The overall Covid-19 situation in the country appears to be stabilising, according to the Union government, but experts have warned that secondary infections like mucormycosis, or “black fungus,” are increasing the country’s mortality rate.

Dr. VK Paul, a member of the Niti Aayog, said that people must control their blood sugar levels, maintain hygiene, and doctors must prescribe steroids with caution to prevent the spread of the rare fungal infection. “Some states are reporting 400 to 500 cases; we do not know the burden of the disease yet. This is an emerging problem and ICMR (Indian Council of Medical Research) has started collecting data. We have also asked states to keep an eye on it,” he said.

According to Dr. Arunaloke Chakrabarti, head of the department of microbiology at the Post Graduate Institute of Medical Education & Research in Chandigarh, black fungus cases increased 2.5 times last year between September and December across 16 centres across the country. He is a member of the Fungal Infection Study Forum and was one of the authors of the government’s mucormycosis advisory.

During a health ministry briefing on Saturday, Union health ministry joint secretary Lav Agarwal said that India’s Covid-19 positivity rate – the proportion of samples that return positive – fell from 21.9 percent last week to 19.8 percent. Although a lower positivity rate indicates that the spread of infection is slowing, experts advise caution.

An increase in cases was seen in Tamil Nadu, which was a “cause of concern,” Agarwal said. Currently, 11 states have over 100,000 active cases, eight states have 50,000 to 100,000 active cases, and 17 have fewer than 50,000 cases, according to data shared by the official.

At the briefing, Dr. Randeep Guleria, director of the All India Institute of Medical Sciences, said that there was a need to ensure good infection control practises in hospitals because secondary infections like Covid-associated mucormycosis were on the rise.

There are at least 23 people with the infection currently admitted to AIIMS, of whom 20 are still positive for Covid-19, Dr Guleria said.

Mucormycosis, also known as black fungus, has been seen in people with uncontrolled diabetes, people with weakened immune systems, and people who have been given too many steroids or immune-modulating drugs like tocilizumab.

Doctors estimate that if left untreated, 80 percent of those infected will die. It affects the orbit of the eye and the mouth, causing people to lose their vision or jaw during debridement — the process of removing dead tissue from an infection or wound — if it is not detected early.