The Delta variant of COVID-19 (B.167.2), first identified in India, set to become the dominant variant of the disease worldwide, according to the World Health Organization. The variant is certainly a force to be reckoned with: It’s more contagious than the dominant Alpha strain that ravaged Europe and the United States last year (which was more contagious than the original strain from Wuhan, China), is more resistant to vaccines, and carries a higher risk of hospitalization. The variant carries another concern, however: a predilection for the fungal infection rhinocerebral mucormycosis to appear among COVID-19 patients who have the Delta variant.
Mucormycosis, previously called zygomycosis and also known as “black fungus,” is a rare but serious fungal infection caused by a group of molds called mucormycetes, according to the Centers for Disease Control and Prevention. The infection mainly affects people who have health problems or who take medicines that lower the body’s immune system.
As of June 7, The Tribune of India reported that there were 28,252 cases of mucormycosis across 28 of India’s 29 states. Of these, 86% had a history of COVID-19 infection. The most common form of the infection seen among COVID-19 patients in India is rhinocerebral mucormycosis, with symptoms of one-sided facial swelling, headache, nasal or sinus congestion, fever, and black lesions on the nasal bridge or upper inside of mouth that quickly become more severe. Treatment must be initiated quickly and involves antifungal treatment, surgical resection, and control of risk factors, with a severe prognosis (Eur Ann Otorhinolaryngol Head Neck Dis. 2016;133:83-86).
One reason for the spike in India is that rhinocerebral mucormycosis is most often found in uncontrolled diabetics (Arch Otolaryngol. 1977;103:600-604). According to The Hindu, one in six people in the world with diabetes is from India, with an estimated 77 million diabetics in the country (www.thehindu.com/sci-tech/health/india-has-second-largest-number-of-people-with-diabetes/article29975027.ece).
A recent study from Johns Hopkins Bloomberg School of Public Health (Patel et al. Multicenter Epidemiologic Study of Coronavirus Disease-Associated Mucormycosis, India. wwwnc.cdc.gov/eid/article/27/9/21-0934_article) examined 295 cases of mucormycosis across 16 participating centers in India. Researchers found that the total number of mucormycosis cases between September 2020 and December 2020 was over twofold higher than the same time period in 2019, even though the number of mucormycosis unrelated to COVID-19 was relatively similar. Patients with COVID-19-associated mucormycosis were more likely to have hypoxia requiring ICU admission than were patients with mucormycosis who did not have COVID-19.