Mucormycosis , a serious and often fatal invasive fungal infection, has entered the public consciousness in response to an outbreak of cases in India. Thousands of cases of mucormycosis have been reported in the wake of the second wave of COVID-19 cases in India, drawing global attention to this deadly but neglected disease.
Mucormycosis is caused by ubiquitous environmental molds with a global distribution, including Rhizopus, Apophysomyces, Mucor, and Lichtheimia species. Although generally harmless to an immunocompetent host, the infection can be fatal in patients with an impaired immune system, such as those with hematologic malignancies or poorly controlled diabetes, or in individuals receiving steroids or other immunosuppressants. Structural breaches, such as traumatic skin inoculation, can also lead to mucormycosis.
The infection manifests as a rapidly developing angioinvasive infection, with rhinoorbital, cerebral, and pulmonary manifestations being the most common forms of disease.
Although prevalent around the world, mucormycosis is much more common in India: even before the COVID-19 pandemic, the incidence of mucormycosis in India was up to 70 times higher than the global average.
It is difficult to overstate the magnitude of the current epidemic. According to a government minister of India, on May 25, 2021 alone, more than 11,700 patients were reported to have been treated for mucormycosis. Some hospitals have opened rooms dedicated to mucormycosis.
The reason for the sharp increase in cases in India is not entirely clear; however, it is likely due to a combination of factors. Such factors include widespread use (and misuse) of steroids , even for mild COVID-19; poorly controlled diabetes, unmasked or aggravated by COVID-19 itself (with poor glucose monitoring capacity in overloaded hospital wards); and, possibly, mucosal damage from the virus.
Additional hypotheses needing investigation include host-related factors, pathogen (higher prevalence and virulence of Mucorales strains in India), or history of SARS-CoV-2 infection (with increased risk imposed by variants predominating in India (i.e. the Delta variant).
Despite the ubiquitous and deadly nature of fungal infections, the field of mycology has suffered from inadequate investment in diagnostic and therapeutic research for many decades. Research funding devoted to fungal diseases pales in comparison to the study of bacterial, viral or even parasitic infections, despite the fact that one billion people worldwide have a fungal infection at some point and that Fungal diseases claim an estimated 1·5 million lives annually.
As a result of this chronic neglect, the medical profession has been left with a shortage of tools to diagnose and treat mucormycosis.
Mortality is unacceptably high, reaching 80% in some case series.
Mucor mold is found in soil, plants, manure, and decaying fruits.
Diagnosis
Timely diagnosis is crucial because initiation of treatment is time critical due to the rapid progression of the infection, but this is hampered by the paucity of available diagnostic tests . Diagnosis is based on histology and tissue culture, which can be invasive, time-consuming, and insensitive. There is no serological test or serum biomarker available to allow early diagnosis. Molecular methods are under development but are generally not available.
Even after a diagnosis is made, management is challenging. Surgical debridement of infected and necrotic tissue is essential to give the patient any chance of survival; however, this can lead to vision loss, severe disfigurement, or both. Many patients cannot access or afford effective antifungal treatment, which is another important pillar of treatment.
Treatment
The mainstay of antifungal treatment is amphotericin B , a nephrotoxic polyene antifungal in use since 1958. Liposomal formulations, preferred due to reduced toxicity, are often prohibitively expensive or simply unavailable in many resource-limited settings. The few alternatives, such as posaconazole and isavuconazole, are out of reach for much of the world due to their cost and availability.
The mucormycosis epidemic in India has highlighted the severity of fungal infections and the relatively poor state of science on their prevention, diagnosis and treatment. Dubbed the so-called black fungus in popular media (due to the black, necrotic tissue seen in patients, rather than the mold itself), there is an unprecedented focus on this deadly infection.
This increased awareness is an opportunity to stimulate action to address the many areas of urgent need in advancing the management of this condition. Beyond uncovering risk factors that could be contributing to the current epidemic, priorities should include developing rapid, reliable, non- or minimally invasive diagnostics for mucormycosis, access to existing treatments, and improving strategies. therapeutics. The crisis provides opportunities, and now is the time to act against mucormycosis.
