As fears grow over the spread of the virus, and sports leagues formulate contingency plans, the NBA on Friday sent a memo to its teams telling them to start "developing" plans on how to play games with only "essential staff" in attendance should that be deemed necessary, American sports broadcaster ESPN reported.

The NBA had sent out a previous memo to teams earlier this week, recommending players to use fist-bumps instead of high-fives with fans. It also said to avoid taking items such as pens, balls and jerseys from fans to sign.

"The health and safety of our employees, teams, players and fans is paramount," the NBA said in a statement on Monday. "We are coordinating with our teams and consulting with the CDC and infectious disease specialists on the coronavirus and continue to monitor the situation closely."

The global spread of COVID-19 has wreaked havoc on the international sporting calendar with Formula One motor racing, golf and athletics among the sports canceling or postponing events.

In Italy, the hardest-hit European country with 148 deaths from the novel coronavirus, all major sports events, including football matches, will be played behind closed doors until April 3.

Davis Cup tennis ties in Italy and Japan are being played behind closed doors this weekend.

The World Health Organization has called the spread of the virus "deeply concerning" as a wave of countries reported their first cases of the disease -- which has now killed nearly 3,500 people and infected more than 100,000 across 92 nations and territories.