Congress chief Sonia Gandhi in a letter to Prime Minister Narendra Modi cited the acute shortage of vital drug - Amphotericin-B - needed to treat Mucormycosis, dubbed Black Fungus, and underscored the need to "take immediate action" to remedy the situation. Several thousand coronavirus patients in the country have contracted Mucormycosis, a deadly and aggressive fungal infection, compounding the country's troubles as it reels from the pandemic.