MEXICO CITY, Jan 7 (Reuters) - More than 70 Grupo Aeromexico pilots have tested positive for the coronavirus during a surge of infections from the Omicron variant, leading to 22 canceled flights, a union that represents pilots of the Mexican airline said. Jose Suarez, press secretary for pilots" association ASPA, told television station Milenio the cases triggered a "domino effect," forcing Aeromexico to isolate entire crews to prevent the virus from spreading. ASPA Secretary General Jose Gual told the same TV station that the pilots who tested positive made up 5% of Aeromexico pilots represented by ASPA. He added the cancellations represented 5% of Aeromexico"s operations and affected planes heading to the Mexican cities of Guadalajara, Cancun and Monterrey, plus an international flight. Among Aeromexico"s flight attendants, 140 had tested positive, according to a statement on Thursday by the Trade Union Association of Aviation Flight Attendants of Mexico (ASSA). An additional 65 of the company"s flight attendants were suspended for not having the valid travel documents, ASSA said. The absent workers represent 10.3% of the airline"s staff, the statement added. "We are seeing a quite severe wave of infections," ASPA"s Gual said. He attributed the jump to the highly contagious Omicron variant that has caused airlines around the world to cancel hundreds of flights during the busy winter travel season. Aeromexico said the new spread of COVID-19 had affected "some flights," without providing details. "The safety of our customers and collaborators is and will always be the main priority," Aeromexico said in a statement. The company did not respond to questions about COVID-19 cases among its pilots and crew members, or about exactly how many flights had been canceled. Mexico is likely to surpass 300,000 deaths from COVID-19 this week as infections rise after the holiday season, fueled by Omicron and largely unrestricted tourism to Mexico City and beach destinations Cancun and Los Cabos.