ODINTSOVSKY DISTRICT, Russia—Olga Ilyina’s husband was struggling to breathe when she called an ambulance. After waiting nearly 24 hours for one to come, she used the Telegram messaging app to beg for assistance. Finally, an ambulance was dispatched, taking him to the same hospital here, 40 miles from Moscow, where she had already been admitted with breathing difficulties after another daylong wait.
Gasping for breath as she recounted her story, Ms. Ilyina, 56 years old, said they had both been diagnosed with Covid-19. “We…