A second deadly infection has swept India as the country's healthcare system continues to cripple under the weight of the coronavirus pandemic.
Secondary infections like mucormycosis or "black fungus" have been adding to India's mortality rate with states having reported more than 500 cases recently in Covid-19 patients with diabetes.
The Indian government has told doctors to look out for signs of black fungus in Covid-19 patients as hospitals report a rise in cases of the rare, but potentially fatal infection.
The disease, which can lead to blackening or discolouration over the nose, blurred or double vision, chest pain, breathing difficulties and coughing blood, is strongly linked to diabetes.
While diabetes combined with Covid-19 is a major risk factor for black fungus, the disease can attack the body of anyone with an underlying condition or weakened immune system.
In recent weeks, thousands of cases of black fungus have been reported across the country, with hundreds of those requiring hospitalisation, CNN reported.
At least 90 people have so far been killed by the disease, with two states having declared it an epidemic and the central government making it a notifiable disease.
Fungus invades blood vessels
The fungi that causes black fungus in people is found in the environment, particularly in soil and in decaying organic matter, such as leaves, compost piles, or rotten wood, according to the United States Centres for Disease Control and Prevention.
The disease is contracted when people come in contact with the fungal spores in the environment, with an infection able to form on the lung or sinus if people breath the spores in.
Black fungus can also develop on the skin after the fungus enters through a cut, scrape, burn, or other type of skin trauma.
Treatment involves all dead or infected tissue in the body being surgically removed, according to the Indian Health Ministry.
"In some patients, this may result in loss of upper jaw or sometimes even the eye. Cure may also involve a 4-6 weeks course of intravenous anti-fungal therapy," a statement released on May 14 read.
"Since it affects various parts of the body, treatment requires a team of microbiologists, internal medicine specialists, intensive neurologists, ENT specialists, ophthalmologists, dentists, surgeons and others."
The fungus works by invading the blood vessels and compromises circulation to the distal organ, causing the death of tissue, Dr Hemant Thacker, consultant physician and cardiometabolic specialist at Breach Candy Hospital in Mumbai said.
The dead tissue turns black, which explains the name of the disease, he said.
In the worst cases, the virus can enter the brain and cause a loss of eyesight or a "gaping hole" in a person's face, Dr Thacker said.
"If not controlled, not treated, it can have a mortality (rate) of anything from 20 to 50 per cent."
India is recording about 340,000 new cases and 4,000 coronavirus deaths each day.
The India travel ban lifted on Saturday last week and about 70 people have since returned to Australia, but there are still almost 10,000 people desperate to come back.
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