TIRUCHY: A paper in a journal of American Society of Microbiology has hypothesised that use of cow dung may be a factor in India reporting a high number of mucormycosis cases in the second COVID-19 wave in 2021.
According to the Union Health Ministry, India had 51,775 cases of black fungus by November 2021 end. The paper, 'Are Unique Regional Factors the Missing Link in India's COVID19-Associated Mucormycosis Crisis?', by Jessy Skaria, Teny M John, Shibu Varkey, and Dimitrios P Kontoyiannis posited that excessive environmental exposure to Mucorales spores might be the unacknowledged factor in India's COVID-associated mucormycosis (CAM) epidemic.
"The alleged factors of steroid use on diabetes patients during COVID apply to many countries around the world. So we felt the need to look at factors unique to India," said Dr Varkey, regional medical director, Maxivision Super Speciality Eye Hospitals, Tiruchy.
"We hypothesise that Mucorales-rich cow excrement, given its use in multiple rituals and practices, especially during the pandemic, probably played a key role in India's CAM epidemic. We also posit that the dispersal of fungal spores most likely occurs through fumes generated from the burning of Mucorales-rich biomass, such as cow dung and crop stubble. We believe this dispersal resulted in a heavy load of Mucorales around immunocompromised and diabetic COVID-19 patients," said the paper.
CAM cases were substantially more common in States that ban cow slaughter and whose residents are more likely to use cow excreta, the paper said. "Kerala, which has the most liberal cow slaughter laws and highest prevalence of diabetes mellitus in India, led the nation in the number of COVID-19 cases, but had one of the smallest caseloads of CAM," the paper stated. "We want to stimulate the scientific community to come up with more investigations," said Dr Varkey.
Virologist Dr Jacob John said the theory is plausible. "Not enough studies have been done on the microbiological risks of handling cow dung. The fungus can remain in the nose without causing issues. When there is a provocation like diabetes, plus COVID, plus steroids, it could flare up. This does not mean cow dung exposure is the direct cause of the illness," he said.
Infectious diseases expert Dr V Ramasubramanian agreed cow dung could be a factor. "Mucor is in the air, and, if inhaled, it can go sit inside sinuses, lungs. Normal immune system will handle this. But there is probably something inherent in Covid that makes you susceptible to infections like mucor. The assumption is increased mucor spores in ambient environment is a factor," he said.