We inhale thousands of potentially pathogenic fungal spores every day, but our immune system simply eliminates them. The interactions between pathogens and hosts can be quite different in immunocompromised people, such as those with pneumonia.
Fungal infections that occurred during the COVID-19 pandemic are reinforcing the actions of SARS-CoV-2 around the world. For example, mortality in severely ill COVID-19 patients infected with the fungus Aspergillus fumigatus has reached 80%.
A review by an international group of researchers analyzing SARS-CoV-2/fungal co-infections during the pandemic states: natural microbiologywith warnings related to current and future pandemics.
“The main problem with fungi is that they are a highly neglected public health problem with few treatment options. Currently, fungal deaths are on the rise. fungal disease It is not surprising that fungal diseases have taken advantage of the fact that more people are hospitalized than malaria and tuberculosis combined.Supported by Brazilian Pharmaceutical Sciences (FCFRP-USP) and FAPESP I am one of the principal investigators of this study.
In addition to aspergillosis, a disease caused by fungi of the genus Aspergillus, co-infections occurring at the same time as COVID-19 are caused by two other groups. Fungi of the order Mucorales are responsible for mucormycosis, which occurs mainly in India and Pakistan, and yeasts of the genus Candida cause candidiasis and are present virtually worldwide.
“COVID-19-associated pulmonary aspergillosis [CAPA] Affects an average of 10% of hospitalized acute respiratory failure patients intensive care unit. Patients with this co-infection are twice as likely to die than those infected with SARS-CoV-2 alone,” Martin Hoenigl, the study’s first author, told Agência FAPESP. Professor at the University of California, San Diego, Jolla (USA) and the University of Graz (Austria).
profit and loss
According to the article, aspergillosis can remain trapped in the upper respiratory tract for days and can be contained with antifungals. blood vessel However, in the lung, mortality exceeds 80% even with systemic antifungal therapy.
Candidiasis occurs almost exclusively in patients in intensive care units and is no more frequent in patients with COVID-19 than in patients admitted for other reasons. However, the emerging fungus, Candida auris, is a concern because it can colonize the skin. Because the species is resistant to all known antifungal agents and is present in a wide variety of environments, it easily infects ventilators and patients on hospital catheters and other invasive life support devices. There is likely to be.
COVID-19-associated mucormycosis (CAM) is a serious problem, especially in India where the number of cases doubled during the pandemic. News of this mycosis has made international headlines in 2021, with more than 47,500 cases reported in India from May to August alone. At the time, the Indian government classified it as an epidemic, but erroneously called it a ‘black fungus’ because of the color of the tissue necrotic caused by the disease. The actual black mold is part of a separate group relatively distant from the Mucorales order and does not cause disease in humans.
In COVID-19 patients, mucormycosis often occurs in the eye and nose area and can reach the brain. In those cases where the two diseases occur simultaneously, the mortality rate is 14%. Because mucormycosis causes necrosis, surgery may be required and ultimately disfiguring the patient. Patients who survive it can lose part of their face and suffer from the problem for the rest of their lives.If the lungs are affected or the fungus spreads throughout the organism, mortality can reach 80% of her. increase.
“The prevalence of this mycosis in India was 0.27% in hospitalized patients with COVID-19, but it can be controlled at home using very high doses of systemic steroids that are readily available to most Indians. It frequently occurs in people outside hospitals, such as patients who have been treated, Hoenigl said.
The use of steroids and other drugs that depress immune system activity is one of the causes of global population growth. fungal infectionThis strategy was successful during the pandemic, with the benefits outweighing the risks, but researchers warn it’s important to avoid overusing immunosuppressive drugs.
Alternatively, some centers at high risk for aspergillosis have successfully implemented antifungal prophylaxis during the pandemic by administering drugs prior to infection with these pathogens. However, fungi are often resistant to most available drugs, and clinical studies are insufficient to evaluate strategies, so it is not recommended at this time.
“Immunosuppressants are a major advance in medicine. They prevent many deaths from cancer and autoimmune diseases, and play an important role in organ transplantation. However, the side effects of their use increase the incidence of fungal infections. It’s up significantly,” Goldman said. “Except for some thermotolerant species such as A. fumigatus, fungi typically cannot withstand mammalian body heat and are easily combated by innate immunity. immune system Too weak to fight off highly inflammatory diseases like COVID-19, they use this opportunity to attack us. “
New drug
Additionally, as the global climate warms, many fungi are adapting to higher temperatures, which also makes humans more vulnerable.As a result, new antifungal drugs are urgently needed. , experts agree. For example, there are currently only four classes of antifungal agents, compared to dozens of classes of antimicrobial agents (antibiotics).
Another problem is that fungal infections are difficult to diagnose.Diagnostic tests are too expensive for most low-income and low-income people middle income countrytest results may take too long to prescribe appropriate treatment.
For example, 100% definitive diagnosis of aspergillosis requires bronchoscopy. Bronchoscopy was considered very dangerous during the COVID-19 pandemic and was therefore avoided whenever possible. The amount of fluid excreted by the patient during the procedure is sufficient to transmit SARS-CoV-2 to the medical team. As a result, cases of aspergillosis are probably underestimated.
“The good news is that several new classes of antifungal agents have been developed and are currently in phase 2 and 3 clinical trials,” Hoenigl said.
But researchers fear these new drugs won’t reach everyone who needs them. Cutting-edge treatments are likely to remain limited to rich countries, as inequalities in availability are likely to persist.
“Fungal infections are very likely to emerge against the backdrop of global warming with few available drugs and diseases that weaken immunity while causing epidemics and pandemics. We need more and more scientists studying different fungi and their mechanisms of action,” Goldman said.
Elucidating the mechanism of deadly fungal infections in addition to influenza and COVID-19
For more information:
Martin Hoenigl et al., COVID-19-associated fungal infections, natural microbiology (2022). DOI: 10.1038/s41564-022-01172-2
Quote: Fungal Infections Increase Mortality in COVID-19 Hospitalized Patients Worldwide (September 12, 2022) https://medicalxpress.com/news/2022-09-fungal-infections-mortality-hospitalized- Retrieved 12 Sep 2022 from covid-.html
This document is subject to copyright. No part may be reproduced without written permission, except in fair trade for personal research or research purposes. Content is provided for informational purposes only.