Cases of mucormycosis, a serious but rare fungal infection, are on the rise among COVID-19 survivors, causing blindness or other serious issues, health officials in Maharashtra and Gujarat said on Saturday.

Mathur Savani, chairman of Surat-based Kiran Super Multi-speciality Hospital, said mucormycosis patients are coming to his hospital from many parts of Gujarat.

''Fifty mucormycosis patients are being treated and 60 more are awaiting treatment,'' Savani told PTI.

Seven such patients lost their eyesight, he said.

The civil hospital in Surat has set up a facility for such patients, said in-charge Resident Medical Officer Dr Ketan Naik.

In Ahmedabad, at least five mucormycosis patients are being operated upon every day at the Asarva civil hospital, a senior doctor said.

''We get five to 10 such cases daily, especially since the second wave of COVID-19 started,'' said Dr Devang Gupta, ENT specialist at the hospital.

''At least one in five cases is related to eyes. Many are suffering from blindness,'' he said.

In Maharashtra, at least eight COVID-19 survivors have lost vision in an eye due to mucormycosis and 200 others are being treated, said Dr Tatyarao Lahane, who heads the state government's Directorate of Medical Education and Research.

''They survived COVID-19 but the fungal infection attacked their weakened immune system,'' he said.

Dr Lahane earlier said the eight COVID-19 survivors had died but later clarified that he said so inadvertently.

This disease is not new but is on the rise among COVID-19 patients because the use of steroids elevates sugar level and some medicines suppress the patients' immunity, he said.

''In such a situation, the fungus infects the patient easily. In one such case, one of the eyes of a patient had to be removed permanently to save his life,'' Dr Lahane said.

Also called the black fungus, it is present in the environment, and those with suppressed immunity or co-morbidities are more vulnerable to infection, he said.

Symptoms of mucormycosis include headache, fever, pain under the eyes, nasal or sinus congestion and partial loss of vision, Dr Lahane said.

The treatment involves injections for 21 days. The basic cost of the injections is around Rs 9,000 per day, he said.

Dr Hetal Marfatia, professor and head of the ENT department at the government-run KEM hospital in Mumbai, said a surge in mucormycosis cases is being witnessed in the last two weeks. ''On average, two or three such patients are visiting the hospital every day,'' he said.

Many of these patients come from outside Mumbai and cannot afford the treatment cost, he said.

This fungal infection came to light during the first 'wave' of the pandemic, typically a couple of weeks after the patient was discharged, Dr Marfatia said.

''But now some patients are contracting this infection even while undergoing COVID-19 treatment,'' he said.

Niti Aayog Member (Health) V K Paul on Friday had said that mucormycosis cases were being found in patients with COVID-19.

''It is caused by a fungus named mucor, which is found on wet surfaces. It, to a large extent, is happening to people who have diabetes. It is very uncommon in those who are not diabetic. There is no big outbreak and we are monitoring it,'' he had said.

''When a patient is on oxygen support, it should be ensured that water does not leak from the humidifier (to prevent the growth of the fungus),'' he said, while also calling for ''a rational usage'' of steroids and medicines such as Tocilizumab to treat COVID-19 patients.