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What Is The "Black Fungus" Ravaging India's COVID-19 Patients?


Tom Hale

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

Senior Journalist


New Delhi, India, April 30, 2021: A worker in PPE walks across a mass cremation at a crematorium in New Delhi. Image credit: Exposure Visuals/

As COVID-19 cases continue to rage in India, a startling number of “black fungus” infections are also being seen across the country.

India's government has reported 8,848 cases of the once-rare fungal infection in COVID-19 patients and people who have recovered from COVID-19, as of May 22, 2021. The majority of cases have been seen in just a handful of states: Gujarat, Maharashtra, and Andhra Pradesh. 


The death toll from the fungal disease has not been revealed, but local media have reported that 250 people have lost their lives to the infection, according to the Associated Press.

The infection is a fungal disease known as mucormycosis, sometimes referred to as “black fungus” since it can turn infected areas black or dark in color. Symptoms can vary depending on where in the body the fungus is growing, but if it takes root in the sinuses or lungs it can lead to a fever, cough, chest pain, and shortness of breath. Left untreated, mucormycosis can even spread to the brain, causing lethargy, seizures, slurred speech, and partial paralysis.

The cases in India are thought to be caused by a group of fungi called mucormycetes. These microscopic fungi are ubiquitous and naturally found throughout the environment, namely in soil and plants, as well as decaying fruits and vegetables. Fortunately, the infection isn’t known to spread from human to human so it's not contagious.

The infection is typically considered very rare. According to the US Centers for Disease Control and Prevention, there are around 1.7 cases per 1 million population each year in the US. Scientists and health authorities aren’t totally sure why India is seeing such a strong surge of "black fungus” infections, but there are few ideas.


Mucormycosis tends to only affect people with weakened immune systems, such as people with diabetes, cancer, or other severe health conditions. People who have fallen severely sick with COVID-19 are also immunocompromised, making them more susceptible to fungal infection. Nevertheless, this alone doesn't explain India's predicament; odd cases of mucormycosis in COVD-19 patients have been reported elsewhere in the world, but the overwhelming majority have been seen in India.

Many suspect that diabetes is playing a strong role. Diabetes is known to be a risk factor for fungal infections and India has the second-highest number of diabetics in the world after China. The overuse of steroids in the treatment of COVID-19 is also likely to be a leading factor. Steroids are used to reduce inflammation in people who are seriously ill from the disease, but medication can compromise the immune system if taken over a prolonged period. 

“90% to 95% of patients getting infected with Mucormycosis are found to have been either diabetic and/or taking steroids. This infection is seen very rarely in those who are neither diabetic nor taking steroids," Dr Randeep Guleria, Director of the All India Institute Of Medical Science, said in a statement

Furthermore, Indian health authorities have suggested there may be some link between the fungal infection and COVID-19 patients undergoing oxygen therapy in intensive care. Since this procedure uses humidifiers to add water to the oxygen, it can introduce moisture to the airways and create the ideal environment for the fungi to reproduce. Some doctors in India have also indicated that unsanitary hospital conditions and, more specifically, the use of contaminated oxygen pipes might also be driving the outbreak. 


While these are all likely suspects, the precise cause of the “black fungus” infections is still evading experts.  


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