LOS ANGELES — Los Angeles County has identified its first cases of an emerging omicron coronavirus subvariant dubbed Arcturus, a strain global health authorities are watching closely as it has been linked to an upswing in cases in India.
Officially designated XBB.1.16, the subvariant also has attracted attention following anecdotal reports linking it to what has been a rare COVID-19 symptom: pink eye.
However, it remains unclear whether this symptom is more pronounced in Arcturus than earlier omicron strains. The latest subvariant has not been shown to cause more severe illness.
It is possible, however, Arcturus is even more infectious than the currently dominant coronavirus strain in the U.S., XBB.1.5. While that likely isn’t enough to trigger another surge in cases, any uptick in transmission heightens the risk for vulnerable individuals.
“This is one to watch. It has been in circulation for a few months,” Maria Van Kerkhove, the World Health Organization’s technical lead on COVID-19, said recently.
It’s unclear how many Arcturus cases there have been in California. However, at least three have been identified in L.A. County, according to Public Health Director Barbara Ferrer.
Because Arcturus is another omicron subvariant, Ferrer said it’s likely that current vaccines and therapeutic drugs will continue to be effective on this strain.
Still, Ferrer said in an interview, “With any new mutation that crowds out what’s already there ... they’re likely to be able to more easily pass on infection. So you could see a bump.”
The unofficial moniker Arcturus is Latin and originated from the Greek word arktouros, which means guardian or watcher of the bear. It’s also the name of the fourth-brightest star in the night sky.
It’s now believed to be the second-most common coronavirus strain in circulation nationwide, accounting for an estimated 7.2% of cases, according to data from the U.S. Centers for Disease Control and Prevention. That’s up notably from its estimated share of 2.1% over the week ending April 1.
XBB.1.5, meanwhile, comprised an estimated 78% of new cases nationwide over the week ending Saturday.
For the southwestern U.S. — including California, Arizona, Nevada, Hawaii and the Pacific territories — Arcturus accounted for an estimated 9.8% of cases, up from an estimated 2.6% over the week ending April 1.
In India, authorities say Arcturus has begun replacing older versions of the coronavirus.
“From early reports in India and more than 20 countries, it doesn’t seem it’s proportionately sending more people to the hospital. But it is causing an increase in cases,” said University of California, San Francisco infectious diseases expert Dr. Peter Chin-Hong. With case rates in the U.S. at relatively low levels, “if you give a little bit more edge to a particular subvariant, it will cause an increase in cases.”
There have also been anecdotal reports of pink eye, or conjunctivitis, in coronavirus-infected people in India, particularly in children.
Before Arcturus, pink eye had been associated as a symptom in 1% to 3% of coronavirus cases, according to Chin-Hong and Ferrer.
“It’s always been a side effect (of COVID-19), although very rare,” Ferrer said. “Untreated, it can actually cause more damage to people’s eyes. If you have pink eye — for whatever reason — it needs to be treated.”
As a general symptom, pink eye is hardly unheard of and can be caused by other viruses and bacteria. According to the National Eye Institute, “It’s one of the most common eye problems for both children and adults.”
“Just because you have pink eye doesn’t necessarily mean you have COVID. You should go and get tested, particularly if you have some other symptoms,” Ferrer said.
According to the National Eye Institute, people who are around someone with pink eye should take care to wash their hands often with soap and water or use hand sanitizer with alcohol in it.
Always wash your hands before touching your eyes and after you touch a person with pink eye or something they have used.
“Don’t share personal items that the person with pink eye has used — including pillows, towels, makeup or glasses,” the institute said.
People with pink eye who wear contact lenses should consult with their eye doctor on how to clean, store and replace their lenses. They should also throw away any lenses, solution and cases they used while they had pink eye. The same goes for face or eye makeup, as well as makeup brushes or sponges.
Coronavirus cases are relatively stable at lower levels in California. As of Wednesday, there was no sign of an increase in coronavirus levels in L.A. County wastewater or in officially reported coronavirus cases.
“But it’s always possible: I would anticipate that if we do see an increase, my hope would be it would be relatively small,” Ferrer said.
While many believe the time of hospitals being overwhelmed by COVID-19 patients is over, any bump in cases could still lead to an increase in hospitalizations — and underscore the importance of staying up to date on vaccines (particularly for older people) and asking for therapeutic anti-COVID-19 drugs like Paxlovid and molnupiravir should you become infected.
Chin-Hong said he suspected the rise in the latest subvariant was a factor in federal officials moving this week to make another booster dose available to older and immunocompromised people.
“I don’t think we’ll ever see anything like a quote-unquote ‘regular surge’ again. But we will see these little bumps. And I feel like XBB.1.16 may cause a little bump in our cases, a little bump in hospitalizations,” he said. “But we’re so low now that when you’re so low, you can only go one way, which is up.”
