Oman announced on Tuesday that its doctors have detected a potentially fatal fungal infection afflicting some coronavirus patients, the first such known cases on the Arabian Peninsula as the sultanate faces a surge in COVID-19 infections that has swamped its hospitals. The country’’s Health Ministry reported that three COVID-19 patients in Oman have become infected with mucormycosis, a life-threatening condition commonly known as “black fungus,” which has spread quickly among virus patients in hard-hit India.