The cause for increased mucor infection in patients is complex and includes an interplay of multiple factors. Mucorales are considered opportunistic fungi, which means that generally infect people who already have an impaired immune system, or damaged tissue.
This is especially true for people with diabetes mellitus. Furthermore, people with diabetes and obesity tend to develop more severe COVID infections. Then the Covid-19 infection can damage airway tissue and blood vessels, which in turn increases susceptibility to fungal infection.
Also, a standard component of treatment for severe cases of COVID is high doses of corticosteroids. These steroids dampen the patient's immune systems which makes them more vunerlable to mucormycosis.
More recently, there is gorwing evidence that patients exposed to the 'delta' variant of covid-19 are especially at risk to mucormycosis.
In summary: high background rates of diabetes in the population; damage to tissue and blood vessels from COVID infection; treatment with corticosteroids; and widespread exposure to the fungus in the environment are all likely to be playing a part in the mucormycosis epidemic in India and its surrounds.
There are three ways humans can contract mucormycosis - by inhaling spores, by swallowing spores in food or medicines, or when spores contaminate wounds. Inhalation is most common. We actually breathe in the spores of many fungi every day. But our immune system and healthy lungs generally prevent them from causing an infection. Mucormycosis is usually classified into six types depending on the part of the body affected:
- Sinuses and brain: rhinocerebral mucormycosis infects the sinuses and can then spread to the brain. This form of mucormycosis is most common in people with uncontrolled diabetes.
- Lungs: pulmonary mucormycosis is the most common type of mucormycosis in people with cancer and in people who have had an organ or stem cell transplant.
- Stomach and intestines: gastrointestinal mucormycosis is more common among young children than adults, who have had antibiotics, surgery, or medications that lower the body's ability to fight germs and sickness.
- Skin: cutaneous mucormycosis occurs after the fungi enter the body through a break in the skin (for example, after surgery, a burn, or other type of skin injury. This is the most common form of mucormycosis among people who do not have weakened immune systems such as people with leukemia, poorly controlled diabetes, HIV and intravenous drug use.
- widespread: disseminated mucormycosis occurs when the infection spreads through the bloodstream to affect another part of the body. The infection most commonly affects the brain, but also can affect other organs such as the spleen, heart, and skin.
Prior to 2019, mucormycosis was quite rare, affecting fewer than 2 people per million people each year. It is around 80 times more prevalent in India, where it is estimated that there are around 0.14 cases per 1000 population.
So far, it is unclear why there were minimal fungus infections in India's first wave of COVID-19. However, during the second wave, an extremely strong association between mucormycosis and COVID-19 has been reported
Globally, outbreaks of mucormycosis have occurred due to contaminated products such as hospital linens, medications and packaged foods. But the widespread nature of the reports of mucormycosis in India suggests it's not coming from a single contaminated source.
The disease has been reported in many recent natural disasters around the world including the 2004 Indian Ocean tsunami and the 2011 Missouri tornado.
As of June 2021, Covid-19 associated mucormycosis has been officially reported in Bangladesh, Brazil, Chile, Egypt, Honduras, India, Mexico, Nepal, Paraguay, Russia, and Uruguay. In addition to this, there have been unofficial reports of cases in Pakistan, Malaysia, Sri Lanka and Iran.
- This website only uses statistics that are published official government agencies or reported by official representatives.
- In some instances, this includes named senior medical practitioners reporting on behalf of their own hospital.
- It does not include statistics that may be reported in the media without specific named attribution.
- It does not include statistics that are part of research papers because these are based on statistics collected across an entire reference periods, and not reported on a (near-)daily basis.
- In the event of two equally credible sources quoting different statistics, the source associated with the greater value is recorded.
- Reported statistics relating to a region, but from different sources, may differ due to different (unquoted( reference periods, or due to different counting rules.
- Some agencies publish statistics based on region of reporting, and some on region of usual reseidence of patients.
- It is most likely, that the actual statistics are greater than official reported statistics.
- National-level statistics are calculated as the greater of: any reported national-level government statistics, or the total of all constituent state statistics.
Primary data sources for official statistics include: The United Nations Office for the Coordination of Humanitarian Affairs, the Central Government of India, the Government of Nepal, the state Governments of India, Goa Medical College, North-Western Medical State University, Kakindada General Hospital, and more.
Secondary data sources include: Reuters, Associated Press, New Indian Express, Hindustani Times, One India and more.