s health ministry said there were 40,215 active Covid cases on April 12, up by 3,122 cases in just one day.
These Covid cases could include those who tested positive while unwell at home as well as in hospital.
The World Health Organization (WHO) is currently monitoring Arcturus, known scientifically as XBB.1.16.
It has not yet been added to the Centers for Disease Control and Prevention (CDC) weekly update on circulating Covid variants.
It was first discovered in late January, with officials saying it contained some worrisome mutations.
It’s been circulating for a few months now,” said Dr Maria Van Kerkhove, technical chief for Covid at the World Health Organization.
We haven’t seen a change in severity in individuals or in populations, but that’s why we have these systems in place.
“It has one additional spike protein mutation that has been shown in laboratory studies to increase infectivity as well as potentially increase pathogenicity.”
Dr Van Kerkhove added that while XBB.1.16 has been detected in other countries, most of the sequences were from India, where it has replaced other variants.
She also said that, to date, no change in disease severity has been reported in XBB.1.16 infection.
Currently, the XBB.1.5 variant is prevalent in the United States, accounting for about 88 percent of cases according to estimates.

The map above shows the weekly incidence of COVID-19 by state in the United States. Although California is an XBB.1.16 hotspot, it does not have the highest number of cases in the United States.

The above shows the number of Covid cases detected in the US by week. Cases are trending downward, but the data is less reliable because fewer people are getting tested

This map shows the Covid death rate in the US per 100,000 people

This graph shows the number of reported Covid-related deaths by week in the United States
Omicron spin-offs have proven to be highly infectious and good at evading immunity when they appear.
But Covid is now a background issue for many Americans.
The United States is currently recording about 1,773 Covid deaths each week, compared to 17,480 deaths at the peak of the latest wave last February.
It also records about 120,000 cases per week, but this is likely an underestimate because many people with the disease do not get tested.
state | Case number |
---|---|
California New Jersey Virginia Texas New York Washington Illinois fl Pennsylvania Georgia Utah Ohio Minnesota Maryland North Carolina nv yeah Indiana Hawaii Delaware Connecticut Wisconsin Oregon, Michigan, Massachusetts, Louisiana, Colorado |
54 38 25 23 21 19 7 7 5 4 3 3 3 3 2 2 2 2 2 2 2 1 1 1111 |