Tens of thousands of COVID-19 survivors in India are developing deadly 'black fungus' infections that can lead to blindness

• As of June, there were more than 31,000 cases of "black fungus" infections in India.
• That was a 150% increase over the prior three weeks.
• Those infections have been on the rise among COVID-19 survivors in the country.

A puzzling epidemic of black fungus in India is spiraling out of control, with tens of thousands of COVID-19 survivors now battling the infection which can lead to blindness and death.

On June 11, NDTV reported that there were 31,216 cases of mucormycosis in the country and 2,109 deaths due to the infection - a 150% increase over the previous three weeks.

The government in India has not released official numbers, according to The New York Times. But last month, Prime Minister Narendra Modi called black fungus a "new challenge" in the COVID-19 outbreak, NDTV reported at the time.

While it's unclear what exactly has caused the surge in mucormycosis cases among COVID-19 survivors, doctors have theorized that it is connected to oxygen shortages during India's most recent surge, The Times reports.

To help patients breathe when bottled oxygen wasn't available, doctors resorted to steroid injections, which may have weakened patients' immune systems and made them more vulnerable to fungal spores in the air.

Patients with diabetes are also already more susceptible to black fungus, and India is one of the countries with the highest prevalence of diabetes, according to the International Diabetes Foundation.

Exacerbating the black fungus outbreak is the fact that there's a shortage of a key anti-fungal medicine - amphotericin-B - to treat it, NDTV reported.