Rare infection is now an epidemic: Experts
It’s official: mucormycosis or black fungus is now an epidemic, within the larger pandemic. It’s usually a rare disease , caused by fungi -- in this case, molds called mucormycetes -- but has now affected thousands of Covid-19 patients across India. As of Thursday, according to the Union government’s submission to the Delhi HC, the number of people affected at present is 7,251.
Worse, according to the US Centres for Disease Control and Prevention, “a review of published mucormycosis cases” put the fatality rate at 54%, with that for those with pulmonary infections (Covid-19 is one) coming in higher at 76%. Worse, the drug used for treating it , Amphotericin b is nephrotoxic , and could lead to kidney damage.
Till Thursday, Maharashtra, one of the states worst affected by mucormycosis has reported 90 deaths , Gujarat, 61, and Madhya Pradesh, 31.
The condition may be reaching epidemic proportions currently because of Covid-19 but mucormycosis was not unheard of in India earlier. Due to the lack of population-level data, its exact burden is unknown but it a rare condition, according to research papers on the disease and critical care experts.
“I cannot talk about disease incidence as such, but in our clinical life, we may have seen a maximum of five to seven such patients in the intensive care units. It was rare,” said Dr Anjan Trikha, professor, department of anaesthesia, critical care and pain medicine, All India Institute of Medical Sciences (AIIMS), Delhi.
The incidence of mucormycosis has over the years increased in India, according to a research paper titled “Epidemiology of mucormycosis in India” published in March in the medical journal Microorganisms.
The paper was authored by Hariprasath Prakash, department of public health, International Higher School of Medicine, Kyrgyzstan, and Arunaloke Chakrabarti, head of the department of medical microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh.
“... [there has been] an increasing trend of mucormycosis from a single centre at successive periods, with an annual incidence of 12.9 cases per year during 1990–1999, 35.6 cases per year during 2000–2004, and 50 cases per year during 2006–2007. The overall numbers increased from 25 cases per year (1990–2007) to 89 cases per year (2013–2015),” says the paper. “…A multicentre study across India reported 465 cases from 12 centres over 21 months; the study reported an annual incidence of 22 cases per year and an average of 38.8 cases for each participating centre…”
The paper said without population-based estimates, it is difficult to determine the exact incidence and prevalence of mucormycosis in the Indian population. “The computational-model-based method estimated a prevalence of 14 cases per 100,000 individuals in India.”
The incidence seems to have grown amid the Covid-19 pandemic.
“The black fungus infections went up 2.5 times last year between September and December across 16 centres in the country,” Chakrabarti told HT on May 12. He is a part of the Fungal Infection Study Forum and is one of the members, who drafted the government advisory on mucormycosis management.
“We did a study across 16 centres between September and December last year which showed that the infection had increased 2.5 times then. It is likely to go up further this time; we are planning to conduct another study.”
In its advisory this week, the Union ministry said mucormycosis mainly affects people on medication for other health problems that reduce their ability to fight environmental pathogens. Clinicians also say several factors found in Covid-19 patients could lead to the secondary infection.
“Mucormycosis needs fertile soil to grow, and high blood glucose levels, lack of oxygen, acidosis and suppressed immunity contribute towards the growth. There is a high probability of all these factors in Covid-19 patients which is, perhaps, leading to an increase in [black fungus] cases,” said Dr Ambrish Mithal, chairman, department of endocrinology and diabetes, Max Healthcare.
The use of poor quality water in humdification for patients on low-flow oxygen -- many being treated for Covid-19 are on this -- is believed to be one reason for the spurt in cases, as is the use on unclean oxygen cylinders. The fungi are found in soil, and dung, although small spores of it are also in the air. The spores are harmles to most people, but could affect those with weak immune systems -- and some experts believe the overuse of steroids on early-stage Covid-19 patients may also be contributing to this.
Reaching hospitals late in most cases could be leading to deaths. “There are not too many drugs available to treat the condition, and in India, one of the major problems is patients reporting late to the hospital which tends to alter the treatment outcome. But the reason for fungus becoming pathological and growing in various parts of the body is compromised immunity [people on high dose steroids for a prolonged period] and uncontrolled diabetes,” said Trikha.
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