Mucormycosis—A serious threat in the COVID-19 pandemic?

We read with great interest the work by Lansbury et al.¹, who perform systematic review and meta-analysis concerning on co-infection in people with COVID-19. At the end of 2019, a new type of coronavirus appeared in China - SARS-CoV-2, which, rapidly spreading around the World, has become a huge challenge for the health care system². The classic picture of COVID-19 disease may vary in severity, from very mild/asymptomatic to life-threatening pneumonia accompanied by bacterial or fungal co-infections^{3 , 4}. There have been reports of the development of severe opportunistic infections such as Gram negative bacteria, Staphylococcus aureus, oropharyngeal candidiasis, Pneumocystis jiroveci pneumonia (PCP), pulmonary aspergillosis, bloodstream candida infections in patients undergoing COVID-19. Opportunistic infections are especially common in patients who, apart from the current COVID-19 disease, also have other comorbidities such as diabetes or COPD. An additional factor contributing to exposure to co-infections is treatment with mechanical ventilation, antibiotic therapy, monoclonal antibodies and the use of corticosteroids. Especially corticosteroids are commonly used to treat serious form of COVID-19 disease and reduce the damage caused by the own body's immune system during SARS-CoV-2 infection. Unfortunately, corticosteroids are also immunosuppressive and increase blood sugar levels in both diabetic and non-diabetic patients. Both of these effects are now believed to contribute to mucormycosis⁵. Recently, the Indian Council of Medical Research (ICMR) recommended that doctors and medical facilities should pay special attention to signs of mucormycosis such as sinus pain, nasal obstruction on one side of the face, one-sided headache, swelling or numbness, toothache, and loosening of the teeth. Mucormycosis usually leads to discoloration or reddening of the nose, blurred or double vision, chest pain, coughing up blood and difficulty breathing which is an additional very heavy burden for COVID-19 patients. The International Diabetes Federation has determined that India has a very high incidence rate of type 2 diabetes (8.9% adults, 77 million patients)⁶. According to the World Health Organization, 2% of all deaths in India are due to diabetes, diabetes itself poses a risk of a very severe course of COVID-19 and is associated with higher in-hospital mortality⁷. Diabetes, being closely related to mucormycosis infection and a much higher risk of SARS-CoV-2 infection, may have tragic consequences for the local community.

In India, where apart from a high percentage of diagnosed diabetes, there are still many people who do not receive health care and do not undergo diagnostics. Mucormycosis with COVID-19 infection can be a very serious problem for them. Hospitals that are overloaded and no longer have places to spread further promote the spread of mycoses, the widespread use of steroids and broad-spectrum antibiotics to combat COVID-19 may lead to the development or significant exacerbation of pre-existing fungal diseases. A very important issue is the high incidence of mucormycosis in India, which is about 0.14 cases per 1000 inhabitants (about 80 times more often than in developed countries) - so secondary invasions with a huge primary occurrence can have dramatic effects⁸. Studies have also shown an increased incidence with a fairly severe course of mycormycosis, in patients with a history of COVID-19, the most common infection was the sinuses (100%), intraorbital dilation was observed in 43.47% of cases, while intracranial dilation was seen only in 8.69%. Diabetes mellitus occurred in over 91% of cases and was not controlled in over 52% of cases. All patients have used steroids in the past while being treated with the COVID-19⁹.

Healthcare professionals should pay special attention to the possibility of invasive secondary fungal infections in patients with COVID-19 infection. Moreover, the use of therapeutic measures should be carefully monitored to achieve a therapeutic effect with the lowest possible dose in the shortest possible time, in line with the gold standard of treatment in order to minimize reduction of the patient's immunity, also the mucormycosis infection itself in the course of COVID-19 and after it should be further investigated.