Turkmenistan is one of only a handful of countries, including North Korea, which says it has no coronavirus cases. But reports suggest it is experiencing its third and possibly strongest wave of Covid-19. Sayahat Kurbanov was suffocating. He gasped for air as if he were running a marathon, the pain in his chest unbearable. He had all the symptoms of coronavirus. The problem was he was in Turkmenistan, where patients like him officially do not exist.