Explained: Why Covid-19 patients are vulnerable to mucormycosis, or black fungus; causes, symptoms, prevention

The photo is for representational purpose only

Amid the carnage that the second wave of the coronavirus pandemic is wreaking on Indians, doctors have reported a rare but serious fungal infection in Covid-19 patients in some parts of the country. Mucormycosis, commonly known as black fungus, has been reported in Mumbai and across Maharashtra, Delhi and Gujarat.

On Sunday, the central government announced that mucormycosis, a fungal infection found in Covid-19 patients with uncontrolled diabetes and prolonged intensive care unit (ICU) stays, could turn fatal if uncared for. The Indian Council of Medical Research (ICMR) and the Union health ministry released an advisory for screening, diagnosis and management of the disease, stating that the fungal infection mainly affects people who are on medication which reduces their ability to fight environmental pathogens.

In an interview with USA Today, Dr Bhakti Hansoti, associate professor in the department of emergency medicine and international health at the Johns Hopkins Bloomberg School of Public Health, said that while only a handful cases were witnessed in India in the past decade, tens of thousands of cases were reported in the past month. "We've seen this skyrocket in recent weeks," she said. "It consumes a lot of resources especially during this pandemic right now in India where health care resources are stretched at the limit."

For a better understanding of the disease and steps to prevent it, Mid-Day.com spoke to Dr Lancelot Pinto, consultant pulmonologist, PD Hinduja Hospital and MRC, and Dr Harish Chafle, chief intensivist and chest physician, Global Hospital, Mumbai.

What is mucormycosis, or black fungus?

Dr Pinto: If you leave a slice of bread out in the open, the fungus that one sees growing on it in a day or so is a type of mucor. This fungus is present in the air and decaying matter, in the soil, and on plants. Human beings with an intact immune system are unaffected by such fungi and it does not cause any disease ordinarily. However, in the presence of an immune deficiency of any kind, these fungi get a foothold in tissues of the body and can grow unabatedly.

Dr Chafle: Mucormycosis mainly affects people who have health problems or take medicines that lower the body's ability to fight germs and sickness. It most commonly affects the sinuses or the lungs after inhaling fungal spores from the air. It can also occur on the skin after a cut, burn, or other type of skin injury.

Dr Lancelot Pinto

What are the symptoms?

Dr Chafle: The symptoms of mucormycosis depend on where in the body the fungus is growing.

Symptoms of rhinocerebral (sinus and brain) mucormycosis include:
• One-sided facial swelling
• Headache
• Nasal or sinus congestion
• Black lesions on the nasal bridge or the upper inside of the mouth, which quickly become more severe
• Fever

Symptoms of pulmonary (lung) mucormycosis include:
• Fever
• Cough
• Chest pain
• Shortness of breath

Cutaneous (skin) mucormycosis can look like blisters or ulcers, and the infected area may turn black. Other symptoms include pain, warmth, excessive redness, or swelling around a wound.

Symptoms of gastrointestinal mucormycosis include:
• Abdominal pain
• Nausea and vomiting
• Gastrointestinal bleeding

Dr Harish Chafle

How is it treated?

Dr Pinto: The fungus is highly invasive and destroys tissues rapidly. Since antifungal drugs are often not able to reach the site of infection in adequate concentrations, staying ahead of such aggressive growth, and removal of dead and infected tissue, in combination with antifungal drugs, is the modality to treat it. This could involve surgery of the sinuses, enucleation (removal) of the eyes, and surgery to remove parts of the lung.

Why are Covid-19 patients getting infected with mucormycosis? What makes them vulnerable to it?

Dr Pinto: High and prolonged doses of steroids often create a lethal combination: significantly lowered immunity, along with an increase in blood glucose. This is especially more pronounced in those with diabetes. This combination becomes a fertile ground for the fungus to thrive, invade and grow rapidly.

Why are some cases being detected post Covid-19 recovery?

Dr Chafle: Mucormycosis can affect those who have a weaker immune system. And this can be the case in patients who are recovering from Covid-19. Coronavirus is a condition that tends to decrease your immunity. Also, the medicines given during this time result in reducing the strength of your immune system. Therefore, it might make way for black fungus to enter one's body. Apart from that, people who are diabetic or those who have undergone organ transplants and even cancer treatment are at a high risk of black fungus.

How can it be prevented?

Dr Chafle: Mucormycosis can be prevented by following these steps:

- Keep blood sugar under control during and after Covid-19 infection
- Use steroids judiciously while treating Covid-19
- Use clean water in humidifiers used for oxygen support
- Maintain overall cleanliness around the patient
- Any oral ulcer should be treated immediately
- Some of the things advocated for prevention are gargles and nasal douching with Betadine solution. Curcumin-present in turmeric is known to have some anti-fungal properties.

Is any particular age group at higher risk of contracting mucormycosis?

Dr Pinto: It is more likely to affect those who have underlying immunosuppressive stated, like those mentioned above (old age, diabetes, chronic kidney disease, chronic liver disease). However, if the dose of steroids is high and or prolonged, it can affect anyone.

How can one clean oxygen masks, concentrators and other equipment at home to prevent this fungal infection?

Dr Chafle: Cleaning instructions for home oxygen equipment are as follows:

Concentrator: Wipe the outside of the cabinet once per week with a damp cloth. Unplug the unit prior to wiping

Filter: Replace the filter in the unit every four months, and between clients

Nasal cannula: Wipe the cannula tips every day with a soapy cloth and rinse. Replace every month or more often if cracked, broken or discoloured

Oxygen tubing: Wipe the outside of the tubing with a damp cloth every week. Do not soak the long tubing in water, as it is very difficult to get all the water out. Replace every four months

Humidifier bottle: Use only when the physician's order is greater than four litres/minute. Throw the water out when the water level reaches the refill line on the outside of the bottle. Wash the bottle once every week following the cleaning steps in the oxygen masks section. Replace the bottle every month

Oxygen mask: Wash once a week in warm soapy water following these cleaning steps:

1. Take apart the mask or bottle as much as possible
2. Soak all parts in warm soapy water
3. Rinse thoroughly in running water
4. Soak in a solution of one-part white vinegar to three-parts water for 20 minutes, rinse thoroughly and let air-dry. Store in a plastic bag when not in use. Always keep a spare replacement at hand. Replace the oxygen mask every month, or more often if cracked, broken or discoloured.

(With inputs from PTI)

Also Read: Maharashtra to compile database of mucormycosis to assess its spread