A combination photo of the Woodlands Causeway between Singapore and Malaysia, before (L) and after Malaysia imposed a lockdown on travel over the coronavirus (COVID-19) outbreak March 17 (L) and 18, 2020. [Photo/Agencies]

Members of firefighters wear protective face masks as they disinfect the streets, ahead of the Iranian New Year Nowruz, March 20, in Tehran, Iran March 18, 2020. WANA (West Asia News Agency)/Ali Khara via REUTERS

Members of Joint Task Force 2, comprising soldiers and airmen from the New York Army National Guard and Air National Guard, sanitize New Rochelle High School during the COVID-19 outbreak in New Rochelle, New York, on Saturday. ANDREW KELLY/REUTERS

Passengers gather at the South African Airways (SAA) customer desk, after SAA announced that it would immediately suspend all intercontinental flights until May 31 in response to a government travel ban aimed at stopping the spread of the coronavirus disease (COVID-19), at the O.R. Tambo International Airport in Johannesburg, South Africa March 20, 2020. [Photo/Agencies]

A man walks after buying groceries in front of the National Palace after El Salvador's President Nayib Bukele ordered home quarantine for 30 days throughout the country in San Salvador, El Salvador March 22, 2020. [Photo/Agencies]