In India, about 1
This severe infection is usually very rare and has a mortality rate of about 50%.
Some medical experts suggest that there is an increase in cases in India due to the high prevalence of diabetes.
But are other factors at work and what is happening in other countries?
Which countries have black fungus?
Prior to the Covid pandemic, at least 38 countries around the world reported cases of mucormycosis, better known as black fungus.
India and Pakistan have the highest rates at about 140 cases per million a year, according to Leading International Fungal Education.
Dr David Denning of the University of Manchester, an expert on fungal infections, says reported cases of black fungus in India were “more than any other part of the world” long before the pandemic.
“Mucormycosis is closely linked to poorly controlled diabetes and there are many [diabetes] in India. “
In patients recovering from Covid-19, according to a recent study looking at cases worldwide, 94% of those who had a fungal infection also suffered from diabetes.
And the majority (71%) of reported cases of black fungus are from India.
Is there a link to diabetes in other countries?
Of the leading countries with a high prevalence of diabetes per capita, others (with the exception of India) have reported cases of mucormycosis.
India’s neighbors, Pakistan and Bangladesh, have a high prevalence of diabetes among their populations and have had cases of mucormycosis – but not in large numbers.
In Bangladesh, doctors are treating a confirmed case of mucormycosis and awaiting test results for another suspected case.
Doctors told the BBC that both patients had diabetes.
Pakistan has also reported five cases of mucormycosis in recent weeks, and four have died by May 12, according to media reports.
So far, Brazil has reported 29 cases, but it is not yet clear how many of them have suffered from Covid and / or have had diabetes.
Russia has also recently reported “isolated” cases of mucormycosis in patients with Covid – but it is not clear how many have been found so far.
In the United States, there is a very high prevalence of diabetes – 9.3% of the population is assessed as a disease.
It also has the highest number of Covid cases worldwide.
But mucormycosis is very rare – cases of diabetes there are largely managed, with only 3% remaining undiagnosed, according to the US Centers for Disease Control.
Why can diabetes be a risk factor?
Experts say less registered cases of diabetes are as important as levels of undiagnosed diabetes.
The IDF estimates that about 57% of those with diabetes in India, Nepal, Bangladesh, and Sri Lanka are undiagnosed – and almost all are found in India.
Pakistan is also thought to have a high rate of undiagnosed diabetes.
“There is a lot of uncontrolled diabetes in India because people don’t get regular health check-ups,” said Dr Hariprasat Prakash of the International School of Medicine in Kyrgyzstan.
He says most cases of diabetes are “discovered through other health complications” and remain untreated.
Poorly controlled diabetes puts you at higher risk for some infections, including some fungal ones.
The African region also has a high proportion of undiagnosed diabetes with nearly 60%, but forecasts show that the incidence of mucormycosis there is low – only 3%.
Dr. Denning points out that “it may be because [mucormycosis] cases can go undiagnosed … it’s not the easiest thing to diagnose. “
Studies show that cases of black fungus remain undiagnosed due to difficulties in collecting tissue samples and the lack of sensitivity of diagnostic tests.
What else can cause black fungus?
Experts also suggest that the indiscriminate use of steroids for some Covid treatments may be linked to mucormycosis or other fungal infections.
Two widely prescribed steroids – dexamethasone and methylprednisolone – are used for patients with Covid in India to reduce inflammation caused by the body’s immune response.
However, as hospitals and doctors are overwhelmed by the growing number of cases, there is evidence that these steroids are taken without medical supervision.
Indian authorities have recently warned against such self-medication, which can have serious harmful effects, including, says Dr. Denning, as an increased risk of developing mucormycosis.
A study in the United Kingdom of about 2,000 patients with Covid showed that dexamethasone helps reduce mortality in those with moderate or severe infection, but could potentially be harmful for those with mild infection.
This study showed the effectiveness of steroids when used in a hospital setting. However, some states in India have reportedly distributed dexamethasone to the public along with home insulation kits.
“It’s very clear (through research) that more steroids aren’t better,” Dr. Denning said.
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