Deadly black fungus: how mucormycosis affects the organs of patients with COVID-19

What is mycoses

Mycoses are diseases of humans and other animals caused by parasitic fungi.

Distinguish between mycoses of the skin and nails - dermatomycosis(other names borrowed from a foreign language: dermatophytosis, dermatophytosis, stomatitis, gingivitis, glossitis) and mycoses of internal organs (candidiasis). Animals may also experience poisoning by toxins of fungi that affect plant feed - mycotoxicosis. Only people or animals get sick with some mycoses, others get infected from animals (for example, microsporia).

  • Dermatomycosis is a skin disease caused by fungi.TrichophytonAndMicrosporum.
  • Candidiasis - causedCandida albicans.
  • Onychomycosis is a fungal nail disease caused by dermatophyte fungi.Trichophyton rubrum,Trichophyton interdigitale,Trichophyton tonsurans, less oftenEpidermophyton floccosumAndMicrosporum canis.
  • Variegated (pityriasis versicolor, multi-colored) lichen - characterized by the formation of scales, caused byMalassezia furfur.
  • Pityriasis nigra - forms brown or black spots on the palms and soles, caused byExophiala werneckii.
  • Black piedra - colonizes hair, is caused byPiedraia hortae.
  • White piedra - mycosis of the scalp, mustache, beard, caused byTrichosporon beigelii.
  • Sporotrichosis is a mycosis caused by fungi of the genusSporotrichium.
  • Black tongue—a black coating forms on the tongue; The exact cause is unknown, but it is believed that the disease is caused by fungi.
  • Seborrhea is a skin disease caused by a yeast-like fungusPityrosporum ovale.
  • Aspergillosis is a group of diseases caused by molds of the genusAspergillus.

Causes and conditions of the disease

  1. Decreased protective functions of the immune system. The risk group also includes people with weakened immunity, people with HIV and AIDS.
  2. Oncology. People undergoing steroid treatment, people undergoing chemotherapy.
  3. Endocrine diseases. Patients with diabetes.
  4. Decreased local immunity. Mostly in the mucous membranes. Conditionally pathogenic microorganisms protect mucous membranes and control the level of pathogens.
  5. Hygiene. Especially personal hygiene. Infection through personal hygiene items, personal belongings (clothes, shoes)
  6. Age.In adolescence, everyone goes through puberty, accompanied by hormonal changes and dysfunction of the sebaceous glands. Elderly people are susceptible to various diseases, which often reduce immunity.

Where fungal outbreaks have occurred

  • Deadly fungus Candida auris

In 2009, in a hospital in Tokyo from the ear of an elderlywomen with otitis media have identified a previously unknown type of pathogenic fungus Candida auris. Later, similar cases were confirmed in another 15 patients. Candida auris has proven to be an extremely aggressive, multidrug-resistant pathogen, and contagious. Its origin and natural focus have not yet been determined.

... From the point of view of its detection, this is quitea young microorganism that is highly lethal - according to some reports, up to 60% of infected people die from it. The main danger of this kind of fungus is the fact that it shows resistance (resistance) to most drugs, including polyenes, azoles and echinocandins.

The first case of infection is reported in Brazil, as reported in an official document by the Brazilian sanitary regulator Anvisa.

the fungus can lead to the development of infections, including in the circulatory system, which, in addition to existing chronic and concomitant diseases, can be deadly.

  • Mucorous fungi

Widespread in the topsoil, alsodevelop on food and organic residues. Some species cause diseases (mucomycosis) of animals and humans, others are used to obtain antibiotics or as a ferment (since some mucor fungi have high enzymatic activity). The mycelium is not divided by septa and is represented by one giant multinucleated branched cell.

Spores of mucorous fungi penetrate the nasopharynx,deposit in the sinuses, grow, release hyphae and produce toxins that decompose tissues and bones. Visually, the hyphae are black, hence the name of the disease - black mold. The infection enters the skull, blocks the main arteries and veins, and causes bleeding.

Dr. Nair believes that patients orof those who have had coronavirus, the impetus to the development of mucormycosis (and in 50% of cases everything ends in death) can be steroids, which are actively and successfully used in the case of a severe course of Covid-19.

Between December and February, six colleaguesDr Naira in Mumbai, Bangalore, Hyderabad and Pune reported 58 cases of mucorvicosis, with most patients contracting 12-15 days after recovering from the coronavirus.

At the same time, 11 infected had to remove oneeye, and six died. Most of Dr. Bradu's patients were middle-aged people with diabetes, and a fungal infection struck them a couple of weeks after they underwent the coronavirus.

How COVID-19 and fungal diseases are related

Most often, pneumonia caused by mycosis occurs against the background of decreased immunity and the use of drugs prescribed for severe forms of COVID-19—dexamethasone, tocilizumab, and others.

Often, a fungal infection is in addition tobacterial: first, a person develops bacterial complications that are treated with antibiotics, and then invasive mycoses join, said Sergei Yakovlev, professor of the Department of Hospital Therapy at Sechenov University, President of the Alliance of Clinical Chemotherapists and Microbiologists of Russia.

60 of 257 patients with COVID-19 (23.3%) had samplesthroat swabs tested positive for Aspergillus, meaning they were co-infected, the article said, citing a study conducted in Jiangsu province in China.

In other works, the number of ventilated patients infected withAspergillus, around 20%. The fungus increases the mortality rate of patients in the ICU by 16-25%, the head of the Department of Clinical Mycology, Allergology and Immunology of the North-Western State Medical University named after II. Mechnikov Nikolay Klimko.

Types of mycosis in coronavirus

  • The first is fungal sepsis due tomushrooms Candida. However, there are no specific risk factors for patients with COVID-19, this is a common problem for all patients who are in the ICU with a central venous catheter for a long time, receive antibiotics and parenteral nutrition (using a dropper). The likelihood of developing fungal sepsis in this case is about 1–2%. Mortality is about 50%, that is, every second dies, - said the professor.
  • The second is fungal pneumonia caused by fungiof the genus Aspergillus. And here there are specific risk factors for COVID-19, says Nikolai Klimko. Such an aggravating factor is the coronavirus infection itself, which can lead to a significant disruption of local and systemic mechanisms of immune defense.
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