Usually, an X-ray or a CT scan of the sinuses is done to detect the infection. The second option is biopsy through nasal endoscopy. Apart from these, doctors sometimes even recommend a polymerase chain reaction (PCR)-based blood test to detect the presence of the fungal infection.
Black fungal infection is not contagious, but it is not only limited to people who have had COVID. Any individual with compromised immunity and underlying medical condition like diabetes and HIV can develop this infection. In case of COVID-19, uncontrolled diabetes and excessive use of steroids are believed to trigger the infection. A recent study has also linked excessive intake of zinc supplement, the combination of antibiotics used in the treatment of coronavirus and intake of steam behind the outbreak of the fungal infection.