Mucormycosis (previously known as Zygomycosis) is a serious but rare fungal infection caused by a group of molds known as micromycetes. Rhino-orbital-cerebral-mucormycosis (ROCM) is caused by molds of the order Mucorales. In this, there are a few subgroups like Rhizopus, Mucor, Rhizomucor which are most commonly involved in this infection. These fungi are angioinvasive i.e, they invade the surrounding blood vessels and destroy them resulting in tissue necrosis and death. These molds live throughout the environment and their spores are present in the air. They get lodged in the nasal cavity and adjoining sinuses.
Sinuses or lungs of such individuals get affected after they inhale fungal spores from the air. Doctors in some states have noted a rise in cases of mucormycosis among people hospitalized or recovering from Covid 19, with some requiring urgent surgery. Usually, mucormycetes does not pose a major threat to those with a healthy immune system.
Why is it occurring in COVID 19 patients?
- Mucormycosis can occur any time after COVID-19 infection, either during the hospital stay or several days to a couple of weeks after discharge.
- The COVID-19 causes favourable alteration in the internal milieu of the host for the fungus and the medical treatment given, unwittingly also abets fungal growth. COVID-19 damages the airway mucosa and blood vessels.
- It also causes an increase in the serum iron which is very important for the fungus to grow. Medications like steroids increase blood sugar. Broad-spectrum antibiotics not only wipe out the potentially pathogenic bacteria but also the protective commensals.
- Antifungals like Voriconazole inhibit Aspergillosis but Mucor remains unscathed and thrives due to lack of competition.
- Long-term ventilation reduces immunity and there are speculations of the fungus being transmitted by the humidifier water being given along with oxygen. All the above make for a perfect recipe for mucormycosis infection
What happens when one contracts it?
Warning signs include pain and redness around the eyes or nose, with fever, headache, coughing, shortness of breath, bloody vomits, and altered mental status. According to the advisory, infection with mucormycetes should be suspected when there is:
* Sinusitis — nasal blockade or congestion, nasal discharge (blackish/bloody);
* Local pain on the cheek bone, one-sided facial pain, numbness or swelling;
* Blackish discoloration over bridge of nose/palate;
* Loosening of teeth, jaw involvement;
* Blurred or double vision with pain;
* Thrombosis, necrosis, skin lesion;
* Chest pain, pleural effusion, worsening of respiratory symptoms.
Experts advise that one should not count all cases of blocked nose as cases of bacterial sinusitis, particularly in the context of immunosuppression and/or Covid-19 patients on immunomodulators. Do not hesitate to seek aggressive investigations for detecting fungal infection, they advise.
Who is susceptible to Mucormycosis?
As previously mentioned, people with reduced immune response are more susceptible to infection. Conditions that reduce our immunity include:
*Diabetes: High blood sugars with an acidic environment as seen in diabetic ketoacidosis are the right recipe for the rapid growth of these organisms. Diabetes is also associated with reduced immune response.
*Steroids medication increases blood sugar levels and decreases the immune response of the body.
*Blood malignancies, which again results in the defective immune system
*Patients on immunosuppressants as seen with organ recipients and haematologic stem cell recipients.
*Patients with excess iron or taking deferoxamine (specifically used in iron overdose).
*Trauma, burns, and malnourished people.
How is mucormycosis treated?
It is a multi-pronged approach. Time is of the essence here. Once a clinical and radiological diagnosis is made, endoscopic evaluation of the nasal cavity can confirm a fungal lesion. Immediate surgical debulking is a must. Surgical intervention should be undertaken a couple of hours after diagnosis.
In tandem, medical management with antifungal drugs, namely injection Liposomal amphotericin-B needs to be instituted. Older form amphotericin deoxycholate is significantly nephrotoxic. However, the liposomal cousin is safe and effective.