Prince William joked he and Kate Middleton were "spreading coronavirus" during their tour of Ireland last week

Coronavirus was top of mind during Monday’s Commonwealth Day service.

Members of the royal family gathered at Westminster Abbey for the annual ceremony, but they refrained from the usual handshakes as they greeted dignitaries. Instead, Prince Charles placed his hands together in “namaste,” a traditional Hindu greeting where the palms are pressed together and accompanied with a slight bow.

Other royals in attendance — including Meghan Markle, Prince Harry, Kate Middleton and Prince William — also appeared to refrain from shaking hands with fellow attendees.

Almost 25,000 people in the U.K. have been tested for the virus so far, with 319 found to be positive for the respiratory infection, according to the BBC.

Prince Charles Boris Johnson Commonwealth Day
Credit: BBC

During Kate and Prince William’s three-day tour of Ireland last week, Queen Elizabeth‘s grandson joked that he and his wife were “spreading coronavirus” while chatting with a National Ambulance Service paramedic during a reception at Dublin’s Guinness Storehouse.

“Sorry! We’re keeping an eye on that, so do tell us if we need to stop!” he said.

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Prince Charles
| Credit: Ben Stansall-WPA Pool/Getty

A royal source tells PEOPLE that William has been taking the threat of the coronavirus seriously and that the couple is following guidance from Public Health England and the Department of Health — and that means “business as usual” for now.

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Prince Harry and Meghan Markle
Commonwealth Day
Kate Middleton

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During a royal outing on Wednesday, Camilla, Duchess of Cornwall and Prince Charles visited the London Transport Museum, where Camilla quipped, “I’m self-isolating,” while ducking into a one-person air raid shelter.

Queen Elizabeth wore gloves for an investiture ceremony recently, prompting speculation whether she was taking precautions against coronavirus. It is not uncommon for the 93-year-old monarch to wear gloves, but she has not been known to wear them during investiture ceremonies.