Fact Check: Fungi inside refrigerators and on onions are not the ones causing mucormycosis

Wouldn't you be fidgety if you're told the fungus causing the much dreaded mucormycosis is present in the items at your house? What if you're told the black fungus is in the vegetables you eat and in the refrigerator where you store your food? Scary, isn't it?

Well, such a claim is circulating on social media at a time India is witnessing an alarming rise in mucormycosis cases.

Part of one such long Facebook post in Hindi translates to, "Beware of domestic black fungus. At times when you purchase onions, you must have noticed a black layer on them. Actually, this is the black fungus. The black film seen on the rubber inside refrigerators is the black fungus that causes mucormycosis. If ignored, this black fungus can easily enter your body through food items stored inside the refrigerator."

The archived version of the post can be seen here.

However, India Today Anti Fake News War Room (AFWA) spoke to experts who confirmed that the fungus which forms a black mold inside a refrigerator and the one that forms a black layer over onions are totally different from the fungus that causes mucormycosis.

Let us talk about these three kinds of fungi one by one.

The fungus inside your refrigerator

Naseem Gaur, senior scientist at the International Centre for Genetic Engineering and Biotechnology in New Delhi, told AFWA that inside a refrigerator and on damp walls, some bacteria (Bacillus and Acinetobacter species), yeast (Saccharomyces and Candida) and different molds such as stachybotrys chartarum can grow.

Molds are a group of fungi, which are specifically multi-cellular microscopic organisms characterised by the presence of multi-cellular filaments, the hyphae.

As per the website "Mold Advisor" as well, the black mold found inside refrigerators is stachybotrys chartarum.

According to the United States Centers for Disease Control and Prevention, stachybotrys chartarum and other similar molds may cause health symptoms that are non-specific. However, if stachybotrys chartarum or other molds are found, they should be removed.

Fungus on the onions you eat

According to the US department of agriculture, the black mold on onions is caused by aspergillus niger, a common fungus found in soil.

The same was confirmed by Dr Shesh R Nawange, a scientist at the Center For Medical Mycology Fungal Disease Diagnostic and Research Center in Jabalpur. "This kind of fungus causes infection in rare cases. However, onions should always be thoroughly washed before consuming," he said.

Fungus that causes mucormycosis

Mucormycosis (earlier known as zygomycosis) is a serious but rare fungal infection caused by a group of molds called mucormycetes, as per the US CDC. These molds live throughout the environment. Mucormycosis mainly affects people who have health issues or those who consume medicines that lower the body's ability to fight germs and sickness.

Dr Arunaloke Chakrabarti, professor and head of the department of medical microbiology at PGIMER Chandigarh, said, "The fungus that causes mucormycosis cannot survive in the refrigerator. Also, it is incorrect to distinguish fungus on the basis of colour."

Naseem Gaur sent us pictures of the three kinds of fungi in question, as seen when grown in a laboratory and their microscopic view.

Thus, it is clear that the fungus which forms a black layer in refrigerators and the one that creates a black covering on onions are completely different from the fungus that causes mucormycosis.